Effects of tai chi on physiology, balance and quality of life in patients with type 2 diabetes: A systematic review and meta-analysis.

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.