Organic Pollutants and Risk of Type 2 Diabetes: A Systematic Review and Meta-analysis

To evaluate the associations between organic pollutants (OPs) and risk of type 2 diabetes (T2D).

We searched Medline, Embase, Scopus, Web of Science, and Cochrane Central from inception through March 18, 2024. We included studies reporting the adjusted or unadjusted association between serum concentration of OPs and risk of T2D. We excluded studies on type 1 diabetes, self-reported exposure, and if fewer than 100 T2D cases. We classified OPs using 2 classification methods and reported pooled risk estimates using a random-effects model (odds ratio [95% CI]) and assessed risk of bias at the levels of OPs and their classes. We conducted sex- and concentration-stratified analyses.

From 20,531 articles, we included 44 (0.2%) studies of 83 individual and 38 combination OPs in 54,967 participants. All but 1 study had low risk of bias. Ten of 12 OP classes were associated with risk of T2D, polychlorinated dibenzo-p-furans had the highest association (OR, 2.54; 95% CI, 1.94-3.33). Polychlorinated dibenzo-p-dioxins showed a significant association in men (OR, 3.21; 95% CI, 1.81-5.71). Polychlorinated biphenyls (OR, 1.72; 95% CI, 1.55-1.92) and dichlorodiphenyltrichloroethane (DDT) and DDT-like compounds (OR, 1.14; 95% CI, 1.01-1.29) showed a significant association in women. Moreover, 28 (33.7%) individual and 21 (55.3%) combination OPs had a significant association. Polychlorinated biphenyl 157 (OR, 1.93; 95% CI, 1.27-2.92) and organochlorine pesticides (OR, 4.35; 95% CI, 1.90-9.98) had the highest risk of T2D.

Several OPs were associated with higher risk of T2D. Future work should evaluate the concentration threshold at which OPs increase risk to inform both T2D screening and OP advisories and regulation.