Abstract 16590: The Association Between Long-Term Changes in Cardiorespiratory Fitness and Mortality Risk

Abstract

Introduction: There is a strong inverse association between cardiorespiratory fitness (CRF) and mortality outcomes. This relationship has predominantly been assessed cross-sectionally, however low CRF is a modifiable risk factor, thus assessing this association using a single baseline measure may be sub-optimal. The primary purpose of this research was to examine the association of the long-term change in CRF, measured using cardiopulmonary exercise testing (CPX) with all-cause and disease-specific mortality. Methods: Participants included 833 apparently healthy men and women (42.9±10.8 y) who underwent two maximal CPXs, the second CPX being ≥ 1 year following the baseline assessment. Participants were followed for 17.7 ± 11.8 years for all-cause, cardiovascular disease (CVD), and cancer mortality. Cox-proportional hazard models were performed to determine the association between the change in CRF, computed as visit 1 (V1) peak oxygen consumption (VO 2peak (ml·kg -1· min -1 )) - visit 2 (V2) VO 2peak , and mortality outcomes. Results: During follow-up, 172 participants died. Overall, the change in CPX-derived CRF was inversely related to all-cause, CVD, and cancer mortality (p<0.05). Each 1 ml·kg -1· min -1 increase was associated with a 10.8, 14.7, and 15.9% reductions in all-cause, CVD, and cancer mortality, respectively. The inverse relationship between CRF and all-cause mortality remained significant (p<0.05) when men and women were examined independently, after adjusting for years since first CPX, baseline VO 2peak , and age. Conclusions: Long-term changes in CRF were inversely related to mortality outcomes, and mortality was better predicted by CRF measured at subsequent examination than baseline CRF. These findings support the recent American Heart Association scientific statement advocating CRF as a clinical vital sign that should be assessed routinely in clinical practice, as well as support regular participation in physical activity to maintain adequate CRF levels across the lifespan.