Email updates

Keep up to date with the latest news and content from Cardiovascular Diabetology and BioMed Central.

Open Access Highly Accessed Original investigation

Does glycemic control reverse dispersion of ventricular repolarization in type 2 diabetes?

Takayuki Miki1, Toshiyuki Tobisawa1, Tatsuya Sato1, Masaya Tanno1, Toshiyuki Yano1, Hiroshi Akasaka1, Atsushi Kuno12, Makoto Ogasawara1, Hiromichi Murase1, Shigeyuki Saitoh3 and Tetsuji Miura1*

Author Affiliations

1 Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, South-1 West-16, Sapporo 060-8543, Chuo-ku, Japan

2 Department of Pharmacology, Sapporo Medical University School of Medicine, Sapporo, Japan

3 Department of Nursing, Sapporo Medical University School of Health Sciences, Sapporo, Japan

For all author emails, please log on.

Cardiovascular Diabetology 2014, 13:125  doi:10.1186/s12933-014-0125-8

Published: 21 August 2014



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.


We analyzed longitudinal changes in repolarization indices of electrocardiograms in retrospectively enrolled 44 patients with type 2 diabetes and 44 age-matched healthy subjects.


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.


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.

Type 2 diabetes; Glycemic control; QT dispersion; Ventricular repolarization