These findings suggest that practicing yoga for 20 wks may lower cardiovascular disease risk in HIV-infected men and women taking cART; a population at increased risk for cardiovascular disease. Specifically, the practice of yoga reduced resting systolic and diastolic blood pressures more than in the standard of care comparison group. These changes occurred in the absence of changes in glucose tolerance, insulin sensitivity, proatherogenic lipid levels, body weight, and central adiposity suggesting that yoga directly acts to lower blood pressure in people living with HIV. Despite these benefits, yoga participants did not perceive an improvement in overall health-related quality of life, except for a tendency for improved emotional well being. It is likely that the perception of more pain at the end of the intervention was due to the challenging and strenuous nature of this form of yoga. Also, the participants were previously sedentary and unfamiliar with this form of physical activity; which likely contributed to this finding. Importantly, yoga did not adversely affect or improve immune or virologic status in these well controlled HIV-infected adults. Yoga appears to be a low cost, simple to administer, safe, non-pharmacological, popular, and moderately effective behavioral intervention for reducing blood pressures in HIV-infected people.
The reduction in blood pressures observed with the practice of yoga in these pre-hypertensive HIV-infected men and women is clinically relevant when considered in the context of anti-hypertension studies conducted in HIV-seronegative populations. Using tightly controlled dietary modification, the DASH study (Dietary Approaches to Stop Hypertension) reduced sodium intake in hypertensive participants who habitually consumed low, intermediate, or high sodium levels, and reduced SBP by 3.0, 6.2, and 6.8 mmHg (42
); similar magnitude to that observed in the current yoga study. In the PREMIER study, the DASH intervention was combined with established behavioral modifications (weight loss by increased physical activity and reduced energy intake) in HIV-negative normo- and hyper-tensive African American and Caucasian men and women (mean age 50yrs), and after only 6-months, SBP was reduced 2.1–5.7 mmHg (43
); similar to those observed for yoga. It is unlikely that changes in dietary salt affected our findings because baseline sodium intake in the HIV-infected participants was greater than AHA recommendations (1.5 g NaCl/day;(44
)), but it was not different between groups and was not changed after either intervention. Our findings support the notion that among traditional lifestyle modifications, the practice of yoga can be used to lower and manage systolic and diastolic blood pressures in pre-hypertensive HIV-infected people.
The magnitude of the reduction in blood pressure observed here is similar to that observed in HIV-negative people with CVD risk factors who followed a yoga lifestyle intervention. Yoga tended to reduce blood pressure in studies of HIV-negative participants with ‘The Metabolic Syndrome’ (32
), with and without previous coronary artery disease (25
), and with hypertension (21
). Perhaps the practice of yoga improves vascular function/tone, and this mediates the lowering of blood pressure (25
). Conversely, in HIV-negative people with cardiovascular disease risk factors, the practice of yoga appears to reduce body weight, glucose, insulin, triglycerides, and proatherogenic lipoprotein levels (8
); beneficial effects that were not observed in the current study of people living with HIV.
In these HIV-infected men and women, the practice of yoga reduced blood pressures similar in magnitude to other lifestyle/behavioral interventions, and if practiced for several years, would be predicted to reduce the incidence of subsequent hypertension and other cardiovascular events, without the added risk for anti-hypertensive drug-related adverse events (45
). For example, when prehypertensive men and women (mean age 49 yrs) were randomized to receive an angiotensin II receptor antagonist (ARB) or placebo for 2 yrs, hypertension developed in 40% of the placebo recipients, and only 14% of the active drug recipients (66% relative risk reduction). When the active drug was discontinued and participants were followed for an additional 2 yrs, those who originally received ARB maintained significantly lower systolic (−2mmHg) and diastolic (−1.1mmHg) blood pressures, and maintained their lower relative risk for developing hypertension (15%) than the placebo recipients. This suggests that even small decrements in systolic and diastolic BP that can be maintained for prolonged periods can postpone the progression of hypertension. In another cohort study (46
), normo-tensive men and women (<120/80 mmHg) with modest coronary artery disease who controlled their blood pressures using either an angiotensin-converting enzyme inhibitor or a calcium-channel blocker had the largest decrease in coronary atheroma volume (using intravascular ultrasound) after 2 yrs, while participants with baseline pre-hypertension or hypertension had no significant reduction or an increase in atheroma volume. This suggests that early anti-hypertensive interventions, even in people with normal blood pressures, effectively reduce the progression of atherogenesis. In HIV-infected people with pre-hypertension and other cardiometabolic risk factors (e.g., tobacco use, central adiposity, dyslipidemia) it seems prudent to recommend lifestyle modifications (including yoga) to reduce blood pressures.
Randomized trials and observational studies are consistent in that a 10 mmHg reduction in systolic and a 5 mmHg reduction in diastolic blood pressure predict ~50–60% lower risk for death from stroke, and ~40–50% lower risk for death from coronary artery (or other vascular) disease (40
). In the current study, average reductions in systolic/diastolic blood pressures were 5/3 mmHg. Assuming that HIV-infected people respond similarly to the general population, our findings suggest that the risk of death from stroke was reduced 25–30% and the risk of death from coronary artery disease was reduced 20–25% by this yoga intervention.
Yoga was selected as the intervention because complementary and alternative medicine advocates believe that yoga’s approach to synchronizing breath inhalation, exhalation or held breath to movement in conjunction with focusing the mind on a specific region of the body optimizes the interaction between the autonomic nervous system and endocrine system (16
). We hypothesized that yoga would reduce body fat because energy expenditure during Hatha/Ashtanga yoga averaged 2.5 METS (3 kcal/min) and peak energy expenditure was 11 METS (14kcal/min;(49
), however fat loss was not observed. In the current study, yoga practice maintained, but did not reduce body weight in HIV-infected adults.
There were some limitations. The sample size was relatively small, but adequately powered to detect the anticipated changes in glucose tolerance/insulin sensitivity. On average, the participant’s baseline CVD risk was not high (Framingham 10-yr Risk score 4.3–4.8) and very few met NCEP ATPIII criteria for ‘The Metabolic Syndrome”. This may have limited our ability to show that yoga significantly reduced CVD risk, or improved metabolic or anthropomorphic variables more than standard of care. Regardless, blood pressure was reduced more by yoga practice, and hypertension is an independent CVD risk factor. The form of yoga utilized was physically demanding and other forms of yoga (restorative) might provide different results.
In HIV-infected adults with mild-moderate cardiometabolic syndrome, 20 wks of supervised yoga significantly reduced resting systolic and diastolic blood pressures, despite the absence of parallel improvements in oral glucose tolerance, body weight, trunk fat content, or proatherogenic lipid levels. These findings suggest that in HIV-infected people with pre-hypertension, the practice of yoga is another lifestyle/behavior intervention that can be recommended to safely reduce blood pressure; one component of the CVD risk profile.