Frailty phenotype transitions and functional improvements during a supervised exercise trial in older people with HIV: results from the HEALTH Trial

BACKGROUND: Frailty and sarcopenia contribute to functional decline in older people with HIV (PWH), yet intervention data remain limited. We evaluated changes in frailty phenotype status, sarcopenia-related outcomes and functional performance during a supervised exercise trial and assessed associations between baseline frailty, study withdrawal and intervention response. METHODS: The High-Intensity Exercise to Attenuate Limitations and Train Habits in Older Adults with HIV (HEALTH) study randomised sedentary PWH aged ≥50 years to 16 weeks of supervised high-intensity interval training (HIIT) or continuous moderate exercise (CME), both combined with progressive resistance training. Frailty was assessed using Fried's phenotype; sarcopenia using current consensus definitions and exploratory HIV-specific cut-points. Functional outcomes included 400-m walk performance and fatigue. RESULTS: Of 118 participants (median age 58 years; 85% male), 94 completed the intervention. Among completers, pre-frailty/frailty status decreased from 48.9% to 30.9% (P < .01), largely reflecting improvements in exhaustion and low activity, with no significant differences between HIIT and CME. Sarcopenia prevalence was low at baseline and changed minimally across definitions. Participants with baseline pre-frailty/frailty were more likely to withdraw (P = .03), yet among retained participants demonstrated greater improvements in 400-m walk performance than non-frail participants (-7.1% [95%CI -8.7, -5.4] vs -4.6% [95% CI -6.3, -2.8]). Fatigue improved among participants with baseline pre-frailty/frailty (-3.3 points [95% CI -5.7, -0.9]) but not in non-frail participants (-1.0 points [95% CI -3.4, 1.4]). CONCLUSIONS: During this supervised exercise trial, favourable frailty phenotype transitions and functional improvements were observed among older PWH, particularly in participants with baseline pre-frailty/frailty. Low sarcopenia prevalence limited conclusions regarding categorical sarcopenia outcomes. Strategies to improve retention among more vulnerable participants may enhance intervention reach and impact.