The Interaction of Inflammation and Exposure to Pyrethroids is Associated with Impaired Fasting Glucose and Type 2 Diabetes

Pyrethroids (PYRs), a widely used class of insecticides, may pose a serious risk to human health. Our study aims to investigate the relationship between six PYRs and impaired fasting glucose (IFG) as well as type 2 diabetes (T2DM), and further explore the role of inflammatory indicators in their relationship. This study was conducted using a case-control design on 2701 individuals from the Henan Rural Cohort Study and measured six PYRs in plasma using gas chromatography-triple quadrupole mass spectrometry. By using generalized linear models, we investigated the potential relationships between six PYR exposures and the risk of IFG and T2DM. Inflammatory indicators were evaluated as mediators of the association between PYRs and T2DM using mediation analyses. After multiple variables were adjusted, per 1 unit increase in ln-cypermethrin and ln-deltamethrin was related to a 12.1% (odd ratio (OR 1.121, 95% confidence interval CI 1.059, 1.187) and an 8.1% (OR 1.081, 95% CI 1.033, 1.132) increased IFG risk, respectively. And there were statistically significant relationships between six PYRs and an increased risk of T2DM. Additionally, PYRs exposure significantly increased fasting plasma glucose, glycated hemoglobin, and HOMA2-IR levels, while they had inconsistent effects on fasting insulin and HOMA2-beta levels. Furthermore, the relationship between cyfluthrin and T2DM is partly mediated by neutrophils (NE) and basophils (BASO), and the explainable percentages were 12.09% and 6.21%, respectively. The study showed that PYRs exposure is statistically significantly associated with the risk of developing IFG and T2DM in rural Chinese populations. In addition, NE and BASO partly mediated the association of cyfluthrin with T2DM.