Screening Criteria of Diabetes Mellitus and Impaired Glucose Tolerance of the Japanese Population in a Rural Area of Japan: The Tottori-Kofu Study

We performed the Tottori-Kofu Study to develop an early detection method of the Japanese with diabetes mellitus (DM) and impaired glucose tolerance (IGT), using simple predictors such as fasting plasma glucose (FPG) and other risk information obtainable from basic medical check-ups. In 2005, 734 residents of Kofu Town received a basic medical check-up including blood examination. Some of them meeting the following criteria further underwent the oral glucose tolerance test (OGTT): 5.5 mmol/L (100 mg/dL) ? FPG < 7.0 mmol/L (126 mg/dL); or FPG < 5.5 mmol/L, HbA1c ? 5.5%, BMI ? 25 kg/m2, triglyceride ? 1.69 mmol/L (150 mg/dL), hypertension treatment and family history of DM. Among the 734, only 4 persons with FPG ? 7.0 mmol/L were newly diagnosed as having DM, and 17 persons with FPG ? 6.1 mmol/L (110 mg/dL) were diagnosed with impaired fasting glucose. Among 220 persons who received the OGTT, 115 had normal glucose tolerance, 85 had IGT and 20 had DM. When the above-mentioned criteria were added to FPG levels, additional 67 persons with abnormal glucose tolerance were found. The optimal level to detect IGT and DM was 5.2 mmol/L (93 mg/dL) for FPG and 5.3% for HbA1c. Of persons only with the single risk factor of hypertension treatment, 39.3% had IGT. In conclusion, the results indicate that FPG of 5.2 mmol/L (93 mg/dL), HbA1c of 5.3% and hypertension treatment are useful in detecting early stages of IGT and DM.