Bisphenol A Levels in the Serum of Brazilian Patients with Type 2 Diabetes Mellitus and Hypothyroidism

Type 2 diabetes mellitus (T2DM) and thyroid dysfunction are the most prevalent endocrine disorders. Bisphenol A (BPA) is a well-known endocrine disruptor that is associated with both T2DM and hypothyroidism (HYPO). However, the relationship between BPA and the combination of T2DM and HYPO remains elusive. Thus, the objective of this study was to evaluate BPA levels in individuals with T2DM and HYPO. The study included 148 individuals categorized into four groups: control, T2DM, HYPO, and T2DM+HYPO. Serum BPA levels were 2.8-fold greater in the T2DM+HYPO group than in the control group; however, the difference was not statistically significant. Moreover, T2DM+HYPO patients had higher HbA1c and lower HDL than did the controls. Among patients whose BPA levels were low (< 0.3 ng/ml), medium (> 0.3 and < 1 ng/ml) or high (> 1 ng/ml), the serum free T4 levels were significantly lower in the high-BPA group than in the low-BPA group. Additionally, a negative correlation between T4 and BPA levels was found in patients, reinforcing the crucial role of BPA as a thyroid disruptor. In conclusion, BPA exposure seems to be associated with the main endocrine effects, namely, diabetes mellitus and thyroid disease, highlighting the importance of the BPA ban.