Association between cardiorespiratory fitness and risk of all-cause and cause-specific mortality

Abstract

Objective: The association of cardiorespiratory fitness (CRF) with all-cause and cause-specific mortality remains unclear in Chinese population. This study aimed to evaluate the risk of all-cause, cardiovascular disease (CVD), cancer and other-cause mortality in Chinese adults using estimated CRF (eCRF).

Patients and methods: We analysed data for 15,566 participants aged ≥20 years recruited in The Rural Chinese Cohort Study during 2007 to 2008 and followed for mortality during 2013 to 2014. eCRF was calculated with sex-specific longitudinal non-exercise algorithms. Cox proportional-hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and cause-specific mortality risk according to baseline eCRF.

Results: During a median of 6.01 years of follow-up, 859 deaths occurred, including 359 from CVD, 221 from cancer, and 279 from other causes. Each 1 metabolic equivalent increment in eCRF was associated with decreased risk of all-cause mortality (men: HR 0.70, 95% CI [0.66-0.74]; women: 0.59, [0.54-0.64]); CVD mortality (men: 0.70 [0.64-0.77]; women: 0.55, [0.48-0.62]); and other-cause mortality (men: 0.68 [0.62-0.75]; women: 0.57, [0.49-0.66]). The area under receiver operating characteristic curve was significantly higher for eCRF than its modifiable components (waist circumference, body mass index and resting heart rate) in predicting all-cause and cause-specific mortality incidence (all p < .001).

Conclusion: eCRF was inversely associated with all-cause, CVD and other-cause mortality.

Keywords: cardiorespiratory fitness; mortality; non-exercise testing; prospective cohort study.