Abstract 10068: Cardiorespiratory Fitness Modifies the Association Between Leisure-Time Physical Activity and the Risk of Sudden Cardiac Death Among Middle-Aged Men

Aim: We investigated whether cardiorespiratory fitness (CRF) modifies the association between leisure-time physical activity (LTPA) and the risk of sudden cardiac death (SCD) among middle-aged men. Methods: The participants were a population sample of 2656 Finnish men aged 42-60 years at baseline. The mean follow-up time was 21 years. LTPA was assessed with a questionnaire and was expressed in kilocalories per day (kcal/d). CRF was measured directly using respiratory gas analysis during maximal exercise test and was expressed in metabolic equivalents (METs). The participants were divided into following 4 groups using the lowest tertiles of CRF (7.9 METs) and LTPA (< 191 kcal/d) as cut-offs: high CRF and LTPA, high CRF and low LTPA, low CRF and high LTPA and low CRF and LTPA. The risk of SCD was analysed using Cox regression models adjusted for age, smoking, alcohol consumption, body mass index, systolic blood pressure, low density lipoprotein cholesterol, C-reactive protein, prevalent type 2 diabetes and prevalent coronary heart disease. Results: Men with low CRF and low LTPA had a 1.8 (95% confidence interval 1.3-2.6, p=0.001) times higher risk of SCD than men with high CRF and high LTPA. The amount of LTPA did not significantly alter the risk of SCD among men with high CRF. Figure 1 shows the cumulative survival from SCD in the 4 groups. Conclusions: Our study shows that men with low CRF and low LTPA have increased risk of SCD. This finding emphasizes increasing LTPA to prevent SCD among men and particularly among those with low CRF.