On average, HIV-positive adults appear to be at increased risk for aging-related complications. One potential strategy to reduce this risk is to engage in regular exercise. However, such a strategy has not been tested in older HIV-positive people.
Researchers at the University of Maryland in the U.S. conducted a randomized pilot study of high-intensity vs. moderate-intensity exercise in 22 older HIV-positive men. The exercise was done under supervision at the same athletic facility three times weekly for 16 consecutive weeks. All participants were relatively healthy and taking HIV treatment (ART).
The body's ability to maximize its use of oxygen is called V02 max for short. Sports exercise specialists generally consider V02 max to be a good indicator of cardiovascular fitness.
In the study, the men who engaged in high-intensity aerobic exercise (but not moderate intensity) showed a significantly increased V02 max. Also, the endurance of all the men increased, more so those who underwent intensive exercise. The improved ability of the men to use oxygen may have clinical implications, discussed later in this report.
As the study was small, conclusions affecting the average HIV-positive person in the community cannot be drawn from it. However, the results pave the way for a larger study of exercise in HIV-positive people, looking at its many benefits, particularly in older people. The results of a larger study can be generalized to more HIV-positive people.
Researchers enrolled relatively healthy volunteers who did not have any of the following health issues:
- higher-than-normal blood pressure (hypertension) that was untreated
- heart pain
Eleven participants were assigned to each of the study interventions.
The average profile of participants was as follows:
- age -- 57 years
- CD4+ count -- 475 cells/mm3
- undetectable viral load -- 94%
- at least one-third of participants had co-existing conditions, such as treated hypertension, type 2 diabetes and hepatitis C virus infection (one-third of participants also had a history of injecting street drugs)
- 75% of participants smoked
Participants underwent extensive monitoring during the study, particularly when exercising, including heart rate, blood pressure, oxygen consumption and carbon dioxide production.
Participants who engaged in high-intensity exercise did so on a treadmill. If they encountered joint pain, they had the option of doing their exercise on an elliptical machine, which has a low impact on joints. Participants who did moderate-intensity exercise walked around a standard running/walking track.
At first, participants underwent exercise training for between 20 and 30 minutes; this was gradually increased by about 10% each week. Toward the end of the study, participants were exercising for about 40 minutes per session.
Participants also received dietary counselling so that their weight remained stable during the study.
Results -- At the End of the Study
In the men who did high-intensity exercise, the following changes were found:
- the ability of the body's muscles to use oxygen increased significantly
- endurance increased by 27%
- levels of HDL-C (so called "good cholesterol") increased significantly
Among the men who engaged in moderate-intensity exercise, the following changes were noted:
- no significant increase in the ability of the body's muscles to use oxygen occurred
- endurance increased by 11%
- levels of HDL-C fell modestly
Six participants (four doing moderate-intensity exercise and two doing high-intensity exercise) prematurely left the study for the following reasons:
- osteoarthritis -- two people
- stroke -- one person
- communication ceased with the study clinic -- three people
Bear in Mind
This was a pilot study, so its results are not broadly generalizable. However, it is a good first step and provides a rationale for a larger and possibly longer study on exercise in HIV-positive men.
The researchers found an increase in VO2 max in participants who underwent high-intensity exercise. They stated that "in the general geriatric population" an increase of similar magnitude over a decade is associated with the following:
- 15% reduced risk of dying from all causes
- 19% reduced risk of dying from complications of cardiovascular disease
However, the present study cannot draw firm conclusions about the health benefits of exercise in older HIV-positive people because it is too small. A larger, longer study is needed for such a purpose.
Other studies have found that HIV-positive people have increased levels of inflammation. This is partially reduced by initiating ART and maintaining an undetectable viral load. However, residual inflammation remains and some researchers are concerned that this heightened inflammation may make some HIV-positive people more susceptible to a range of chronic conditions, including inflammatory disorders. A longer study of high- vs. low-intensity exercise in HIV-positive people could explore the impact of exercise on the following issues:
- blood sugar
- lipid levels in the blood
- cognitive functioning
- health-related quality of life
Exploring HIV and inflammation -- TreatmentUpdate 223
Exercise -- Potential impact on inflammation and mood -- TreatmentUpdate 205
Healthy Living -- A practical guide to a healthy body for people living with HIV
- Oursler KK, Sorkin JD, Ryan AS, et al. A pilot randomized aerobic exercise trial in older HIV-infected men: Insights into strategies for successful aging with HIV. PLoS One. 2018 Jun 12;13(6):e0198855.
- Quigley A, O'Brien K, Parker R, et al. Exercise and cognitive function in people living with HIV: a scoping review. Disability and Rehabilitation. 2018 Jan 29:1-12.
[Note from TheBody: This article was originally published by CATIE in Aug. 2018. We have cross-posted it with their permission.]