title: Development of an HbA1c-based conversion equation for estimating glycated albumin in a Korean population with a wide range of glucose intolerance.
abstract: BACKGROUND
  Compared to the golden standard glycation index of HbA1c, glycated albumin (GA) has potentials for assessing insulin secretory dysfunction and glycemic fluctuation as well as predicting diabetic vascular complications. However, the reference ranges of GA and a conversion equation need to be clearly defined. We designed this study to determine the reference ranges in patients with normal glucose tolerance (NGT) based on conventional measures of glycemic status and to devise a conversion equation for calculating HbA1c and GA in a Korean population.
  
  
  RESULTS
  In this multicenter, retrospective, cross-sectional study, we recruited antidiabetic drug-naïve patients with available glycemic variables including HbA1c, GA, and fasting plasma glucose regardless of glucose status. For the reference interval of serum GA, 5th to 95th percentile value of GA in subjects with NGT was adopted. The conversion equation between HbA1c and GA was devised using an estimating regression model with unknown break-points method. The reference range for GA was 9.0-14.0% in 2043 subjects. The 95th percentile responding values for FPG, and HbA1c were approximately 5.49 mmol/l, and 5.6%, respectively. The significant glycemic turning points were 5.868% HbA1c and 12.2% GA. The proposed conversion equation for below and above the turning point were GA (%) = 6.960+0.8963 × HbA1c (%) and GA (%) = -9.609+3.720 × HbA1c (%), respectively.
  
  
  CONCLUSIONS
  These results should be helpful in future studies on the clinical implications of high GA relative to HbA1c and the clinical implementation of diabetes management.
authors.affiliation: Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Chang Hee
authors.initials: CH
authors.lastname: Jung
authors.affiliation: Department of Internal Medicine, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: You-Cheol
authors.initials: YC
authors.lastname: Hwang
authors.affiliation: Department of Internal Medicine, Severance Hospital, University of Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Kwang Joon
authors.initials: KJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Severance Hospital, University of Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Bong Soo
authors.initials: BS
authors.lastname: Cha
authors.affiliation: Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Cheol-Young
authors.initials: CY
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Won Seon
authors.initials: WS
authors.lastname: Jeon
authors.affiliation: Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jae Hyeon
authors.initials: JH
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Sang-Man
authors.initials: SM
authors.lastname: Jin
authors.affiliation: Department of Internal Medicine, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: Sang Youl
authors.initials: SY
authors.lastname: Rhee
authors.affiliation: Department of Internal Medicine, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: Jeong-Taek
authors.initials: JT
authors.lastname: Woo
authors.affiliation: Department of Internal Medicine, Severance Hospital, University of Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Byung-Wan
authors.initials: BW
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D044466:Asian People; D001786:Blood Glucose; D003430:Cross-Sectional Studies; D005260:Female; D018149:Glucose Intolerance / Q000097:blood*; D006442:Glycated Hemoglobin / Q000378:metabolism*; D017127:Glycation End Products, Advanced; D006801:Humans; D008297:Male; D008875:Middle Aged; D062486:Public Health Surveillance; D056910:Republic of Korea; D012189:Retrospective Studies; D012307:Risk Factors; D012709:Serum Albumin / Q000378:metabolism*; D000093423:Glycated Serum Albumin
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D017127:Glycation End Products, Advanced; D012709:Serum Albumin; D000093423:Glycated Serum Albumin
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