TY - JOUR

T1 - Sustained heart rate-corrected QT prolongation during recovery from hypoglycaemia in people with type 1 diabetes, independently of recovery to hyperglycaemia or euglycaemia

AU - Andreasen, Christine R.

AU - Andersen, Andreas

AU - Hagelqvist, Per G.

AU - Maytham, Kaisar

AU - Lauritsen, Julius V.

AU - Engberg, Susanne

AU - Faber, Jens

AU - Pedersen-Bjergaard, Ulrik

AU - Knop, Filip K.

AU - Vilsbøll, Tina

N1 - Publisher Copyright: © 2023 John Wiley & Sons Ltd.

PY - 2023

Y1 - 2023

N2 - Aim: To investigate changes in cardiac repolarization abnormalities (heart rate-corrected QT [QTc] [primary endpoint], T-wave abnormalities) and heart-rate variability measures in people with type 1 diabetes during insulin-induced hypoglycaemia followed by recovery hyperglycaemia versus euglycaemia. Methods: In a randomized crossover study, 24 individuals with type 1 diabetes underwent two experimental clamps with three steady-state phases during electrocardiographic monitoring: (1) a 45-minute euglycaemic phase (5-8 mmol/L), (2) a 60-minute insulin-induced hypoglycaemic phase (2.5 mmol/L), and (3) 60-minute recovery in either hyperglycaemia (20 mmol/L) or euglycaemia (5-8 mmol/L). Results: All measured markers of arrhythmic risk indicated increased risk during hypoglycaemia. These findings were accompanied by a decrease in vagal tone during both hyperglycaemia and euglycaemia clamps. Compared with baseline, the QTc interval increased during hypoglycaemia, and 63% of the participants exhibited a peak QTc of more than 500 ms. The prolonged QTc interval was sustained during both recovery phases with no difference between recovery hyperglycaemia versus euglycaemia. During recovery, no change from baseline was observed in heart-rate variability measures. Conclusions: In people with type 1 diabetes, insulin-induced hypoglycaemia prolongs cardiac repolarization, which is sustained during a 60-minute recovery period independently of recovery to hyperglycaemia or euglycaemia. Thus, vulnerability to serious cardiac arrhythmias and sudden cardiac death may extend beyond a hypoglycaemic event, regardless of hyperglycaemic or euglycaemic recovery.

AB - Aim: To investigate changes in cardiac repolarization abnormalities (heart rate-corrected QT [QTc] [primary endpoint], T-wave abnormalities) and heart-rate variability measures in people with type 1 diabetes during insulin-induced hypoglycaemia followed by recovery hyperglycaemia versus euglycaemia. Methods: In a randomized crossover study, 24 individuals with type 1 diabetes underwent two experimental clamps with three steady-state phases during electrocardiographic monitoring: (1) a 45-minute euglycaemic phase (5-8 mmol/L), (2) a 60-minute insulin-induced hypoglycaemic phase (2.5 mmol/L), and (3) 60-minute recovery in either hyperglycaemia (20 mmol/L) or euglycaemia (5-8 mmol/L). Results: All measured markers of arrhythmic risk indicated increased risk during hypoglycaemia. These findings were accompanied by a decrease in vagal tone during both hyperglycaemia and euglycaemia clamps. Compared with baseline, the QTc interval increased during hypoglycaemia, and 63% of the participants exhibited a peak QTc of more than 500 ms. The prolonged QTc interval was sustained during both recovery phases with no difference between recovery hyperglycaemia versus euglycaemia. During recovery, no change from baseline was observed in heart-rate variability measures. Conclusions: In people with type 1 diabetes, insulin-induced hypoglycaemia prolongs cardiac repolarization, which is sustained during a 60-minute recovery period independently of recovery to hyperglycaemia or euglycaemia. Thus, vulnerability to serious cardiac arrhythmias and sudden cardiac death may extend beyond a hypoglycaemic event, regardless of hyperglycaemic or euglycaemic recovery.

KW - cardiac arrhythmias

KW - hyperglycaemia

KW - hypoglycaemia

KW - type 1 diabetes

U2 - 10.1111/dom.15005

DO - 10.1111/dom.15005

M3 - Journal article

C2 - 36752677

AN - SCOPUS:85148525992

VL - 25

SP - 1566

EP - 1575

JO - Diabetes, Obesity and Metabolism

JF - Diabetes, Obesity and Metabolism

SN - 1462-8902

IS - 6

ER -