Urinary bisphenol A concentration and the risk of central obesity in Chinese adults: A prospective study.

Background: Bisphenol A (BPA) exposure has been associated with diabetes and related metabolic disorders, such as obesity, but studies of the association of urinary BPA concentrations with central obesity risk are limited. The aim of this study was to prospectively investigate the association between urinary BPA and incident central obesity in a Chinese population aged ≥40 years.

Methods: The study followed 888 participants from Shanghai, China, who did not have central obesity at baseline (in 2009) for 4 years. Concentrations of BPA were measured in baseline morning spot urine samples. Central obesity was defined as waist circumference ≥90 cm in men and ≥80 cm in women.

Results: During a mean follow-up of 4 years, 124 (14.0%) participants developed central obesity. Each 1-unit increase in log [BPA] was positively associated with a 2.30-fold risk of incident central obesity (95% confidence interval [CI] 1.39-3.78; P  < 0.001) after adjustment for confounders. Compared with the lowest tertile of urinary BPA concentration, Tertiles 2 and 3 were associated with a higher risk of incident central obesity (odds ratios 1.73 [95% CI 1.04-2.88] and 1.81 [95% CI 1.08-3.05], respectively). Stratified analysis showed significant associations of BPA with incident central obesity in women and individuals <60 years of age, with normal weight, non-smokers, non-drinkers, or non-hypertensives.

Conclusions: The results indicate that higher urinary BPA concentrations may be associated with a greater risk of incident central obesity in Chinese adults. The study emphasizes the effects of BPA exposure on metabolic risk from a public health perspective.