Bisphenol A is associated with insulin resistance and modulates adiponectin and resistin gene expression in obese children

Background: Bisphenol A (BPA) exposure has been associated with increased incidence of diabetes and obesity in adults. Objectives: To evaluate whether an association between BPA urinary levels and insulin resistance as well as adiponectin and resistin production and serum concentrations may occur in obese children. Methods: Clinical and biochemical features of 141 obese children were collected. Serum resistin and adiponectin were evaluated. Insulin resistance and urinary BPA levels were assessed. Moreover, the effect of BPA on adiponectin and resistin gene expression in adipocytes from eight normal weight prepubertal children was investigated by quantitative real-time RT-PCR (qPCR). Results: Direct association between BPA and homeostasis model assessment (r = 0.23; p: 0.0069) and a strong inverse association between BPA and adiponectin have been found (r = -0.48; p<0.0001). In adipocytes, resistin expression was detected only after BPA treatment, while adiponectin expression resulted down-regulated after BPA exposure (p<0.05 at both 10 and 100nM BPA concentrations). Conclusions: We suggest the involvement of BPA in the development of insulin resistance in childhood obesity highlighting that urinary BPA levels are directly associated with insulin resistance regardless of BMI. This association may be explained, at least partly, by the findings that BPA affects resistin and adiponectin production in adipose tissue cultures.