Introduction & Objective: In females living with T1D (FwT1D), the impact of the menstrual cycle on glucose fluctuations is not well known. Our aim is to examine the relationship between the menstrual cycle phases, glycemic fluctuations and insulin needs in FwT1D.
Methods: This is a preliminary analysis of observational data over 3 menstrual cycles in eumenorrheic FwT1D. The menstrual cycle was split into 3 phases: follicular, periovulatory, and luteal phases. Included participants (n=15) shared their CGM and daily insulin (total, basal and bolus) data. CGM data were used to calculate mean glucose, coefficient of variance (CV), and time below (TBR), in (TIR), and above (TAR) range. One-way repeated-measures ANOVAs with Bonferroni post-hoc tests were used to compare glycemia, glycemic variation and insulin doses across the 3 menstrual cycle phases.
Results: Of the 15 FwT1D, 14 (93%) did not use hormonal contraception. Participants were (mean ± SD) 37.2 ± 5.9 years old, with a BMI of 25.7 ± 4.6 kg/m2, an HbA1c of 6.5 ± 0.7%, and diabetes duration of 19.3 ± 10.6 years. Glycemic and insulinemic data across the 3 cycle phases can be found in Table 1.
Conclusion: In FwT1D, the luteal phase of the menstrual cycle is associated with higher glucose levels, more time spent in hyperglycemia, and greater insulin needs compared to the follicular and periovulatory phases.
A. Bonhoure: Consultant; Dexcom, Inc. J.E. Yardley: Speaker's Bureau; Dexcom, Inc. Research Support; LifeScan Diabetes Institute. V. Boudreau: None. V. Messier: None. E. Nguyen: None. A. Brazeau: Other Relationship; Dexcom, Inc. Research Support; Canadian Institutes of Health Research, Juvenile Diabetes Research Foundation (JDRF), Diabète québec, Fonds de recherche du Québec en Santé. R.P.R. Rabasa-Lhoret: Other Relationship; Abbott, AstraZeneca, Bayer Inc., Boehringer-Ingelheim, Dexcom, Inc. Research Support; Diabetes Canada. Other Relationship; Eli Lilly and Company. Research Support; Cystic Fibrosis Canada, Canadian Institutes of Health Research, FFRD - Fondation Francophone pour la Recherche du Diabète. Other Relationship; Janssen Pharmaceuticals, Inc. Research Support; Juvenile Diabetes Research Foundation (JDRF). Other Relationship; Novo Nordisk, GlaxoSmithKline plc. Consultant; HLS Therapeutics Inc., Insulet Corporation. Speaker's Bureau; CPD Networks. Other Relationship; Medtronic. Consultant; Pfizer Inc. Speaker's Bureau; Tandem Diabetes Care, Inc. Other Relationship; Sanofi. Speaker's Bureau; Vertex Pharmaceuticals Incorporated. Research Support; SFD - Société Francophone du Diabète.
