Prevalence and Associated Factors of Prolonged QTc Interval among Adult Patients with Type 1 Diabetes Mellitus

Abstract

Objective: The aim of this study was to evaluate the prevalence and risk factors of prolonged QTc interval in adult patients with type 1 diabetes mellitus (DM).

Methods: A total of 166 inpatients with type 1 DM who received treatment in Department of Endocrinology, The First Affiliated Hospital, Sun Yat-sen University during the period from 2007 to 2016, were enrolled in this study. The patients were divided into prolonged QTc group (n=63, QTc interval >0.44 s) and normal QTc group (n=103, QTc interval≤0.44 s) according to the 12-lead ECG synchronized recordings, and the QTc interval was calculated using Bazett formula. Baseline characteristics and laboratory findings were compared between the two groups. Multivariate Logistic regression analysis was performed to explore the influencing factors of prolonged QTc interval.

Results: The prevalence of prolonged QTc interval among the patients with type 1 DM was 38.0% (63/166). Compared with the patients with normal QTc interval, those with prolonged QTc interval were older, and they had higher proportion of females, longer duration of DM, higher prevalence of chronic complications 〔diabetic nephropathy (DN), diabetic peripheral neuropathy (DPN), diabetic retinopathy (DR)〕, but lower average BMI (P<0.05). There were no significant differences in smoking rate, drinking rate, waist-hip ratio, systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) between the two groups (P>0.05). No significant differences in serum levels of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), uric acid (UA), creatinine (Cr) and blood urea nitrogen (BUN) were found between the two groups (P>0.05), while glycosylated hemoglobin (HbA1c) level of prolonged QTc interval group was significantly higher than that of normal QTc interval group (P<0.05). Multivariate Logistic regression analysis showed that sex, age, DPN, BMI and HbA1c were the influencing factors of QTc prolongation in type 1 diabetic patients (P<0.05).

Conclusion: Prolongation of QTc interval in patients with type 1 DM is very common. Female, aging, decreased BMI, prevalence of DPN and increased HbA1c are risk factors for QTc prolongation in these patients. Monitoring the risk factors, timely detection of prolonged QTc interval, and early intervention will help to improve the prognosis of high-risk patients.