title: A1c variability can predict coronary artery disease in patients with type 2 diabetes with mean a1c levels greater than 7.
abstract: BACKGROUND
  Recent studies suggested that the association of acute glucose variability and diabetic complications was not consistent, and that A1c variability representing long term glucose fluctuation may be related to coronary atherosclerosis in patients with type 1 diabetes. In this study, we attempt to determine whether or not A1c variability can predict coronary artery disease (CAD) in patients with type 2 diabetes.
  
  
  METHODS
  We reviewed data of patients with type 2 diabetes who had undergone coronary angiography (CAG) and had been followed up with for 5 years. The intrapersonal standard deviation (SD) of serially-measured A1c levels adjusted by the different number of assessments among patients (adj-A1c-SD) was considered to be a measure of the variability of A1c.
  
  
  RESULTS
  Among the 269 patients, 121 of them had type 2 diabetes with CAD. In patients with A1c ≥7%, the mean A1c levels and A1c levels at the time of CAG among the three groups were significantly different. The ratio of patients with CAD was the highest in the high adj-A1c-SD group and the lowest in the low adj-A1c-SD group (P=0.017). In multiple regression analysis, adj-A1c-SD was an independent predictor for CAD in subjects with A1c ≥7% (odds ratio, 2.140; P=0.036).
  
  
  CONCLUSIONS
  Patients with higher A1c variability for several years showed higher mean A1c levels. A1c variability can be an independent predictor for CAD as seen in angiographs of patients with type 2 diabetes with mean A1c levels over 7%.
authors.affiliation: Department of Internal Medicine, Inje University College of Medicine, Busan, Korea.
authors.forename: Eun Ju
authors.initials: EJ
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Inje University College of Medicine, Busan, Korea.
authors.forename: You Jeong
authors.initials: YJ
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Inje University College of Medicine, Busan, Korea.
authors.forename: Tae Nyun
authors.initials: TN
authors.lastname: Kim
authors.affiliation: Division of Cardiology, Department of Internal Medicine, Maryknoll Medical Center, Busan, Korea.
authors.forename: Tae Ik
authors.initials: TI
authors.lastname: Kim
authors.affiliation: Division of Biostatistics, Kyungpook National University School of Medicine, Daegu, Korea.
authors.forename: Won Kee
authors.initials: WK
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, Inje University College of Medicine, Busan, Korea. ; Paik Inje Memorial Institute for Clinical Medicine Research, Inje University College of Medicine, Busan, Korea.
authors.forename: Mi-Kyung
authors.initials: MK
authors.lastname: Kim
authors.affiliation: Department of Internal Medicine, Inje University College of Medicine, Busan, Korea. ; Paik Inje Memorial Institute for Clinical Medicine Research, Inje University College of Medicine, Busan, Korea.
authors.forename: Jeong Hyun
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Internal Medicine, Inje University College of Medicine, Busan, Korea.
authors.forename: Byoung Doo
authors.initials: BD
authors.lastname: Rhee
keywords: A1c variability; Coronary artery disease; Diabetes mellitus, type 2