Nocturnal hypoglycemia in young people with type 1 diabetes was associated with a higher frequency of bradycardia compared with matched euglycemia (IRR 6.44; 95% CI 6.26-6.63; P<0.001).
Observational (n=37)
Blinded CGM
Does spontaneous hypoglycemia increase the risk of cardiac arrhythmias and alter cardiac repolarization compared to euglycemia in young people with type 1 diabetes?
Spontaneous hypoglycemia in young adults with type 1 diabetes is proarrhythmogenic, with distinct arrhythmic risks and repolarization changes occurring during nocturnal versus daytime episodes.
Effect estimate: IRR 6.44 (95% CI 6.26, 6.63)
p-value: p=<0.001
OBJECTIVE Hypoglycemia may exert proarrhythmogenic effects on the heart via sympathoadrenal stimulation and hypokalemia. Hypoglycemia-induced cardiac dysrhythmias are linked to the “dead-in-bed syndrome,” a rare but devastating condition. We examined the effect of nocturnal and daytime clinical hypoglycemia on electrocardiogram (ECG) in young people with type 1 diabetes. RESEARCH DESIGN AND METHODS Thirty-seven individuals with type 1 diabetes underwent 96 h of simultaneous ambulatory ECG and blinded continuous interstitial glucose monitoring (CGM) while symptomatic hypoglycemia was recorded. Frequency of arrhythmias, heart rate variability, and cardiac repolarization were measured during hypoglycemia and compared with time-matched euglycemia during night and day. RESULTS A total of 2,395 h of simultaneous ECG and CGM recordings were obtained; 159 h were designated hypoglycemia and 1,355 h euglycemia. A median duration of nocturnal hypoglycemia of 60 min (interquartile range 40–135) was longer than daytime hypoglycemia of 44 min (30–70) (P = 0.020). Only 24.1% of nocturnal and 51.0% of daytime episodes were symptomatic. Bradycardia was more frequent during nocturnal hypoglycemia compared with matched euglycemia (incident rate ratio IRR 6.44 95% CI 6.26, 6.63, P 0.001). During daytime hypoglycemia, bradycardia was less frequent (IRR 0.023 95% CI 0.002, 0.26, P = 0.002) and atrial ectopics more frequent (IRR 2.29 95% CI 1.19, 4.39, P = 0.013). Prolonged QTc, T-peak to T-end interval duration, and decreased T-wave symmetry were detected during nocturnal and daytime hypoglycemia. CONCLUSIONS Asymptomatic hypoglycemia was common. We identified differences in arrhythmic risk and cardiac repolarization during nocturnal versus daytime hypoglycemia in young adults with type 1 diabetes. Our data provide further evidence that hypoglycemia is proarrhythmogenic.
Novodvorský et al. (Fri,) conducted a observational in Type 1 diabetes (n=37). Spontaneous hypoglycemia (nocturnal and daytime) vs. Time-matched euglycemia was evaluated on Frequency of bradycardia during nocturnal hypoglycemia (IRR 6.44, 95% CI 6.26, 6.63, p=<0.001). Nocturnal hypoglycemia in young people with type 1 diabetes was associated with a higher frequency of bradycardia compared with matched euglycemia (IRR 6.44; 95% CI 6.26-6.63; P<0.001).