Cardiorespiratory fitness and the risk for stroke in men.

BACKGROUND: Low cardiorespiratory fitness is considered to be a major public health problem. We examined the relationship of cardiorespiratory fitness, as indicated by maximum oxygen consumption VO(2)max with subsequent incidence of stroke. We also compared VO(2)max with conventional risk factors as a predictor for future strokes.

METHODS: Population-based cohort study with an average follow-up of 11 years from Kuopio and surrounding communities of eastern Finland. Of 2011 men with no stroke or pulmonary disease at baseline who participated in the study, 110 strokes occurred, of which 87 were ischemic. The VO(2)max was measured directly during exercise testing at baseline.

RESULTS: The relative risk for any stroke in unfit men VO(2)max, <25.2 mL/kg per minute) was 3.2 (95% confidence interval [CI], 1.71-6.12; P<.001; P<.001 for the trend across the quartiles); and for ischemic stroke, 3.50 (95% CI, 1.66-7.41; P =.001; P<.001 for trend across the quartiles), compared with fit men VO(2)max, >35.3 mL/kg per minute), after adjusting for age and examination year. The associations remained statistically significant after further adjustment for smoking, alcohol consumption, socioeconomic status, energy expenditure of physical activity, prevalent coronary heart disease, diabetes, systolic blood pressure, and serum low-density lipoprotein cholesterol level for any strokes or ischemic strokes. Low cardiorespiratory fitness was comparable with systolic blood pressure, obesity, alcohol consumption, smoking, and serum low-density lipoprotein cholesterol level as a risk factor for stroke.

CONCLUSIONS: Our findings show that low cardiorespiratory fitness was associated with an increased risk for any stroke and ischemic stroke. The VO(2)max was one of the strongest predictors of stroke, comparable with other modifiable risk factors.