Validity and reliability of a Dietary Index for a Child's Eating (DICE) to assess diet quality of children living in New Zealand : a thesis presented in partial fulfillment of the requirement for the degree of Master Science in Human Nutrition at Massey University, Albany, New Zealand

Background: At present, in New Zealand, there is no valid and reliable dietary index, which can assess the adherence of children to the ‘New Zealand Food and Nutrition Guidelines for Healthy Children and Young People (Aged 2 -18 years)’. Aim: To examine the validity and reliability of the Dietary Index for a Child’s Eating (DICE) in children aged 2 to 8 years living in Auckland, New Zealand. Methods: Caregivers of healthy children (2-8 years) living in NZ were recruited by email and print advertising. Caregivers completed a four day estimated food record (4DFR) for their child, and completed the DICE online on 2 separate occasions, eight weeks apart. The DICE consists of 17 questions that refer to current statements in the ‘New Zealand Food and Nutrition Guidelines for Healthy Children and Young People (Aged 2-18 years)’, with greater adherence to guidelines indicated by a higher score (maximum 100). The 4DFR was the reference method for assessing validity of the DICE, and the repeated completion of the DICE questionnaire for assessing its reliability. Relative validity was assessed by comparing the DICE total score and component sub-scores with 4DFR total score and the same 4DFR component sub-scores from the questionnaire using Wilcoxon signed rank test, Spearman correlation coefficients, cross-classification, and weighted kappa (ĸ) statistic. For evaluating construct validity, the DICE (total score and individual components) were compared with energy and nutrient intake extracted from the 4DFR using Pearson’s rank correlation coefficient and linear contrast analysis. Intra-class correlation coefficients (Cronbach's α) were used to assess the reliability of DICE. Results: From a possible score of 100, the mean ± SD of DICE was 78.2 ± 11.5 (range from 47 to 100) and the 4DFR was 73.8 ± 10.8. Pearson’s correlation coefficient showed a significant, high correlation between the total scores for DICE and 4DFR (r = 0.72; P < 0.001). Results from the weighted ĸ-statistic also showed that the DICE total score and 4DFR total score had very good agreement (ĸ = 0.94). There was a significant positive relationship between the DICE total score and vitamin C (r = 0.53), folate (r = 0.45), and calcium (r = 0.44) (P < 0.001). Results from linear contrast analysis showed that higher intake of fibre, vitamin C, vitamin , vitamin D, folate (P 0.0 ), and calcium (P 0.001) were associated with increasing tertile of the DICE total score. Almost perfect agreement (0.87) was found through the Intra-class correlation coefficient for reliability test (P < 0.001). Discussion and Conclusion: Results from this study demonstrated that DICE is a valid and reliable tool for the assessment of children’s adherences to a health-promoting diet, as suggested in the ‘New Zealand Food and Nutrition Guidelines for Healthy Children and Young People (Aged 2 -18 years)’

Bone health and fracture risk factors in children living in New Zealand : a thesis presented in partial fulfilment of the requirement for the degree of Doctor of Philosophy in Nutritional Science at Massey University, Albany, New Zealand

Background: Fractures are common in childhood but are a neglected public health issue. A complex interplay of non-modifiable (e.g. genetics) and modifiable risk factors (e.g. obesity, physical activity, calcium intake, sugar-sweetened beverages (SSB), and vitamin D status) have been associated with childhood fractures. Early identification of risk factors during childhood could enable lifestyle changes to be instigated, thus enhancing bone mineralisation, preventing fractures, and improving adult bone health. Vitamin D is an essential nutrient for the absorption of calcium from the intestine, regulation of serum calcium, and bone health. An adequate 25(OH)D concentration is considered important for ensuring bone health during childhood since there is a relationship between vitamin D deficiency and insufficiency and skeletal health problems such as rickets, metabolic bone disease, and hypocalcaemia during childhood. Unfortunately, there is limited data available regarding the vitamin D status and risk factors for vitamin D deficiency in New Zealand children. Measuring paediatric bone mineral status can help us to find children who could be exposed to an increased risk of bone problems (e.g. osteopenia, osteoporosis) later in their life. Quantitative ultrasound (QUS) is a measuring method commonly employed in paediatric populations for assessing skeletal status. Childhood overweight and obesity are also associated with developing musculoskeletal problems, injuries, and fractures early in childhood. Recently, bioelectrical impedance analysis (BIA) has received much attention as a method for measuring body composition. However, the validity of these two devices needs to be investigated in a New Zealand paediatric population. Aims: The main aim of this study is to explore fracture history and related risk factors in children living in Auckland, New Zealand. The secondary aims are to determine the wintertime vitamin D status of children living in Auckland and its determinants and to validate the QUS and in-built algorithm of BIA measurements against dual-energy X-ray absorptiometry (DXA) in children. Methods: This was an observational, cross-sectional study in a sample of school-age children (aged 8 – 13 years old) living in Auckland (during August 2016 and 2017 – late winter in the southern hemisphere). Six local primary schools across Auckland were selected. We originally approached schools through a collaboration of primary school science teachers and asked for expressions of interest. We then endeavoured to recruit schools specifically to include a wide range of socio-demographic levels and ethnicities. All school children within the specified age group were invited to participate. Children were stratified by gender (2 groups), ethnicity (6 categories), and skin colour (4 groups), and logistic regression used to determine the contribution of risk factors for fracture and vitamin D deficiency. A sample of 10-15 per factor per group is the standard requirement for regression analysis, meaning that 480-720 participants would be required to investigate the above-mentioned factors. To validate the QUS and BIA, a sample of 128 children was calculated based on the G*Power program [version 3.1 software: medium effect size: 0.6; power: 95%; the level of significance: 5%]. Healthy children were recruited from primary schools. Children were excluded if they had 1) a history of any disease affecting vitamin D metabolism (e.g. cardiac, kidney or liver disease) or 2) a history of any long-term medication use (e.g. steroids) 3) had any surgical implants, metal screws or similar, or 4) had a cast. Children received an envelope containing a study information sheet, consent form, and some questionnaires (e.g. fracture history, siblings’ history of fractures, family osteoporosis history, physical activity (PA), ethnicity, skin colour, and sun exposure). A dairy and other calcium-containing foods food frequency questionnaire and SSB questionnaire were completed by the children with help from parents. Children who, together with their parents, gave written consent and returned the completed questionnaires, were measured at school. Tests included anthropometric (weight and height) and body composition (bioelectrical impedance analysis, InBody720, Seoul, Korea) measurements, and finger-prick blood spot to measure capillary 25-hydroxyvitamin D (25(OH)D) concentrations. Some children were invited to the Nutrition Research Facility at Massey University, Albany on one occasion to test the validity of the QUS and BIA measurements against a DXA scan. Total body less head (TBLH), bone mineral content (BMC), bone mineral density (BMD), and body composition (fat-free mass, fat mass, and body fat percentage (%BF)) were measured with DXA (QDR Discovery A, Hologic, USA); calcaneal BMD and stiffness index (SI) with QUS (Sahara QUS, Hologic, USA), and total mass and %BF on the InBody 230 (Biospace Ltd., Seoul, Korea). Relative validity was assessed using Pearson’s and Lin’s concordance correlation coefficients (CCC), and Bland-Altman plots. Results: A total of 647 children (354 girls) with the mean ± standard deviation (SD) age of 9.8 ± 0.7 years were recruited. New Zealand European (n = 252) (NZE) and South Asian (n = 68) children reported the lowest (20.2%) and highest (44.1%) fracture incidence, respectively. New Zealand European, compared to South Asian children, had higher 25(OH)D concentrations (74.6 ± 19.8 vs. 48.4 ± 19.3 nmol/L, P < 0.001), higher total calcium intake (764.0 ± 394.4 vs. 592.7 ± 266.3 mg/day, P < 0.018), and lower %BF (19.5 ± 6.6 vs. 23.4 ± 8.4, P < 0.003). The main determinants of fracture history for boys were high %BF, low 25(OH)D, low calcium intake, high SSB consumption, siblings’ fracture history, family osteoporosis history, and being South Asian; and for girls were high SSB consumption, siblings’ fracture history, and family osteoporosis history. Five hundred and seven children agreed to do the finger prick test. Mean ± SD 25(OH)D concentration were 64.0 ± 20.8 nmol/L, with 30.8% of the population presenting with 25(OH)D ≥ 75 nmol/L, 41.4% 50-75 nmol/L, and 27.8% < 50 nmol/L. Capillary 25(OH)D was significantly higher in NZE compared to all other ethnic groups (75.0 ± 20.1 nmol/L, P < 0.001). Children with dark/brown skin colour had lower 25(OH)D concentration compared to other categories of skin colour (51.7 ± 18.0 nmol/L, P < 0.001). Using multiple logistic regression analysis, determinants of 25(OH)D were %BF and ethnicity. In 124 healthy children, positive correlations between QUS SI and DXA (BMC and BMD) were observed (range = 0.30-0.45, P < 0.01). Results from Lin’s CCC test showed that almost perfect correlations between BIA and DXA fat-free mass (0.96), fat mass (0.92), and substantial correlation for %BF (0.75) (P < 0.05). Conclusion: Approximately one-quarter of our participants reported one or more fractures during their childhood. Our results showed that being of South Asian ethnicity was a significant risk factor for fracture in boys. Some children were at high risk of vitamin D deficiency during winter months, for whom vitamin D supplementation might be recommended. Good nutrition (especially good sources of calcium and reducing SSB intakes) should be recommended to children during growth and development to reduce their risk of fractures. Among 507 children, approximately one-third had 25(OH)D < 50 nmol/L. Determinants of a 25(OH)D < 50 nmol/L included %BF and ethnicity. Wintertime serum 25(OH)D was highly variable. There are some children at high-risk of 25(OH)D < 50 nmol/L for whom supplementation may be considered. The current study was the first to evaluate the validity of calcaneal QUS and BIA against DXA in a paediatric New Zealand population for measuring bone density and body composition, respectively. Although BIA results were not as accurate as DXA and DXA remains the gold standard method for clinical assessment, BIA can be an alternative method for investigating body composition among children in large cohort field studies. Calcaneal QUS and DXA are not interchangeable methods for measuring bone density in children similar to our study population

Protective effect of aerobic physical activity on mir-21 and mir-146-b changes in renal tissue of male rats exposed to cadmium chloride

Background and Aims: Cadmium (Cd) is a nephrotoxic environmental pollutant, and microRNAs have been recently investigated as potential biomarkers for the diagnosis and pathology study of certain diseases. The present study aimed to determine the protective effect of aerobic physical activity on the changes of mir-21 and mir-146-b in renal tissue caused by cadmium chloride in male rats. Materials and Methods: This experimental study was conducted on 32 healthy adult male Wistar rats with a mean weight of 250±30 grams and an age of 12 weeks. They were randomly assigned to four groups (n=8):   1- control group (C), 2- Exercise group (E), 3- Cadmium chloride group (CC), and 4- Cadmium+exercise group (CE). Aerobic exercises were performed five times a week for five weeks. It was run at a speed of 27 meters per minute with a zero slope for 16 min. During the study period, the rats received the cadmium chloride as gavage (a daily dose of three milligrams per kilogram of body weight diluted with distilled water orally). The mir-21 and mir-146-b were measured by the reverse transcription polymerase chain reaction (RT-PCR) method. The data were analyzed in SPSS software (version 24) using a one-way analysis of variance and Bonferroni's post hoc test at a significance level of 0.05. Results: The present study demonstrated a significant lower expression of miR-21 (P=0.001) and a higher expression of miR-146-b (P=0.014) in the cadmium group than in the control group. Compared to the control group, aerobic training illustrated a more balanced state through a significant increase in miR-21 gene expression, as well as a significant decrease in miR-146-b. Conclusion: The obtained results indicated that regular moderate-intensity exercise in cadmium-treated rats leads to microRNA secretion regulation associated with renal toxicity

Iodine status and thyroid parameters of pregnant women living in an iodine sufficient area

During the last few decades painstaking efforts have been made to eliminate iodine deficiency throughout the world. Todays in regions where dietary iodine intake is adequate or borderline, the main focus is increasing dietary iodine supply in the target population during pregnancy and the first years of life. Objective: The aim of this study was to obtain longitudinal data on urinary iodine excretion and the changes of maternal thyroid parameters in two groups of healthy women with mild-to-moderate iodine deficiency and iodine sufficiency residing in an iodine replete area of Tehran capital city of IR Iran, for more than one decade. Research designs and methods: The present study is part of a cohort study, investigating the relative influences of iodine intake on thyroid size and function of mothers and their infants during and after pregnancy. A total of 500 pregnant women enrolled from two mother-child health care centers and was divided into group I, with median urinary iodine excretion (MUIE) &lt; 150 &micro;g/L, and group II with MUIE &ge; 150 &micro;g/L. Sonographic thyroid volume measurement, urinary iodine excretion and thyroid function tests were measured sequentially in all pregnant women during the three trimesters (T) of pregnancy. Results: The mean &plusmn; SD age of the participants was 25.1 &plusmn; 5.1 years. The MUIE in group I and II in the first, second and third trimester were 123 and 250 &micro;g/L, 127 and 166 &micro;g/L, 120 and 150 &micro;g/L, respectively. The MUIE in the third trimester of pregnancy in group I did not differ significantly from the values in the first and second trimesters (p = 0.67), but it did decline significantly in group II (p &lt; 0.001). The median thyroid volume of subjects, in the first, second and third trimesters were 7.8, 8.2 and 8.1 ml in group I and 7.5, 8.0 and 8.4 ml in group II, respectively. No difference in thyroid volume was found between two groups in each of the three trimesters of pregnancy (p &gt; 0.05). The mean (&plusmn; SD) TSH concentration of subjects in first, second and third trimester was 2.3(&plusmn; 2.6), 2.1(&plusmn; 1.8), 2.3(&plusmn; 1.7) mIU/L in group I and 2.1(&plusmn; 3.1), 2.1(&plusmn; 1.8) and 2.0(&plusmn; 1.3) mIU/L in group II, respectively. The trend of TSH rising in group I was 26.7% and in group II it was 13.3%. The mean TSH value in three trimesters did not differ significantly in either groups (p &gt; 0.05). The mean (&plusmn; SD) total T4 concentrations of subjects in first, second and third trimesters were 13.2(&plusmn; 3.4), 13.8(&plusmn; 3.3), 13.0(&plusmn; 2.9) &micro;g/dl in group I and 13.1(&plusmn; 3.2), 13.7(&plusmn; 2.9), 13.4(&plusmn; 3.2) &micro;g/dl in group II, respectively. The mean total T4 value in three trimesters did not differ significantly in either groups (p &gt; 0.05). There was no correlation between the thyroid volume and three observed parameters (UIE, total T4 and TSH) during the pregnancy in either groups. Conclusion: Even in areas with well-established universal salt iodization program, pregnancy could be a risk of having iodine deficiency and systematic dietary fortification needs to be implemented in this vulnerable group

Leisure time physical activity and its determinants among adults in Tehran: Tehran lipid and glucose study

Objectives: The aim of this study was to assess leisure time physical activity and its determinants among adults in Tehran. Methods: This cross-sectional study comprised adults (n = 7285), aged 20 years and older. The subjects were participants of the Tehran Lipid and Glucose Study between 2002 and 2004. Information on the number of days spent on different activities during a week and the time devoted to each activity on a typical day was recorded. In addition, each activity, weighted by its relative intensity, was referred to as a metabolic equivalent. Results: The prevalence of inactivity was 69.8% (95% CI: 68.7-70.8) in the whole population and 30.2% (95% CI: 27.2-33.1%) of men and 30.3% (95% CI: 27.7-32.8%) of women were considered as active. Leisure time physical activity less than 30 min/week was scored in 1590 (50.6%) men and 1803 (43.5%) women. The most frequent leisure time physical activity performed by men (96.1%) and women (95.2%) was walking. A negative association was observed in men between leisure time physical activity and increased work hours, older age, more cigarette smoking and higher body mass index (69.8% were overweight and 75.3% were obese; P < 0.05). Leisure time physical activity was more likely to be associated with high educational levels in men. In addition, there was a statistically significant relationship between physical inactivity and occupation in both men and women. Conclusions: The prevalence of physical inactivity among adults in Tehran was high. Leisure time physical inactivity was more likely to be associated with older age, more cigarette smoking, more working hours, and higher body mass index. Public health efforts are needed to improve people′s participation in physical activities in Iran

Continuous Adequate Iodine Supplementation in Fars Province: The 2007 Goiter and Urinary Iodine Excretion Survey in Schoolchildren

Background: The iodine deficiency elimination program thatbegan two decades ago resulted in Iran becoming an iodinedeficiency disorders free country in the Middle East region.The present study was performed to evaluate the adequacy ofiodine supplementation after 17 years of universal salt iodizationin Fars province.Methods: In a cross-sectional study, 1200 schoolchildren (480girls and 720 boys) aged 8 to10 years, were randomly selectedfrom Fars province and evaluated in 2007. Goiter prevalence,urinary iodine excretion, and iodine content of household saltswere measured and the data were compared with those obtainedin 1996 and 2001.Results: Total prevalence of goiter was 1.3% (CI: 0.53-2.47)and no grade 2 goiter was found. One-tenth of the childrenenrolled for goiter assessment, were randomly selected forurinary iodine measurement. The median urinary iodine inthese 120 schoolchildren was 159.4 μg/L (85.6-252.3), with14.8% having urinary iodine excretion less than 50 μg/L. 98%of households were using purified iodized salt. 70% of householdshad appropriate salt storage and none of the householdsalts contained less than 15 μg iodide.Conclusion: Goiter prevalence has significantly decreased inthe Fars province, 17 years after universal salt iodization. Themedian urinary iodine of schoolchildren was adequate as thatreported in 1996 and 2001, indicating a well established sustainableiodine deficiency elimination program in the province

Trend of lipid and thyroid function tests in adults without overt thyroid diseases: A cohort from Tehran thyroid study.

ContextWhile the role of overt hypothyroidism in lipid disorders is clear, the association between dyslipidemia and subclinical thyroid diseases remains unclarified.ObjectiveTo examine lipid trends based on thyroid function over a 10-year period.DesignThis is a prospective population based cohort study.SettingGeneral community.Participants2383 euthyroid participants, as well as those with subclinical thyroid diseases, in all residents of district 13 of Tehran were examined. Subjects who were on levothyroxine, anti-hyperthyroid drugs, and glucocorticoids, those with a history of thyroid surgery or RAI and pregnant women were excluded.Main outcome measuresLipid trends in Model 1 were adjusted for age and follow up duration, and in Model 2 gender-specific multivariate adjustments were performed for thyroid status, diabetes mellitus, smoking status, education, BMI, lipid lowering medications, age and follow up duration by using generalized estimating equations.ResultsIn every four years of assessments, there were significant decreases in levels of all lipid parameters (all Ps ConclusionDuring a 10 year follow-up, decrescendo trends were observed in levels of total cholesterol, triglycerides, which were not be accounted for by the consumption of lipid lowering drugs and thyroid status

Association between physical activity and metabolic risk factors in adolescents: Tehran lipid and glucose study

Background: Physical activity (PA) is associated with the metabolic syndrome (MetS) and its components. This study aimed to examine the association between PA and MetS and its components among normal weight and overweight/obese adolescent in Tehran Lipid and Glucose Study (TLGS). Methods: This cross-sectional study includes 777 adolescents, aged 12-18 years, who were selected by multi-stage random cluster sampling from among TLGS participants. Subjects were classified as normal weight and overweight/obese based on the age- and sex-specific standardized percentile curves of BMI for Iranian population. Levels of PA were assessed using a standardized and modifiable activity questionnaire (MAQ), and categorized into tertiles. MetS was defined according to the Cook′s criteria. Results: Prevalence of the MetS was higher in overweight/obese than normal group (35% vs. 3%; P: 0.02). Normal groups were more physically active (50% vs. 44%); however, difference was not significant. There was a significant association between the light PA and risk of lower level of HDL-C before and after adjustment, in normal weight group (OR: 1.61, CI 95%: 1.11, 2.35; OR: 1.65, CI 95%: 1.12, 2.44, respectively). The overweight/obese group with light and moderate PA had a higher risk of having abdominal obesity than those with vigorous PA, only after adjustment for determined covariates (OR: 1.11, CI 95%: 1.07, 1.21; OR: 1.06, CI 95%: 1.01, 1.08, respectively); the association between MetS and PA was not significant. Conclusions: The results of this study confirm the association between PA and some individual components of MetS such as waist and HDL-C

Validity of Quantitative Ultrasound and Bioelectrical Impedance Analysis against Dual X-Ray Absorptiometry for Measuring Bone Quality and Body Composition in Children

Background: Dual energy X-ray absorptiometry (DXA) is a well-regarded device for primarilymeasuring bone mineral density (BMD) and body composition. [...