Intensity of physical activity and cardiovascular and all-cause mortality in diabetic patients: A cohort study (NHANES 1999–2018)

Evidence guiding physical activity (PA) recommendations for individuals with diabetes, particularly those engaging in high-intensity activity, remains limited. Here, the associations between different levels of PA and mortality risk were investigated among adults with clinically diagnosed diabetes. Data from the National Health and Nutrition Examination Survey collected between 1999 and 2018 were analyzed. Adults aged 18 to 85 years with diabetes were categorized according to self-reported PA into sedentary (n = 2069), moderate-intensity (n = 498), or vigorous-intensity (n = 1661) groups. We applied Cox proportional hazards regression to assess associations between PA levels and all-cause mortality (ACM), cardiovascular mortality, and cardiocerebrovascular mortality. Overall, 4228 individuals were enrolled (mean age, 57.97 years; 53.73% male). The median follow-up period for the 3 groups was 5.25 years, 6.58 years, and 6.17 years, respectively. Over the follow-up period, 886 (17.73%) deaths from all causes and 265 (5.52%) cardiovascular deaths were recorded. The highest mortality rates were observed in the sedentary group (25.40% ACM, 8.18% cardiovascular mortality, and 9.56% cardiocerebrovascular mortality). Compared with moderate-intensity PA, the ACM risk in the sedentary group was significantly increased (hazard ratio = 1.58, 95% confidence interval: 1.23-2.02, P < .01), whereas the mortality risk in the vigorous-intensity PA group did not differ significantly from the moderate-intensity group (hazard ratio = 1.07, 95% confidence interval: 0.82-1.40, P > .05). These results indicate that the moderate-intensity group had the lowest mortality risk, whereas the sedentary group had the highest; however, vigorous-intensity PA did not further significantly reduce mortality risk. These patterns were consistent across major demographic subgroups. Moderate or vigorous PA was associated with lower all-cause, cardiovascular, and cerebrovascular mortality compared with sedentary behavior. However, after full adjustment, these associations weakened, with no significant reduction in mortality risk for vigorous activity, indicating similar survival benefits for different exercise intensities. Future research should explore the differential effects of various exercise types on mortality risk in diabetic patients to support more targeted clinical interventions.