Polychlorinated biphenyls (PCBs) and risk of hypertension: A population-based cohort study in a North Italian highly polluted area

This study aimed to assess the longitudinal association between PCB exposure and the subsequent occurrence of hypertension in a highly polluted area. The study subjects had at least one PCB serum measurement between 2003 and 2014 and were followed up to the end of 2017. Hypertension cases were obtained from the Brescia Health Protection Agency database. Risk ratios of hypertension for total PCBs, high-, middle- and low-chlorinated groups and some common congeners were estimated using Poisson regression models. 1031 subjects were included (43.4% males, mean age 45.3 years). 229 subjects developed hypertension during the follow-up. Total PCBs, middle- and high-chlorinated PCBs, and particularly PCB congeners 138, 153 and 180 were associated with an about 2-fold increased risk of hypertension comparing the third with first tertile of distribution. After lipid-standardization of PCB serum values, the excess risk showed only a slight attenuation. A dose-response linear relationship of the risk of hypertension by PCB serum concentrations as continuous variables was also observed. The PCBs-hypertension association was stronger in overweight/obese subjects than those with normal body mass index. In this prospective cohort study the serum levels of total and middle to high chlorinated (≥6 Cl) PCBs were associated with an increased risk of hypertension, particularly among overweight/obese subjects.