Chronotropic Incompetence Among People With HIV Improves With Exercise Training in the Exercise for Healthy Aging Study

Abstract

Abstract Background People with HIV (PWH) have lower exercise capacity than peers without HIV, which may be explained by chronotropic incompetence, the inability to increase heart rate during exercise. Methods The Exercise for Healthy Aging Study included adults aged 50 to 75 years with and without HIV. Participants completed 12 weeks of moderate-intensity exercise, before randomization to moderate or high intensity for 12 additional weeks. We compared adjusted heart rate reserve (AHRR; chronotropic incompetence <80%) on cardiopulmonary exercise testing by HIV serostatus and change from baseline to 12 and 24 weeks using mixed effects models. Results Among 32 PWH and 37 controls (median age, 56 years; 7% female), 28% of PWH vs 11% of controls had chronotropic incompetence at baseline (P = .067). AHRR was lower among PWH (91% vs 101%; difference, 10%; 95% CI, 1.9%–18.9%; P = .02). At week 12, AHRR normalized among PWH (+8%; 95% CI, 4%–11%; P < .001) and was sustained at week 24 (+5%; 95% CI, 1%–9%; P = .008) versus no change among controls (95% CI, −4% to 4%; P = .95; interaction P = .004). After 24 weeks of exercise, 15% of PWH and 10% of controls had chronotropic incompetence (P = .70). Conclusions Chronotropic incompetence contributes to reduced exercise capacity among PWH and improves with exercise training.