High chlordane exposure ups diabetes risk

Higher exposure to chlordane compounds (CHLs), a class of endocrine-disrupting chemicals (EDCs), may worsen the risk of diabetes, a recent meta-analysis has found.

Thirty-one eligible studies were retrieved from the databases of PubMed and Web of Science, excluding those that enrolled individuals with existing diseases or who had consistently high exposure levels to chlordanes. Quality was assessed using the Strengthening the Reporting of Observational Studies in Epidemiology guideline.

Seven studies were eligible for meta-analysis regarding the effect of oxychlordane exposure on adiposity as expressed by body mass index (BMI). They found a beta coefficient of 0.04 (95 percent confidence interval [CI], 0.00–0.07), suggesting that an interaction was very weak or nonexistent. The same was true when adiposity was expressed as fat mass (β, 0.03, 95 percent CI, –0.01 to 0.07).

Similarly, exposure to trans-nonalchor CHLs had only a very weak effect on BMI adiposity (β, 0.02, 95 percent CI, –0.01 to 0.06).

In contrast, researchers detected significant interactions between CHL exposure and diabetes features. In particular, higher levels of oxychlordane exposure almost doubled the risk of diabetes (odds ratio [OR], 1.96, 95 percent CI, 1.19–3.23). Trans-nonalchor CHLs had an even stronger effect (OR, 2.43, 95 percent CI, 1.64–3.62).

“Although our overall estimates do not reveal a strong association between these compounds and adiposity or diabetes, considering the ubiquitous use of these chemicals, even if the increased risk is small, its impact on public health will still be relevant,” the researchers said.

“The consistency of results across the assessed compounds gives us confidence in our meta-analyses results, although, in general, evidence is still scarce to draw firm conclusions,” they added.