Severe Hypoglycemia may Increase Risk of QTc Prolongation in diabetes patients

Several studies have demonstrated that insulin-induced hypoglycemia in diabetes causes the prolongation of corrected QT (QTc) interval, which is associated with ventricular arrhythmias and sudden death. However, only a few large studies have addressed SH and QTc intervals in people with T2D. Therefore, Dr Justin B Echouffo-Tcheugui and his team conducted a study to evaluate the association of SH with QTc prolongation in adults with T2DM.

In this prospective analysis, the researchers assessed data of 8277 participants without baseline QTc prolongation from the Action to Control Cardiovascular Risk in Diabetes Study. They evaluated SH over a 24-month period. They monitored incident QTc prolongation using follow-up electrocardiograms. They used modified Poisson regression to generate risk ratios (RR) and 95% confidence intervals (CI) for QTc prolongation.

Key findings of the study:

• Over a median of 5 years, the researchers observed that 517 individuals developed QTc prolongation (6.3%).
• They found that the participants with SH had a 66% higher risk of QTc prolongation (RR 1.66).
• They also found that the incidence of QTc prolongation was 10.3% (27/261) and 14.3% (9/63) for participants with 1 and ≥2 SH, respectively.
• Compared to no SH, they noted that the RRs for patients with 1 and ≥2 SH were 1.57 and 2.01, respectively.
• They noted that age modified the association of SH with QTc prolongation (PInteraction=0.008).
• They reported that the association remained significant among younger participants (<61.9years [median age]: RR 2.63), but was nonsignificant among older participants (≥61.9years: RR 1.37).

The authors concluded, "In a large population with T2DM, SH was associated with an increased risk of QTc prolongation independently of other risk factors such as cardiac autonomic neuropathy. The association was strongest among younger participants".

For further information:

DOI: https://doi.org/10.1210/clinem/dgac195

Keywords: hypoglycaemia, QT interval, type 2 diabetes, epidemiology, electrocardiography, QTc Prolongation, severe hypoglycemia, Journal of Clinical Endocrinology & Metabolism.