Chlorinated persistent organic pollutants and type 2 diabetes - A population-based study with pre- and post- diagnostic plasma samples.

Abstract

BACKGROUND:

Persistent organic pollutants (POPs) have been associated with type 2 diabetes (T2D), but causality is uncertain.

OBJECTIVE:

Within longitudinal population-based data from northern Sweden, we assessed how POPs associated with T2D prospectively and cross-sectionally, and further investigated factors related to individual changes in POP concentrations.

METHODS:

For 129 case-controls pairs matched by age, sex and date of sampling, plasma concentrations of hexachlorobenzene (HCB), dichlorodiphenyl-dichloroethylene (p,p'-DDE), dioxin-like (DL) polychlorinated biphenyl congeners (PCB-118 and PCB-156), and non-dioxin like (NDL-PCB: PCB-74, -99, -138 -153, -170, -180, -183 and PCB-187) were analyzed twice (baseline and follow-up, 9-20 years apart). The cases received their T2D diagnose between baseline and follow-up. Prospective (using baseline data) and cross-sectional (using follow-up data) odds ratios (ORs) for T2D on lipid standardized POPs (HCB, p,p'-DDE, ∑DL-PCBs, ∑NDL-PCBs) were estimated using conditional logistic regression, adjusting for body mass index (BMI) and plasma lipids. The influence of BMI, weight-change, and plasma lipids on longitudinal changes in POP concentrations were evaluated among non-diabetic individuals (n = 306).

RESULTS:

POPs were associated with T2D in both the prospective and cross-sectional assessments. Of a standard deviation increase in POPs, prospective ORs ranged 1.42 (95% CI: 0.99, 2.06) for ∑NDL-PCBs to 1.55 (95% CI: 1.01, 2.38) for HCB (p < 0.05 only for HCB), and cross-sectional ORs ranged 1.62 (95% CI: 1.13; 2.32) for p,p'-DDE to 2.06 (95% CI: 1.29, 3.28) for ∑DL-PCBs (p < 0.05 for all POPs). In analyses of non-diabetic individuals, higher baseline BMI, decreased weight and decreased plasma lipid concentrations were associated with a slower decrease of POPs. Cases had, besides a higher BMI, reduced cholesterol and weight gain at follow-up compared to controls, which can explain the higher ORs in the cross-sectional assessments.

DISCUSSION:

The association between POPs and T2D was confirmed, but an indication that individuals body fat history might influence POP-T2D associations weakens the epidemiological support for a causal association. It also warrants studies based on other exposure metrics than biomonitoring. In addition, we note that a cross-sectional design overestimates the ORs if T2D cases have successfully intervened on weight and/or blood lipids, as changes in these factors cause changes in POPs.

• Authors: Andreas Tornevi, Johan Sommar, Panu Rantakokko, Agneta Åkesson, Carolina Donat-Vargas, Hannu Kiviranta, Olov Rolandsson, Lars Rylander, Maria Wennberg, Ingvar A Bergdahl
• Journal: Environmental research (Environ Res) Vol. 174 Pg. 35-45 (07 2019) ISSN: 1096-0953 [Electronic] Netherlands
• PMID: 31029940 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2019. Published by Elsevier Inc.

Chemical References

• Environmental Pollutants
• Hydrocarbons, Chlorinated
• Dichlorodiphenyl Dichloroethylene
• Polychlorinated Biphenyls

Topics

• Cross-Sectional Studies
• Diabetes Mellitus, Type 2 (epidemiology)
• Dichlorodiphenyl Dichloroethylene
• Environmental Exposure (statistics & numerical data)
• Environmental Pollutants
• Humans
• Hydrocarbons, Chlorinated
• Polychlorinated Biphenyls
• Prospective Studies
• Sweden