Background: Bisphenol A (BPA) is a widely used chemical in the manufacture of polycarbonate plastics and epoxy resins. Recent animal studies have suggested that BPA exposure may have a role in the development of weight gain, insulin resistance, pancreatic endocrine dysfunction, thyroid hormone disruption, and several other mechanisms involved in the development of diabetes. However, few human studies have examined the association between markers of BPA exposure and diabetes mellitus.
Methods: We examined the association between urinary BPA levels and diabetes mellitus in the National Health and Nutritional Examination Survey (NHANES) 2003-2008. Urinary BPA levels were examined in quartiles. The main outcome of interest was diabetes mellitus defined according the latest American Diabetes Association guidelines.
Results: Overall, we observed a positive association between increasing levels of urinary BPA and diabetes mellitus, independent of confounding factors such as age, gender, race/ethnicity, body mass index, and serum cholesterol levels. Compared to quartile 1 (referent), the multivariate-adjusted odds ratio (95% confidence interval) of diabetes associated with quartile 4 was 1.68 (1.22-2.30) (p-trend = 0.002). The association was present among normal-weight as well as overweight and obese subjects.
Conclusions: Urinary BPA levels are found to be associated with diabetes mellitus independent of traditional diabetes risk factors. Future prospective studies are needed to confirm or disprove this finding.