Relevance of Fitness to Mortality Risk in Men Receiving Contemporary Medical Care

Abstract

BackgroundAn inverse association between cardiorespiratory fitness and mortality was robustly demonstrated 3 decades ago. ObjectivesThe purpose of this study was to determine whether significant advances in disease prevention, detection, and treatment since that time have modified this association. MethodsA total of 47,862 men completed baseline examinations, including a maximal treadmill test. Cohort 1 (n = 24,475) was examined during 1971 to 1991 and followed for mortality through 1992. Cohort 2 (n = 23,387) was examined during 1992 to 2013 with follow-up through 2014. Men were categorized as low fit, moderate fit, or high fit using Cooper Clinic normative data. Hazard ratios (HRs) for all-cause, cardiovascular disease, and cancer mortality were determined across fitness categories in the 2 cohorts. ResultsA significant inverse trend between fitness categories and all-cause (HR: 1.0, 0.60, and 0.53 in cohort 1 and HR: 1.0, 0.76, and 0.52 in cohort 2) and cardiovascular disease mortality (HR: 1.0, 0.55, and 0.43 in cohort 1 and HR: 1.0, 0.84, and 0.52 in cohort 2) was observed (p trend <0.001 for all). The trend across fitness categories and cancer mortality was significant for cohort 1 (HR: 1.0, 0.62, and 0.48; p < 0.001), but not for cohort 2 (HR: 1.0, 1.08, and 0.74; p = 0.19). HRs for all-cause mortality were 0.86 (95% confidence interval: 0.82 to 0.90) and 0.87 (95% confidence interval: 0.83 to 0.91) per 1-MET increment in fitness for cohorts 1 and 2, respectively (p < 0.001 for both). Similar values were seen for cardiovascular disease and cancer mortality. ConclusionsDespite significant advances in disease prevention, detection, and treatment since fitness was first shown to be associated with mortality, the inverse association between fitness and mortality remains consistent in a contemporary cohort of men.