Objective: Physical activity reduces high-sensitivity C-reactive protein (hs-CRP), cardiovascular disease (CVD), and total mortality in type 2 diabetic patients. However, it is not known whether the effects of physical activity on mortality depend on the levels of hs-CRP in patients with type 2 diabetes.
Research design and methods: We prospectively followed-up on 569 type 2 diabetic patients, aged 45-64 years, who were free of CVD at baseline. Participants were stratified according to the level of hs-CRP (<1.0, 1.0-3.0, or >3.0 mg/L) and the degree of physical activity (0-4 metabolic equivalent tasks [METs] or >4 METs). The Cox proportional hazards model was used to estimate the joint association between physical activity and hs-CRP levels and the risk of mortality.
Results: During an 18-year follow-up, 356 patients died, 217 of whom died of CVD. Those who were physically more active had significantly reduced total, CVD and coronary heart disease (CHD) mortality among patients with elevated hs-CRP levels (>3 mg/L). These findings persisted in multivariable analyses. However, in patients with an hs-CRP level<1 mg/L or between 1 and 3 mg/L, there was no statistically significant relationship between physical activity and CVD or CHD mortality.
Conclusions: Physical activity reduces total, CVD, and CHD mortality in type 2 diabetic patients with elevated hs-CRP levels. This suggests that the anti-inflammatory effect of physical activity may counteract increased CVD and CHD morbidity and mortality associated with high CRP levels.