Hypoglycaemia and rebound hyperglycaemia increase left ventricular systolic function in patients with type 1 diabetes

Abstract

Aim: To investigate echocardiographic changes during acute hypoglycaemia followed by recovery to hyperglycaemia or euglycaemia in patients with type 1 diabetes. Materials and Methods:In a randomized crossover study, 24 patients with type 1 diabetes took part in two experimental study days, consisting of a hyperinsulinaemic-euglycaemic phase (5.0-8.0 mmol/L) for 45 minutes followed by a hyperinsulinemic-hypoglycaemic phase (2.5 mmol/L) for 60 minutes, and a recovery phase in either hyperglycaemia (20 mmol/L) or euglycaemia (5.0-8.0 mmol/L) for 60 minutes. Cardiac function was evaluated with echocardiography during each phase.Results: Acute hypoglycaemia increased all markers of left ventricular (LV) systolic function, including LV ejection fraction (LVEF), global longitudinal strain (GLS), GLS rate and peak systolic velocity of mitral annular longitudinal movement (s'; P < 0.001 for all). During the recovery phases, all markers of LV systolic function were increased during hyperglycaemia (P < 0.01 for all), and LVEF and GLS remained increased during euglycaemia (P = 0.0116 and P = 0.0092, respectively).The increment in LVEF during the recovery phase was greater during hyperglycaemia than euglycaemia (P = 0.0046).Conclusions: Hypoglycaemia, recent hypoglycaemia, and overcorrection of hypoglycaemia to rebound hyperglycaemia increased LV systolic function in type 1 diabetes and may imply consideration of plasma glucose when evaluating LV function in patients with type 1 diabetes. An increase in LV systolic function may cause increased strain on the heart and partly explain the link between hypoglycaemia, high glycaemic variability and cardiovascular disease.

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

“…The study is part of the Hypo‐Heart‐1 Study, which has been published separately, 17 as prespecified in the protocol (H‐18034040). The Scientific Ethical Committee of the Capital Region of Denmark approved the study (H‐18034040), and it was registered at the Danish Data Protection Agency and http://clinicaltrials.gov (NCT03956173).…”

“…As previously described, 17 the study was conducted at the Center for Clinical Metabolic Research, Gentofte Hospital, University of Copenhagen, Hellerup, Denmark. Individuals with type 1 diabetes aged 18‐70 years and with diabetes duration of more than 3 years were recruited for this randomized 1:1 crossover study, including two experimental clamp days separated by at least 30 days.…”

“…Plasma potassium and counterregulatory hormones were obtained, and blood pressure was measured. Heart rate, blood pressure and counterregulatory data during the clamp days have previously been described 17 . Here, we included heart rate, blood pressure, epinephrine and norepinephrine data from the steady‐state phases only to contribute to the interpretation of our results.…”

“…The primary endpoint in this study was the difference in mean QT c prolongation during recovery from hypoglycaemia to hyperglycaemia compared with euglycaemia. The secondary endpoints included differences in cardiac haemodynamics measured by echocardiography during recovery from hypoglycaemia to hyperglycaemia compared with euglycaemia, and have been published separately 17 …”

“…As previously described, 17 1). Prior to the experimental clamp day, the participants were monitored with continuous glucose monitors to ensure no level 2 hypoglycaemic events (< 3 mmol/L) within the previous 48 hours.…”