The Combined Effect of Leisure-Time Physical Activity and Diabetes on Cardiovascular Mortality

OBJECTIVE To examine if leisure-time physical activity could cancel out the adverse effect of diabetes on cardiovascular mortality. RESEARCH DESIGN AND METHODS This study prospectively examined the combined effect of clinical diabetes and reported leisure-time physical activity on cardiovascular mortality. Data on 53,587 Norwegian men and women participating in the population-based Nord-Trøndelag Health (HUNT) Study (1995-1997) were linked with the Cause of Death Registry at Statistics Norway. RESULTS Overall, 1,716 people died of cardiovascular disease during follow-up through 2008. Compared with the reference group of 3,077 physically inactive people without diabetes, 121 inactive people with diabetes had an adjusted hazard ratio (HR) of 2.81 (95% CI 1.93-4.07). The HR (95% CI) among people who reported ≥3 h of light activity per week was 0.89 (0.48-1.63) if they had diabetes (n = 403) and 0.78 (0.63-0.96) if they did not (n = 17,714). Analyses stratified by total activity level showed a gradually weaker association of diabetes with mortality with increasing activity level (P(interaction) = 0.003). CONCLUSIONS The data suggest that even modest physical activity may cancel out the adverse impact of diabetes on cardiovascular mortality.