Diabetes technology & therapeutics | 2021
Impact of hybrid closed loop therapy on hypoglycemia awareness in individuals with type 1 diabetes and impaired hypoglycemia awareness.
Abstract
OBJECTIVE\nThis study evaluated the efficacy of using a hybrid closed loop (HCL) system in restoring hypoglycemia awareness in individuals with impaired awareness of hypoglycemia (IAH).\n\n\nRESEARCH DESIGN AND METHODS\nParticipants with IAH (Gold Score ≥4) were recruited into a randomized crossover pilot study. They participated in two 8-week periods using a HCL system (Medtronic 670GTM) (intervention) and standard insulin pump therapy (control). Hyperinsulinemic hypoglycemic clamp studies were undertaken at baseline and at the end of each study period for the evaluation of the counter-regulatory hormonal and symptomatic responses to hypoglycemia.\n\n\nRESULTS\nSeventeen participants (mean age (SD) 35.8y (11.2y)) were included in the study. Peak epinephrine levels (median, IQR) in response to hypoglycemia were similar post intervention and control periods; 234.7 pmol/L (109.2; 938.9) vs 188.3 pmol/L (133.7; 402.9), p=0.233. However, both peak adrenergic and neuroglycopenic symptom scores were higher after intervention; 5.0 (4.5; 9.0) vs 4.0 (4.0; 5.5), p=0.009, and 8.5 (6.0; 15.0) vs 6.5 (6.0; 7.0) p=0.014, respectively. Self-reported hypoglycemia awareness improved: median (IQR) Gold score was 4.0 (3.0; 5.5) vs 5.5 (4.5; 6.0); intervention vs control, p=0.033. Time spent <3.9mmol/L and <3.0mmol/L was lower in the intervention group compared to control, p=0.002. Other patient reported outcomes (hypoglycemia fear and diabetes treatment satisfaction) did not change.\n\n\nCONCLUSIONS\nA short-term use of a HCL system failed to demonstrate an improvement in counter-regulatory hormonal responses. However, higher hypoglycemia symptom scores during controlled hypoglycemia, better self-reported hypoglycemia awareness and less time spent in hypoglycemia suggest the potential benefits of a HCL system in people with IAH.