Endocrine Abstracts

JOINT1492

Objective: The frequency of cardiovascular mortality is increased in type-1 diabetes mellitus(T1DM). Both hyperglycemia and hypoglycemia increase the risk of cardiac complications. This study aimed to use the ECG parameters of ventricular repolarisation times to assess the risk of arrhythmogenesis in patients with T1DM.

Methods: Age, sex, age at diagnosis of T1DM, duration of T1DM, insulin-pump use status, duration of insulin-pump use, biological and diabetic age at insulin pump insertion, continuous glucose monitoring(CGM) status, carbohydrate counting status, diet compliance status, history of technical problems with insulin-pump, total insulin doses, presence of hypertension, history of diabetic foot, hyperlipidemia, stroke, coronary heart disease, symptomatic hypoglycemia at least once a week, diabetic foot, peripheral vascular disease, hospitalization for hypoglycemia, presence of diabetic neuropathy, presence and type of diabetic retinopathy, diabetic nephropathy status, hemoglobin A1c(HbA1c) value, creatinine, microalbuminuria status, and spot urine microalbumin/creatinine ratio levels were recorded. Electrocardiographic(standard 12-lead ECG) parameters, parameters corresponding to ventricular repolarisation times, and used as indicators of arrhythmogenesis were collected. These were P-wave, QRS-wave, T-wave, PR-interval, QT, QTmax, QTmin, QTc, QTcmax, QTcmin, QT-dispersion, QTc-dispersion, Tp-e, JTc, Tp-e/QT, Tp-e/QTc, index of cardio-electrophysiological-balance(iCEB). Obtained parameters were evaluated between patients with T1DM and the control group. In addition, the patient group was divided according to the method of insulin therapy used(basal-bolus insulin therapy vs insulin-pump) and compared within themselves.

Results: 125 patients with T1DM and 50 controls were included in the study. 62 patients were on basal-bolus insulin therapy, and 63 were on insulin pump therapy. Patients who used insulin pumps had lower HbA1c than those who did not(8. 45±1. 60 vs 9. 62±2. 01, P = 0. 001). The incidence of symptomatic hypoglycaemia was lower in the insulin pump group, but the history of hospitalisation due to hypoglycaemia was similar in both treatment groups. P-wave, QT, QTmax, QTmin, QTc, QTcmax, QTcmin, Tp-e, and JTc were longer in T1DM patients(p values=0. 024, 0. 012, 0. 007, 0. 001, <0. 001, <0. 001, 0. 001, 0. 001, and 0. 004, respectively). QRS duration was significantly shorter, and JTc, iCEB, and iCEBc were significantly longer in insulin pump patients(p values=0. 045, 0. 031, 0. 019, and 0. 005, respectively).

Conclusion: In conclusion, patients with T1DM have prolonged ventricular repolarisation time and may be predisposed to arrhythmias. This study also suggests that insulin pump therapy may provide better glycemic control and less hypoglycemia. However, when assessing the effect of this condition on the risk of arrhythmia, it is essential to consider the patient’s medical history and to remember that the risk of arrhythmia may persist despite improvements in the course of the disease.