Association of muscle-strengthening training with risk of type 2 diabetes in Japanese men and women
METHODS: This is a cohort study among 29,296 men and women free of diabetes, cancer, cardiovascular disease, and stroke, aged 16 to 80 years in Japan 2006. Weekly time spent on muscle-strengthening training was elicited using a self-reported questionnaire. Type 2 diabetes was diagnosed by fasting glucose, hemoglobin A1c, and a self-reported use of anti-diabetic drug in an annual health check-up. Association with incidence of type 2 diabetes was assessed using Cox proportional hazards model.
RESULTS: During a mean follow-up of 5.2 years, 1,857 individuals developed type 2 diabetes. Compared with subjects who were not involved in the muscle-strengthening training, those involved in the training had a 35% lower risk of type 2 diabetes (95% confidence interval, 11% to 52%) after adjustment for age, sex, smoking, alcohol use, sleep duration, aerobic exercise, occupational physical activity, shift work, hypertension, and family history of diabetes. Additional adjustment for body mass index (BMI) did not materially affect the result. Stratified analysis showed that a lower risk of diabetes associated with the muscle-strengthening training was observed in older subjects (ages ≥50 years), men, and those with BMI ≥23 kg/m2.
CONCLUSIONS: The results suggest that engagement in muscle-strengthening training can prevent the development of type 2 diabetes in Japanese population, especially in older individuals, men, and overweight/obese adults.