Body Mass Index is Associated with Arsenic Metabolites in three studies in Bangladesh

Abstract

TPS 636: Metals and health 2, Johan Friso Foyer, Floor 1, August 28, 2019, 3:00 PM - 4:30 PM Worldwide, over 140 million individuals are exposed to arsenic (As) in drinking water above 10 μg/L, the WHO safety standard. The methylation of ingested arsenic (As) forms mono-methyl (MMA) and dimethyl (DMA) arsenicals, facilitates urinary As (uAs) elimination, and potentially reduces As toxicity. Higher MMA% in urine has been associated with a greater risk for cardiovascular disease, skin lesions, and various cancers. Conversely, lower MMA% in urine has been associated with increased risk of diabetes-related outcomes in populations from the US and Mexico. Methods. To estimate the association between body mass index (BMI) and uAs metabolites in Bangladeshi populations this study examined a total of 1606 (783 male and 823 female) participants from the Folic Acid and Creatine Trial (FACT), Folate and Oxidative Stress (FOX), and the Health Effects of Arsenic Longitudinal (HEAL) adolescent ancillary studies. Multiple linear regression models were used to analyze the relationship between BMI and uAs metabolites. Results. uAs metabolites were associated with BMI in females in all three studies. For instance, the adjusted mean difference (95% confidence) in BMI for a 5% difference in MMA% and DMA% for the FACT study was -0.74 (-1.24, -0.25) kg/m2 and 0.46 (0.18, 0.75) kg/m2, respectively. Across all studies, lower MMA% was associated with higher BMI levels in females. Conclusions. While the reason underlying the sex-specific findings is unclear, we speculate that it may be related to differences in body fat and/or hormone levels. These data are consistent with negative associations between MMA% and diabetes-related outcomes in previous studies. The current analyses were cross-sectional and reverse causality is possible. Future studies are needed to evaluate these sex-differences, especially during adolescence as it is a period of hormonal change, and determine whether the relationship between BMI and As methylation influences risk for As-related health outcomes.