Associations between persistent organic pollutants and metabolic syndrome in morbidly obese individuals

Background and aims

Persons with “metabolically healthy” obesity may develop cardiometabolic complications at a lower rate than equally obese persons with evident metabolic syndrome. Even morbidly obese individuals vary in risk profile. Persistent organic pollutants (POPs) are widespread environmental chemicals that impair metabolic homeostasis. We explored whether prevalence of metabolic syndrome in morbidly obese individuals is associated with serum concentrations of POPs.

Methods and results

A cross-sectional study among 161 men and 270 women with BMI >35 kg/m² and comorbidity, or >40 kg/m². Circulating concentrations of 15 POPs were stratified by number of metabolic syndrome components. In multiple logistic regression analysis odds ratios between top quartile POPs and metabolic risk factors versus POPs below the top quartile were calculated adjusting for age, gender, body mass index, smoking status, alcohol consumption and cholesterol concentrations. Age-adjusted concentrations of trans-nonachlor and dioxin-like and non-dioxin-like polychlorinated biphenyls (PCBs) increased with number of metabolic syndrome components in both genders (p < 0.001), while the organochlorine pesticides HCB, β-HCH and p,p’DDE increased only in women (p < 0.008). Organochlorine pesticides in the top quartile were associated with metabolic syndrome as were dioxin-like and non-dioxin-like PCBs (OR 2.3 95% CI 1.3–4.0]; OR 2.5 95% CI 1.3–4.8] and 2.0 95% CI 1.1–3.8], respectively). Organochlorine pesticides were associated with HDL cholesterol and glucose (OR = 2.0 95% CI = 1.1–3.4]; 2.4 95% CI = 1.4–4.0], respectively). Dioxin-like PCBs were associated with diastolic blood pressure, glucose and homeostatic model assessment-insulin resistance index (OR = 2.0 95% CI = 1.1–3.6], 2.1 95% CI = 1.2–3.6] and 2.1 95% CI = 1.0–4.3], respectively).

Conclusion

In subjects with morbid obesity, metabolic syndrome was related to circulating levels of organochlorine pesticides and PCBs suggesting that these compounds aggravate clinically relevant complications of obesity.