Impact of Lifestyle on the Association between Ambient Air Pollution and Insulin Resistance

Background: This study aimed to evaluate the impact of air pollution (AP) on insulin resistance (IR) in Korean adults and analyze how lifestyle factors, such as smoking, physical activity, and alcohol consumption, affect this association. Methods: Data from 18,391 participants who underwent health checkups at Seoul National University Hospital Health Promotion Center between 2015 and 2019 were analyzed. Exposure to particulate matter with diameters of 2.5 μm or less (PM2.5) and 10 μm or less (PM10) was assessed using data from 300 air quality monitoring stations nationwide. The triglyceride-glucose (TyG) index was used as a surrogate marker for IR. Lifestyle factors were assessed using a questionnaire. Results: Both concentrations of PM2.5 and PM10 were significantly associated with the TyG index (PM2.5: coefficient=0.0076, P<0.001; PM10: coefficient=0.0129, P<0.001) and IR (PM2.5: odds ratio [OR], 1.07; 95% confidence interval [CI], 1.03 to 1.10; PM10: OR, 1.11; 95% CI, 1.06 to 1.16). Interactions with smoking status, physical activity, and alcohol consumption were not significant. Conclusion: PM2.5 and PM10 were independent risk factors for IR regardless of lifestyle factors. Our findings can aid in developing policies aimed at controlling AP, a risk factor for IR, and its associated health risks.