Diabetes, frequency of exercise, and mortality over 12 years: Analysis of the national health insurance service-health screening (NHIS-HEALS) database

Background: The goal of this study was to analyze the relationship between exercise frequency and all-cause mortality for individuals diagnosed with and without diabetes mellitus (DM). Methods: We analyzed data for 505,677 participants (53.9% men) in the National Health Insurance Service-National Health Screening (NHIS-HEALS) cohort. The study endpoint variable was all-cause mortality. Results: Frequency of exercise and covariates including age, sex, smoking status, household income, blood pressure, fasting glucose, body mass index, total cholesterol, and Charlson comorbidity index were determined at baseline. Cox proportional hazard regression models were developed to assess the effects of exercise frequency (0, 1-2, 3-4, 5-6, and 7 days per week) on mortality, separately in individuals with and without DM. We found a U-shaped association between exercise frequency and mortality in individuals with and without DM. However, the frequency of exercise associated with the lowest risk of all-cause mortality was 3-4 times per week (hazard ratio [HR], 0.69; 95% confidence interval [CI], 0.65-0.73) in individuals without DM, and 5-6 times per week in those with DM (HR, 0.93; 95% CI, 0.78-1.10). Conclusion: A moderate frequency of exercise may reduce mortality regardless of the presence or absence of DM; however, when compared to those without the condition, people with DM may need to exercise more often.