Endocrine-disrupting chemicals and risk of diabetes: an evidence-based review

Abstract

The purpose of this study was to review the epidemiological and experimental evidence linking background exposure to a selection of environmental endocrine-disrupting chemicals (EDCs) with diabetes and impaired glucose metabolism. The review summarises the literature on both cross-sectional and prospective studies in humans, as well as experimental in vivo and in vitro studies. The findings were subjected to evidence grading according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) classification. We found >40 cross-sectional and seven prospective studies regarding EDCs and risk of diabetes. Taken together, there is moderate evidence for a relationship between exposure to dichlorodiphenyldichloroethylene (p,p'-DDE), a metabolite of the pesticide dichlorodiphenyltrichloroethane, and diabetes development. Regarding polychlorinated biphenyls (PCBs), it is likely that the rodent models used are not appropriate, and therefore the evidence is poorer than for p,p'-DDE. For other EDCs, such as bisphenol A, phthalates and perfluorinated chemicals, the evidence is scarce, since very few prospective studies exist. Brominated flame retardants do not seem to be associated with a disturbed glucose tolerance. Thus, evidence is accumulating that EDCs might be involved in diabetes development. Best evidence exists for p,p'-DDE. For other chemicals, both prospective studies and supporting animal data are still lacking.

Keywords: BPA; Bisphenol A; Chemicals; DDE; DDT; Diabetes; EDCs; Endocrine-disrupting chemicals; Pesticides; Review.

Fig. 1

Summary of a meta-analysis of available cross-sectional (a) and prospective (b) studies on the association between environmental contaminants and diabetes published in 2016 by Song et al [3]. ORs (circles) and 95% CI (horizontal bars) are shown and are based on comparisons between the highest and lowest values presented in the different studies underlying the meta-analysis. The number of studies concerning each of the different chemical classes is shown in parentheses. This figure is available as a downloadable slide