Prevalence of diabetes estimated by plasma glucose criteria combined with standardized measurement of HbA1c among health checkup participants on Miyako Island, Japan.

OBJECTIVE: To estimate the prevalence of diabetes in participants of an annual health checkup in the district of the Miyako Public Health Center (Okinawa, Japan) by using the revised criteria of the Japan Diabetes Society (JDS). RESEARCH DESIGN AND METHODS: The subjects studied here were all Japanese and 45-75 years of age at the time of the health examination in 1998. Diagnosis of diabetes was based on the following: 1) fasting plasma glucose > or =7.0 mmol/l, 2) casual plasma glucose > or =11.1 mmol/l, 3) HbA(1c) > or =6.1%, and 4) self-report on a special questionnaire given at the examination. The HbA(1c) value was standardized by the measurement of 2 standard samples provided by the JDS. RESULTS: Among the 2,621 subjects, 59.7% had their fasting blood glucose levels measured. Of the subjects diagnosed as having diabetes, 154 (12.6%) were men and 115 (8.6%) women. Among the subjects newly diagnosed with diabetes from their fasting blood glucose levels. 27.5% of the men and 21.9% of the women had diagnoses based on HbA(1c) alone. Overall, 34.9% of the subjects with newly diagnosed diabetes were identified by plasma glucose (PG) alone and 33.0% were diagnosed by HbA(1c) alone. CONCLUSIONS: The combination of PG and HbA(1c) resulted in a considerable increase in newly diagnosed diabetes as compared with the use of only one of these parameters. Considering the convenience and correlation with vascular complications, use of the 2 tests may be beneficial in epidemiological studies of the Japanese population to identify high-risk groups for micro- and macrovascular diseases.