Objectives: The primary objective of this study was to explore the relationship between the Time Below Range (TBR) and Impaired Awareness of Hypoglycemia (IAH) and Severe Hypoglycemia (SH).

Methods: Our study used data from people with diabetes using isCGM in the ABCD audit. Hypoglycemia awareness was evaluated using the Gold score, with a score of ≥4 denoting Impaired Awareness of Hypoglycemia (IAH). SH was defined as hypoglycemia necessitating third-party assistance. Logistic regression analysis was used to identify the association between TBR% (<70 mg/dl) at the last follow-up (used as a continuous independent variable) and follow-up Gold score and the number of SH between isCGM initiation and follow-up. Youden’s J index was used to identify the optimal TBR% cutoffs for detecting IAH and SH.

Results: The study consisted of 15,777 people with diabetes with at least one follow-up, of which TBR data was available for 5030 people. The median TBR% in the study population was 4% (IQR 2%-6.6%). Following adjustment for age, gender, and BMI, TBR was significantly associated with both SH (Beta=0.02 P=0.001) and IAH (Beta=0.01 P=0.006). The determined optimal TBR cutoffs for identifying follow-up IAH and SH were 3.35% and 3.95%, respectively. These cutoffs yielded sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 65%, 43%, 19%, and 85% for IAH and 73%, 42%, 5%, and 97% for SH.

Conclusion: Our study, based on real-world data, shows a clear association between TBR% and IAH and SH in people with diabetes. Our findings broadly align with the international consensus recommending a TBR of <4% in individuals with type 1 diabetes. However, we observed that this cutoff has limited discriminatory power in predicting SH and IAH, emphasising the need for nuanced approaches in establishing optimal TBR thresholds for distinct diabetes-related outcomes.

Disclosure

H. Deshmukh: None. E.G. Wilmot: Other Relationship; Abbott. Speaker's Bureau; AstraZeneca. Other Relationship; Dexcom, Inc., Eli Lilly and Company, Insulet Corporation, embecta, Medtronic, Novo Nordisk. Advisory Panel; Roche Diabetes Care. Other Relationship; Sanofi. Speaker's Bureau; Ypsomed AG. P. Choudhary: Advisory Panel; Abbott, Biolinq. Speaker's Bureau; Dexcom, Inc., Eli Lilly and Company, Novo Nordisk, Sanofi. Advisory Panel; Ypsomed AG, Vertex Pharmaceuticals Incorporated. M.L. Cull: None. R.E. Ryder: Speaker's Bureau; Abbott, Besins Healtcare, BioQuest, GI Dynamics. Consultant; GI Dynamics. Other Relationship; Novo Nordisk. T. Sathyapalan: Research Support; Abbott. Advisory Panel; Rhythm Pharmaceuticals, Inc., Pfizer Inc. C. Walton: None.

© 2024 by the American Diabetes Association
2024
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