Influences of cardiorespiratory fitness and other precursors on cardiovascular disease and all-cause mortality in men and women.
Level 3 - non-randomized controlled study
Prospective observational cohort study evaluating cardiorespiratory fitness and subsequent mortality.
What was done
An observational cohort study evaluated 25,341 men and 7,080 women attending a preventive medicine clinic who completed a baseline preventive medical examination including a maximal exercise test. Cardiorespiratory fitness was categorized into low (least fit 20%), moderate (middle 40%), and high (most fit 40%). Cardiovascular disease and all-cause mortality were tracked over 211,996 man-years and 52,982 woman-years of follow-up across strata of smoking status, cholesterol level, blood pressure, and health status.
What was found
During follow-up, 601 men and 89 women died. In multivariable models, low fitness was an independent predictor of all-cause mortality in both men (adjusted RR 1.52; 95% CI, 1.28-1.82) and women (adjusted RR 2.10; 95% CI, 1.36-3.21). In men, other significant predictors were smoking (RR 1.65; 95% CI, 1.39-1.97), abnormal electrocardiogram (RR 1.64; 95% CI, 1.34-2.01), chronic illness (RR 1.63; 95% CI, 1.37-1.95), elevated cholesterol (RR 1.34; 95% CI, 1.13-1.59), and elevated systolic blood pressure (RR 1.34; 95% CI, 1.13-1.59). In women, the only other statistically significant predictor was smoking (RR 1.99; 95% CI, 1.25-3.17). Fit individuals with smoking, elevated blood pressure, or high cholesterol had lower adjusted death rates than unfit individuals with none of these risk factors.
Why it matters
This study demonstrates that cardiorespiratory fitness objectively assessed via maximal exercise testing independently predicts mortality and substantially attenuates the risks associated with conventional cardiovascular risk factors.
Limits
The observational design precludes establishing causation. Participants were recruited from a single preventive medicine clinic, which may limit generalizability. Total mortality events in women were relatively low (89 deaths), and risk factors along with fitness were assessed at a single baseline visit.
Cited by
- supports Steven Blair and his team showed in large databases starting in the late 1980s that cardiorespiratory fitness and VO2 max predicted longevity better than traditional clinical markers like blood pressure and cholesterol.