title: Association between blood glucose level derived using the oral glucose tolerance test and glycated hemoglobin level.
abstract: OBJECTIVE
  Glycated hemoglobin (HbA1c) is widely used as a marker of glycemic control. Translation of the HbA1c level to an average blood glucose level is useful because the latter figure is easily understood by patients. We studied the association between blood glucose levels revealed by the oral glucose tolerance test (OGTT) and HbA1c levels in a Korean population.
  
  
  METHODS
  A total of 1,000 subjects aged 30 to 64 years from the Cardiovascular and Metabolic Diseases Etiology Research Center cohort were included. Fasting glucose levels, post-load glucose levels at 30, 60, and 120 minutes into the OGTT, and HbA1c levels were measured.
  
  
  RESULTS
  Linear regression of HbA1c with mean blood glucose levels derived using the OGTT revealed a significant correlation between these measures (predicted mean glucose [mg/dL] = 49.4 × HbA1c [%] - 149.6; R (2) = 0.54, p < 0.001). Our linear regression equation was quite different from that of the Alc-Derived Average Glucose (ADAG) study and Diabetes Control and Complications Trial (DCCT) cohort.
  
  
  CONCLUSIONS
  Discrepancies between our results and those of the ADAG study and DCCT cohort may be attributable to differences in the test methods used and the extent of insulin secretion. More studies are needed to evaluate the association between HbA1c and self monitoring blood glucose levels.
authors.affiliation: Department of Internal Medicine, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Hyoung Joo
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Young Geon
authors.initials: YG
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Jin Soo
authors.initials: JS
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Young Hwan
authors.initials: YH
authors.lastname: Ahn
authors.affiliation: Department of Endocrinology and Metabolism, Ajou University School of Medicine, Suwon, Korea.|Department of Cardiovascular and Metabolic Disease Etiology Research Center, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Kyoung Hwa
authors.initials: KH
authors.lastname: Ha
authors.affiliation: Department of Endocrinology and Metabolism, Ajou University School of Medicine, Suwon, Korea.|Department of Cardiovascular and Metabolic Disease Etiology Research Center, Ajou University School of Medicine, Suwon, Korea.
authors.forename: Dae Jung
authors.initials: DJ
authors.lastname: Kim
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005215:Fasting / Q000097:blood; D044882:Glucose Metabolism Disorders / Q000097:blood / Q000175:diagnosis*; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism*; D006801:Humans; D016014:Linear Models; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D056910:Republic of Korea; D013997:Time Factors
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D006442:Glycated Hemoglobin; C517652:hemoglobin A1c protein, human
keywords: Diabetes mellitus; Hemoglobin A, glycosylated; Mean blood glucose level; Oral glucose tolerance test