Home-based exercise for middle-aged Chinese at diabetic risk: A randomized controlled trial

Objective: To evaluate short- (3. months) and long-term (9. months) effects of home-based exercise on adiponectin, exercise behavior and metabolic risk factors in middle-aged adults at diabetic risk. Methods: One hundred and thirty-five middle-aged adults (38 men, 97 women) with at least one diabetic risk factor were randomly assigned to either a home-based exercise group (Ex-group) or a usual care group (C-group). Outcome measures included plasma adiponectin, exercise self-efficacy, physical activity, and metabolic risk factors, as follows: insulin levels, insulin resistance by homeostasis model assessment (HOMA-IR), physical fitness, and components of metabolic syndrome. This study was conducted in metropolitan Taipei from 2004 to 2005. Results: The Ex-group had improvements in exercise self-efficacy (+2.5, p=0.01), body mass index (BMI) (-0.6kg/m², p<0.001) and flexibility (+2.4cm, p<0.001) at 3-month follow-up and maintained BMI and flexibility at 9-month follow-up. The Ex-group exhibited significantly increased physical activity while the C-group exhibited decreased physical activity at 9-month follow-up (p<0.001). No intervention effect was found on adiponectin (p=0.64) or other outcome measures over time. Conclusions: Home-based exercise did not improve adiponectin levels, but significantly improved exercise behavior, and certain metabolic risk factors, with the effects maintained for 9-months in subjects with type 2 diabetic risk.