Hybrid closed-loop insulin therapy and risk of severe hypoglycaemia and diabetic ketoacidosis in young people (aged 2–20 years) with type 1 diabetes: a population-based study

BACKGROUND: The effect of closed-loop insulin delivery on the risk of acute diabetes complications in people with type 1 diabetes is unclear. We investigated whether the rates of severe hypoglycaemia and diabetic ketoacidosis are lower with hybrid closed-loop insulin therapy compared with sensor-augmented (open-loop) pump therapy in a large cohort of young people. METHODS: levels, percentage of time in glucose range of 3·9-10·0 mmol/L, and glycaemic variability. To account for relevant confounders, we applied propensity score inverse probability of treatment weighting considering several baseline characteristics. FINDINGS: of 8·5% or higher in the closed-loop therapy group (5·25 per 100 patient-years) compared with the open-loop therapy group (1·53 per 100 patient-years; incidence rate ratio 3·43 [95% CI 1·69 to 6·97], p<0·0001). INTERPRETATION: Hybrid closed-loop insulin delivery has no significant effect on the rate of severe hypoglycaemia, and is associated with an increased risk of diabetic ketoacidosis, but is associated with a reduced risk of hypoglycaemic coma and improved glycaemia. These findings indicate the need for additional educational measures for the use of closed-loop insulin delivery.