The most recent estimates indicate that 36.9 million people worldwide are living with HIV (Human Immunodeficiency Virus).1 The highest percentage of people living with HIV (PLWH) is in Sub-Saharan Africa, having 53% of the global prevalence.2 Those at risk of HIV transmission include women, men who have sex with men, transgender individuals, people who use drugs, and sex workers.3
Approximately 15–69% of people living with HIV (PLWH) worldwide experience some form of cognitive impairment,4–7 presenting as deficits in attention, memory, and executive function.8,9 There are sex differences in cognitive performance among PLWH, with women scoring lower on tests of attention, processing speed, executive function, and fine motor performance than men.10 In addition to cognitive impairment, balance and gait deficits are common among PLWH11 and are associated with elevated falls risk and mortality.12 Some evidence has emerged to indicate that a relationship exists between physical and cognitive performance in this population.13
Mind-body exercise is a type of therapy, such as Tai Chi and yoga that includes concentration, breathing, and body movement.14 These interventions can have a positive effect on cognitive performance among older adults without HIV. A recent meta-analysis of 32 randomized controlled trials (RCTs) evaluated mind-body interventions (of which, 8 RCTs included a yoga intervention), showing significant improvements in overall cognitive performance, working memory, verbal fluency, cognitive flexibility, and learning among older adults.14 Another meta-analysis of 11 RCTs (4 RCTs with yoga interventions) conducted with older adults determined that mind-body exercise had a positive effect on overall cognition, memory, executive function, learning, and language.15 A prominent theory explaining these cognitive benefits with yoga includes the down-regulation of the stress response and up-regulation of the parasympathetic nervous system.16,17 No RCTs to date have evaluated the impact of a yoga intervention on cognitive performance outcomes among PLWH.
Over half of PLWH in Western countries have sought complementary or alternative therapies, which include mind-body interventions such as yoga and Tai Chi.18–20 Some authors have evaluated the impact of Tai Chi on health-related quality of life and mental health in this population. A single group observational study conducted with male (n = 35) and female (n = 24) PLWH reported a positive effect of Tai Chi on HIV-related psychological distress in addition to emotional, social, and overall health-related quality of life.21 An RCT of 38 male PLWH living with AIDS (Acquired ImmunoDeficiency Syndrome) conducted by Galantino and colleagues (2005) in the United States found significant improvements in overall health-related quality of life in both aerobic exercise and Tai Chi groups versus controls.22
RCTs and meta-analyses have also demonstrated positive effects of yoga on affective outcomes such as health-related quality of life and mental health among PLWH. An RCT demonstrated significant improvements in anxiety, depression, fatigue, well- being, and quality of life in a sample of mostly female PLWH who participated in an integrated yoga intervention compared to controls following an 8-week intervention.23 Another RCT demonstrated positive effects on health-related quality of life and mental health among mostly female PLWH following a 12-week Sudarshan Kriya yoga intervention compared to controls.24 However, the intervention did not include a physical activity component, and PLWH taking antiretrovirals were excluded from the study.24 An RCT with a 1-month integrated yoga intervention conducted with male (n = 24) and female (n = 20) PLWH showed a significant reduction in depression scores among yoga participants compared to controls.25 A meta-analysis of 7 RCTs conducted with PLWH determined that yoga interventions resulted in large improvements in perceived stress, positive affect, and anxiety compared to controls.26 Finally, a systematic scoping review of 84 studies showed that mindfulness, relaxation techniques, cognitive-behavioral strategies, and yoga had beneficial effects on health-related quality of life and physical and psychological symptoms among PLWH.18
Emerging evidence also suggests that mind-body exercise can improve physical performance among PLWH. Participants in the abovementioned RCT by Galantino and colleagues (2005) who performed aerobic exercise and Tai Chi had significant improvements in balance using the functional reach test.22 Kietrys and colleagues (2018) also observed improvements in gait and balance with their integrative yoga intervention among two of three case-series participants.27 Yoga has the potential to address both physical and cognitive impairments in this population. However, no RCTs to date have evaluated the feasibility and impact of yoga on cognitive and physical outcomes among PLWH.
Women are frequently under-represented in health research, particularly in HIV trials.28 To address this gap, the Sex and Gender Equity in Research (SAGER) guidelines recommend authors report how sex (biological attributes) and gender (socially-constructed roles, behaviours, and identity) factor into the study design and present study data disaggregated by sex and gender if possible.29 As such, we will discuss and evaluate the role of sex and gender in this study where applicable.
Purpose, Objectives, & Hypothesis
Our overall goal was to inform the design of a future, full-scale, multisite, community- based RCT to evaluate the effects of yoga on cognitive and physical function among PLWH from Halifax, Nova Scotia, Canada. Our primary objective was to assess the feasibility of a 12- week yoga intervention for PLWH in terms of participant recruitment, assessments, safety, adherence, and satisfaction with the intervention. Our second objective was to evaluate the effect of a 12-week yoga intervention (yoga group) versus usual care (control group) on cognitive performance and self-reported cognition among PLWH. Our third objective was to compare the effects of the yoga intervention versus control on balance, walking speed, mental health, medication adherence, physical activity, and health-related quality of life outcomes among PLWH. The fourth objective was to explore the relationships between cognitive performance and self-reported cognition, physical activity, and balance performance. Our alternative hypotheses were: 1. The yoga group would experience larger improvements in cognitive performance and self-reported cognition than the control group and 2. The yoga group would experience larger improvements in physical function, health-related quality of life, and mental health outcomes than the control group.