ABSTRACT
BACKGROUND: Significant ethnic and geographic differences exist in the prevalence of diabetes mellitus, which has increased dramatically in South Korea. But a few population-based studies were performed in South Korea. The purpose of this study was to determine the prevalence of diabetes mellitus, impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) by the World Health Organization (WHO) and the American Diabetic Association (ADA) diagnostic categories, and to investigate their associated risk factors. METHODS: Between march 22, 1999 and July 14, 1999, a random sampling of 1445 residents over 40 year of age in five villages in the Namwon county of South Korea was carried out. Among these subjects, 665 (46.0%) participants completed 75 g OGTT. WHO and ADA diagnostic criteria were used for the diagnosis of diabetes mellitus, IGT and IFG. Detailed questionnaire were performed and anthropometric data were collected. RESULTS: After age-adjustment for population projection for Korea (1999), the prevalence of diabetes and IGT were 13.7% and 13.8% with WHO criteria, while the prevalence of diabetes, IGT and IFG were 15.8%, 12.8% and 5.7% with ADA criteria. The age-adjusted prevalence of previously diagnosed diabetes was 5.8%. The level of agreement between WHO and ADA diagnostic criteria except IFG was high (K=0.94; p<0.001). The ROC curve analysis determined FSG of 114.5 mg/dL (6.4 mmol/L) to yield optimal sensitivity and specificity corresponding to a PP2SG 200 mg/dL (11.1 mmol/L). The prevalence of diabetes and IGT with ADA diagnostic criteria rose with increasing age (p<0.05). The difference in the prevalence of diabetes, IGT and IFG by BMI was not significant. The prevalence of diabetes rose with increase in the waist-hip ratio. The prevalence of diabetes was increased in subjects with dyslipidemia (Odds ratio 2.29, 95% CI: 1.16-3.49). CONCLUSION: The age-adjusted prevalence of Diabetes Mellitus in populations over 40 year of age in the Namwon county was substantially higher than previously observed. Ethnic differences in obesity with BMI and in the effect on diabetes risk of obesity may exist in the Korean population. The adequate cut-off point for fasting serum glucose was lower than that by the ADA diagnostic category. These results may show that not only fasting serum glucose but also postprandial 2-h serum glucose are important for diagnosing diabetes in Korean.