Novodvorsky Peter, Bernjak Alan, Downs Ellen, Smith Amelia, Arshad Muhammad Fahad, Oprescu Andrei I, Jacques Richard M, Lee Justin, Heller Simon R, Iqbal Ahmed
Clinical Medicine, School of Medicine and Population Health, University of Sheffield, Sheffield, UK.
Sheffield Teaching Hospitals NHS Foundation Trust, Sheffield, UK.
Diabet Med. 2025 Jul;42(7):e70019. doi: 10.1111/dme.70019. Epub 2025 Feb 27.
Hypoglycaemia causes abnormal cardiac repolarisation, which has been related to sympathoadrenal activation. We examined whether individuals with type 1 diabetes (T1D) and impaired awareness of hypoglycaemia (IAH) were protected against proarrhythmogenic alterations on their electrocardiogram during clinical episodes of hypoglycaemia.
Adults with T1D and IAH underwent 96 h of simultaneous ambulatory electrocardiogram and blinded continuous interstitial glucose (IG) monitoring. Measures of cardiac repolarisation and heart rate variability (HRV) were compared during hypoglycaemia versus time and person-matched euglycaemia. We compared these data to a historical control group of individuals with T1D and no IAH.
Fourteen individuals (10/14 female) with a mean (SD) age of 39 (10) years and T1D duration of 24 (9) years were examined. Fourteen daytime and 12 nocturnal hypoglycaemic episodes were analysed. During daytime hypoglycaemia versus euglycaemia, the mean (SD) QT interval was prolonged to 443 (38) versus 422 (27) ms, p = 0.027; the Tpeak-to-Tend interval was prolonged to 93 (18) versus 77 (9) ms, p = 0.002; and the T wave area symmetry decreased to 1.19 (0.37) versus 1.39 (0.23), p = 0.014. High-frequency power decreased during daytime hypoglycaemia versus euglycaemia to 1.66 (0.41) versus 1.92 (0.52), p = 0.038. At daytime, the Tpeak-to-Tend interval decreased significantly more (hypoglycaemia vs. euglycaemia) in the IAH group in comparison to the decrease observed in the historical control group of T1D individuals without IAH (p for interaction 0.005). Cardiac arrhythmias were infrequent and of no clinical significance.
Hypoglycaemia can still lead to proarrhythmogenic electrocardiographic changes in individuals with T1D and IAH. We observed diurnal, inter- and intraindividual variability in responses to hypoglycaemia.
低血糖会导致心脏复极异常，这与交感肾上腺激活有关。我们研究了1型糖尿病（T1D）且伴有低血糖意识受损（IAH）的个体在低血糖临床发作期间，其心电图上的致心律失常性改变是否受到保护。
患有T1D和IAH的成年人接受了96小时的同步动态心电图监测和盲法连续组织间液葡萄糖（IG）监测。比较了低血糖期间与时间和个体匹配的血糖正常期间的心脏复极和心率变异性（HRV）指标。我们将这些数据与一组无IAH的T1D个体的历史对照组进行了比较。
对14名个体（10/14为女性）进行了检查，其平均（标准差）年龄为39（10）岁，T1D病程为24（9）年。分析了14次白天和12次夜间低血糖发作。与血糖正常相比，白天低血糖期间，平均（标准差）QT间期延长至443（38）毫秒对422（27）毫秒，p = 0.027；T峰至T末间期延长至93（18）毫秒对77（9）毫秒，p = 0.002；T波面积对称性降至1.19（0.37）对1.39（0.23），p = 0.014。与血糖正常相比，白天低血糖期间高频功率降至1.66（0.41）对1.92（0.52），p = 0.038。在白天，与无IAH的T1D个体历史对照组相比，IAH组的T峰至T末间期（低血糖与血糖正常相比）下降更为显著（交互作用p = 0.005）。心律失常很少见且无临床意义。
低血糖仍可导致T1D和IAH个体出现致心律失常性心电图改变。我们观察到对低血糖反应存在昼夜、个体间和个体内差异。
