Cross-sectional associations of persistent organic pollutants measured in adipose tissue and metabolic syndrome in clinically diagnosed middle-aged adults

Introduction: Although often overlooked in clinical settings, accumulation of persistent organic pollutants (POPs) in visceral adipose tissue (VAT) is thought to be a relevant risk factor for metabolic syndrome (MetS). Methods: One hundred and seventeen patients undergoing non-oncological surgery were randomly recruited and classified as MetS + if presented 3 out of the 5 MetS components: waist circumference (WC), systolic and dia-stolic blood pressure (SBP and DBP, respectively), serum glucose, insulin, triglycerides (TG) and high-density lipoprotein (HDL) cholesterol levels, according International Diabetes Federation (IDF) criteria. Seventeen organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were measured in adipose tissue sam-ples. Linear, logistic and weighted quantile sum (WQS) regression models, adjusted for age and sex, were performed. Results: One third of the participants were males (36.8%) with a median age of 44 years, showing clinical evi-dences of MetS (35.0%). Adjusted linear regression models showed that WC correlated positively with all OCP concentrations. Higher fasting serum glucose levels were related to higher HCB and gamma-HCH concentrations. The remaining OCPs and PCBs were not associated with this MetS component. HCB was inversely associated with HDL cholesterol levels, while PCB-180 was positively associated. HCB and gamma-HCH concentrations were also positively correlated with DBP and SBP levels. PCB-138 was also positively associated with SBP. Adjusted logistic models revealed that exposure to HCB and gamma-HCH were associated with increased odds of MetS [ORs (95%CI) 1.53 (1.22-1.92) and 1.39 (1.10-1.76) respectively; p < 0.01]. No associations were observed for the remaining POPs. WQS models showed a positive and significant mixture effect of POPs on the odds of MetS (exp [beta] = 2.34; p < 0.001), with gamma-HCH (52.9%), o,p'-DDT (26.9%) and HCB (19.7%) driving the association. Conclusions: Our findings support that POPs accumulated in VAT, specifically HCB and (gamma)-HCH, are associated with both isolated components and clinically diagnosed SMT.