A cohort study of the association between prenatal arsenic exposure and age at menarche in a rural area, Bangladesh.

BACKGROUND: Millions of individuals worldwide, particularly in Bangladesh, are exposed to arsenic, mainly through drinking water from tube wells. Arsenic is a reproductive toxicant, but there is limited knowledge of whether it influences pubertal development. OBJECTIVES: We evaluated the association between prenatal arsenic exposure and age at menarche. METHODS: This prospective study was based on data from two studies conducted in Matlab, Bangladesh-the Maternal and Infant Nutrition Interventions in Matlab (MINIMat) trial and the Health Consequences of Arsenic in Matlab (AsMat) study. We included 809 MINIMat girls who participated in assessing age at menarche from July 2016 to June 2017 and had prenatal arsenic exposure data through the AsMat study via measurements in tube well water used by the mothers during pregnancy. The exposure was categorized into <10, 10-49, 50-99, 100-199, and ≥200 µg/L. We used Kaplan-Meier and Cox proportional hazards analyses with adjustment for potential confounders to evaluate the association between arsenic exposure and age at menarche. The results were presented by adjusted hazards ratio (aHR) with a 95% confidence interval (CI). RESULTS: The median arsenic concentration in tube well water consumed by pregnant women was 80 µg/L (interquartile range 2-262 µg/L), and 55% drank water with concentrations above Bangladesh's acceptable value of 50 µg/L. The median age at menarche was 13.0 years. The unadjusted analysis revealed 3.2 months delay in menarche for girls exposed to arsenic concentrations ≥200 µg/L compared with the girl exposed to arsenic concentrations <10 µg/L. Girls exposed to the same higher arsenic concentrations were 23% (aHR 0.77, 95% CI: 0.63-0.95) less likely to have reached menarche than girls exposed to low arsenic concentrations. CONCLUSIONS: Increased levels of prenatal arsenic exposure were associated with older age at menarche. This delay may indicate endocrine disruptions that could potentially result in adverse health consequences in later life. This finding, along with other severe adverse health reinforces the need for arsenic mitigation at the population level.

Exploring Rural Adolescents' Dietary Diversity and Its Socioeconomic Correlates: A Cross-Sectional Study from Matlab, Bangladesh.

The majority of 36 million Bangladeshi adolescents live in rural areas. Improved understanding of their dietary patterns is of great public health importance. This study aimed to explore dietary diversity (DD) with its socioeconomic and gender stratification in a rural adolescent cohort and to isolate factors associated with inadequate DD. Household survey provided data for constructing dietary diversity scores (DDS) and assessing relevant socio-demographic variables. Final analysis included 2463 adolescents. Means and proportions were compared, and a binary logistic regression model was fitted. Inadequate DD was observed among 42.3% (40.3-44.2). Consumption of nutrient-rich foods varied significantly across gender and SES categories. Belonging to the poorest households (adjusted odds ratio (aOR) 1.59; 95% CI: 1.27, 2.00) and food insecure households (aOR 1.34; 95% CI: 1.13, 1.59), adolescents' attainment of secondary education (aOR 1.38; 95% CI: 1.11, 1.71), and having mothers with secondary education or above (aOR 0.76; 95% CI: 0.60, 0.96) were associated with inadequate DD. Compared with girls from food secure households, girls from food insecure ones had higher odds of inadequate DD (aORgirl 1.42; 95% CI: 1.12, 1.81). Improving rural adolescents' DD would require targeted interventions as well as broader poverty alleviation.