title: Does glycemic control reverse dispersion of ventricular repolarization in type 2 diabetes?
abstract: BACKGROUND
  Abnormal ventricular repolarization is a predictor of cardiovascular mortality. In this study, we tested the hypothesis that glycemic control reverses abnormal ventricular repolarization in patients with type 2 diabetes.
  
  
  METHODS
  We analyzed longitudinal changes in repolarization indices of electrocardiograms in retrospectively enrolled 44 patients with type 2 diabetes and 44 age-matched healthy subjects.
  
  
  RESULTS
  In the diabetic group, BMI was greater, levels of HbA1c (10.0 ± 1.6 vs. 5.6 ± 0.3%) and triglyceride were higher and level of HDL cholesterol was lower than those in the control group. Although mean QTc intervals were similar (413.6 ± 18.5 vs. 408.3 ± 22.7 ms), QT dispersion (41.8 ± 15.4 vs. 28.7 ± 7.7 ms) and Tpeak-Tend in lead V5 (83.6 ± 13.6 vs. 71.3 ± 10.3 ms) were significantly longer in the diabetic group than in the control group, indicating increased heterogeneity of ventricular repolarization in type 2 diabetes. During follow-up of 36 patients in the diabetic group for 787 ± 301 days, HbA1c level decreased to 7.3 ± 1.6%, while BMI did not significantly change. In contrast to HbA1c, QT dispersion (45.8 ± 15.0 ms) and Tpeak-Tend in lead V5 (83.6 ± 10.6 ms) were not significantly reduced during the follow-up period. There was no correlation between the change in HbA1c and the change in QT dispersion or Tpeak-Tend.
  
  
  CONCLUSIONS
  Increased heterogeneity of ventricular repolarization in type 2 diabetic patients was not reduced during the relatively short follow-up period despite significantly improved glycemic control.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Miki
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Tobisawa
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Sato
authors.forename: Masaya
authors.initials: M
authors.lastname: Tanno
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Yano
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Akasaka
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kuno
authors.forename: Makoto
authors.initials: M
authors.lastname: Ogasawara
authors.forename: Hiromichi
authors.initials: H
authors.lastname: Murase
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Saitoh
authors.affiliation: Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, South-1 West-16, Sapporo 060-8543, Chuo-ku, Japan. miura@sapmed.ac.jp.
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Miura
mesh_terms: D000368:Aged; D001786:Blood Glucose / Q000378:metabolism*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000503:physiopathology*; D004562:Electrocardiography / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D038321:Glycemic Index / Q000502:physiology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D018754:Ventricular Dysfunction / Q000097:blood* / Q000503:physiopathology*
chemical_list: D001786:Blood Glucose