45-PUB: Glycemia in Perimenopausal vs. Preperimenopausal Age Groups in Women with Type 1 Diabetes

Introduction and Objective: Transition to menopause is associated with higher glycemia in type 2 diabetes; little is known about its impact in type 1 diabetes (T1D). We evaluated differences in continuous glucose monitor (CGM) metrics in perimenopause (PERI) and pre-perimenopause (PRE) age groups in women with T1D. Methods: Cross-sectional study of the T1D Exchange Registry (2023-2024) with inclusion criteria: female sex, 35-39 (PRE) or 43-47 (PERI) years, and ≥70% CGM wear time in the 180 days prior to survey response date. PERI was defined using age bands centered on the US mean age of PERI onset with a 5-year window around the mean, a 3-year buffer to reduce misclassification, and the preceding 5-year age band defining the PRE group. Exclusion criteria: T1D diagnosis in past 1 year, GLP-1 RA or SGLT2 inhibitor use, and CGM time in range ≥90% (to ensure sufficient glycemic variability). Demographics and clinical characteristics (self-reported HbA1c, diabetes duration, body mass index, technology use) were summarized descriptively and stratified by group. Over 25 CGM metrics were calculated and summarized similarly. Group differences were tested using Wilcoxon rank-sum and Pearson’s chi-square tests. Results: PERI (N=181) and PRE (N=280) groups were similar across demographic and clinical characteristics (p≥0.05) except for age and diabetes duration, supporting unadjusted analysis. Self-reported HbA1c was higher in the PERI vs PRE group, 6.8 vs 6.6% (p<0.05). Multiple CGM metrics showed higher glycemia in PERI vs PRE, including mean glucose 162 vs 157mg/dL (p<0.05), % time above range 250mg/dL 9.4 vs 8.5% (p<0.05), % time above range 180mg/dL 30.6 vs 28.0% (p=0.06), % time in tight range 70-140mg/dL 41.9 vs 44.9% (p<0.05). Hypoglycemia CGM metrics were similar or lower in PERI vs PRE. Conclusion: Women in PERI years exhibited higher overall glycemia than PRE across self-reported HbA1c and multiple CGM metrics. Further evaluation of this population is warranted to determine contributing factors and interventions. Disclosure J. Lucove: None. E.M. Cornelius: None. H.T. Nguyen: None. G. O'Malley: Research Support; Ended; Dexcom, Inc. Research Support; Current; Abbott, MannKind Corporation. C. Levy: Research Support; Current; Tandem Diabetes Care, Inc., Novo Nordisk, Abbott Diabetes, MannKind Corporation. Consultant; Current; MannKind Corporation, Tandem Diabetes Care, Inc. Research Support; Current; Deka/Sequel, Dexcom, Inc., Genti Bio. Consultant; Current; Deka/Sequel. V. Shah: Advisory Panel; Current; Abbott Diabetes, Dexcom, Inc. Advisory Panel; Ended; Medtronic. Advisory Panel; Current; Novo Nordisk, Eli Lilly and Company. Consultant; Current; Insulet Corporation, T1D Exchange. Advisory Panel; Current; Sanofi, Tandem Diabetes Care, Inc. Consultant; Ended; DreaMed Diabetes, Ltd. Funding The T1D Exchange Registry is funded by a grant from The Leona M. and Harry B. Helmsley Charitable Trust (G-2103-05086).