More physical activity independently predicted lower inflammation, less pericardial fat and greater carotid distensibility in 147 U.S. clinical trial participants. Results of this SATURN-HIV trial analysis led researchers to suggest that physical activity "may be an adjuvant to decreasing comorbidities in HIV+ adults."
Ongoing inflammation despite suppressive antiretroviral therapy (ART) probably contributes to heightened rates of cardiovascular disease and other illnesses in people with HIV. The placebo-controlled SATURN-HIV trial found that daily rosuvastatin significantly lowered markers of inflammation and lymphocyte and monocyte activation in people responding to ART. But the statin worsened insulin resistance in this trial population. This SATURN-HIV nested substudy aimed to measure the impact of self-reported physical activity on inflammation and markers of cardiometabolic health.
SATURN-HIV participants had taken a stable antiretroviral regimen for at least three months and had a viral load below 1000 copies/mL and low-density lipoprotein cholesterol at or below 130 mg/dL. Participants could not have a history of coronary disease or diabetes, and they could not have an active infectious or inflammatory condition. At entry and weeks 24, 48 and 96, blood samples were taken to measure markers of systemic inflammation, immune activation and coagulation. Other baseline and week 48/96 measures included carotid artery intima media thickness, carotid distensibility, flow-mediated dilation of the brachial artery, pericardial fat volume and coronary artery calcium.
Participants completed the Adult AIDS Clinical Trials Group Physical Activity Assessment, which asks respondents to report the number of times they engaged in any of 27 activities in the past two weeks and the average length of each activity. The researchers created three physical activity categories: Moderate intensity summed the amount of time walking and doing yoga. Moderate to high intensity summed the amount of time jogging or running, hiking, doing aerobics or dancing, doing calisthenics, biking, swimming and weight lifting. Overall activity summed the amount of time engaged in all nine of these activities. The SATURN-HIV team used multivariable regression analyses to explore associations between physical activity, cardiometabolic health and inflammation.
The analysis included all 147 SATURN-HIV participants (72 assigned to rosuvastatin and 75 to placebo), 119 of whom completed all substudy measures. Median age measured 46 years, 79% of participants were men and 68% were African American. Median minutes of overall physical activity per week stood at 66 minutes in the rosuvastatin group and 22.5 minutes in the placebo group (P = .003). But 24% in each group reported more than 150 minutes of physical activity weekly.
In unadjusted analyses, baseline physical activity was associated with lower leptin, lower interleukin 6 (IL-6) and lower high-sensitivity C-reactive protein (hs-CRP) (the latter two both inflammation markers). Through the 96-week course of the study, overall physical activity was associated with carotid distensibility, that is, less carotid stiffness (β = 2.533, P = .008), lower pericardial fat volume (β = -6.13, P = .001) and lower IL-6 (β = -0.468, P < .001). In an analysis also controlling for randomization group (rosuvastatin or placebo), through 96 weeks overall physical activity was associated with lower pericardial fat volume (β = -10.671, P < .001), lower IL-6 (β = -0.690, P = .042) and lower hs-CRP (β = -0.393, P = .048).
These results mean that people taking ART who reported at least 2.5 hours of moderate-intensity exercise per week -- not necessarily supervised exercise -- had lower levels of subclinical vascular disease and systemic inflammation markers (IL-6 and hs-CRP). The findings may reflect general-population research showing that regular physical activity trims the risk of metabolic and cardiovascular disease.
Mark Mascolini writes about HIV infection.