Abstract
Evidence from clinical trials has shown positive effects of yoga on hypothyroidism. To date, there is no review of these studies. This systematic review evaluates the efficacy of yoga as a therapeutic intervention for hypothyroidism. PubMed, Medline, PsycINFO, and Science Direct databases were searched to identify relevant literature. The review included clinical studies that evaluated the effects of yoga on hypothyroidism. Studies that were not conducted inenglish, unavailable, non-experimental, or those that were reviews, case studies, case reports, not based on yoga, involved yoga as a intervention, or included a mixed population were excluded. Eleven studies (n = 516) met the eligibility criteria. Of these, four studies were RCTs, two non-RCTs and five were pretest-posttest studies. The duration of the yoga intervention varied from 1 to 6 months. Most of these studies adopted a combination of suryanamaskar, asana, pranayama and meditation. On quality assessment, one study had a low risk of bias (1 RCT), six studies had a moderate risk of bias (3 RCTs, one non-RCT and two pretest-posttest studies), and four studies had a high risk of bias (1 non-RCT and three pretest-posttest studies). The outcome measures assessed were TSH, T3, T4, and thyroid medication usage, lipid indices, BMI, heart rate variability, pulmonary measures, blood glucose, anxiety, depression, self-esteem, quality of life and sleep. The majority of the studies reported significant improvements in these outcomes following yoga intervention. This systematic review reports evidence for effects of yoga on various outcome measures in hypothyroidism, suggesting its possible role in the management of hypothyroidism. However, there is a need for adequately powered, high-quality RCT studies in the future to draw a definitive conclusion.