Additive interaction of urinary total arsenic concentrations with being overweight/obesity on the risk of insulin resistance: NHANES 2007-2016.

Arsenic exposure has been associated with the risk of diabetes or insulin resistance (IR), which are also related with overweight/obesity. This study aimed to explore the interaction between arsenic exposure and being overweight/obesity on diabetes or IR risk. Data from the National Health and Nutrition Examination Survey (NHANES) in cycles 2007-2016 were used to assess the interaction between arsenic exposure and being overweight/obesity on IR or diabetes risk among adults. Urinary total arsenic concentrations (UTAs) were used as a biomarker for arsenic exposure. The homeostasis model of insulin resistance (HOMA-IR) was calculated to index IR. Survey-weighted logistic regression and restricted cubic spline (RCS) analyses were performed to determine the association and dose-response relationship between UTAs and IR or diabetes risk. Additive interaction was evaluated by relative excess risk due to interaction (RERI), attributable proportion of interaction (AP), and synergy index (S). A total of 3,133 participants were included. The median (interquartile range) UTAs were 6.61 (3.83, 13.95) μg/L. The adjusted OR of IR was 1.40 (95% CI: 0.99-1.97) for UTAs, comparing the highest with the lowest quartile. And significant additive interaction was observed between high UTAs and being overweight/obesity on IR risk (RERI = 2.47, 95% CI: 0.30-4.63; AP = 0.29, 95% CI: 0.07-0.50; S = 1.48, 95% CI: 1.03-2.13). Our results suggested that there might be a potential additive interaction between high UTAs with being overweight/obesity on diabetes risk (AP = 0.27, 95%CI: 0.04-0.51). Our results indicated an additive interaction between arsenic exposure and being overweight/obesity on IR risk.