The association of organochlorine pesticides and polychlorinated biphenyls exposure with dyslipidemia and blood lipids: The mediating effect of white blood cell counts

Epidemiological evidence regarding the associations of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) with lipid metabolism and its potential biological mechanisms remain largely unknown. We intended to explore the associations of OCPs and PCBs with dyslipidemia and blood lipid levels, and further evaluate the mediating role of total and differential white blood cell (WBC) counts. We measured the blood lipid levels, the concentration of OCPs/PCBs and WBC counts in serum among 2036 adults in Wuhan city, China. In the multiple-pollutant models, the results showed that beta-hexachlorocyclohexane (HCH), p,p '-dichlorodiphenyldichloroethylene (DDE), and PCB-153 were positively correlated with increased odds of dyslipidemia. p,p '-DDE and PCB-153 were correlated with elevated triglyceride (TG) and lowered high-density lipoprotein cholesterol (HDL-c). A positive relationship was observed between p,p '-DDE and total cholesterol (TC) as well. Meanwhile, weighted quantile sum (WQS) regression analyses revealed that PCB and OCP mixtures were positively related to dyslipidemia risk and TG and negatively associated with HDL-c, to which p,p '-DDE was the major contributor. BMI, gender and age might modify the associations of OCPs and PCBs with dyslipidemia and TG. Furthermore, we found that WBC counts were significantly associated with dyslipidemia and blood lipid levels, and a positive correlation was also found between p,p '-DDE and lymphocyte count. Mediation analysis further indicated that lymphocyte count might mediate the associations of p,p '-DDE with dyslipidemia, TG, and TC. Accordingly, our results showed that OCPs and PCBs were related to abnormal lipid metabolism, which was partially mediated by WBC counts.