A Three-Group Randomized Controlled Trial
Parco M. Siu, PhD*, Angus P. Yu, MPhil*, Edwin C. Chin, BScEd, Doris S. Yu, PhD,
Central obesity is a major manifestation of metabolic syndrome, which is a common health problem in middle-aged and older adults.
To examine the therapeutic efficacy of tai chi for management of central obesity.
Randomized, controlled, assessor-blinded trial. (ClinicalTrials.gov: NCT03107741)
A single research site in Hong Kong between 27 February 2016 and 28 February 2019.
Adults aged 50 years or older with central obesity.
543 participants were randomly assigned in a 1:1:1 ratio to a control group with no exercise intervention (n = 181), conventional exercise consisting of aerobic exercise and strength training (EX group) (n = 181), and a tai chi group (TC group) (n = 181). Interventions lasted 12 weeks.
Outcomes were assessed at baseline, week 12, and week 38. The primary outcome was waist circumference (WC). Secondary outcomes were body weight; body mass index; high-density lipoprotein cholesterol (HDL-C), triglyceride, and fasting plasma glucose levels; blood pressure; and incidence of remission of central obesity.
The adjusted mean difference in WC from baseline to week 12 in the control group was 0.8 cm (95% CI, −4.1 to 5.7 cm). Both intervention groups showed reductions in WC relative to control (adjusted mean differences: TC group vs. control, −1.8 cm [CI, −2.3 to −1.4 cm]; P < 0.001; EX group vs. control: −1.3 cm [CI, −1.8 to −0.9 cm]; P < 0.001); both intervention groups also showed reductions in body weight (P < 0.05) and attenuation of the decrease in HDL-C level relative to the control group. The favorable changes in WC and body weight were maintained in both the TC and EX groups, whereas the beneficial effect on HDL-C was only maintained in the TC group at week 38.
High attrition and no dietary intervention.
Tai chi is an effective approach to reduce WC in adults with central obesity aged 50 years or older.