The effect of glucose variability on QTc duration and dispersion in patients with Type 2 Diabetes Mellitus

Abstract

Objective:Glycemic variability (GV) is a new term with the episodes of hyper and hypoglycemia in diabetic patients. Both prolonged QT interval and QTd are potential risk factors for malignant ventricular arrhythmias affecting the mortality of different groups of patients including diabetes mellitus. In this study, we aimed to evaluate if the glucose variability increasing the QTc interval and QTc dispersion in type 2 diabetes mellitus.Methods:We included 275 consecutive patients with type 2 diabetes. We quantified the GV with standard deviation (SD) and coefficient of variation (CV) from 7 point glucose measures. We investigated the relationship of GV parameters with QT parameters.Results:The prevalence of prolonged QTc duration was 21%, no patients have prolonged QTc dispersion (> 80 ms). SD of the patients with prolonged QTc duration was significantly higher than the others (45.14 ±24.45 vs. 37.78 ±9.03 p<0.05). There was also a significant relationship between SD and QTc dispersion (r: 0.164; p: 0.007). There were no relationship between the QT parameters and microvascular diabetic complications. SD and HbA1c levels were significantly higher on the patients having peripheral neuropathy (p<0.005).Conclusion:The result of this study demonstratess that increased glycemic variability is associated with prolonged QTc duration and QTc dispersion. It is important to focus on targeting optimal glycemic control with GV as an additional goal point along with the traditional following parameters such as fasting-postprandial blood glucose and HbA1c.

Glycaemic variability in diabetes: clinical and therapeutic implications

“…52 These data are consistent with the evidence that indicate short-term GV may adversely affect diabetes plaque stability, 53 subclinical coronary atherosclerosis 54 and extends QTc duration and dispersion. 55 More recently, longer-term HbA1c variability has been associated with a higher risk of developing atrial fibrillation 56 and the incidence of heart failure. 57 Moreover, reducing GV with insulin via continuous subcutaneous infusion is accompanied by an increase in circulating endothelial progenitor cells in T1D.…”

Glycaemic variability: The under‐recognized therapeutic target in type 1 diabetes care

“…GV after acute stroke, according to four‐point glucose profiles, has been associated with increased CV events and mortality . GV measured using MAGE has been associated with a 10‐year CV risk, while GV according to seven‐point profiles, SD and CoV, has been associated with QTc prolongation in those with T2DM . Intervention studies would provide much needed insight into the relationship between GV and long‐term outcomes; we are not aware of any intervention studies to investigate the long‐term impact of CGM‐derived measures of GV in T1DM.…”

“…39 GV measured using MAGE has been associated with a 10-year CV risk, while GV according to seven-point profiles, SD and CoV, has been associated with QTc prolongation in those with T2DM. 40,41 Intervention studies would provide much needed insight into the relationship between GV and long-term outcomes; we are not aware of any intervention studies to investigate the long-term impact of CGM-derived measures of GV in T1DM. In T2DM, investigators of the HEART2D study could not show any CV benefits as the result of tightly controlling variations in post-prandial glucose.…”

Nursing Diagnosis Risk for Unstable Blood Glucose Level in Patients with Diabetes Mellitus

“…Seven studies presented the concept of unstable blood glucose (Akirov, Diken-Cohen, Masri-Iragi, & Shimon, 2017;Cavalot, 2013;Deane & Horowitz, 2013;Fabris et al, 2014;Hirsch et al, 2012;Sertbas et al, 2017;Teixeira et al, 2017). Glycemic variability is a term used for diabetic patients who have similar mean glucose levels in varying degrees, leading to episodes of hyperglycemia and hypoglycaemia (Sertbas et al, 2017).…”