Impact of an advanced hybrid closed-loop system on glycemic control throughout the menstrual cycle in women with type 1 diabetes prone to hypoglycemia.

Abstract

This study aimed to evaluate the impact of advanced hybrid closed-loop (AHCL) on glycemic control throughout the menstrual cycle (MC) in women with type 1 diabetes (T1D). We included 39 pairs of spontaneous MC from 13 participants, before and after switching from sensor-augmented pump to AHCL. Baseline time below range <70 mg/dL (TBR<70) was significantly higher during the mid-follicular phase than during late luteal phase (5.7±5.0% vs. 4.1±3.0%), but similar time in range 70-180 mg/dL (TIR) was observed throughout the MC. After switching to AHCL, a reduction in TBR<70 and an increase in TIR were observed in all phases. Phase-dependent changes in insulin infusion were detected and pre-existing differences in TBR<70 were eradicated (3.5±3.2% vs. 3.0±3.0%). However, TIR became significantly higher during the early follicular than during the late luteal phase (79.1±9.3% vs. 74.5±10.0%). In conclusion, AHCL improved glycemic control throughout the MC, but performance differed according to phase.