Estimated Cardiorespiratory Fitness and Incident Cardiometabolic Multimorbidity in Older Adults: A Prospective Cohort Study

Objective To evaluate the association of estimated cardiorespiratory fitness (eCRF) with incident cardiometabolic multimorbidity (CMM) and its potential contribution to CMM risk prediction in an older adult population. Patients and Methods The analysis included 3326 participants from the English Longitudinal Study of Aging (mean age 63 years; 1820 (54.7%) women) who were free of hypertension, cardiovascular disease, diabetes, and stroke at baseline (wave 4; 2008-2009). Estimated CRF was derived using validated nonexercise prediction equations (heart rate-based, body mass index-based, and Nord-Trøndelag Health Study-based eCRF). Incident CMM was defined at wave 10 (2021-2023) as the presence of ≥2 of the following: hypertension, cardiovascular disease, diabetes, or stroke. Multivariable-adjusted odds ratios (ORs) (95% CIs) and discrimination indices were calculated. Results During 12-15 years of follow-up, 197 (5.9%) participants developed CMM. Each eCRF measure reported an inverse linear association with CMM risk. Higher heart rate-based eCRF was associated with lower odds of CMM (per 1- metabolic equivalents (MET) increment: OR=0.78; 95% CI, 0.70-0.87; highest vs lowest tertile: OR=0.42; 95% CI, 0.25-0.69). Similar associations were observed for body mass index-based eCRF (per 1-MET increment: OR=0.78; 95% CI, 0.68-0.89; highest vs lowest tertile: OR=0.42; 95% CI, 0.25-0.70) and Nord-Trøndelag Health Study-based eCRF (per 1-MET increment: OR=0.73; 95% CI, 0.65-0.82; highest vs lowest tertile: OR=0.36; 95% CI, 0.22-0.58). Incorporation of each eCRF measure into a conventional risk prediction model modestly improved discrimination. Conclusion Estimated CRF derived from validated nonexercise equations was similarly and inversely associated with incident CMM in older adults, with all models reporting comparable modest predictive utility.