Non-exercise Estimated Cardiorespiratory Fitness and Mortality Among Adults With Hypertension.

Background: The non-exercise estimated cardiorespiratory fitness (eCRF) has been recognized as an important predictor of mortality among the general population. This study sought to evaluate the relationship between eCRF and mortality from all causes, cardiovascular disease (CVD), and cancer in hypertensive adults.

Methods: We included 27,437 adults with hypertension from the National Health and Nutrition Examination Survey (NHANES) III and 10 NHANES cycles from 1999 to 2018. Multivariate Cox proportional hazard models were used to assess the hazard ratios and 95% confidence intervals (CIs) of eCRF for mortality.

Results: A total of 8,023 deaths were recorded throughout a median 8.6-year follow-up, including 2,338 from CVD, and 1,761 from cancer. The eCRF with per 1 metabolic equivalent increase was linked to decreased risk of all-cause (adjusted HR 0.78, 95% CI: 0.75-0.81) and CVD mortality (adjusted HR 0.79, 95% CI: 0.74-0.84), rather than cancer mortality (adjusted HR 0.94, 95% CI: 0.86-1.03). Moreover, a stronger protective effect of eCRF was observed for females (HR 0.66 (95% CI: 0.62-0.72) versus HR 0.78 (95% CI: 0.73-0.83), Pinteraction < 0.001 for all-cause mortality; HR 0.70 (95% CI: 0.61-0.80;) versus HR 0.82 (95% CI: 0.73-0.92), Pinteraction = 0.026 for CVD mortality) compared with males. Findings did not significantly differ in subgroup analyses and sensitivity analyses.

Conclusions: Among adults with hypertension, eCRF was inversely related to all-cause and CVD mortality, but not cancer mortality. A significant interaction effect existed between sex and eCRF. Further studies are needed to verify this association in different populations.