Human Adipose Tissue Levels of Persistent Organic Pollutants and Metabolic Syndrome Components: Combining a Cross-Sectional With a 10-year Longitudinal Study Using a Multi-Pollutant Approach

Environ Int. 2017 Jul;104:48-57. doi: 10.1016/j.envint.2017.04.002. Epub 2017 Apr 14.

Abstract

We aimed to assess the influence of long-term exposure to POPs on the risk of metabolic syndrome, combining a cross-sectional with a 10-year longitudinal follow-up design. Residues of eight POPs were quantified in adipose tissue samples from 387 participants recruited between 2003 and 2004 in Granada province (Spain). The outcome ("metabolically compromised") was defined as having ≥1 diagnosis of type 2 diabetes, hypertension, hypertriglyceridemia, and/or low HDL cholesterol. The cross-sectional analysis was conducted in the initial cohort, while the 10-year longitudinal analysis was conducted in those 154 participants free of any of the so-mentioned metabolic diseases and classified as "metabolically healthy" at recruitment. Statistical analyses were performed using single and multi-pollutant approaches through logistic and Cox regression analyses with elastic net penalty. After adjusting for confounders, β-hexachlorocyclohexane (β-HCH) and hexachlorobenzene (HCB) were independently associated with an increased risk of being metabolically compromised (unpenalized ORs=1.17, 95% CI=1.01-1.36 and 1.17, 95% CI=0.99-1.38, respectively). Very similar results were found in the 10-year longitudinal analysis [HRs=1.28, 95% CI=1.01-1.61 (β-HCH); 1.26, 95% CI=1.00-1.59 (HCB)] and were in line with those obtained using elastic net regression. Finally, when the arithmetic sum of both compounds was used as independent variable, risk estimates increased to OR=1.25, 95% CI=1.03-1.52 and HR=1.32, 95% CI=1.02-1.70. Our results suggest that historical exposure to HCB and β-HCH is consistently associated with the risk of metabolic disorders, and that these POPs might be partly responsible for the morbidity risk traditionally attributed to age and obesity.

Keywords: Metabolic disruption; Metabolic syndrome; Organochlorine pesticides; Persistent organic pollutants; Polychlorinated biphenyls.

MeSH terms

  • Adipose Tissue / chemistry*
  • Adult
  • Aged
  • Cross-Sectional Studies
  • Diabetes Mellitus, Type 2 / epidemiology
  • Dyslipidemias / epidemiology
  • Environmental Exposure / analysis
  • Environmental Pollutants / analysis*
  • Female
  • Humans
  • Hydrocarbons, Chlorinated / analysis*
  • Hypertension / epidemiology
  • Longitudinal Studies
  • Male
  • Metabolic Syndrome / epidemiology*
  • Middle Aged
  • Spain / epidemiology
  • Young Adult

Substances

  • Environmental Pollutants
  • Hydrocarbons, Chlorinated