Effect of changes in METs and incident cardiovascular disease in type 2 diabetes : A nationally representative cohort study

Abstract Background: Physical activity is known to have strong benefits on prevention and management of cardiovascular disease (CVD). Also, diabetes is known to increase the risk of cardiovascular disease-related morbidity and mortality. However, the evidence of association between changes in physical activity and risk of cardiovascular disease is limited, especially among patients with type 2 diabetes (T2DM). Methods: A total of 20,598 patients with newly diagnosed diabetes were extracted from the Korean National Health Insurance Service-Health Screening Cohort. Self-reported questionnaires using a 7-day recall method were used to assess physical activity and calculated in metabolic equivalent task (MET) score. Physical activity level was measured in the screening period Ⅰ (2009-10) and period Ⅱ (2011-12) and assessed the change in physical activity level with CVD risks. Hazard ratio (HR) and 95% confidence interval (CI) were calculated using multivariable-adjusted Cox proportional hazards regression. Results: Compared with the patients from the screening period Ⅰ(2009-10) to period Ⅱ (2011-12), those who increased their physical activity level from sedentary to active showed a 35% lower risk of overall CVD risk (aHR 0.65, 95% CI 0.44-0.96). Inversely, those who decreased their physical activity level from active to sedentary showed a 79% higher risk of overall CVD risk (aHR 1.79, 95% CI 1.17-2.72). Conclusions: Among patients with newly diagnosed T2DM, change in physical activity showed an inverse relationship with CVD risk. Maintaining a modest level of physical activity is important in reducing CVD risk.