Fasting plasma glucose concentrations for specified HbA1c goals in Korean populations: data from the Fifth Korea National Health and Nutrition Examination Survey (KNHANES V-2, 2011)

AIMS To examine the correlation between the fasting plasma glucose and HbA1c levels using regression equation and to assess the average fasting plasma glucose levels for the specific HbA1c (A1C) goals in the patients with diabetes using each A1C-and fasting plasma glucose-based diagnostic criteria. METHODS This study included data from 4481 participants with A1C and fasting plasma glucose, but with no diabetic medications in the Korean National Health and Nutritional Examination Survey 2011. The correlation between fasting plasma glucose and A1C was examined using linear regression models. RESULTS The A1C levels corresponding to the fasting plasma glucose of 5.5 and 7 mmol/L were 5.75 and 6.42 %. However, in the subjects with diabetes diagnosed by the A1C criteria only, 5.5 and 7 mmol/L in the fasting plasma glucose predicted A1C of 6.49 and 7.14 % respectively. The average fasting plasma glucose levels to achieve specified A1C levels of 5.0-5.9, 6.0-6.9, 7.0-7.9, 8.0-8.9, and 9.0-9.9 % were 5.1, 6.1, 7.7, 8.8 and 11.2 mmol/L, respectively. CONCLUSIONS The association between A1C and fasting plasma glucose levels is in concordance with the existing criteria for diagnosis of diabetes. However, the average fasting plasma glucose concentrations to achieve targeted A1C may be lower than those in western populations.