Fitness, body mass index and the risk of sudden cardiac death in middle-aged men: the Kuopio Ischemic Heart Disease Study

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Background: Both improved cardiorespiratory fitness (CRF) and normal body mass index (BMI) are associated with a lower risk of sudden cardiac death (SCD), but the relative contributions of CRF and BMI to reduce the associated mortality remain unclear. The purpose of this study was to examine the associations of combined CRF and BMI on the risk of SCD in middle-aged men.

Methods:This prospective study was based on a population sample of 2357 men aged 42–60 years, who were followed up for an average of 22 years in the Kuopio Ischemic Heart Disease cohort study. CRF was directly measured by peak oxygen uptake during progressive exercise testing to volitional fatigue. Participants were divided into 4 groups (fit-normal weight (≥8.6 metabolic equivalents [METs],

Results: A total of 253 (10.7%) SCDs occurred during an average of 22 years follow-up. Fit-normal weight men and fit-overweight/obese men had 55% (Relative risk [RR], 0.45, 95% confidence interval [CI], 0.38–0.52) and 41% (RR 0.59, 95% CI, 0.50–0.70) lower risk of SCD as compared with unfit-overweight/obese men after adjusting for potential confounding variables (age, smoking, blood pressure, serum lipids, family history of coronary artery disease, previous myocardial infarction and physical activity). In contrast, unfit-normal weight men were not at decreased risk of SCD (RR 0.95, 95% CI, 0.82–1.11) as compared with their unfit-overweight/obese counterparts.

Conclusion: These results indicate that CRF levels ≥8.6 METs in middle-aged men are independently associated with a lower risk of SCD, regardless of BMI, suggesting that improving low-to-average fitness levels should be strongly encouraged to reduce the risk of SCD.


European Society of Cardiology Congress 2017, Barcelona, Spain August 26- 30, 2017. Awarded: Best Poster