Training can improve exercise capacity in older people living with HIV, reports US study

Among people aged 50 and older, the inability to sufficiently raise the heart rate during exercise—i.e., chronotropic incompetence—is more common among those who are living with HIV than those who are not, according to recent study results. However, the condition can be improved through exercise training.

About This Study

“Chronotropic Incompetence among People with HIV Improves with Exercise Training in the Exercise for Healthy Aging Study” was published online on May 28, 2024, in The Journal of Infectious Diseases. The lead author is Matthew S. Durstenfeld, M.D., M.A.S., of the Division of Cardiology at Zuckerberg San Francisco General Hospital and of the Department of Medicine at the University of California in San Francisco.

Key Research Findings

This small study, a secondary analysis of data from a trial of exercise in older people, investigated chronotropic incompetence–the inability to get one’s heart rate up sufficiently during exercise–among 32 people living with HIV and 37 HIV-negative controls. Median participant age was 56 years, 7% of participants were women, and the mean body mass index was 28 kg/m². By study end (24 weeks after baseline), 27 participants remained in the HIV group and 29 participants in the control group.

At baseline, 28% of participants in the HIV group and 11% of participants in the control group met criteria for chronotropic incompetence as measured by oxygen consumption during exercise treadmill testing. After 12 weeks of moderate-level exercise, heart rate capacity in the HIV group approached that of the control group.

At that point, participants were randomized to continue moderate-intensity exercise or start a high-intensity routine. Twelve weeks later, chronotropic incompetence had dropped to 15% of participants in the HIV group while remaining fairly steady at 10% of participants in the control group. This result did not differ by exercise intensity.

Discussion Highlights and Implications for Practice

There were a number of limitations reported. Most participants were relatively sedentary prior to the study, resulting in low oxygen consumption during exercise at baseline. The study was small, included few women, and only 13 participants (nine living with HIV and four controls) had chronotropic incompetence at baseline. In addition, the researchers pointed out that this was a secondary analysis of an already completed trial.

The study authors emphasized that these findings suggest that chronotropic incompetence is not just due to deconditioning in people with HIV and that exercise training can improve exercise capacity in this population.

It is unclear why chronotropic incompetence is more common among people living with HIV than HIV-negative persons, the authors said, but virus-related chronic inflammation may play a role. It is also possible that the higher cardiometabolic risk among people living with HIV compared to the general population limits heart rate or keeps them from exercising to their full capacity.

Whatever the cause, the researchers emphasized that these results show that an exercise regimen can improve the ability to achieve peak heart rate in people living with HIV.

By Barbara Jungwirth