1367-P: Correlation between Severe Hypoglycemia (SH) and CGM-Detected Level 2 Hypoglycemia (Lv2 Hypo) in a Clinical Trial Setting

Introduction and Objective: Limited evidence supports the use of CGM-detected hypo as a surrogate marker for SH in clinical trials. We examined the correlation between person-reported SH and CGM-detected Lv2 hypo in adults with type 1 diabetes participating in a clinical trial. Methods: The 1-year pilot trial enrolled 40 adults with type 1 diabetes who, at baseline, spent ≥1% of time 54 mg/dL in the prior month or experienced SH in the prior 6 months. Self-reported past-6-month SH frequency at baseline, 26 weeks, and 52 weeks as well as 1-month CGM data preceding baseline and 3-month CGM data preceding 12, 26, and 52 weeks were collected. Spearman rank correlations assessed associations between SH frequency and CGM hypo metrics, as well as associations between changes in SH frequency and CGM metrics over time (α=0.05). Results: Across the study period, 232 SH episodes and 3,920 CGM-detected Lv2 hypo episodes were recorded. SH frequency did not correlate with the number of Lv2 hypo episodes or with other CGM hypo metrics at baseline, 26, or 52 weeks, regardless of whether 1-, 3-, or 6-month CGM data were used. Changes in SH frequency from baseline to 26 weeks and from 26 weeks to 52 weeks likewise did not correlate with changes in Lv2 hypo frequency or with most other CGM hypo metrics. Conclusion: In this trial cohort, SH frequency showed poor correlation with CGM-detected Lv2 hypo, questioning the use of Lv2 hypo as a surrogate marker for SH. Disclosure Y. Lin: Other - Clinical trial site; Current; DEKA, Zucara Therapeutics. W. Ye: None. I. Gaynanova: None. A. Martin-Schwarze: None. A. Ratzki-Leewing: Advisory Panel; Current; Sanofi. Consultant; Current; Vertex Pharmaceuticals Incorporated, Dexcom, Inc. Research Support; Current; Sanofi. Other - Paid presentation; Ended; Abbott. Consultant; Current; Sanofi. J. Piette: None. S.A. Amiel: Other - Chaired Vertex satelite symposia at EASD on 2 occasions (2024,2025); Ended; Vertex Pharmaceuticals Incorporated. Advisory Panel; Ended; Vertex Pharmaceuticals Incorporated. Funding National Institutes of Health (K23DK129724, P30DK020572, P30DK092926)