Publications

OBJECTIVES:

To assess sociodemographic predictors of prevalence, incidence and remission of overweight including obesity among adults (aged ≥18 years) in rural Eastern India.

DESIGN:

Prospective cohort study.

SETTING:

Birbhum Health and Demographic Surveillance System, West Bengal, India.

PARTICIPANTS:

Self-weighted sample of 24 115 adults (men: 10915, women: 13200) enrolled in 2008 were followed up for body mass index (BMI) reassessment in 2017.

PRIMARY AND SECONDARY OUTCOME MEASURES:

Measured BMI was categorised as: underweight (<18.5 kg/m²), normal weight (18.5-22.9 kg/m²) and overweight including obesity (≥23 kg/m²; hereinafter overweight). Incident overweight was defined as transition from normal weight in 2008 to overweight in 2017, whereas if overweight individuals in 2008 measured normal BMI in 2017, it was classified as remission from overweight.

RESULTS:

In 2008, 10.1% of men and 14.6% of women were overweight, whereas 17.3% of men and 24.7% of women were overweight in 2017. At the same time, in 2017, 35.6% of men and 33.3% of women were underweight. Incident overweight was 19.0% among men and 27.2% among women, whereas remission among men was higher (15.4%) than women (11.5%). Women were more likely to be overweight in 2008 and to experience incident overweight than men. For men and women, education level and wealth were positively associated with prevalence and incidence of overweight. Remission from overweight was less likely in Sainthia, a business hub in the district, as compared with Mohammad Bazar, a more rural area.

CONCLUSION:

A nutrition transition to higher risk of overweight is evident in this rural setting in India, especially among women and individuals with high socioeconomic status. At the same time, a high prevalence of underweight persists, resulting in a significant double burden. Culturally sensitive interventions that address both ends of the malnutrition spectrum should be prioritised.

Industrial fortification of wheat flour is a potentially effective strategy for addressing micronutrient deficiencies in Mongolia, given its ubiquitous consumption and centralized production. However, Mongolia has not mandated fortification of any foods except for salt with iodine. This study modeled the effectiveness and safety of mandatory industrial fortification of wheat flour alone and in combination with edible oil and milk in reducing the prevalence of multiple micronutrient intake deficiencies among healthy non-pregnant adults in Mongolia. Six days of diet records (3 summer, 3 winter) were collected from 320 urban and rural adults across the country and analyzed for food and nutrient consumption using a purpose-built food composition table, and the Intake Monitoring and Planning Program (IMAPP) was used to project the effects of fortification on summer and winter bioavailable micronutrient intake and intake deficiency under different fortification guidelines within population subgroups defined by urban or rural locality and sex. Projections showed that flour fortification would be effective in reducing intake deficiencies of thiamin and folate, while marginal benefits of fortification with iron and riboflavin would be smaller given these nutrients' higher baseline consumption, and fortification with zinc, niacin, and vitamin B12 may be unnecessary. Fortification of flour, oil, and milk with vitamins A, D, and E at levels suggested by international guidelines would substantially reduce vitamin A intake deficiency and would increase vitamin D intake considerably, with the greatest benefits elicited by flour fortification and smaller benefits by additionally fortifying oil and milk. These results support mandatory industrial fortification of wheat flour, edible oil, and milk with iron, thiamin, riboflavin, folate, and vitamins A, D, and E in Mongolia. Considerations will be necessary to ensure the fortification of these nutrients is also effective for children, for whom the potential benefit of zinc, niacin, and vitamin B12 fortification should be assessed.

Household consumption and expenditure surveys are frequently conducted around the world and they usually include data on household food consumption, but their applicability to nutrition research is limited by their collection at the household level. Using data from Mongolia, this study evaluated four approaches for estimating diet from household surveys: direct inference from per-capita household consumption; disaggregation of household consumption using a statistical method and the "adult male equivalent" method, and direct prediction of dietary intake. Per-capita household consumption overestimated dietary energy in single- and multi-person households by factors of 2.63 and 1.89, respectively. Performance of disaggregation methods was variable across two household surveys analyzed, while the statistical method exhibited less bias in estimating intake densities (per 100 kcal) of most dietary components in both of the surveys. Increasingly complex prediction models explained 54% to 72% of in-sample variation in dietary energy, with consistent benefits incurred by inclusion of basic dietary measurements. In conclusion, in Mongolia and elsewhere, differences in how household and dietary measurements are recorded make their comparison challenging. Validity of disaggregation methods depends on household survey characteristics and the dietary components that are considered. Relatively precise prediction models of dietary intake can be achieved by integrating basic dietary assessment into household surveys.

OBJECTIVE:

To study the magnitude and predictors of underweight, incident underweight and recovery from underweight among rural Indian adults.

DESIGN:

Prospective cohort study. Each participant's BMI was measured in 2008 and 2012 and categorized as underweight (BMI<18·5 kg/m2), normal (BMI=18·5-22·9 kg/m2) or overweight/obese (BMI ≥23·0 kg/m2). Incident underweight was defined as a transition from normal weight or overweight/obese in 2008 to underweight in 2012, and recovery from underweight as a transition from underweight in 2008 to normal weight in 2012. Bivariate and multivariable logistic regression analyses were employed.

SETTING:

The Birbhum Health and Demographic Surveillance System, West Bengal, India.

SUBJECTS:

Predominantly rural individuals (n 6732) aged ≥18 years enrolled in 2008 were followed up in 2012.

RESULTS:

In 2008, the prevalence of underweight was 46·5 %. From 2008 to 2012, 25·8 % of underweight persons transitioned to normal BMI, 12·9 % of normal-weight persons became underweight and 0·1 % of overweight/obese persons became underweight. Multivariable models reveal that people aged 25-49 years, educated and wealthier people, and non-smokers had lower odds of underweight in 2008 and lower odds of incident underweight. Odds of recovery from underweight were lower among people aged ≥36 years and higher among educated (Grade 6 or higher) individuals.

CONCLUSIONS:

The current study highlights a high incidence of underweight and important risk factors and modifiable predictors of underweight in rural India, which may inform the design of local nutrition interventions.

RATIONALE:

Existing trials of adjunctive vitamin D in the treatment of pulmonary tuberculosis (PTB) are variously limited by small sample sizes, inadequate dosing regimens, and high baseline vitamin D status among participants. Comprehensive analyses of the effects of genetic variation in the vitamin D pathway on response to vitamin D supplementation are lacking.

OBJECTIVES:

To determine the effect of high-dose vitamin D₃ on response to antimicrobial therapy for PTB and to evaluate the influence of single-nucleotide polymorphisms (SNPs) in vitamin D pathway genes on response to adjunctive vitamin D₃.

METHODS:

We conducted a clinical trial in 390 adults with PTB in Ulaanbaatar, Mongolia, who were randomized to receive four biweekly doses of 3.5 mg (140,000 IU) vitamin D₃ (n = 190) or placebo (n = 200) during intensive-phase antituberculosis treatment.

MEASUREMENTS AND MAIN RESULTS:

The intervention elevated 8-week serum 25-hydroxyvitamin D concentrations (154.5 nmol/L vs. 15.2 nmol/L in active vs. placebo arms, respectively; 95% confidence interval for difference, 125.9-154.7 nmol/L; P < 0.001) but did not influence time to sputum culture conversion overall (adjusted hazard ratio, 1.09; 95% confidence interval, 0.86-1.36; P = 0.48). Adjunctive vitamin D₃ accelerated sputum culture conversion in patients with one or more minor alleles for SNPs in genes encoding the vitamin D receptor (rs4334089, rs11568820) and 25-hydroxyvitamin D 1α-hydroxylase (CYP27B1: rs4646536) (adjusted hazard ratio ≥ 1.47; P for interaction ≤ 0.02).

CONCLUSIONS:

Vitamin D₃ did not influence time to sputum culture conversion in the study population overall. Effects of the intervention were modified by SNPs in VDR and CYP27B1. Clinical trial registered with www.clinicaltrials.gov (NCT01657656).

BACKGROUND AND OBJECTIVES:

Assay cost, quality, and availability pose challenges for vitamin D surveys in limited resource settings. This study aimed to validate an inexpensive vitamin D assay (ELISA) under real-world conditions in Mongolia, the northernmost developing country, to characterize the assay's usefulness and inform the design of epidemiologic studies in similar regions.

METHODS AND STUDY DESIGN:

We collected paired summer and winter serum samples from 120 men and women (aged 20-57 years) in urban and rural Mongolia, analyzed each sample for 25(OH)D concentration using both Immunodiagnostic Systems ELISA and DiaSorin LIAISON 25(OH)D TOTAL, and compared the assays using multiple statistics. LIAISON was itself validated by participation in the DEQAS program.

RESULTS:

Correlation and agreement between assays were higher in summer (Pearson's correlation=0.60, Spearman's rank correlation=0.67, Lin's concordance correlation=0.56) than winter (rP=0.37, rS=0.43, rC=0.33), although ELISA less accurately assigned subjects to sufficiency categories in summer (percent agreement=44%) than winter (58%), during the latter of which most subjects were deficient ([25(OH)D] categories used: >75 nmol/L (optimal), 50-75 nmol/L (adequate), 25-50 nmol/L (inadequate), <25 nmol/L (deficient)). Compared with LIAISON, ELISA tended to indicate higher vitamin D status in both seasons (mean paired difference: 7.0 nmol/L (95% CI: 3.5-10.5) in summer, 5.2 nmol/L (95% CI: 2.9-7.5) in winter).

CONCLUSIONS:

ELISA proved useful for measuring and ranking subjects' vitamin D status in Mongolia during summer, but levels were too low in winter to sensitively discriminate between subjects, and ELISA overestimated status in both seasons. These findings have implications for the timing and interpretation, respectively, of vitamin D surveys in highly deficient populations.

This prospective study evaluated the relationship between long-term dietary habits and total arsenic (As) concentration in toenail clippings in a cohort of 1616 pregnant women in the Bangladeshi administrative regions of Sirajdikhan and Pabna Sadar. Diet was assessed at Gestation Week 28 and at Postpartum Month 1, using a locally-validated dish-based semi-quantitative food-frequency questionnaire. Toenail As concentration was analyzed by microwave-assisted acid digestion and inductively coupled plasma mass spectrometry. Associations between natural log-transformed consumption of individual food items and temporally matched natural log-transformed toenail As concentration were quantified using general linear models that accounted for As concentration in the primary drinking water source and other potential confounders. The analysis was stratified by As in drinking water (≤50 μg/L versus >50 μg/L) and the time of dietary assessment (Gestation Week 28 versus Postpartum Week 1). Interestingly, toenail As was not significantly associated with consumption of plain rice as hypothesized. However, toenail As was positively associated with consumption of several vegetable, fish and meat items and was negatively associated with consumption of rice, cereal, fruits, and milk based food items. Further studies in pregnant women are needed to compare As metabolism at different levels of As exposure and the interaction between dietary composition and As absorption.

BACKGROUND:

Population-based dietary assessment is important for informing national nutrition policy. The developing country setting presents challenges for robust implementation of dietary surveys, yet effective nutrition interventions are often urgently required.

OBJECTIVE:

To develop and evaluate a low-cost approach to epidemiologic dietary assessment in Mongolia, involving the use of large cohorts of local public health and medical students as research assistants for collecting diet records.

METHODS:

From 2011 to 2016, over 200 Mongolian medical and public health university students were trained to collect paired summer and winter 3-day weighed diet records from urban and rural study populations across the geographic expanse of Mongolia. Students were supervised during data collection, and their performance and experience during training and data collection were qualitatively evaluated from their own perspectives as well as those of the investigators.

RESULTS:

Students collected detailed and thorough diet records and generally reported positive feedback regarding training and data collection. Frequent supervision of students during data collection proved to be extremely worthwhile. While rural participants were amenable to having students follow them, students faced several challenges in assessing the diets of urban participants. These challenges may best be addressed by separately training these participants beforehand.

CONCLUSIONS:

With adequate training and supervision, university students may be a useful and cost-effective resource for large-scale dietary surveys in regions where their use would be practical and culturally appropriate. Further research is warranted to study how well this approach may be adapted outside Mongolia and to other dietary assessment methods and technologies.

A locally validated tool was needed to evaluate long-term dietary intake in rural Bangladesh. We assessed the validity of a 42-item dish-based semi-quantitative food frequency questionnaire (FFQ) using two 3-day food diaries (FDs). We selected a random subset of 47 families (190 participants) from a longitudinal arsenic biomonitoring study in Bangladesh to administer the FFQ. Two 3-day FDs were completed by the female head of the households and we used an adult male equivalent method to estimate the FD for the other participants. Food and nutrient intakes measured by FFQ and FD were compared using Pearson’s and Spearman’s correlation, paired t-test, percent difference, cross-classification, weighted Kappa, and Bland–Altman analysis. Results showed good validity for total energy intake (paired t-test, p < 0.05; percent difference <10%), with no presence of proportional bias (Bland–Altman correlation, p > 0.05). After energy-adjustment and de-attenuation for within-person variation, macronutrient intakes had excellent correlations ranging from 0.55 to 0.70. Validity for micronutrients was mixed. High intraclass correlation coefficients (ICCs) were found for most nutrients between the two seasons, except vitamin A. This dish-based FFQ provided adequate validity to assess and rank long-term dietary intake in rural Bangladesh for most food groups and nutrients, and should be useful for studying dietary-disease relationships.

BACKGROUND:

Bangladesh incurs among the highest prevalence of stunting and micronutrient deficiencies in the world, despite efforts against diarrheal disease, respiratory infections, and protein-energy malnutrition which have led to substantial and continuous reductions in child mortality over the past 35 years. Although programs have generally paid more attention to other micronutrients, the local importance of calcium to health has been less recognized.

OBJECTIVE:

To synthesize available information on calcium deficiency in Bangladesh in order to inform the design of an effective national calcium program.

METHODS:

We searched 3 online databases and a multitude of survey reports to conduct a narrative review of calcium epidemiology in Bangladesh, including population intake, determinants and consequences of deficiency, and tested interventions, with particular reference to young children and women of childbearing age. This was supplemented with secondary analysis of a national household survey in order to map the relative extent of calcium adequacy among different demographics.

RESULTS:

Intake of calcium is low in the general population of Bangladesh, with potentially serious and persistent effects on public health. These effects are especially pertinent to young children and reproductive-age women, by virtue of increased physiologic needs, disproportionately poor access to dietary calcium sources, and a confluence of other local determinants of calcium status in these groups.

CONCLUSION:

A tablet supplementation program for pregnant women is an appealing approach for the reduction in preeclampsia and preterm birth. Further research is warranted to address the comparative benefit of different promising approaches in children for the prevention of rickets.

AIM:

This study assessed weight and height changes among underweight children who received a locally produced, cereal-based, ready-to-use supplementary food.

METHODS:

We recruited 500 underweight Bangladeshi children aged 6-23 months from a Dhaka slum and individually matched them by sex and neighbourhood with 480 well-nourished controls. The intervention group received the daily food supplement for five months, and both groups received daily micronutrient supplements. Their weight, height, mid-upper-arm circumference and head circumference were measured monthly.

RESULTS:

The children's mean daily weight gain decreased from 1.27 to 0.66 grams per kilogram per day (g/kg/day) in the intervention group and 0.77 to 0.49 g/kg/day in the controls after adjusting for age differences between the two groups from baseline to five months of follow-up. The mean monthly height gain decreased from 1.13 to 1.03 millimetres per metre per month in the intervention children and 1.26 to 1.01 in the controls. The weight gain was highest in the intervention children who were most wasted at baseline and the controls who were least stunted.

CONCLUSION:

The children showed suboptimal growth despite food supplements, highlighting the need for ongoing research to develop inexpensive, locally sourced food supplements to improve the nutrition of underweight children in Bangladesh.

Many factors put Mongolians at risk of vitamin D deficiency. Despite low levels observed in Mongolian children and pregnant women, there are few data published on the vitamin D status of non-pregnant adults. Between summer 2011 and winter 2013, paired summer and winter blood samples were collected from 320 healthy men and women (20-58 years) living in eight Mongolian provinces. Mean serum 25(OH)D concentrations were 22.5 ng/mL (95% CI: 14.5, 32.5) in summer and 7.7 ng/mL (95% CI: 4.6, 10.8) in winter, with a distribution (<10/10-20/20-30/≥30 ng/mL) of 3.1%/39.3%/39.6%/17.9% in summer and 80.1%/19.5%/0.3%/0.0% in winter. Residents of the capital, Ulaanbaatar, had lower levels in both seasons than any other region, whereas residents of the Gobi desert had the highest. In summer, indoor workers had significantly lower levels than outdoor workers (-2.3 ng/mL; 95% CI: -4.1, -5.7) while levels in males exceeded those in females (4.0 ng/mL; 95% CI: 2.3, 5.7). Effects of region, occupation, and sex were also significant in multivariable regression. In conclusion, Mongolian adults had extremely low serum 25(OH)D, particularly in winter, when 80.1% had concentrations below 10 ng/mL. These results indicate a need for effective vitamin D interventions for the Mongolian adult population, particularly among women and residents of Ulaanbaatar.