A case-control study of risk factors for development of type 2 diabetes: emphasis on physical activity.

The aim of this case-control study was to evaluate the association between the lifestyle risk factors, especially physical activity, and the prevalence of type 2 diabetes and the comorbidity of type 2 diabetes and dyslipidemia in middle-aged Japanese urban population. Subjects (279 males and 119 females, 53.5+/-6.8 years old) were selected from one city office in Tokyo and consisted of type 2 diabetes cases (n=53), dyslipidemia cases (n=130), the comorbidity cases (n=58) and sex- and age-matched controls (n=155). A self-administered questionnaire was used to collect physical activity data using Baecke's questionnaire translated and other lifestyle data. Our results revealed that physical activity was significantly associated with the reduction of the prevalence of type 2 diabetes and the comorbidity, and the sex- and age-adjusted odds ratios of the fourth quartile to the lowest one were 0.31 (95%CI:0.12-0.81) and 0.32 (95%CI:0.13-0.81), respectively. Family history of diabetes and smoking were independent risk factors for the prevalence of type 2 diabetes and the comorbidity.