118-LB: Glucose Variability throughout the Menstrual Cycle on Closed-Loop Control in Type 1 DM

Many women with type 1 DM report change in glucose (GLU) control and insulin (INS) dosing throughout the menstrual cycle (MC). No trials have reported the effect of closed loop control (CLC) on INS delivery across the MC. Women enrolled in Phase 1 of the IDCL hybrid CLC trial logged MCs to estimate late luteal and early follicular dates. Data from 64 MC across 27 women (13 CLC), 7 using hormonal contraception, aged 28±11 years, weight 67 kg (IQR: 61-80) was analyzed for diurnal GLU control and CLC INS delivery. MC phase did not impact trends toward increased time in range with CLC. There were no differences in GLU and INS variables. While median CLC INS delivery did not change across the MC, there was intrasubject variability across the MC. CLC has the potential to elucidate individual dosing variability and may mitigate reported change in GLU control across the MC. Disclosure C.J. Levy: Advisory Panel; Self; Novo Nordisk A/S, Sanofi. Employee; Spouse/Partner; Allergan. G. OMalley: None. S.A. Brown: Research Support; Self; Ascensia Diabetes Care, Dexcom, Inc., Roche Diabetes Care, Tandem Diabetes Care. D. Raghinaru: None. Y.C. Kudva: Advisory Panel; Self; Novo Nordisk Inc. Other Relationship; Self; Dexcom, Inc., Roche Diabetes Care, Tandem Diabetes Care. E. Dassau: Consultant; Self; Eli Lilly and Company, Insulet Corporation. Research Support; Self; Dexcom, Inc., DreaMed Diabetes, Ltd., Insulet Corporation, Roche Diabetes Care, Tandem Diabetes Care, Xeris Pharmaceuticals, Inc. Speaker’s Bureau; Self; Roche Diabetes Care. Other Relationship; Self; ModAGC. B. Kovatchev: Advisory Panel; Self; Sanofi. Board Member; Self; TypeZero Technologies, Inc. Consultant; Self; Sanofi, Tandem Diabetes Care. Research Support; Self; Dexcom, Inc., Roche Diabetes Care, Tandem Diabetes Care. Speaker’s Bureau; Self; Dexcom, Inc. Stock/Shareholder; Self; TypeZero Technologies, Inc. Other Relationship; Self; Johnson & Johnson, Sanofi. S. Anderson: Research Support; Self; Medtronic MiniMed, Inc. Funding National Institutes of Health