413
Fig. 7. Forest plot of the effects of tai chi on: (A) body mass index; (B) balance. StudyID:study reference; Tn: number of participants in treatment
group; Cn: number of participants in control group; WMD: weighted mean difference; 95% CI: 95% confidence interval.
Effects of tai chi on type 2 diabetes
Fig. 8. Forest plot of the effects of tai chi on blood pressure. (A) systolic blood pressure; (B) diastolic blood pressure; StudyID: study reference;
Tn: number of participants in treatment group; Cn: number of participants in control group; WMD: weighted mean difference; 95% CI: 95%
confidence interval.
tai chi could reduce HbA1c by 0.88%. Previous study
found tai chi could contribute to increased CD4+/
CD25+ T-lymphocytes, and the latter was related to the
decrease in HbA1c (58). Consistent with our findings,
Huang & Yeh (25) also suggested favourable effects
of tai chi in decreasing FPG and HbA1c. Due to high
heterogeneity of HbA1c across studies, the stability of
the results was tested by excluding included studies
in turn to detect the sources. Analysis showed that 2
studies (37, 45) carried huge weight in the stability of
results. Detailed analyses were performed, in which
remarkable differences were found in the interven-
tion regimens between these 2 studies and the others.
In Bao’s study (37) the duration of intervention was
up to 24 weeks, with a frequency of 14 sessions per
week and 2 h per session, which was the longest among
included studies. Similarly, in Wu’s study (45) the
shortest session was over 1 h, with at least 3 sessions
per week; thus it is impossible to specify the total time
of practicing tai chi. It was therefore assumed that the
total time of treatment might be the main source of
heterogeneity.
Further analyses found favourable effects of tai chi,
in reducing IR (MD –0.41; 95% CI –0.78 to –0.04;
p = 0.029), TC (SMD –0.59; 95% CI –0.90 to –0.27;
p < 0.001) and BMI (MD –0.82 kg/m 2 ; 95% CI –1.28 to
–0.37 kg/m 2 ; p < 0.001). The relatively small magnitude
of the above outcomes may be due to the short duration
of intervention (59). Tai chi also decreased BP (SBP
(MD –10.03 mmHg; 95% CI –15.78 to –4.29 mmHg;
p = 0.001) and DBP (MD –4.85mmHg; 95% CI –8.23
to –1.47 mmHg improved; p = 0.005)), QoL (physical
function (MD 7.07; 95% CI 0.79–13.35; p = 0.027)
decreased, bodily pain (MD 4.30; 95% CI 0.83–7.77;
p = 0.015) and increased social function (MD 13.84;
95% CI 6.22–21.47; p < 0.001)). Thus, tai chi was more
J Rehabil Med 51, 2019