Cardiorespiratory fitness as a predictor of short-term and lifetime estimated cardiovascular disease risk.

Development of cardiovascular disease (CVD) remains a public health concern for young to middle-aged adults, now exacerbated by the increasing prevalence of obesity and sedentary lifestyles. Cardiorespiratory fitness (CRF) improves the reclassification of short-term (10-year) CVD risk, but has not been uniformly defined across studies. This study evaluated cross-sectional differences in short-term and lifetime CVD risk scores, across both absolute metabolic equivalent (MET) and sex- and age-standardized CRF categories in 805 apparently healthy young to middle-aged adults (68% male; 47.4 ± 7.2 years). CVD risk factors were evaluated, and estimated cardiorespiratory fitness (CRF) measurements (METS and peak VO ) were derived from a submaximal Bruce treadmill test. CRF measures also included post-exercise heart rate recovery (HRR) data. Consistent trends showing more favorable risk factor profiles and lower short-term CVD (QRISK2), and CVD mortality (SCORE) scores, associated with higher levels of CRF were evident in both sexes. Lifetime CVD risk (Q-Lifetime) was highest in the lowest CRF categories. Peak VO and HRR following submaximal exercise testing contributed to the variability in short-term and lifetime CVD risk. Global CVD risk predictions were examined across different contemporary CRF classifications with inconsistent findings. Recommended absolute MET and sex- and age-standardized CRF categories were significantly associated with both short-term and lifetime risk of CVD outcomes. However, compared to internationally derived normative CRF standards, cohort-specific CRF categories resulted in markedly different proportion of individuals classified in the "poor" CRF category at higher CVD risk.