Association of cardiorespiratory fitness with total, cardiovascular, and noncardiovascular mortality across 3 decades of follow-up in men and women.

BACKGROUND

The inverse, dose-dependent association between cardiorespiratory fitness and mortality is well-established; however, the pattern of the association between low fitness and mortality across short- (0 to 10 years), intermediate- (10 to 20 years), and long-term (>20 years) follow-up has not been studied.

METHODS AND RESULTS

We included 46 575 men and 16 151 women (mean age 44 years) from the Cooper Center Longitudinal Study. Participants were categorized as either "low fit" or "not low fit," based on age- and sex- adjusted treadmill times, and were followed for mortality, determined from the National Death Index. Multivariable-adjusted Cox proportional hazards models were constructed to compare the association between fitness and traditional risk factors, with mortality outcomes across short-, intermediate-, and long-term follow-up. After a median follow-up of 16 years, there were 1295 cardiovascular disease and 2840 noncardiovascular disease deaths. Low fitness was associated with all-cause mortality across all periods in men [0 to 10 years: hazard ratios (HR), 1.99 (95% confidence interval [CI], 1.66 to 2.40); 10 to 20 years: HR, 1.61 (95% CI, 1.41 to 1.84); and >20 years: HR, 1.42 (95% CI, 1.27 to 1.60)] and in women [0 to 10 years: HR, 1.98 (95% CI, 1.27 to 3.10); 10 to 20 years: HR, 1.90 (95% CI, 1.40 to 2.56); and >20 years: HR, 1.54 (95% CI, 1.15 to 2.07)]. Similar results were seen for both cardiovascular disease and noncardiovascular disease mortality. Although these associations were also consistent across most subgroups, low fitness appeared to be most strongly associated with mortality in the short term among individuals at highest short-term risk (ie, older age, abnormal exercise test).

CONCLUSIONS

Similar to traditional risk factors, fitness is associated with mortality across short-, intermediate-, and long-term follow-up.