Aims: Severe hypoglycemia is one of the strongest predictors of adverse clinical outcomes in patients with type 2 diabetes. Our study addressed the question whether there is a relationship between hypoglycemic events (HE) and severe cardiac arrhythmias in type 2 diabetic patients with established clinical risk factors under real-world conditions.
Methods: We included 94 patients with type 2 diabetes and documented cardiovascular disease, in which interstitial glucose values and Holter ECG were recorded for 5 days in parallel. Patients received a stable treatment with insulin and/or sulfonylurea and were instructed to record symptoms of hypoglycemia or arrhythmias.
Results: Continuous glucose monitoring revealed 54 HE (interstitial glucose <3.1 mmol/l) in a total of 26 patients. Patients perceived only 39 % of HE during the day and 11 % of HE during the night. Patients with HE had a significantly higher number of severe ventricular arrhythmias [ventricular tachycardia (VT) 32.8 ± 60 vs. 0.9 ± 4.2, p = 0.019], and multivariate regression analysis revealed the duration of severe HE and TSH level as independent predictors of the occurrence of a VT.
Conclusions: In conclusion, our study suggests that hypoglycemia might be able to trigger at least under certain circumstances, such as low TSH, ventricular arrhythmias under real-world conditions. The large number of unrecognized HE and VT in vulnerable patients treated with insulin or sulfonylurea should encourage the practitioner to focus on stable glucose control and to search for silent HE.
Keywords: CGM; Holter ECG; Hypoglycemia; Type 2 diabetes; Ventricular arrhythmia.