NUTRITIONAL INADEQUACIES AND DETERMINANTS AMONG ADOLESCENT SCHOOL GIRLS IN RURAL TANZANIA By Saidah Mohamed Bakar A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of 2016 ABSTRACT NUTRITIONAL INADEQUACIES AND DETERMINANTS AMONG ADOLESCENT SCHOOL GIRLS IN RURAL TANZANIA By Saidah Mohamed Bakar Nutritional inadequacies are significant problems in developing nations such as Tanzania. Nutritionally high-risk groups are children under 5 years of age, adolescent girls, pregnant and lactating women, and the elderly. The high rates of adolescent pregnancies in Tanzania exacerbates the viscous cycle of maternal-child malnutrition and under development for the nation. This study aimed to investigate the prevalence and determinants of nutritional inadequacies such as stunting, underweight, anemia, and low iodine status (UIC <50 µg/L) among adolescent schoolgirls in rural Tanzania, Kilolo district. A cross-sectional survey was conducted in lean season between January and March of 2016 when the secondary schools were in session. This study involved 208 adolescent girls (12-19 years of age) who enrolled in the secondary day school with approval of their caregivers. Nutritional inadequacies were evaluated by anthropometrics, biochemical and dietary assessment approaches. We found high prevalence of stunting (22.8%), underweight (5.8%), anemia (22.8%), low iodine status (16.4%) and inadequate dietary intakes of energy (91.3%) and micronutrients Socio-economic status of the more important determinants of nutritional inadequacies of adolescent girls than characteristics of adolescents. The present study provides the evidences that caregivers are important predictors in determining adolescent nutritional inadequacies in Kilolo district of Tanzania. This study could not discern the differences among adolescents who attend schools from those who dropped out or have never enrolled in secondary schools. In the future, the impacts of the nutritional inadequacies of adolescent girls should be investigated by a longitudinally designed study. Copyright by SAIDAH MOHAMED BAKAR 2016 iv TABLE OF CONTENTS LIST OF TABLES ................................................................................................................... vii LIST OF FIGURES .................................................................................................................... ix KEYS TO ABBREVIATIONS ..................................................................................................... x Chapter 1. Background ............................................................................................................. 1 1.1 Nutritional issues in Tanzania............................................................................................... 1 1.2 Adolescent girls in developing countries ............................................................................... 2 1.3 Problem statement ............................................................................................................... 3 1.4 Objectives and specific aims ................................................................................................ 4 1.5 Significance of the study ...................................................................................................... 4 Chapter 2. Literature Review ..................................................................................................... 5 2.1. Introduction ......................................................................................................................... 5 2.2. Public health issues associated with nutritional inadequacies in adolescent girls in developing countries ........................................................................................................... 6 2.3. Nutritional inadequacies of women of reproductive age in Tanzania ................................... 7 2.3.1 Underweight ............................................................................................................... 7 2.3.2 Stunting ...................................................................................................................... 8 2.3.3 Iron deficiency anemia ............................................................................................... 9 2.3.4 Iodine deficiency ...................................................................................................... 10 2.4 Determinants of nutrition status among adolescent girls..................................................... 13 2.4.1 Household food security ........................................................................................... 13 2.4.1.1 Individual dietary diversity ............................................................................. 14 2.4.1.2 Eating habits among adolescent girls ........................................................... 15 2.4.2 Poor public health and unhealthy environment ......................................................... 15 2.4.2.1 Malaria and malnutrition among adolescent girls .......................................... 16 2.4.2.2 Parasitic infestation due to inadequate care towards adolescent girls ........... 17 2.5 School system in Tanzania ............................................................................................... 18 Chapter 3. Methods ................................................................................................................. 19 3.1 Kilolo district ....................................................................................................................... 19 3.2 Pilot survey ........................................................................................................................ 19 3.3 Study design and recruitment of study subjects ................................................................. 19 3.4 Inclusion criteria ................................................................................................................. 20 3.4.1 Research team .......................................................................................................... 21 3.5. Sample size calculation and sampling procedure .............................................................. 23 3.5.1 Sample size calculation ............................................................................................. 23 3.5.2 Sampling procedure .................................................................................................. 24 3.5.2.1 District level ................................................................................................... 24 3.5.2.2 School level ................................................................................................... 24 3.5.2.3 Classroom level ............................................................................................. 25 3.6 Ethical clearance ................................................................................................................ 25 3.7 Data collection tools and measures .................................................................................... 26 v 3.8 Different methods for assessing nutrition status of adolescent girls .................................... 26 3.8.1 BMI-for-age ............................................................................................................... 26 3.8.2 Iron status assessment in the population ................................................................... 27 3.8.2.1 HemoCue machine ........................................................................................ 27 3.8.2.2 Massimo Pronto-7 with Rainbow ................................................................... 28 3.8.3 Methods of assessing iodine status in the population ................................................ 28 3.8.3.1 Salt iodine...................................................................................................... 28 3.8.3.2 UIC from urine sample ................................................................................... 29 3.8.4 Dietary and nutrient intake assessment ..................................................................... 30 3.8.4.1 Twenty-four-hour dietary recall methods ........................................................ 30 3.8.4.2 Individual dietary diversity score (IDDS) ........................................................ 31 3.9 Data processing and statistical analyses ............................................................................ 32 Chapter 4. Results .................................................................................................................. 34 4.1 General characteristics of the study subjects and their caregivers ..................................... 34 4.1.1 Sociodemographic, school and home environment of study subjects ........................ 34 4.1.2 General health status, menstruation experience, and deworming practice of study subjects ..................................................................................................................... 35 4.1.3 Consumption of iodized salt among study subjects ................................................... 35 4.1.4 Socioeconomic characteristics of caregivers of the study subjects ............................ 35 4.2 Diet diversity and nutrient adequacy among study subjects ............................................... 40 4.2.1 Individual diet diversity of study subjects ................................................................... 40 4.2.2 Macronutrient and micronutrient intakes of study subjects ......................................... 42 4.3 Prevalence of nutritional inadequacies among study subjects ............................................ 45 4.3.1 Prevalence of underweight and stunting among study subjects ................................. 45 4.3.2. Prevalence of Iron deficiency anemia among study subjects .................................... 45 4.3.3 Iodine status and prevalence of UIC <50 µg/L among study subjects ........................ 46 4.4 Determinants of nutritional inadequacies of study subjects ................................................ 48 4.4.1 Associations of characteristics of study subjects and their caregivers with nutritional inadequacies ............................................................................................................. 48 4.4.2 Odds ratios for nutritional inadequacies according to characteristics of study subjects and their caregivers ................................................................................................... 55 4.4.3 Odds ratios for nutritional inadequacies according to dietary intakes of study subjects ..................................................................................................................... 60 Chapter 5. Discussion and Conclusion .................................................................................... 63 5.1 Nutrition inadequacies among adolescent girls in Kilolo district .......................................... 63 5.1.1 Stunting among study subjects .................................................................................. 63 5.1.2 Underweight among study subjects ........................................................................... 64 5.1.3 Iron deficiency anemia (IDA) among study subjects .................................................. 66 5.1.4 Iodine status among study subjects ........................................................................... 67 5.2 Nutrition status and diet diversity among adolescent girls in Kilolo district .......................... 68 5.3 Conclusion ......................................................................................................................... 69 5.4 Strengths ........................................................................................................................... 70 5.5 Limitations .......................................................................................................................... 70 APPENDICES.......................................................................................................................... 72 APPENDIX A: Briefing script (English version) ................................................................... 73 APPENDIX B: Parent/guardian informed consent form for subjects 13-17 years old (English version) .............................................................................................................................. 74 APPENDIX C: Introduction to students before interviewing (English version) ..................... 76 vi APPENDIX D: Survey questionnaire (English version) ....................................................... 77 APPENDIX E: Maelezo kwa Ufupi (Briefing script) (Kiswahili version) ................................ 82 APPENDIX F: Fomu ya ridhaa ya Mzazi/Mlezi wa Msichana wa miaka chini ya 13-17 (Kiswahili version) .............................................................................................................. 83 APPENDIX G: Fomu ya ridhaa ya Mzazi/Mlezi/Msichana wa miaka 18-19 (Kiswahili version) .............................................................................................................................. 86 APPENDIX H: Utambulisho Introduction to students before interviewing (Kiswahili version) .............................................................................................................................. 89 APPENDIX I: Survey questionnaire (Kiswahili version) ...................................................... 90 BIBLIOGRAPHY ..................................................................................................................... 97 vii LIST OF TABLES Table 1. BMI-for-age cut-off point for adolescent girls aged 2-20 years ..................................... 7 Table 2. Height-for-age cut-off point for adolescent girls aged 2-20 years ................................. 9 Table 3. Hemoglobin levels to diagnose anemia (g/dL) .............................................................10 Table 4. Epidemiological criteria for assessing iodine nutrition based on median UIC of school-age children (6 years of age, non-pregnant and non-lactating) ...............................12 Table 5. Sociodemographic, school and environment of the study subjects ..............................36 Table 6. General health status, menstruation experience and deworming practice of study subjects .....................................................................................................................37 Table 7. Consumption of iodized salt among study subjects .....................................................38 Table 8. Socioeconomic characteristics of caregivers1 of the study subjects ............................39 Table 9. Frequency of each food group component of Individual Diet Diversity Score (IDDS) among study subjects ...............................................................................................40 Table 10. Percent consumption of different food groups by Individual Diet Diversity Score (IDDS) and its components .......................................................................................41 Table 11. Percent of subjects whose intake meets Recommended Dietary Allowance (RDA) of nutrients ....................................................................................................................43 Table 12. The nutrients adequacy ratios (NAR) and mean adequacy ratio (MAR) among study subjects and its correlation with Individual Diet Diversity Score (IDDS) among study subjects .....................................................................................................................44 Table 13. Prevalence of nutritional inadequacies among study subjects ...................................47 Table 14. Independent association of sociodemographic characteristics of the study subjects and their caregivers with the presence of stunting and underweight among study subjects .....................................................................................................................49 Table 15. Independent association of sociodemographic characteristics of the study subjects and their caregivers with the presence of anemia and UIC <50 µg/L among study subjects .....................................................................................................................51 viii Table 16. Independent association of sociodemographic characteristics of the study subjects and their caregivers across the tertile categories of urinary iodine concentration (UIC) ..................................................................................................................................53 Table 17. Adjusted odds ratios for stunting and underweight by characteristics of study subjects and their caregivers1 .................................................................................................56 Table 18. Adjusted odds ratios for anemia and UIC <50 µg/L by characteristics of study subjects and their caregivers1 .................................................................................................58 Table 19. Adjusted odds ratios (AORs) for stunting and underweight according to dietary intakes of study subjects1 ..........................................................................................61 Table 20. Adjusted odds ratios (AORs) for anemia and UIC <50 µg/L according to dietary intakes of study subjects1 ..........................................................................................62 ix LIST OF FIGURES Figure 1. Modified UNICEF conceptual framework of malnutrition ............................................. 5 Figure 2. Map of Iringa in Kilolo district .....................................................................................21 Figure 3. Modified research design on determinants of nutritional status..................................22 Figure 4. Summary of the logistic regression model used in the present study .........................33 x KEYS TO ABBREVIATIONS AI Adequate Intake BMI Body Mass Index FAO Food Agriculture Organization IDA Iron Deficiency Anemia IDDS Individual Dietary Diversity Score IOM Institute of Medicine LBW Low Birth Weight MAR Mean Nutrient Adequacy Ratio MDG Millennium Development Goal NAR Nutrient Adequate Ratio RDI Recommended Dietary Intake RNI Reference Nutrient Intake UIC Urinary Iodine Concentration UNICEF WHO World Health Organization 1 Chapter 1. Background 1.1 Nutritional issues in Tanzania Tanzania, a sub-Saharan Africa country, is a young nation with the total population of 47 million people. Of the total population, 47% are women of reproductive age (15-49 years) (NBS, 2013; UNICEF, 2013). According to the 2010 Tanzanian Demographic and Health Survey (TDHS) results, 20%women of reproductive age had never attended schools, 50% had completed primary education, and only 16% attained secondary school (NBS and ICF Macro, 2011). At the primary school level, the enrollment rate of girls is about the same as that of boys. Starting at the first year of secondary school, the gender disparities in net enrollment ratio begin to increase between the two sexes. In 2012, one girl for every three boys enrolled in the first year (Form I) of the secondary school (URT, 2014). Among the reasons for this difference was the failure to be promoted to the next level due to truancy and school dropout due to pregnancies (UNICEF, 2010; URT, 2014). Adolescent pregnancies are reported to start as early as the third year (Standard III) of primary school (URT, 2014). Tanzania is among the nations with the highest rate of adolescent pregnancies (UNICEF, 2010). Aaccording to the 2010 national report, 52% of women participated in a national health survey reported to have given births to children by the age of 19 years (NBS and ICF Macro, 2011). In addition, 28% of women between the ages of 20-24 years have also reported to give birth before 18 years of age (UNFPA, 2013). One of the major reasons for the high prevalence of adolescent pregnancies is the minimum legal age of marriage of 15 years for girls (UNICEF, 2010). Adolescent pregnancies contribute to poor health indicators of maternal and infant mortality (Delisle, 2005) and childbirth -related complications. In fact, Tanzania reports high rate 2 of pregnancy and/or delivery-related complications (UNICEF, 2010) which have increased maternal mortality ratio (450/100,000 live births) and under-five mortality (68/1,000 live births) (UNICEF, 2013). Mothers who bear children at an early age are more likely to have more children than those who delay marriage and childbearing. On average, women in Tanzania bear more than five children during their lifetime (NBS, 2011). These scenarios of childbearing at an early age contribute to high fertility rate in Tanzania, pose significant public health problems for both young mothers and their offspring, and thus perpetuate the viscous cycle of maternal and child malnutrition. 1.2 Adolescent girls in developing countries Adolescence is the transitional stage of development between 10-19 years of age (Delisle, 2005). Adolescents experience intensive biological, emotional, social, and cognitive changes to reach adult maturity (Delisle, 2005). These changes increase demand for nutrients needed for growth and failure to meet the nutrient requirements leads to adverse short- and long-term nutritional and health problems (Delisle, 2005). The consequences of nutritional problems facing adolescent girls include delayed cognitive development and function (Delisle, 2005), poor work capacity (NBS, 2011), decreased performance in school (UNICEF, 2010; Ecker et al., 2011), increase in the risk of maternal and child mortality (UNICEF, 2010; MoHSW, 2008; Delisle, 2005), and other poor birth outcomes such as low birth weight (TFNC, 2014; MoHSW, 2008). These consequences would be much more serious in adolescent girls when further compounded with pregnancies (Ecker et al., 2011). Women of reproductive age in Tanzania are affected by some nutritional problems. About 53% of pregnant women and 40% of nonpregnant women were affected by anemia, respectively, similarly 42% of adolescent girls have iron deficiency anemia (hemoglobin (Hb) 3 <12 g/dl). Among reproductive aged women, 11% experience chronic energy deficiency (body mass index (BMI) <18.5 kg/m2) with a higher rate in women aged 15-19 years (10.2%) than in older women aged 45-49 years (7%) (NBS and ICF Macro, 2011). In developing countries such as Tanzania, optimal nutritional status is achieved primarily by improving individual accessibility to diversified diet at household level and adequate nutrient intake at individual level (Kalinjuma et al., 2013; Minot et al., 2006; Arimond et al., 2004). In addition, advocates for appropriate health care practice (UNICEF, 2013; Ivers et al., 2011), proper, good sanitation and healthy environment for the vulnerable groups are important (UNICEF, 2013; Ecker, 2011; Blössner et al., 2005). However, very little attention is directed towards adolescent girls given their vulnerability to nutritional health problems compared to those in other life stages and industrialized countries (Delisle, 2005). 1.3 Problem statement Tanzania has high rates of adolescent pregnancies due to the cultural aspects and legal age of marriage of 15 years that allows girls to become pregnant at early age. Adolescent pregnancies carry additional stress of nutritional requirements for both growing mother and fetus. At the same time, girls are involved in agricultural activities that make them prone to consequences of nutritional inadequacy. Notably, pregnancy complications and poor birth outcomes have lasting effects on major health indicators such as maternal death, infant mortality, low birth weight and stunting which is one of the most serious public health problems. However, there is insufficient information on the extent and determinants of nutritional inadequacies among adolescent girls in rural Tanzania. 4 1.4 Objectives and specific aims The purpose of this study was to assess nutritional inadequacies and identify their determinants among adolescent girls in rural Tanzania. Specific aims were to 1) assess nutritional inadequacies using various nutrition status assessment methods (i.e., 24-hour dietary recalls, anthropometric measurements and biochemical testing), 2) identify sociodemographic and household characteristics associated with nutritional inadequacies, and 3) explore determinants of nutritional inadequacies (underweight, stunting, anemia, and low iodine) among adolescent girls in rural Tanzania. 1.5 Significance of the study Optimal nutrition among adolescent girls is very important given their role as students, mothers/caregivers, farmers, and providers. Poor maternal-child health indicators in Tanzania are complicated with high rates of adolescent pregnancies that are particularly high in rural Tanzania. Findings of the present study on determinants of nutritional inadequacies among adolescent girls in rural Tanzania would contribute to the existing scientific body of knowledge that can be the basis for health policies and program planning of appropriate interventions in rural schools of Tanzania. Giving birth to healthy newborns and rearing healthy children are expected to render prosperous national development and public health. 5 Chapter 2. Literature Review 2.1. Introduction Malnutrition andundernutrition (Blössner et al., 2005) imply lack of proper nutrition caused by not having enough to eat (UNICEF, 2013). Causes of undernutrition and determinants of micronutrient inadequacy among adolescent girls can be explained using the United Nations International Children's Emergency Fund (UNICEF) conceptual framework of malnutrition (Figure 1). These causes of undernutrition are categorized into three groups; basic (e.g., household food security), underlying (e.g., inadequate access to food, in adequate care, and insufficient health services and unhealthy environment) and immediate causes (e.g., inadequate dietary intake and diseases) (UNICEF, 2013). Figure 1. Modified UNICEF conceptual framework of malnutrition 6 2.2. Public health issues associated with nutritional inadequacies in adolescent girls in developing countries Overall, the interaction between food and nutrient intake, and health status of an individual affects his/her nutritional status (UNICEF, 2013), while socioeconomic status of the household is the major hindrance to accessibility of food in most developing countries (IFPRI, 2014). Recently, studies have reported that members in food insecure families had the least resources (Kisanga et al. 2013; Ntwenya et al., 2015) and lacked access to improved health care services (Hokororo et al., 2015; IFPRI, 2014; UNICEF, 2013). Adolescent girls are one of the vulnerable members within households that can be disproportionately exposed to the effect of having low socioeconomic status of households. A bilateral relationship exists between food insecurity and human immunodeficiency virus (HIV) (Weiser et al., 2011). Lack of food may cause those with economic dependency to find such ways to seek for foods as involvement in transactional sex, staying in high-risk or abusive sexual relationships (FAO, 2008). Women are more vulnerable because of reliance on men to provide food for themselves and their children (Miller et al., 2011). On the other hand, food availability improves nutrition and health of people living with HIV (Piwoz and Preble, 2000). Food insecurity has also made some adolescents run away from their homes with the intention to find strategy of acquiring food (Whitbeck et al, 2006); hence inadequate dietary intake increases the vulnerability of adolescent girls leading to public health issues in developing countries. 7 2.3. Nutritional inadequacies of women of reproductive age in Tanzania 2.3.1 Underweight BMI is an anthropometric index of body weight and overall nutrition status. BMI is defined as the ratio of body weight in kilograms divided by height in meters squared. Having poor nutritional status is indicated by a low BMI. Pregnant women with low BMI have high risks for obstructed labor, losing life (UNICEF, 2010) and/or giving birth to a baby with low birth weight which constrains his/her later stages of life (UNICEF, 2010; NBS and ICF Macro, 2011). In Tanzania, 11% of women of reproductive age have BMI below 18.5 kg/m2, indicating underweight. The prevalence of underweight is higher among adolescent girls in the rural areas (NBS and ICF Macro, 2011) than those in urban areas and women aged between 45-49 years (TFNC, 2014). BMI-for-age percentile is the recommended anthropometric index for assessing and monitoring nutrition status of adolescent girls (WHO and CDC, 2007; Delisle, 2005; Kuczmarski et al., 2002). The World Health Organization (WHO) growth reference charts of BMI-for-age percentiles (WHO and CDC, 2007) deduce the nutrition status of the population by six-month increment in age. Table 1. BMI-for-age cut-off point for adolescent girls aged 2-20 years Percentile Body Weight th Overweight th to < 95th Risk of overweight th to <85th Normal weight < 5th Underweight Source: WHO, 2007; Kuczmarski et al., 2002. 8 2.3.2 Stunting Stunting indicates a long-term effect of poor socioeconomic conditions and inadequate nutrition during childhood and adolescence (Woodruff and Duffield, 2002). Fetal malnutrition, infections, and inadequate dietary intake during the preschool-age have been reported to lead to stunting in adolescence (Delisle, 2005). Women with the height below 145 cm also indicates stunting during adolescence (Bosch et al., 2008). Stunting can be noticed by short maternal stature, and increases the risk of small-for-gestational-age and preterm births in low- and middle-income countries (Kozuki et al., 2015). Kinabo and Shirima (2005) reported short stature asthe cause of poor birth outcomes among adolescent girls in three regions in Tanzania. Additionally, pregnant women stunted are at a high risk of obstetric complications due to small pelvic size (NBS and ICF Macro, 2011; Delisle, 2005). In Tanzania, 5.4% of adolescent women aged 15-19 years had heights below 145 cm. Iringa region is one of the five regions in Tanzania with the highest prevalence of stunting in women (6.8%) (NBS and ICF Macro, 2011). Furthermore, Iringa region has the highest prevalence (40%) of stunting in under 5-year-old children (TFNC, 2014). The prevalence of stunting is the highest in children between 25-36 months old (Kalinjuma et al., 2013), hence stunting continues to be one of the most serious nutritional problems in Tanzania. Height-for-age percentile is the recommended anthropometric index for assessing and monitoring nutrition status (linear growth) of adolescent (WHO and CDC, 2007; Delisle, 2005; Kuczmarski et al., 2002). These WHO growth reference charts of height-for-age percentiles are age- and gender-specific and easy to use (WHO and CDC, 2007). 9 Table 2. Height-for-age cut-off point for adolescent girls aged 2-20 years Percentile Stature <3rd Short Normal Tall Source: WHO, 2007; Kuczmarski et al., 2002. 2.3.3 Iron deficiency anemia Iron deficiency anemia (IDA) is caused by nutrient deficiency (WHO and CDC, 2007) and indicates disease status that may be associated with hemolysis, suppressed erythropoiesis, exposure to toxins and hemoglobinopathy (Grantham-McGregor and Ani, 2001; UNICEF/UNU/WHO, 2001). Most commonly identified and studied causes of IDA in developing countries are low dietary intake of iron (NBS and ICF Macro, 2011; Eicher-Miller et al., 2009; Darnton-Hill et al., 2005; Tatala et al., 1998), infectious diseases such as malaria and parasite infestations (Steketee, 2003; NBS and ICF Macro, 2011; Shaw and Friedman, 2011). The prevalence and consequences of IDA are more common in adolescent girls than in boys (Ivers and Kimberly, 2011; Halterman et al., 2001) because of monthly blood losses through menstruation (Delisle, 2005). Most adolescent girls suffer from deficiencies of multiple micronutrients including vitamin A deficiency (WHO and CDC 2007; Haider and Bhatia, 2006; Delisle, 2005) resulted from poor diet in quantity and quality (Delisle, 2005; UNICEF/UNU/WHO, 2001). Most significant consequences of IDA are impairment of cognitive function (Halterman et al., 2001), leading to poor performance in school (Sungthong et al., 2002) and fatigue that prevents girls from being physically active and productive (Delisle, 2005; UNICEF/UNU/WHO, 2001). Therefore, IDA can hinder girls to attain their full potential in life (Lozoff et al., 2000) or to loss of life (WHO and CDC, 2007). IDA is still the major public health problems (NBS and ICF Macro, 2011; Zimmermann, 2008; Delisle, 2005) both in industrialized and developing countries. 10 In Tanzania, 40% of women of reproductive age suffered from IDA in 2010 and the incidence increases with age among adolescent girls (NBS and ICF Macro, 2011). Moreover, 42% of adolescents aged 15-19 were anemic (NBS and ICF Macro, 2011) mostly because they do not meet the increased iron requirements for rapid pubertal growth. This pubertal growth comes with a sharp increase in lean body mass, blood volume and red blood cell mass (Zimmermann, 2008; WHO, 2004; UNICEF/UNU/WHO, 2001) which in turn heightens iron needs for myoglobin in muscles and hemoglobin in blood (WHO and CDC, 2007). Table 3. Hemoglobin levels to diagnose anemia (g/dL) Normal Mild Moderate Severe years of age) 11-11.9 8-10.9 <8 Pregnant women 10-10.9 7-9.9 <7 Source: http://www.who.int/vmnis/indicators/haemoglobin 2.3.4 Iodine deficiency Iodine is an essential component of thyroid hormones and must be obtained from the diet (Rohner et al., 2014). Iodine content varies dependent on geographical demographics (Assey et al., 2006) and across a region. This variation is due to differences in geological formation, for example, impact of glaciations, flooding, soil erosion, and human activities especially densely populated area (Zimmermann, 2008). A study conducted in Somalia confirmed that iodine intake was very high among those who used drinking water from boreholes in a particular location (Kassim et al., 2014). Iodine deficiency and its health consequences exist in many parts of the world where iodide salt is not available. Inadequate dietary iodine intake leads to iodine deficiency which may impact on thyroid hormone production. Thyroid hormone plays very important roles in the regulation of key aspects of numerous physiological processes, including growth, neurologic development, and 11 reproductive function (Rohner et al., 2014). Severe cases of iodine deficiencies lead to hypothyroidism, goiter and cretinism (WHO et al., 2007). During adolescence and pregnancy, iodine requirements increase because of high growth velocity (WHO and CDC, 2007; Haider and Bhatia, 2006). Adolescent girls who get married at early age and bear children (UNFPA, 2012; UNICEF, 2011; Haider and Bhatia, 2006) have high burden of meeting increased iodine requirements to support their own growth as well as for the needs of the fetus. Iodine deficiency during pregnancy are associated with increased incidence of miscarriages, stillbirths, birth defects and mental retardation (Zimmermann 2008, Rohner et al. 2014). Mild to moderate iodine deficiency has also been related to increased risks for secondary neurologic impairments such as decreased work capacity, reduced physical endurance, and poor cognitive ability (WHO 2004, WHO and CDC, 2007). Children with moderate iodine deficiency have been reported to have 10-13 IQ points less than the well-nourished counterparts (Hynes et al., 2013; Zimmermann, 2008). The recommended dietary intake (RDI) of iodine for nonpregnant adolescents and pregnant women is 150 µg/day and 250 µg/day, respectively (Delisle, 2005). However, in developing countries, few adolescents meet the RDI through diet due to poor eating habits and use of non-iodized salt in addition to consumption of goitrogenic compounds (Zimmermann, 2008; Mannar and Zimmermann, 2013; Rohner et al,. 2014). Mandatory universal salt iodization (USI) is the widely implemented intervention to reduce iodine deficiency in many countries (Pearce et al., 2013; Assey, 2009). Since there is variation in iodine content in foods, the adequate amount of iodine added to salt should be above 15 ppm (15 µg/g) to provide 150 µg of recommended daily allowance of iodine (WHO and CDC, 2007). The WHO recommends that a country could be iodine adequate when 90% of the households consume adequate amount of iodized salt (WHO el al., 2007). However, in Tanzania only 59% of the households consumed iodized salt and 82% of households used iodized salt (NBS and ICF Macro, 2011). This is partially explained by the proliferation of small-12 scale salt producers who do not iodize their salt at the recommended levels before putting the salt on markets and poor quality at production level (Assey et al., 2009). Median urinary iodine concentration (UIC) is the widely used biomarker to determine iodine intake at the community level. Since more than 90% of dietary iodine is excreted in urine in well-nourished individuals, adequate iodine intake leads to the high level of UIC (WHO, 2013). In Tanzania, only 22% women of reproductive age have optimal UIC (TFNC, 2014), therefore, iodine deficiency is still one of the most serious public health problems which need to be addressed especially in adolescent girls who are attending school. Table 4. Epidemiological criteria for assessing iodine nutrition based on median UIC of school--pregnant and non-lactating) Source: Adapted from Assessment of Iodine Deficiency Disorders and monitoring their Elimination (WHO, 2013) Median urinary iodine (µg/L) Iodine intake Iodine status <20 Insufficient Severe iodine deficiency 20-49 Insufficient Moderate iodine deficiency 50-99 Insufficient Mild iodine deficiency 100-199 Adequate Adequate iodine nutrition 200-299 Above Good for pregnant/lactating mothers Excessive Risk of adverse health consequences 13 2.4 Determinants of nutrition status among adolescent girls 2.4.1 Household food security Food security is achieved when all people at all times have physical, social and economic access to sufficient, safe, and nutritious food that meets their dietary needs and food preferences for a healthy, active and productive life (FAO, 2008; Ivers and Cullen, 2011). due to supply deficit (Delisle, 2005). Most of adolescents at this age are dependent to their families, thus inadequate household food access leads to dietary inadequacy which is the underlying cause of malnutrition among adolescent girls. Globally, more than 805 million people are chronically undernourished with the highest prevalence recorded in sub-Saharan Africa (FAO et al., 2014). Tanzania, one of the nations in this region, had 17 million people reported as undernourished in 2012-2014 with some fluctuation. This has resulted in Tanzania failing to reach both the World Food Summit target and Millennium Development Goal of halving the proportion of undernourished people by 2015 (FAO et al., 2014). Household food insecurity status in the country differs from region to region (Kisanga et al., 2013), and one season to another (Ntwenya et al., 2015). The worst scenarios of prevalent household food insecurity are documented to be during the rainy season (Ntwenya et al., 2015). Majority Tanzanians consume three or less daily meals with little snacking, regardless of the locality (urban or rural) (Mazengo et al., 1997). However, this may be different during rainy seasons because accessibility to food before harvesting is very low and agriculturalists experience increased workload, due to various farm operations, which can affect the balance of energy intake and expenditure. The association between food intake and nutrition status at the household level has been confirmed in recent studies. Household food security was inversely 14 associated with undernutrition in Tanzanian adolescents (Cordeiro et al., 2012), this association was also found elsewhere in infants and young children (Saha et al., 2009). Food insecurity mostly affects households of low income status (Ntwenya et al., 2015). Those in the rural setting (Kisanga et al., 2013) of which about 73% of the Tanzanian population reside in the rural communities (NBS, 2013) and members in these communities access food from own production (MAFAP, 2013; Kisanga et al., 2013), which is mostly through cultivation. A good example is the Iringa region whose 70% of households cultivate their own food (Kalinjuma et al., 2013). Relying on cultivation for household food affects their consumption patterns (Ntwenya et al., 2015). More than 29% of households in Tanzania are classified as highly food energy deficient (Kisanga et al., 2013) and there is high consumption of monotonousdiet as opposed to diversified diet. 2.4.1.1 Individual dietary diversity Dietary diversity is defined as any one of the following: the number of unique foods consumed over a given period of time (Hoddinott and Yohannes, 2002), a simple count of foods or the number of food groups consumed over the past 24 hours (Nguyen et al., 2013). It is one of the food security indicators that show either adequate dietary intakes or micronutrients (Mirmiran et al., 2004; Hoddinott and Yohannes, 2002). Previous studies showed the significant association between dietary diversity and dietary energy density, nutrition status, and a probability of nutritional adequacy among various populations such as university female students (Azadbakht and Esmaillzadeh, 2012), children (Arimond and Ruel, 2004; Nguyen et al., 2013), and lactating women (Henjum et al.,2015). Unfortunately, majority of households in Tanzania lack a diversified diet because of over reliance on home-cultivated foods. Most nutrients are obtained from one or two food groups, where the main source of calories is cereals and root tubers in households (Kisanga et al., 2013). 15 2.4.1.2 Eating habits among adolescent girls Inadequate care and inappropriate education towards eating habits provided by caregivers are one of the underlying causes of inadequate dietary intake among adolescent girls (UNICEF, 2010; Delisle, 2005). These poor eating habits make adolescent girls fail to meet nutritional requirements, which in turn affect their nutrient adequacy and their ability to be free from common nutritional problems such as underweight, IDA, iodine deficiency and their related consequences. Still and colleagues (2014) reported female students are more likely to be anemic compared to male counterparts and the reason was females consumed junk foods more than males. In Tanzanian, 37% of adolescent women prefer to consume tea and/or coffee with meals (NBS and ICF Macro, 2011). Consuming these beverages with meals affects dietary intakes and nutrient adequacy due to compounds present in beverages such as caffeine and tannins that inhibit absorption of iron and other micronutrients in the gut and cause a poor eating habits. The social environment such as school influences food intake due to the relaxed atmosphere that peers create during mealtime, which affects individual preference to particular foods (Drewnowski and Hann, 1999). A study found out that adolescents prefer eating fatty and sweetened foods and drinks over fruits, vegetables, lean meat, and fish during their mealtime (Álvarez, 2015). 2.4.2 Poor public health and unhealthy environment Poor public health infrastructure and an unhealthy environment are the third underlying factor of underweight. . During rainy season, the health environment alters according to rainfall, the rate of infection and infestation increases due to the ideal breeding environment for the vectors and parasites. Malaria infections increase due to exposure of the agriculturalist to these breeding sites during farm work. 16 2.4.2.1 Malaria and malnutrition among adolescent girls Having malaria parasites reduces red blood cell count because it involves increased removal of circulating red blood cells as well as their decrease in production at the site hence the reactions leading to anemia (MoHSW, 2008). Malaria infections cause nausea, vomiting, fever, and loss of appetite. In Tanzania, the estimated prevalence of maternal anemia due to malaria infections is about 15% (MoHSW, 2008). The use of insecticide-treated mosquito net is the most applied intervention to prevent malaria and its related consequences of maternal and under-five mortality (UNICEF, 2010). The insecticide-treated mosquito nets are provided to pregnant mothers during antenatal visits (NBS and ICF Macro, 2011) and progressively, the practice of sleeping under insecticide-treated mosquito net has improved among majority of households. Additionally, 64% of children under 5 years slept under these insecticide-treated mosquito nets the night before the interview, although, the usage decreases with increase in age (NBS and ICF Macro, 2011) which may be possible that some non-pregnant adolescents aged 10-15 years are not captured by the interventions. Another preventive measure for malaria is the provision of two doses of sulfadoxine-pyrimethamine for intermittent preventive treatment during routine antenatal care visits (UNICEF, 2010; MoHSW, 2008). However, some pregnant mothers visiting antenatal clinics do not receive intermittent preventive treatment due to supply deficit (Shirima and Kinabo, 2004). In addition, the strategy of providing intermittent preventive treatment during antenatal care visits maybe a barrier to the intervention of preventing malaria, especially pregnant adolescent due to barriers associated with seeking reproductive health (Hokororo, 2015). Moreover, few pregnant mothers turn up for these visits and it was ascertained in 2010 DHS that only 43% of women received the recommended 4+ antenatal care visits, and only 15% received their first antenatal care visit during the first trimester of pregnancy (NBS and ICF Macro, 2011). 17 2.4.2.2 Parasitic infestation due to inadequate care towards adolescent girls Poor disposal of waste creates unhealthy environment for adolescents particularly for those in early adolescence stage. This poor practice creates a conducive environment for worms and other helminthes. Intestinal worm infestation is a global health problem (Henjum et al., 2015) with soil-transmitted helminthes being the most common cause of intestinal worm infections (Kumar et al., 2014). Intestinal infestation with helminthes is among the causes of anemia in children and adolescents (Steketee, 2003; Nelima, 2015) because the presence of worm infestation in the gut decreases bioavailability of nutrients for example iron from the host tissues (Shaw and Friedman, 2011) and physically damage the gut leading to inflammation that in turn result to iron loss and anemia. In Tanzania, worm infestations are one of the leading causes of anemia (NBS and ICF Macro, 2011). Prevention of intestinal infection is done during antenatal and post-natal clinic visits, by providing deworming drugs and nutritional advice to improve dietary intake of iron through a balanced and adequate diet (NBS and ICF Macro, 2011; MoHSW, 2008). About 70% of children under five years of age have received deworming drugs (TFNC, 2014). However, there is still a missing piece about deworming information of adolescent girls, especially nonpregnant ones despite their risk to worm infestations (Briscoe and Aboud, 2012). Adolescent girls would remain vulnerable to severity of IDA when parents neglect the practice of deworming. This is because young women are frequently affected by one or more existing micronutrient deficiencies in developing countries (Shaw and Friedman, 2011). 18 2.5 School system in Tanzania In Tanzania, the average age to enroll into primary education level is seven years old. Majority of adolescent girls (10-19 years of age) are enrolled in schools, and they are expected to go to secondary school at an average age of 13 years. The net enrollment ratio for primary schools has been increasing since the national universal education policy was included in Millennium Developmental Goals in 1999 (URT, 2014). About 95% of children in Tanzania attend government schools while the remaining attends non-governmental or private schools (URT, 2014). Students are selected on merit bases in schools. They go to schools around their residence for easy accessibility of education services (Mrosso, 2016). Although not all wards have respective government schools, some wards have more than one schools while other wards have nogovernment schools. This means that some students are enrolled in schools away from their residential ward and walk long distance every day to school. The academic year starts at the beginning of the calendar year and end in December with three school breaks in each year. This indicates that adolescents would be easily accessible from schools to capture information during lean period of January through March (Mrosso, 2016). The majority of government schools in the region are day schools, in which students attend schools between 8:00 am and 6:00 pm. Day school students obtain only snacks from school canteens and the main meals of the day are consumed from households because most day schools do not provide meals to students. Therefore, day schools are one of the most effective channels of promoting good nutrition (McNaughton, 2011). 19 Chapter 3. Methods 3.1 Kilolo district Kilolo district among the six district of the Iringa region is located in the northeastern direction of the region. The district has total population of 218,130 (105,856 males and 112,274 females) with an average household size of 4.3 (NBS, 2013). Administratively the district is divided into 22 wards (NBS, 2013). The main economic activity of Kilolo district is agriculture for cultivation of maize, sunflower and tomatoes. The district had the least per capita GDP in 2008 and the least service activities with poor roads, hospitals and schools (NBS, 2011). This was the reason of choosing rural schools from Kilolo district as our sample frame. 3.2 Pilot survey Apilot survey was carried out before the onset of the main study in order to assess the tools and instruments for the study. This pilot survey was carried out at Mjimkuu primary school (Morogoro region) among adolescent girls, while waiting for a permission to carry out our study in Iringa region. The pilot study helped the researcher gaining confidence in collecting the data from adolescent girls. Five adolescent girls recruited for the pilot survey from Morogoro region had similar characteristics as adolescent girls in Kilolo district (day scholars and same age as those who were to be recruited from Iringa). This pilot study was necessary for the researcher to practice research instruments (Pronto Massimo-7 with Rainbow) and test the questionnaires. 3.3 Study design and recruitment of study subjects This cross-sectional study was conducted between January-March, 2016 with a multistage, random sampling design that followed proportionate to sample size techniques at district, school and class levels. 20 Four out of 24 schools were selected because each school had a capacity of providing more than 50 adolescent girls. These four schools were selected from four clusters of eight schools categorized according to the campus direction from the Kilolo district office (i.e., East, West, North and South of Kilolo district council head office). Randomizing allowed all schools to get a chance of participating in their respective clusters, while proportionate to sample size made it easy to have a systematic approach to getthe sample size at all levels (Kothari, 2004). First step was to obtain total number of participants from a respective class in a respective school using proportionate to sample size technique. Then a briefing session was carried out to provide a description about the study to the students in the entire school, and then randomly selected participants. The selected students were asked if they were willing to participate and further checked if they met inclusion criteria to be fully recruited in the study. 3.4 Inclusion criteria This study involved adolescent girls between 12-19 years of age enrolled in form I-IV of the secondary ordinary level (middle school) and only students who reported not to have felt any symptom of illness and/or not on medication, mentally well, willing to participate and had parent/guardian approval (with a signed consent form) were recruited. In addition, only day scholars and one participant per household were included in the study. The study purposively selected government schools, which are typical school settings in a rural area such as Kilolo district and normally adolescent girls are enrolled. 21 Figure 2. Map of Iringa in Kilolo district 3.4.1 Research team Two female research assistants (nutritionist undergraduate students from Sokoine University of Agriculture) were recruited and a nurse from a health service of Iringa to help in data collection. The main researcher (Saidah Bakar) liaised with the team, participants, supervised all activities, and got involved in data collection. Research team members were fluent in Kiswahili and Hehe (local dialect) language so this made communication easy, made interviewees to be comfortable, and helped to get the intended responses (Kothari, 2004). Two days training of research team was conducted before data collection. Interviewers gained knowledge and skills on a 24-hour dietary recall methods and how to probe for responses in a non-offensive manner, estimate portion size using locally available household measurements, and weigh food samples using 1kg kitchen digital scale. They also gained skills 22 on handling biological samples such as urine and blood. Moreover, they had hands on both invasive (HemoCue and MBI Kits) and non-invasive (Massimo Pronto-7 with Rainbow) machines to test hemoglobin concentrations and the salt iodine content and accurately measured weights and heights during the practice. Figure 3. Modified research design on determinants of nutritional status 23 3.5. Sample size calculation and sampling procedure 3.5.1 Sample size calculation Kilolo district council has 24 ward secondary day schools, a ward is the second lowest administrative level before a village level (Mrosso, 2016). These 24 day schools had 4,783 female students enrolled in first-forth year (Form I-IV) of secondary school. Using the formula, Where, p = sample proportion, which we set at 0.5 and q = 1 - p; z = the value of the standard variant at a given confidence level with the 95% the z value is 1.96; n = size of sample and N is the total number of students in all schools in Kilolo district. We desired to work with 200 students because of the time and budget constrain. In addition, collecting data from 200 subjects was enough to get a generalizable relationship (Kothari, 2004) and to infer the outcomes to the entire Kilolo adolescent girls. From Fishers formula, required sample size is estimated to be less than 10,000, Where, nf = obtained sample size 24 n = desired sample size N = total population Therefore, sample size was 200 was set at confidence interval of 95% and p value 0.05 (Israel, 1992). 3.5.2 Sampling procedure This was multistage sampling at three stages: first sampling at district level to get four schools, second sampling at the school level to get actual number of participants per each school, and lastly at classroom level. 3.5.2.1 District level The Kilolo District Education Office provided secondary information on number of government day schools in the district, geographical location, population of female students in each of the 24 schools and contact information of heads of each school. Categorization of schools into four geographical location clusters from Kilolo district with help from an education officer. Four out of the 24 day schools were randomly selected to representthe entire Kilolo district. Overall, of the four schools surveyed, three were located in the typical rural settings and one in the semi urban geographical areas, thus 65% and 35% of subjects were found in typical rural and semi-urban residence, respectively. 3.5.2.2 School level Prior to the survey, the main researcher made a courtesy call to the office of head of school. The head of school provided personnel to work with during the visit, generally either a 25 biology teacher or a matron. The assigned personnel acquired class registers from class teacher and these registers helped in systematically obtaining a number of adolescent girls randomly selected in each classroom. The whole study set up was discussed with the personnel who was assigned before the day of data collection. A brief session was conducted either in the classroom or at a school assembly, usually a day before the survey. Three topics were discussed: 1) consequences of nutritional inadequacy (i.e., iodine deficiency and IDAand iron and iodine status), and 3) description about the study with emphases on confidentiality and benefit of the study. 3.5.2.3 Classroom level After the briefing sessions, random selection of the student from respective classes was made. Upon accepting to participate, a respondent was given a parents/guardians consent form. The recruited students were given containers for salt sample from home and instructions on how to keep the salt sample safe. Both the signed consent form and salt samples were collected from participating subjects on the data collection day, then coded with correspondent code. 3.6 Ethical clearance The study was conducted under the permission from Michigan State University Institute Review Board certificate number: 15-666 and Tanzania, the National Institute for Medical Research: NIMR/HQ/R.8a/Vol.IX/2027. Correspondingly, the postgraduate research committee (Faculty of Agriculture), at Sokoine University of Agriculture, the Iringa regional offices, Kilolo district and Kilolo district medical offices allowed the study to be carried out after reviewing the protocol. Furthermore, participating students gave verbal consent after their parents/guardians 26 signed consent forms to allow their girls to take part in the study (certificates, letters and consent forms in the APPENDICES). 3.7 Data collection tools and measures During data collection, a trained team of three interviewers conducted data. Adolescent girls, our primary sampling unit, provided information on their socioeconomic as well as their d consumption of iodized salt. The trained team took anthropometric and biochemical measurements and a 24-hour dietary recall. Sequential interviewing procedure following questionnaire sections by each interviewer made sure that all respondent completed the assigned section that day before the respondent headed to the next interviewer. 3.8 Different methods for assessing nutrition status of adolescent girls 3.8.1 BMI-for-age Underweight is defined as BMI-for-age less than 5th percentile of the WHO growth reference for the population. The condition of underweight is due to the short-term situation of inadequate nutrient intake, or malnutrition that results from condition of diseases or chronic food insecure circumstances. BMI is a well acceptable anthropometric indicator in assessing body weight status of adults and children (Delisle, 2005; NBS and ICF Macro, 2011; NOO, 2011; Patton et al., 2013). However, due to the difficulties of using the same indices in adolescent subjects and disparities in age and geographic location (Woodruff and Duffield, 2002), the use of BMI-for-age has been 27 recommended (NOO, 2011). Due to this recommendation, further uses of gender- and age-specific charts (BMI-for-age charts for girls aged 2 to 20 years) have made the task friendly. 3.8.2 Iron status assessment in the population 3.8.2.1 HemoCue machine Hemoglobin is widely used biomarker for assessing iron status due to the convenience of measuring, ease of interpreting and relatively economical procedure for clinical and field studies. Hemoglobin measurement has such drawbacks as low specificity and sensitivity (Zimmermann, 2008) as the measurement can be affected by attitude of 3000 meters above sea level (WHO, 2001). Hemoglobin is measured in g/dL using blood samples from either vein or capillary (Morris et al., 1999). HemoCue machine is a reliable machine that uses quantitative method for screening for hemoglobin concentrations in field surveys based on the cyanmethemoglobin method. The machine is either an electric or a battery-operated HemoCue photometer (HemoCue AB, Ängelholm, Sweden). The machine uses pre-treated disposable cuvettes that collect small amount of blood samples (WHO, 2001) and quickly generates results. The HemoCue system is suitable for rapid field surveys as it gives satisfactory accuracy and precision when evaluated against standard laboratory methods (WHO, 2001). However, HemoCue machine uses semi-invasive collection of capillary blood drawn after a small finger prick of a non-dominant hand with minor discomfort left behind. The procedure of drawing blood samples tends to stress subjects in different ways. In areas of high HIV/AIDS epidemic, the participation and compliance can be reduced. Compliance in the field can be increased when subjects consent to the research tools used (Kothari, 2004). Using a non-invasive instrument and procedures for testing hemoglobin levels 28 has been recommended for by reducing pain and discomfort, saving time, and increasing recruitment rate (Gayat et al., 2012; Al-Khabori et al., 2014). 3.8.2.2 Massimo Pronto-7 with Rainbow A non-invasive quick spot-checking total hemoglobin measuring instrument is battery operated and portable to be carried. This machine has been used in several studies (Gayat et al.,2012), validated (Al-Khabori et al., 2014) for use in pediatric populations, blood donors (Al-Khabori et al., 2014) and in population where compliance to invasive machines is a problem. Massimo Pronto-7 with Rainbow measures hemoglobin by using the arterial blood with a technique of multi-wave length spectrophotometry that measures multiple components of several hemoglobin moieties. The machine has been validated and the difference of less than 2 g/dL was observed at both below normal value and above normal value of 12 g/dL observed in 99% and 94%, respectively (Masimo, 2016). 3.8.3 Methods of assessing iodine status in the population 3.8.3.1 Salt iodine Iodine concentrations in iodized salt at the point of production should be within the range of 20-40 mg of iodine per kg of salt (i.e., 20-40 ppm of iodine) in order to provide 150 µg of iodine per person per day (WHO and CDC, 2007). Iodine intake is assessed from diets using salt or foods prepared with iodized salt. Both quantitative and qualitative methods are used to determine iodized salt consumption. The easiest method of qualitative assessment in field has been the use of rapid salt test kits. Of many rapid field test kits, validated MBI Kits has been commonly used in developing countries for its low cost and simplicity (MBI Kits, Madras, India) (Assey et al., 2009; 29 Zimmermann, 2008). The MBI Kits have a reagent, which makes iodine in the salt to go through a series of reactions and develop color. The color is compared with a color chart in the MBI Kit, showing whether or not the salt sample iodine is either below or above 15 ppm WHO and CDC, 2007; WHO, 2013). Presence of iodine is determined depending on the color of the chart present in the kit. Therefore, the populations are categorically classified based on proportion as However, there are no gold standard analytical measure for iodine intake or iodine in foods. A proxy for iodine intake and iodine status is UIC (WHO, 2013). 3.8.3.2 UIC from urine sample Urinary iodine excretion, a good marker of very recent diet, is used as an indicator to assess iodine status in the population using median UIC (WHO and CDC, 2007). The ily basis or even during the same day (Zimmermann, 2008; WHO and CDC, 2007). Therefore, use of median UIC for a population is recommended (Rohner et al., 2014; Zimmermann, 2008). Research protocol was carefully observed during urine collection. Urine samples ranging from 0.5-1.0 mL were collected in small cups, transferred to tubes, tightly sealed with screw tops and then kept in cool, dry place to avoid evaporation, which would artificially increase the concentration (Zimmermann, 2008; WHO and CDC, 2007). Iodine concentration of urine was determined by ammonium per sulfate digestion with spectrophotometry, based on the Sandell Kolthoff reaction (Pino et al., 1996; WHO and CDC, 2007). This method required a heating block, a spectrophotometer, and chemical reagents. For each urine sample, an aliquot of 0.25-0.5 mL was digested with ammonium per sulfate at 110 °C for 1 hour; arsenious acid and ceric ammonium sulphate were added to the sample and left to stand until the decrease in yellow color over a fixed time period was observed and then absorbance of the solution at 405 nm was measured spectrophotometrically. Iodine standards 30 with known data were then entered into the computer and a standard curve constructed by plotting the log of the absorbance at 405 nm on the X-axis versus the standard iodine concentration in µg/L on the Y-axis with a scatter plot, using Excel on a desktop computer. The iodine concentration in microgram per liter (µg/L) of each specimen was calculated by using the equation of the linear trend line of this chart. There was an inverse endpoint color reaction, all specimen that had absorbance value lower than the acceptable standard curve (or -assayed using a dilution of 1:3 or 1:5. To ascertain the validity and reliability of the results, reference materials (urine samples) supplied by the US Center for Diseases Prevention and Control (WHO and CDC, 2007) were used concurrently during the analysis. 3.8.4 Dietary and nutrient intake assessment 3.8.4.1 Twenty-four-hour dietary recall methods Twenty-four-hour dietary recall method is among the most commonly used method to measure food and nutrient intake of an individual. Twenty-four-hour dietary recall method is also referred to as a retrospective diet assessment method, because an individual is asked about food and beverage they consumed during the previous day(s) before the study. This tool uses a proxy measure to assess nutrition status, and nutrient adequacy (Thompson and Subar, 2013). The 24-hour dietary recall method is inexpensive and has less recall errors. However, one of its limitation is the failure to determine habitual diet at an individual level if single 24-hour dietary recall is taken (Raina, 2013) and misreporting by the respondents especially adolescents (Kerr et al., 2015) hence more than one 24-h dietary recall data are needed to find a reliable and precise association between food intake and nutritional status of an individual (Holmes et al., 2008). 31 Foods intakes of an individual were computed after direct weight of estimates with food images or household utensil to obtain portion size. These foods were appropriately identified from Tanzania food composition tables (Lukmanji et al., 2008). Nutrient intake was estimated by multiplying the amount of each food item consumed by the nutrient composition and then summing the nutrient intake from all food items consumed. Only average intake was measured to compare among groups of individual. By comparing total nutrient intake to the reference nutrient intake (RNI) or using mean nutrient adequacy ratios (MARs) for nutrient, an individual nutrient intake was calculate. Formula: 3.8.4.2 Individual dietary diversity score (IDDS) IDDS is defined as the number of foods or food groups consumed by an individual in the past 24 hours. The number of food groups and the kind of food group to include in the questionnaire depends on the specific objective of the study (Webb et al., 2006). The IDDS questionnaire consists of 5-14 food groups; the tool is used as a means to calculate for micronutrient adequacy and food security. The subject is asked to recall the foods eaten in the previous day before the survey and from the list of food groups, respondent confirm the 32 3.9 Data processing and statistical analyses Responses to the questionnaires were checked daily for completeness of responses after data collection, and there after entered in the Excel spread sheet. Data were cleaned on the criteria that respondents who were mistakenly recruited (did not meet inclusion requirement). For example, data of one student was removed when the researcher found that a respondent was from an orphanage. The information she provided would have changed the meaning of the study for instance having 100 members of the household as maximum. Descriptive analysis was performed for socio-economic variables, anthropometric characteristics, dietary intake-related variables including nutrient intakes and IDDS, and biochemical measurement such as hemoglobin level and UIC. Categorical variables were presented as frequencies (n) and percentages (%). Continuous variables were presented as means with standard deviations (SDs). Chi-square tests were conducted to examine independent associations of nutritional inadequacy measurements such as stunting, underweight, anemia, and low iodine status with various characteristics of study subjects. Pearsoncorrelation tests were conducted to examine NAR of each nutrients, MAR, and IDDS. To identify socioeconomic and nutritional determinants of various nutritional inadequacies, the multivariate logistic regression analyses were conducted to estimate adjusted odds ratios (AORs) with 95% confidence intervals (95% CIs) for nutritional inadequacies (e.g., underweight, stunting, anemia, and iodine status) after adjustment for age (continuous), locality, religion, Illness within the past two weeks, experience of menarche, household size, total energy intake, and sex, marital status, education level, and occupation of caregiver, household size, and total energy intake. All statistical analyses were conducted using the Statistical Package for Social Sciences (SPSS) version 20 (Chicago, IL, USA), EXCEL and SAS (version 9.4, SAS Institute Inc, Cary, NC, USA). P values less than 0.05 were considered as statistically significant. 33 Figure 4. Summary of the logistic regression model used in the present study Confounders Sociodemographic of studentsGeneral health status Deworming practices Caregiver socioeconomic status Outcome variables Nutritional Inadequacy(underweight, stunting, anemia &iodine deficiency ) Determinant/ predictor variable Inadequate dietary intake and diseases 34 Chapter 4. Results The findings and discussion are presented in the order of the following specific objectives: 1) assessing nutritional status of adolescent girls bydifferent nutrition status assessment methods (i.e., anthropometric, biochemical measurements, and dietary recall), 2) associations between individual characteristics and nutrition status of adolescent girls, 3) associations between household characteristics and nutrition status of adolescent girls, 4) associations between dietary intake and nutrition inadequacies of adolescent girls, and 5) determinants of nutrition inadequacies among adolescent girls. 4.1 General characteristics of the study subjects and their caregivers 4.1.1 Sociodemographic, school and home environment of study subjects This study includes 208 subjects with 16.4% from Mtitu, 22.6% from Irole, 26.0% from Kilolo and 35.1% from Ilula secondary school. Out of the 208, Ilula secondary school had slightly higher number of subjects (n=73) while Mtitu secondary had least number of participant subjects (n=35) (Table 5). Overall, results showed that majority of the subject (66.4%) were over 15 years of age, followed by those between 12-14 years of age (33.7%). Almost all subjects belonged to Christianity (92.3%) followed by Muslims (7.7%). Most subjects reported the main caregiver to be biological father (46.2%).The proportions of those that referred biological mother and relatives as main caregivers were similar with 25.0% and 28.9%, respectively. In addition, majority of subjects reported to be staying with their immediate family (mother and father) during the school days (65.0%) while small percents reported staying independently (2.9%) or with relatives (4.8%). Almost all subjects (96.2%) reported that they walk to school and very few use public transport (4%). On average, subjects walk a distance of 3.0±1.8 Km. 35 4.1.2 General health status, menstruation experience, and deworming practice of study subjects About 26% of subjects reported having at least one symptom of illness in the past two weeks prior to the study. Most of those who reported sick suffered from cough (77.8%), followed by malaria (18.5%) and diarrhea episodes (3.7%) (Table 6). Majority of subjects reported having had experienced menarche (66.4%) and had their menstrual period few days before the survey. More than 67% of the total population had heard about deworming practice. Of the study subjects who heard of deworming, 96% had actually ever dewormed. However, the deworming practice was irregular because majority of subject reported having last deworming more than one year before the survey (94.1%). 4.1.3 Consumption of iodized salt among study subjects Majority of the subjects (70.7%) brought salt samples from home on the day of survey. All subjects who brought salt samples reported that they used the same salt to cook household food a day prior to survey (Table 7). Almost all the salt samples (n=147) brought in had iodine (98.6%). More than 95% of salt with iodine contained more than 15 ppm of iodine. 4.1.4 Socioeconomic characteristics of caregivers of the study subjects Result showed that proportion of male caregivers was slightly higher (53.9%) than female counterpart (46.2%). The proportion of those in marriage institution was also found to be three times higher (71.2%) than caregivers who were single (i.e., divorced, separated, never married, widowed or in an open relationship) (28.9%) (Table 8). Majority of caregivers had attained primary school education (62.5%) followed by secondary/tertiary (25.0%) and no schooling (12.5%). Furthermore, majority of caregivers were peasant farmers (74.5%) followed by education/health professional/businessmen (25.5%). About 55% of the households had 36 household size ranging from 5-14 people and more than 34% of household had at least three members who were under 18 years of age. Table 5. Sociodemographic, school and environment of the study subjects Variables Frequency (n) Percentage (%) Total 208 100.0 School Kilolo 54 26.0 Mtitu 34 16.4 Irole 47 22.6 Ilula 73 35.1 Locality Rural 135 64.9 Semi-urban 73 35.1 Religion Christian 192 92.3 Muslim 16 7.7 Age (years)1 12-14 70 33.7 15-19 138 66.3 Currently living with Independent 6 2.9 Family 135 64.9 Relatives 57 27.4 Friends 10 4.8 Transportation to school Walk 200 96.1 Public car 8 3.9 Distance to school (km)1 51 24.5 91 43.8 36 17.3 >4.5 30 14.4 Relationship with caregiver (n=202) Mother 52 25.0 Father 96 46.2 Relative 60 28.8 1Mean age was 15.11±1.48 years and mean distance to school was 2.95±1.82 km. 37 Table 6. General health status, menstruation experience and deworming practice of study subjects Variables Frequency (n) Percentage (%) Illness within the past two weeks Yes 54 26.0 No 154 74.0 Type of illness Malaria 10 18.5 Diarrhea 2 3.7 Cough 42 77.8 Experienced menarche Yes 138 66.4 No 70 33.7 Last menses (n=138) Few days 97 70.3 Four weeks 35 25.4 More than three months 6 4.4 Ever heard of deworming Yes 140 67.3 No 68 32.7 Ever dewormed (n=140) Yes 135 96.4 No 5 3.6 Timing of last deworming (n=135) Three months 8 5.9 More than a year 127 94.1 38 Table 7. Consumption of iodized salt among study subjects Variables Frequency (n) Percentage (%) Brought salt Yes 147 70.7 No 61 29.3 Used salt brought in cooking1 Yes 147 100.0 No 0 0.0 Presence of iodine in brought salt1 Yes 145 98.6 No 2 1.4 Amount of iodine in brought salt (ppm)2 <15 7 95.2 15 138 4.8 1The total n for those variables was 147. 2The total n for the variable was 145. 39 Table 8. Socioeconomic characteristics of caregivers1 of the study subjects Variables Frequency (n) Percentage (%) Sex Men 112 53.9 Women 96 46.2 Marital status Married 148 71.2 Single2 60 28.9 Education level No school 26 12.5 Primary 130 62.5 Secondary 36 17.3 Tertiary 16 7.7 Education level No school 26 12.5 Primary 130 62.5 Secondary/tertiary 52 25.0 Occupation Peasant farmer 155 75.0 Education/health professional/business 53 25.0 Household size3 94 74.5 >5 114 25.5 No. of household member under 18 years of age4 137 45.2 71 54.8 1Caregiver referred to a person who provides food or money for purchasing food. 2Single included those who divorced, separated, never married, widowed or are in an open relationship. 3Mean household size was 5.74±2.01 and the largest household size was 14. 4Mean number of household member under 18 years of age was 3.04±1.47. 40 4.2 Diet diversity and nutrient adequacy among study subjects 4.2.1 Individual diet diversity of study subjects IDDS calculated from dietary diversity questionnaires indicated that the most consumed foods are from starchy staples (group 1) including cereals and white root and tubers (100%, all subjects consumed) followed by dark green leafy vegetables (group 2) (71.6%) and legumes, nuts, and seeds (group 8) (49.0%). Organ meats (group 5) (0.48%) and milk and milk products (group 9) (3.37%) were the least consumed food groups by the subjects (Table 9). On average, study subjects consumed 3.0±1.5 food groups and all subjects consumed at least two and at most 7 food groups (Table 10). A larger percentage of adolescent girls consumed one or more food groups of meat/fish, eggs, legumes/nuts/seeds, and milk/milk products with increasing IDDS of study subjects. Only those with an IDDS of 5 or more showed more than half (>50%) of the study subjects consumed meat/fish, legumes/nuts/seeds, and other fruits and vegetables. In addition, only at an IDDS of 7 were 25% of subjects having milk and milk products. Table 9. Frequency of each food group component of Individual Diet Diversity Score (IDDS) among study subjects Food group Frequency (n) Percentage (%) Group 1: Starchy staples 208 100.0 Group 2: Dark green leafy vegetables 149 71.6 Group 3: Other vitamin A rich fruits and vegetables 91 43.8 Group 4: Other fruits and vegetables 71 34.1 Group 5: Organ meat 1 0.5 Group 6: Meat and fish 84 4.5 Group 7: Eggs 12 5.8 Group 8: Legumes, nuts and seeds 102 49.0 Group 9: Milk and milk products 7 3.4 41 Table 10. Percent consumption of different food groups by Individual Diet Diversity Score (IDDS) and its components IDDS n % Starchy staples Dark green leafy vegetables Other vitamin A rich fruits and vegetables Other fruits and vegetables Organ meat Meat and fish Eggs Legumes, nuts and seeds Milk and milk products % 2 24 11.5 100.0 41.7 0.0 8.3 0.0 16.7 0.0 33.3 0.0 3 70 33.7 100.0 74.3 25.7 25.7 0.0 24.3 2.9 35.7 1.4 4 64 30.8 100.0 75.0 59.4 39.1 0.0 45.3 4.7 48.4 3.1 5 30 14.4 100.0 76.7 63.3 50.0 3.3 53.3 6.7 73.3 6.7 6 16 7.7 100.0 81.3 87.5 50.0 0.0 87.5 18.8 81.3 6.3 7 4 1.9 100.0 75.0 50.0 75.0 0.0 100.0 50.0 75.0 25.0 42 4.2.2 Macronutrient and micronutrient intakes of study subjects Dietary intake data were collected using 24-hour dietary recall questionnaires. Twenty-four-hour dietary recalls were used to estimate total nutrient intakes from all foods and beverages consumed by study subjects and then NAR values of energy, protein and 11 micronutrients (energy, protein, vitamin A, thiamin, riboflavin, niacin, vitamin B6, vitamin B12, vitamin C, folate, calcium, iron, and zinc) and MAR were calculated. Dietary intake of majority nutrients did not meet the Recommended Dietary Allowance (RDA) (Table 11). More than 90% of subjects did not obtain the recommended level of energy intake with mean energy intake of 1390±541 kcal/day. Likewise, only about 15% of subjects consumed more than the recommended level of iron with mean iron intake of 9.0±3.1 mg/day. correlation analyses indicated that intake of nutrients, except vitamin A, vitamin B2, and calcium, were significantly correlated with IDDS (all, P <0.05). Most of nutrients, except thiamin and vitamin B6, had an average NAR below 75%. The mean MAR was 0.6±0.2 and significantly correlated with IDDS (Pearson correlation coefficient=0.3, P <0.01) (Table 12). 43 Table 11. Percent of subjects whose intake meets Recommended Dietary Allowance (RDA) of nutrients Nutrients RDA % meeting RDA 12-13 yrs 14-18 yrs 19 yrs Energy (kcal) 2071 2368 2403 8.7 Carbohydrates (g/day) 130 130 130 89.9 Carbohydrates (% energy) 45-65 45-65 45-65 89.9 Protein (g/day) 34 46 46 19.7 Protein (% energy) 10-30 10-30 10-35 93.3 Total fat (% energy) 25-35 25-35 20-35 38.9 Fiber (g/day) 26 26 25 16.4 Vitamin A (µg/day) 600 700 700 25.0 Thiamin (mg/day) 0.9 1 1.1 27.9 Riboflavin (mg/day) 0.9 1 1.1 19.2 Niacin (mg/day) 12 14 14 12.0 Vitamin B6 (mg/day) 1 1.2 1.3 28.9 Vitamin B12 (µg/day) 1.8 2.4 2.4 4.8 Pantothenic acid (mg/day) 4 5 5 10.1 Vitamin C (mg/day) 45 65 75 37.5 Vitamin D (µg/day) 5 5 5 1.0 Vitamin E (mg/day) 11 15 15 4.3 Folic acid (µg/day) 300 400 400 2.9 Sodium (g/day) 1.5 1.5 1.5 4.3 Potassium (g/day) 2.3 2.3 2.3 15.9 Manganese (mg/day) 1.6 1.6 1.8 87.5 Magnesium (mg/day) 240 360 310 27.9 Copper (µg/day) 700 890 900 88.9 Calcium (mg/day) 1300 1300 1000 0.0 Iron (mg/day) 8 15 18 14.9 Zinc (mg/day) 8 9 8 12.5 Phosphorus (mg/day) 1250 1250 700 2.4 44 Table 12. The nutrients adequacy ratios (NAR) and mean adequacy ratio (MAR) among study subjects and its correlation with Individual Diet Diversity Score (IDDS) among study subjects Nutrients NAR Correlation1 with IDDS mean SD Energy 0.59 0.21 0.2395** Protein 0.68 0.24 0.2479** Vitamin A 0.55 0.35 0.0047 Thiamin 0.75 0.23 0.2206** Riboflavin 0.62 0.27 0.1178 Niacin 0.66 0.21 0.2195** Vitamin B6 0.77 0.21 0.3377** Vitamin B12 0.21 0.28 0.2304** Vitamin C 0.71 0.30 0.3191** Folic acid 0.47 0.19 0.1531* Calcium 0.15 0.11 0.0904 Iron 0.63 0.22 0.1701* Zinc 0.67 0.21 0.2196** MAR 0.57 0.15 0.3034** 1* P <0.05, ** P <0.01 45 4.3 Prevalence of nutritional inadequacies among study subjects 4.3.1 Prevalence of underweight and stunting among study subjects BMI-for-age percentiles indicated that more than 90% of the study subjects had BMI between 5th and 85th percentiles with a mean BMI of 19.81±3.55 kg/m2. The prevalence of underweight (BMI-for-age <5th percentile) was significantly higher in adolescent girls who had not experienced menarche compared to those who had experienced (P <0.05) (Table 9). Height-for-age percentiles showed that more than 78% of subjects had normal stature (5th -for-age <85th percentile) with mean height of 152.4±5.77 cm. However, the prevalence of stunting was 21.6% as indicated by Height-for-age <5th percentile and not significantly different between experience of menarche. 4.3.2. Prevalence of Iron deficiency anemia among study subjects Iron status of the study subjects was tested using semi-invasive (HemoCue) and non-invasive (Massimo Pronto-7) machines. HemoCue machine had lower number of subjects willing to test hemoglobin levels (n=184) compared to Massimo Pronto-7 machine (n=200). However, HemoCue machine was more reliable than Massimo Pronto-7 when considering the ability to measure the level of hemoglobin. HemoCue machine managed to read hemoglobin levels of all 184 subjects who agreed to use the machine whereas Massimo Pronto-7 machine failed to read hemoglobin levels of 44% (n=88) of the study subjects who agreed to be tested (Table 9). Results from the Massimo Pronto-7 with Rainbow showed that the prevalence of anemia was 25.9% with mean hemoglobin level of 12.7±1.2 g/dL. When using HemoCue machine, the prevalence of anemia was 22.8% with mean hemoglobin level of 12.9±1.3 g/dL. There is no 46 association of the experience of menarche with the prevalence of IDA diagnose by HemoCue and Massimo Pronto-7 machines. 4.3.3 Iodine status and prevalence of UIC <50 µg/L among study subjects Majority (n=175) of the study subjects provided urine samples while 16% refused to participate. The reasons for refusal were that providing urine sample did not feel comfortable due to menstrual status or no reason. Based on UICs from urine samples, iodine status of the study subjects was adequate since the median UIC was 227.1 µg/L. The prevalence of UIC <50 µg/L was 16.4% and there is no significant difference between those who had and had not experienced menarche (Table 9). 47 Table 13. Prevalence of nutritional inadequacies among study subjects Nutritional status Total Ever experienced menarche P value Yes No n % n % n % Stunting No 163 78.4 50 24.0 113 54.3 0.1082 Yes 45 21.6 20 9.6 25 12.0 Underweight No 196 94.2 62 29.8 134 64.4 0.0231*1 Yes 12 5.8 8 3.9 4 1.9 Anemia diagnosed by HemoCue2 No 142 77.2 51 27.7 91 49.5 0.8549 Yes 42 22.8 14 7.6 28 15.2 Anemia diagnosed by Pronto3 No 83 74.1 30 26.8 53 47.3 0.8635 Yes 29 25.9 11 9.8 18 16.1 UIC <50 µg/L No 174 83.7 54 26.0 120 57.7 0.1082 Yes 34 16.3 16 7.7 18 8.7 1* P <0.05 2The total n for the variable was 184. 3The total n for the variable was 112. 48 4.4 Determinants of nutritional inadequacies of study subjects 4.4.1 Associations of characteristics of study subjects and their caregivers with nutritional inadequacies The presence of stunting was significantly associated with occupation of caregivers (P = 0.0325) (Table 14). Underweight was significantly associated with experience of menarche (P = 0.0231). Anemia had a significant association with caregivers sex (P = 0.0341) and education level (P = 0.0053) (Table 15). Chi-square test showed that low iodine status (UIC <50 µg/L) was associated with locality (rural vs. semi-urban). No associations were found between iodine status and socioeconomic characteristics of caregivers. Characteristics of subjects and their caregivers stratified by UIC are shown in Table 16. UIC tend to be associated with socioeconomic characteristics of their caregivers than general characteristics of adolescent girls. Highest tertile of UIC groups were from household caregivers with high educated (P <0.01) and from a larger household (P <0.01). However, no significant associations were found between characteristics of adolescent girls and UIC. 49 Table 14. Independent association of sociodemographic characteristics of the study subjects and their caregivers with the presence of stunting and underweight among study subjects Variables Total Stunting P value Underweight P value Yes No Yes No n % n % n % n % n % Total 208 100.0 45 21.6 163 78.4 12 5.8 196 94.2 General characteristics of subjects Age (years) 12-14 70 33.7 13 6.3 57 27.4 0.4814 4 1.9 66 31.7 0.9807 15-19 138 66.4 32 15.4 106 51.0 8 3.9 130 62.5 Locality Rural 135 64.9 33 15.9 102 49.0 0.2182 7 3.4 128 61.5 0.7567 Semi-urban 73 35.1 12 5.8 61 29.3 5 2.4 68 32.7 Religion Christian 192 92.3 42 20.2 150 72.1 0.7705 10 4.8 182 87.5 0.2327 Muslim 16 7.7 3 1.4 13 6.3 2 1.0 14 6.7 Illness within the past two weeks Yes 54 26.0 13 6.3 41 19.7 0.7011 2 1.0 52 25.0 0.7352 No 154 74.0 32 15.4 122 58.7 10 4.8 144 69.2 Experienced menarche Yes 138 66.4 25 12.0 113 54.3 0.1082 4 1.9 134 64.4 0.0231*1 No 70 33.7 20 9.6 50 24.0 8 3.9 62 29.8 Socioeconomic characteristics of caregivers Sex Men 112 53.9 25 12.0 87 41.8 0.8665 4 1.9 108 51.9 0.2319 Women 96 46.2 20 9.6 76 36.5 8 3.9 88 42.3 50 Variables Total Stunting P value Underweight P value Yes No Yes No n % n % n % n % n % Marital status Married 148 71.2 30 14.4 118 56.7 0.4617 7 3.4 141 67.8 0.3333 Single 60 28.9 15 7.2 45 21.6 5 2.4 55 26.4 Education level No school 26 12.5 6 2.9 20 9.6 0.5136 2 1.0 24 11.5 0.3848 Primary 130 62.5 25 12.0 105 50.5 9 4.3 121 58.2 Secondary/tertiary 52 25.0 14 6.7 38 18.3 1 0.5 51 24.5 Occupation Peasant farmer 155 74.5 28 13.5 127 61.1 0.0325* 11 5.3 144 69.2 0.3032 Education, health professional, And business 53 25.5 17 8.2 36 17.3 1 0.5 52 25.0 Household size 94 45.2 19 9.1 75 36.1 0.7359 8 3.9 86 41.4 0.1442 >5 114 54.8 26 12.5 88 42.3 4 1.9 110 52.9 Consumption of iodized salt Amount of iodine in brought salt (ppm)2 15 138 95.2 30 20.7 108 74.5 0.6389 9 6.2 129 89.0 0.4003 <15 7 4.8 1 0.7 6 4.1 1 0.7 6 4.1 1* P <0.05 2The total n for the variable was 145. 51 Table 15. Independent association of sociodemographic characteristics of the study subjects and their caregivers with the presence of anemia and UIC <50 µg/L among study subjects Variables Total Anemia1 P value UIC <50 µg/L P value Yes No Yes No n % n % n % n % n % Total 208 100.0 42 22.8 142 77.2 34 16.4 174 83.7 General characteristics of subjects Age 12-14 70 33.7 12 6.5 51 27.7 0.4604 13 6.3 57 27.4 0.5556 15-20 138 66.4 30 16.3 91 49.5 21 10.1 117 56.3 Locality Rural 135 64.9 33 17.9 96 52.2 0.1862 9 4.3 126 60.6 <0.0001** Semi-urban 73 35.1 9 4.9 46 25.0 25 12.0 48 23.1 Religion Christian 192 92.3 37 20.1 133 72.3 0.3164 31 14.9 161 77.4 0.7298 Muslim 16 7.7 5 2.7 9 4.9 3 1.4 13 6.3 Illness within the past two weeks Yes 54 26.0 11 6.0 39 21.2 0.8705 5 2.4 49 23.6 0.1342 No 154 74.0 31 16.9 103 56.0 29 13.9 125 60.1 Experienced menarche Yes 138 66.4 28 15.2 91 49.5 0.8549 18 8.7 120 57.7 0.0773 No 70 33.7 14 7.6 51 27.7 16 7.7 54 26.0 Socioeconomic characteristics of caregivers Sex Men 112 53.9 16 8.7 82 44.6 0.0341* 18 8.7 94 45.2 0.9079 Women 96 46.2 26 14.1 60 32.6 16 7.7 80 38.5 52 Variables Total Anemia1 P value UIC <50 µg/L P value Yes No Yes No n % n % n % n % n % Marital status Married 148 71.2 27 14.7 105 57.1 0.2445 26 12.5 122 58.7 0.5383 Single 60 28.9 15 8.2 37 20.1 8 3.9 52 25.0 Education level No school 26 12.5 11 6.0 11 6.0 0.0053** 2 1.0 24 11.5 0.4123 Primary 130 62.5 22 12.0 93 50.5 22 10.6 108 51.9 Secondary/tertiary 52 25.0 9 4.9 38 20.7 10 4.8 42 20.2 Occupation Peasant farmer 155 74.5 33 17.9 105 57.1 0.6856 28 13.5 127 61.1 0.2896 Education, health professional, and business 53 25.5 9 4.9 37 20.1 6 2.9 47 22.6 Household size 94 45.2 18 9.8 63 34.2 0.8626 17 8.2 77 37.0 0.5755 >5 114 54.8 24 13.0 79 42.9 17 8.2 97 46.6 Consumption of iodized salt Amount of iodine in brought salt (ppm)3 15 138 95.2 30 22.6 98 73.7 0.5873 26 17.9 112 77.2 0.5246 <15 7 4.8 0 0.0 5 3.8 2 1.4 5 3.5 1The total n for anemia was 184. 2P <0.05, ** P <0.01 3The total n for the variable was 145. 53 Table 16. Independent association of sociodemographic characteristics of the study subjects and their caregivers across the tertile categories of urinary iodine concentration (UIC) Variables Total UIC Chi-square Tertile 1 Tertile 2 Tertile 3 n % n % n % n % Total 175 100.00 58 33.1 58 33.1 59 33.7 General characteristics of subjects Age (years) 2.29 12-14 57 32.6 15 26.3 19 33.3 23 40.4 15-19 118 67.4 43 36.4 39 33.1 36 30.5 Locality 3.02 Rural 127 72.6 45 35.4 44 34.7 38 29.9 Semi-urban 48 27.4 13 27.1 14 29.2 21 43.8 Religion 4.99 Christian 162 92.6 56 34.6 55 34.0 51 31.5 Muslim 13 7.4 2 15.4 3 23.1 8 61.5 Illness within the past two weeks 5.00 Yes 49 28.0 10 20.4 19 38.8 20 40.8 No 126 72.0 48 38.1 39 31.0 39 31.0 Experienced menarche 0.65 Yes 121 69.1 42 34.7 38 31.4 41 33.9 No 54 30.9 16 29.6 20 37.0 18 33.3 Socioeconomic characteristics of caregivers Sex 1.16 Men 94 53.7 30 31.9 29 30.9 35 37.2 Women 81 46.3 28 34.6 29 35.8 24 29.6 54 Table 16. Variables Total UIC Chi-square Tertile 1 Tertile 2 Tertile 3 n % n % n % n % Marital status 0.91 Married 123 70.3 43 35.0 41 33.3 39 31.7 Single 52 29.7 15 28.9 17 32.7 20 38.5 Education level 13.32** No school 25 14.3 10 40.0 8 32.0 7 28.0 Primary 108 61.7 42 38.9 37 34.3 29 26.9 Secondary/tertiary 42 24.0 6 14.3 13 31.0 23 54.8 Occupation 9.05* Peasant farmer 128 73.1 48 37.5 45 35.2 35 27.3 Education/health professional/business 47 26.9 10 21.3 13 27.7 24 51.1 Household size 10.72** 77 44.0 25 32.5 17 22.1 35 45.5 >5 98 56.0 33 33.7 41 41.8 24 24.5 Consumption of iodized salt Amount of iodine in brought salt (ppm)2 0.26 <15 113 95.8 31 27.4 42 37.2 40 35.4 5 4.2 2 40.0 3 60.0 0 0.0 1P <0.05, ** P <0.01 2The total n for the variable was 145. 55 4.4.2 Odds ratios for nutritional inadequacies according to characteristics of study subjects and their caregivers The multiple logistic regressions were conducted to identify determinants for various nutritional inadequacies including stunting, underweight, anemia, and low iodine status. The AORs of stunting (AOR=1.61; 95% CI=1.18-2.19; P for trend = 0.0025) and underweight (AOR=1.78; 95% CI=1.06-2.99; P for trend = 0.0299) increased with age (Table 17). Adolescent girls who had not experienced menarche were more likely to be at risks of stunting (AOR=3.93; 95% CI=1.62-9.50; P = 0.0024) and underweight (AOR=13.54; 95% CI=2.58-71.15; P = 0.0021) compared to those who had experienced menarche. In addition, compared to non-stunted counterparts, stunted adolescent girls were 2.96 times more likely to have caregivers who are working as peasant farmers (AOR=2.96; 95% CI=1.24-7.03; P = 0.0142). Anemic adolescent girls were 3.77 time more likely to have caregivers with no education (AOR=3.77; 95% CI=1.32-10.82; P = 0.0407) than their non-anemic counterparts (Table 18). Adolescent girls living in semi-urban had a higher AOR of UIC <50 µg/L (AOR=16.32; 95% CI=4.92-54.11; P <0.001) than those living in rural area. Additionally, compared to those with adequate iodine status, adolescent girls with low iodine status (UIC <50 µg/L) were less likely to have caregivers working as blue-collar employees (AOR=0.17; 95% CI=0.03-0.97; P = 0.0460). 56 Table 17. Adjusted odds ratios for stunting and underweight by characteristics of study subjects and their caregivers1 Variables Stunting P value Underweight P value AOR 95% CI AOR 95% CI General characteristics of subjects Age 1.61 1.18 2.19 0.0025**2 1.78 1.06 2.99 0.0299* Locality Rural (ref) 1.00 1.00 Semi-urban 0.52 0.23 1.19 0.1186 1.60 0.36 7.19 0.5394 Religion Christian (ref) 1.00 1.00 Muslim 0.92 0.23 3.68 0.9094 4.61 0.62 34.32 0.1359 Illness within the past two weeks Yes (ref) 1.00 1.00 No 0.89 0.40 2.00 0.7804 3.18 0.49 20.50 0.2242 Experienced menarche Yes (ref) 1.00 1.00 No 3.93 1.62 9.50 0.0024** 13.54 2.58 71.15 0.0021** Socioeconomic characteristics of caregivers Sex Men (ref) 1.00 1.00 Women 0.67 0.29 1.58 0.3603 3.65 0.75 17.85 0.1102 Marital status Married (ref) 1.00 1.00 Single 1.37 0.55 3.40 0.5003 0.74 0.15 3.63 0.7100 Education level No school 1.38 0.45 4.21 0.8000 0.76 0.11 5.21 0.5736 Primary (ref) 1.00 1.00 Secondary/tertiary 1.25 0.50 3.10 0.28 0.03 3.03 57 Variables Stunting P value Underweight P value AOR 95% CI AOR 95% CI Occupation Peasant farmer (ref) 2.96 1.24 7.03 0.0142* 0.27 0.02 3.03 0.2888 Education, health Professional, and business 1.00 1.00 Household size 1.49 0.67 3.32 0.3303 1.74 0.39 7.80 0.4688 >5 (ref) 1.00 1.00 Dietary intake of Study subjects Total energy intake 1.00 1.00 1.00 0.3594 1.00 1.00 1.00 0.7377 1The multiple logistic regression models included covariates including age (continuous), locality, religion, Illness within the past two weeks, experience of menarche, sex, marital status, education level, and occupation of caregiver, household size, and total energy intake. 2P value obtained from multiple logistic regression model with diagnosis of anemia and UIC <50 µg/L as the outcome variables (* P <0.05, ** P <0.01). 58 Table 18. Adjusted odds ratios for anemia and UIC <50 µg/L by characteristics of study subjects and their caregivers1 Variables Anemia P value UIC <50 µg/L P value AOR 95% CI AOR 95% CI General characteristics of subjects Age 0.84 0.61 1.17 0.3053 1.01 0.67 1.52 0.9772 Locality Rural (ref) 1.00 1.00 Semi-urban 0.64 0.25 1.61 0.3394 16.32 4.92 54.11 <0.0001**3 Religion Christian (ref) 1.00 1.00 Muslim 3.08 0.89 10.69 0.0762 0.24 0.04 1.66 0.1485 Illness within the past two weeks Yes (ref) 1.00 1.00 No 1.48 0.63 3.46 0.3714 2.99 0.69 12.97 0.1431 Experienced menarche Yes (ref) 1.00 1.00 No 0.84 0.33 2.16 0.7148 1.35 0.36 5.11 0.6559 Socioeconomic characteristics of caregivers Sex Men (ref) 1.00 1.00 Women 2.24 0.93 5.39 0.0728 2.43 0.71 8.37 0.1587 Marital status Married (ref) 1.00 1.00 Single 1.07 0.43 2.67 0.8895 0.64 0.16 2.52 0.5233 Education level No school 3.77 1.32 10.82 0.0407* 0.15 0.01 1.75 0.1449 Primary (ref) 1.00 1.00 Secondary/tertiary 1.01 0.38 2.73 2.32 0.59 9.16 59 Variables Anemia P value UIC <50 µg/L P value AOR 95% CI AOR 95% CI Occupation Peasant farmer (ref) 0.77 0.29 2.05 0.5962 0.17 0.03 0.97 0.0460* Education, health professional, and business 1.00 1.00 Household size 0.65 0.29 1.49 0.3107 0.60 0.18 2.03 0.4095 >5 (ref) Dietary intake of Study subjects Total energy intake 1.00 1.00 1.00 0.1847 1.00 1.00 1.00 0.3963 Consumption of iodized salt Presence of iodine in salt2 Yes (ref) - - - 1.00 No - - 0.38 0.04 3.66 0.4017 1The multiple logistic regression models included covariates including age (continuous), locality, religion, Illness within the past two weeks, experience of menarche, sex, marital status, education level, and occupation of caregiver, household size, and total energy intake. 2The models also included presence of iodine in salt as an independent variable. 3P value obtained from multiple logistic regression model with diagnosis of anemia and UIC <50 µg/L as the outcome variables (* P <0.05, ** P <0.01). 60 4.4.3 Odds ratios for nutritional inadequacies according to dietary intakes of study subjects AORs of stunting, underweight, anemia, and low iodine status according to dietary intakes are presented in Table 19 and Table 20. Only two micronutrients (iron and zinc) showed significance in AOR of stunting. Adolescent girls consuming less than recommendations for iron and zinc had lower odds for stunting (AOR: 0.21; 95% CI: 0.06-0.72; P = 0.0125 for iron, AOR: 0.28; 95% CI: 0.09-0.85; P = 0.0249 for zinc) than did those consuming more than recommendation levels after controlling for age, locality, religion, illness within the past two weeks, experience of menarche, total energy intake, household size and sex, marital status, education level, and occupation of caregiver. However, there was no significant association among dietary intakes, underweight, anemia, and low iodine status. 61 Table 19. Adjusted odds ratios (AORs) for stunting and underweight according to dietary intakes of study subjects1 Variables Stunting P value Underweight P value AOR 95% CI 95% CI AOR 95% CI 95% CI Protein