Physical Activity Modifies the Association Between Atherogenic Index of Plasma and New-Onset Diabetes in Middle-Aged...

Background: While existing research has examined the association between the atherogenic index of plasma (AIP) and the incidence of new-onset diabetes, there is a paucity of evidence concerning the influence of physical activity (PA) on this relationship. This study aims to elucidate the intricate relationships among AIP, PA, and new-onset diabetes in middle-aged and older adults. Methods: Data from the 2011-2020 CHARLS cohort were analyzed. Multivariable logistic regression and restricted cubic splines (RCS) assessed the association between AIP and diabetes risk. Effect modification by physical activity was examined via interaction terms and subgroup analyses, with sensitivity analyses excluding participants with dyslipidemia. Results: During follow-up, 717 participants developed diabetes. Each one-standard-deviation increase in AIP was associated with a significantly increased risk of diabetes (odds ratio (OR) = 2.266, 95% confidence interval (CI): 1.807-2.843), with a linear dose-response relationship. A significant interaction was observed between AIP and physical activity. The association between AIP and diabetes was robust among non-exercisers (OR = 2.735, 95% CI: 2.087-3.582), but was markedly attenuated and non-significant among regular exercisers (OR = 1.471, 95% CI: 0.962-2.247). Sensitivity analysis yielded consistent results (OR = 2.259, 95% CI: 1.776-2.873). Conclusions: AIP is independently associated with an increased risk of new-onset diabetes in Chinese adults aged ≥45 years. Subgroup analyses indicated that physical activity significantly modified this association. The association was robust among non-exercisers but was markedly attenuated and became non-significant among regular exercisers.