by Aishwarya Rajagopalan, MHS
It’s easy to list the touted benefits of yoga: improved physical fitness, reduced stress, and improved spirituality and mindfulness- the list goes on and on.
However, the support of these benefits is mixed. The authors of “Yoga in the Management of Chronic Disease: A Systematic Review and Meta-analysis” examined the impact of yoga on improving health related quality of life (HRQL), exercise capacity, and psychological wellbeing among individuals with COPD, heart disease, and stroke, three of the leading causes of morbidity in the United States. Through a comprehensive literature review of randomized control trials surrounding the implementation of yoga based interventions for individuals with these conditions, the authors sought to understand whether yoga should be used as an adjunct for these chronic conditions.
A number of studies were identified using electronic databases such as MEDLINE, PubMed, PEDro, EMBASE, and Cochrane, in addition to searching the International Journal of Yoga Therapy and the Journal of Yoga and Physical Therapy. Studies were included if: they randomized participants into treatment, had a control group not receiving yoga therapy, included patients with at least one of the three aforementioned chronic conditions, measured the HRQL, exercise capacity or psychological status, and were published in English. These criteria resulted in the inclusion of ten studies assessing n=431 participants. Of the ten studies, two focused on stroke, five focused on cardiovascular disease, and three focused on COPD. The interventions employed in the studies were heterogenous in nature, ranging from brief (2 weeks) to extended (6 months), with varying levels of intensity and different settings.
Of the studies, seven evaluated exercise capacity among 174 individuals living with heart disease, 22 individuals who had suffered a stroke, and 74 individuals living with COPD. The analysis showed a standard mean difference of 2.69% in exercise capacity, a statistically significant improvement, associated with yoga therapy. The estimates were adjusted to remove any influence of geographical area, age, disease category, and program duration. In a subgroup analysis, the authors found a significant weighted difference in six minute walk test results. Six studies measured HRQL among 257 individuals living with cardiovascular disease, 69 individuals after a stroke, and 74 individuals living with COPD, although the studies employed four different tools to describe HRQL. The standard mean change was estimated to be 1.24, though this was not a statistically significant result. The authors attributed this in part to the diversity of the studies being considered in terms of intervention type, geographical area and study participants.
Three studies including 29 individuals living with COPD and 36 individuals after a stroke assessed improvements in anxiety. Two of the three studies found improvements in symptoms of anxiety, though it is unclear from the meta-analysis whether these individuals had clinically significant anxiety disorders. The third study did not report statistically significant improvements took place in the United States, while the other studies took place in Australia. As with many other factor, geographical and cultural differences may have impacted the outcomes of the studies. Four studies examined the impact of yoga on depression across 17 individuals living with cardiovascular disease, 36 individuals after a stroke, and 29 individuals living with COPD; albeit with different measures (Center for Epidemiologic Studies Depression Scale, the Hamilton Depression Rating Scale, and the Geriatric Depression Scale). Given the variety in the measures, program lengths and structures, the authors concluded that it was difficult to perform a “meaningful meta analysis.”
Despite finding a few inconclusive results, this study provides important insights into the potential for yoga to serve as an adjunct therapy in helping individuals with cardiovascular disease, COPD, and stroke. While the psychological impact of yoga in these individuals was not evident, there were improvements in exercise capacity, which is a part of the rehabilitation process for all three conditions. Because of the variety of interventions used, it would be interesting for future work to study psychological impacts, physical activity, and HRQL measures in standardized yoga regimens. With that information we may be able to make more generalized conclusions about the applicability of yoga in treatment protocols. The authors concluded that the results were sufficient to suggest that yoga be considered as an adjuvant to physical rehabilitative programs. I would agree, and expand on the notion that further research should be conducted into the impact of yoga on chronic health conditions.
Aishwarya Rajagopalan is a first-year medical student at the Philadelphia College of Osteopathic Medicine. She completed her BA and MHS training in Public Health at Johns Hopkins University.