Association between physical activity and insulin resistance using the homeostatic model assessment for insulin resistance independent of waist circumference

Only a few studies have evaluated the relationship between physical activity (PA) and Homeostatic model assessment for insulin resistance (HOMA-IR). Therefore, we aimed to analyze the association between HOMA-IR and PA. We included 280,194 Korean without diabetes who underwent health examinations. The short form of the International Physical Activity Questionnaire was completed. PA level was divided into sedentary, mild PA, and health-enhancing PA (HEPA). The HOMA-IR levels were calculated. Confounding factors including waist circumference were adjusted. The median follow-up duration was 4.13 years. A significant inverse relationship was observed between PA level and HOMA-IR (p < 0.001). Compared with the sedentary group, HOMA-IR was lower in the HEPA group (p < 0.001), even when HEPA group decreased PA level over time (p < 0.001). Mild PA (p < 0.001) or HEPA showed a lower risk of HOMA-IR progression (p < 0.001). Increasing PA or maintaining HEPA was significantly associated with a lower HOMA-IR (p < 0.001), HOMA-IR improvement (p < 0.001), and a lower risk of HOMA-IR progression (p < 0.001). Our findings support the inverse relationship between PA and HOMA-IR in a population without diabetes. PA might improve IR and prevent its progression among populations without diabetes, independent of the waist circumference.