LAUSR

OBJECTIVE To systematically synthesize and critically evaluate evidence on the effects of tai chi for patients with type 2 diabetes mellitus. DATA SOURCES Seven electronic databases (Wan Fang, SinoMed, China National Knowledge Infrastructure, VIP, PubMed, Embase, and Cochrane Library) were systematically searched from their inception to March 2018. STUDY SELECTION Randomized controlled trials investigating the effects of tai chi on individuals with type 2 diabetes mellitus were eligible. DATA EXTRACTION Biomedical outcomes (fasting plasma glucose, glycosylated haemoglobin (HbA1c), fasting insulin, insulin resistance, body mass index, total cholesterol, blood pressure) as well as balance and quality of life-related outcomes were extracted independently by 2 reviewers. Stata 12.0 software was used to synthesize data if there was no or moderate heterogeneity across studies. Otherwise, narrative summaries were performed. DATA SYNTHESIS A total of 23 studies (25 articles) involving 1,235 patients were included in this meta-analysis. Significant changes in tai chi-related effects were observed in lowering fasting plasma glucose (standardized mean difference; SMD -0.67; 95% confidence interval (95% CI) -0.87 to -0.47; p <0.001), HbA1c (mean difference; MD-0.88%; 95% CI -1.45% to -0.31%; p =0.002) and insulin resistance (MD -0.41; 95% CI -0.78 to -0.04; p = 0.029). Beneficial effects of tai chi were also found in decreasing body mass index (MD -0.82 kg/m2; 95% CI -1.28 to -0.37 kg/m2; p < 0.001) and total cholesterol (SMD -0.59; 95% CI -0.90 to -0.27; p < 0.001). In addition, tai chi reduced blood pressure (systolic blood pressure (MD -10.03 mmHg; 95% CI -15.78 to -4.29 mmHg; p = 0.001), diastolic blood pressure (MD -4.85 mmHg; 95% CI -8.23 to -1.47 mmHg; p = 0.005)) and improved quality of life-related outcomes (physical function (MD 7.07; 95% CI 0.79-13.35; p = 0.027), bodily pain (MD 4.30; 95% CI 0.83-7.77; p = 0.015) and social function (MD 13.84; 95% CI 6.22-21.47; p < 0.001)). However, no impact was exerted on fasting insulin (SMD -0.32; 95% CI -0.71 to 0.07; p = 0.110) or balance (MD 2.71 s; 95% CI -3.29 to 8.71 s; p = 0.376). CONCLUSION Tai chi is effective in controlling biomedical outcomes and improving quality of life-related outcomes in individuals with type 2 diabetes mellitus, although no effects were observed on balance and fasting insulin. Further high-quality research is needed to elucidate the effects of different types of tai chi, the long-term effects of tai chi, the impact on respiratory function, and the association between tai chi and the risk of developing type 2 diabetes mellitus in healthy individuals.