Automated Insulin Delivery in Adults With Type 1 Diabetes and Suboptimal HbA1c During Prior Use of Insulin Pump and Continuous Glucose Monitoring: A Randomized Controlled Trial

Merete B Christensen; Ajenthen G Ranjan; Karen Rytter; Olivia M McCarthy; Signe Schmidt; Kirsten Nørgaard

doi:10.1177/19322968241242399

Automated Insulin Delivery in Adults With Type 1 Diabetes and Suboptimal HbA_1c During Prior Use of Insulin Pump and Continuous Glucose Monitoring: A Randomized Controlled Trial

J Diabetes Sci Technol. 2024 Apr 11:19322968241242399. doi: 10.1177/19322968241242399. Online ahead of print.

Authors

Merete B Christensen¹, Ajenthen G Ranjan¹, Karen Rytter¹, Olivia M McCarthy^{1

2}, Signe Schmidt¹, Kirsten Nørgaard^{1

3}

Affiliations

¹ Copenhagen University Hospital, Steno Diabetes Center Copenhagen, Herlev, Denmark.
² Applied Sports, Technology, Exercise and Medicine Research Centre, Swansea University, Swansea, UK.
³ Department of Clinical Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.

Abstract

Background: Automated insulin delivery (AID) systems offer promise in improving glycemic outcomes for individuals with type 1 diabetes. However, data on those who struggle with suboptimal glycemic levels despite insulin pump and continuous glucose monitoring (CGM) are limited. We conducted a randomized controlled trial to assess the effects of an AID system in this population.

Methods: Participants with hemoglobin A_1c (HbA_1c) ≥ 58 mmol/mol (7.5%) were allocated 1:1 to 14 weeks of treatment with the MiniMed 780G system (AID) or continuation of usual care (UC). The primary endpoint was change in time in range (TIR: 3·9-10·0 mmol/L) from baseline to week 14. After this trial period, the UC group switched to AID treatment while the AID group continued using the system. Both groups were monitored for a total of 28 weeks.

Results: Forty adults (mean ± SD: age 52 ± 11 years, HbA_1c 67 ± 7 mmol/mol [8.3% ± 0.6%], diabetes duration 29 ±13 years) were included. After 14 weeks, TIR increased by 18.7% (95% confidence interval [CI] = 14.5, 22.9%) in the AID group and remained unchanged in the UC group (P < .0001). Hemoglobin A_1c decreased by 10.0 mmol/mol (95% CI = 7.0, 13.0 mmol/mol) (0.9% [95% CI = 0.6%, 1.2%]) in the AID group but remained unchanged in the UC group (P < .0001). The glycemic benefits of AID treatment were reproduced after the 14-week extension phase. There were no episodes of severe hypoglycemia or diabetic ketoacidosis during the study.

Conclusions: For adults with type 1 diabetes not meeting glycemic targets despite use of insulin pump and CGM, transitioning to an AID system confers considerable glycemic benefits.

Keywords: automated insulin delivery; continuous glucose monitoring; glycemic control; hybrid closed-loop; insulin pump; time in range; type 1 diabetes.