Effects of Tai Chi on exercise capacity and health-related quality of life in patients with chronic obstructive pulmonary disease: a systematic review and meta-analysis

BACKGROUND Tai Chi is a traditional Chinese mind-body exercise that has been widely practiced in the People's Republic of China for many centuries. This exercise has also been applied as a training modality in pulmonary rehabilitation programs for stable chronic obstructive pulmonary disease (COPD). This systematic review and meta-analysis aimed to assess the effects of Tai Chi on exercise capacity and health-related quality of life (HRQoL) in COPD patients. METHODS Electronic databases (PubMed, Embase, Web of Science, The Cochrane Library, Cumulative Index to Nursing and Allied Health Literature, ClinicalTrials.gov, China National Knowledge Infrastructure, and China Biology Medicine disc) were searched. Entries published from January 1980 to March 2014 were included in the search. Eligible studies included those that involved randomized controlled trials and those that lasted for at least 12 weeks. The primary outcome measures were six-minute walking distance (6 MWD), St George's Respiratory Questionnaire (SGRQ), and Chronic Respiratory Disease Questionnaire (CRQ). Effect estimates were pooled with random-effects meta-analysis. RESULTS Eleven articles involving 824 patients met the inclusion criteria. All included articles compared COPD patients in a Tai Chi group versus COPD patients in nonexercise and/or physical exercise groups. The meta-analysis showed that compared with the nonexercise group, the COPD patients practicing Tai Chi demonstrated significantly enhanced 6 MWD (mean difference 35.99, 95% confidence interval [CI] 15.63-56.35, P=0.0005), decreased SGRQ total score (mean difference -10.02, 95% CI -17.59, -2.45, P=0.009), and increased CRQ total score (mean difference 0.95, 95% CI 0.22-1.67, P=0.01). Compared with the physical exercise group, the Tai Chi group showed significantly reduced SGRQ total score (mean difference -3.52, 95% CI -6.07, -0.97, P=0.007), but no statistical significance was found for 6 MWD between the two groups (mean difference 13.65, 95% CI -1.06, 28.37, P=0.07) in COPD patients. CONCLUSION Preliminary evidence suggests that Tai Chi has beneficial effects on exercise capacity and HRQoL in COPD patients. This exercise can be recommended as an effective alternative training modality in pulmonary rehabilitation programs. Further studies are required to support the preliminary evidence and to observe the long-term effects of Tai Chi.