[Risk factors for diabetes mellitus evaluated by long-term observation]

To evaluate the risk factors for diabetes mellitus, I examined 2573 people (1851 males and 722 females) who received medical checkups more than twice at a health examination center in Tokyo during the period from 1976 through 1991. Diabetic patients were excluded at the beginning. The mean follow up duration was 5.2 years. A self-registering questionnaire was administered at the time of the health checkup. The standard of this study was the onset of diabetes mellitus or glucose intolerance (fasting blood sugar over 110 mg/dl). I compared two prognosis groups (a normal group and a diabetic group) in terms of age, examination findings and prevalence of health risks (lifestyle, stress and working form). I also assessed family history of diabetes and past history including hypertension, hepercholesterolemia and hyperuricemia. After assessing each variable, I employed Cox's proportional hazards model analysis. 1) Among the subjects, 296 persons (243/1851 [13.1%] males, and 53/722 [7.3%] females) were newly diagnosed with diabetes during the observation period. 2) The diabetic group had significant differences compared to the normal group in age, BMI (Body Mass Index), FBS (fasting blood sugar), smoking, drinking, eating no breakfast, dairy intake, hypertension, hypercholesterolemia, hyperuricemia, and family history by t-test and chi 2 test. 3) According to proportional hazards model analysis, FBS, age, family history, hypertension, smoking and BMI were selected as significant risk factors for diabetes in males. For females, breakfast, FBS, age, drinking and hypertension were selected. 4) Diabetes seemed to be related to fixed factors such as age, or genetic factors such as family history and FBS in males. For females, lifestyle, such as eating no breakfast and drinking habit played an important role.