Impact of smoking and physical activity on cardiovascular outcomes in type 2 diabetes across steatotic liver disease categories

This study investigated the effect of smoking and regular physical activity (PA) on the composite risk of cardiovascular disease (CVD) in patients with type 2 diabetes mellitus (T2DM) across different steatotic liver disease (SLD) categories. We analyzed data for 1,921,310 patients with T2DM aged 20 years and older. The participants were categorized by SLD status, with hepatic steatosis (fatty liver index ≥ 30). Among current smokers, the adjusted hazard ratios (HR) for composite CVD events significantly increased from the no steatosis to metabolic dysfunction-associated steatotic liver disease (MASLD), metabolic dysfunction and alcohol-related steatotic liver disease (MetALD), and alcohol-related liver disease (ALD) groups, with the highest HR observed in the ALD group (aHR, 2.14; 95% confidence interval [CI], 2.04–2.24). The ALD group without regular PA had the highest risk of composite CVD events (aHR, 1.33; 95% CI, 1.28–1.38). The highest risk of composite CVD events was found among current smokers without regular PA, with the aHR increasing in a stepwise manner from no steatosis to MASLD, MetALD, and ALD groups, with the latter showing the highest risk. Smoking and physical inactivity significantly increased the CVD risk in patients with T2DM, with the highest risk in the ALD group.