Fully closed-loop glucose control compared to insulin pump therapy with continuous glucose monitoring in adults with type 1 diabetes and sub-optimal glycemic control: a single-centre, randomized, crossover study

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posted on 2023-08-24, 20:11 authored by Charlotte K Boughton, Sara Hartnell, Rama Lakshman, Munachiso Nwokolo, Malgorzata E Wilinska, Julia Ware, Janet M Allen, Mark L Evans, Roman Hovorka

Objective

We evaluated the safety and efficacy of fully closed-loop with ultra-rapid insulin Lispro in adults with type 1 diabetes and sub-optimal glycemic control compared with insulin pump therapy with continuous glucose monitoring (CGM).

Research Design and Methods

In a single-centre, randomized, crossover study, 26 adults with type 1 diabetes using insulin pump therapy with sub-optimal glycemic control (mean±SD, age 41±12 years, HbA1c 9.2±1.1%[77±12mmol/mol]) underwent two 8-week periods of unrestricted living comparing fully closed-loop with ultra-rapid insulin Lispro to insulin pump therapy with CGM in random order. Trial registration:NCT04977908.

Results

In an intention-to-treat analysis, the proportion of time glucose was in range (3.9 to 10.0mmol/L; primary endpoint) was higher during closed-loop than during pump with CGM (mean±SD 50.0±9.6% vs. 36.2±12.2%; mean difference 13.2 percentage points [95%CI 9.5 to 16.9]; P<0.001). Time with glucose above >10.0mmol/L and mean glucose were lower during closed-loop than during pump with CGM (mean±SD time >10.0mmol/L: 49.0±9.9% vs. 62.9±12.6%; mean difference -13.3 percentage points [95%CI -17.2 to -9.5], P<0.001; mean glucose 10.7±1.1mmol/L vs 12.0±1.6mmol/L; mean difference -1.2mmol/L [95%CI -1.8 to -0.7], P<0.001). The proportion of time with glucose <3.9mmol/L was similar between periods (median[IQR] closed-loop 0.88% [0.51-1.55] vs. pump with CGM 0.64% [0.28-1.10]; P=0.102). Total daily insulin requirements did not differ (median[IQR] closed-loop 51.9units/day [35.7-91.2] vs. pump with CGM 50.7units/day [34.0-70.0]; P=0.704). No severe hypoglycaemia or ketoacidosis occurred.

Conclusions

Fully closed-loop insulin delivery with CamAPS HX improved glucose control compared to insulin pump therapy with CGM in adults with type 1 diabetes and sub-optimal glycemic control.