Self-rated health status and cardiorespiratory fitness as predictors of mortality in men

Background: Self- rated health (SRH) and cardiorespiratory fitness are independent risk factors for all-cause mortality. The hypotheses being examined are that there is a protective effect of SRH on mortality after controlling for fitness, and vice versa. The secondary hypothesis is to evaluate the combined effects of SRH and fitness on mortality. Methods: The study included 18,488 men who completed a health survey and performed a maximal treadmill exercise test in the during 1987-2003. SRH was defined by the question, “How do you rank your overall health?”; and fitness was defined as total duration of the maximal exercise test. Mortality follow-up was through December 31, 2003 using the National Death Index. Cox regression analysis was used to quantify the associations of SRH and fitness with all-cause mortality. Results: During 17 years of follow-up, 262 deaths were identified. After controlling for BMI, physical activity, smoking, alcohol consumption, abnormal ECG, cancer, cardiovascular disease, diabetes, hypertension, hypercholesterolemia, and fitness, SRH was inversely associated with mortality (p_trend = 0.09). Adjusting the same covariables and SRH, we found an inverse correlation between fitness and mortality (p_trend = 0.006). The combined influence of SRH and fitness showed that participants with moderate to high fitness and good or excellent SRH had a 58% lower risk of mortality than their counterparts. Conclusions: SRH and fitness were independent predictors of all-cause mortality in men. Fit men with good or excellent SRH have the lowest risk of mortality compared to unfit men with poor or fair SRH.