2231-P: RECLASS-T1D: Real-World Evaluation of AABBCC Criteria for Diabetes Classification: Experience from 6.7 Million U.S. Patients

Introduction and Objective: The AABBCC approach (Age <35 years, Autoimmunity [family or personal history], BMI <25 kg/m2, Background, Control [not responding to oral agents], and Comorbidities) has been proposed by the American Diabetes Association to help distinguish between diabetes types. This study examined the reclassification rates from prediabetes or type 2 diabetes (T2D) to type 1 diabetes (T1D) and evaluated AABBCC criteria applicability. Methods: Individuals in the US with diagnosis codes for prediabetes (ICD-10-CM R73.09; R73.03; HbA1c 5.7–6.4%) or T2D (ICD-10-CM E11*) from July 2016 to October 2024 were identified using TriNetX electronic health records. Baseline was the 6 months before the first diagnosis of prediabetes or T2D. Follow-up was from the first prediabetes or T2D diagnosis until T1D diagnosis (ICD-10-CM E10*), end of study, death, or loss to follow-up. Results: Among 6,759,145 individuals with a prediabetes or T2D diagnosis, 2.2% were reclassified as having T1D. Data availability for AABBCC criteria was limited (age 100%, BMI 35.8%, comorbidities 9.7%, HbA1c 6.1%, autoimmune comorbidities 5.1%); thus, analyses focused on age and BMI. Among individuals <35 years of age, 5.1% (34,787 of 676,077) were reclassified as having T1D, representing 23.6% of all reclassified cases. Thus, most reclassified individuals were ≥35 years of age. Among those <35 years of age with BMI <25 kg/m2, 4.1% (2,353 of 57,325) were reclassified, accounting for only 1.6% of reclassified cases. Overall, approximately 75% of individuals could not be identified using AABBCC criteria, underscoring its limitations in differentiating T1D within this T2D/prediabetes population. Conclusion: Differentiating T1D from T2D remains challenging because of overlap in clinical features. These data suggest that readily available clinical data such as age and BMI are not sufficient to identify adult patients with T1D. Disclosure J. Shubrook: Advisory Panel; Current; Abbott Diabetes. Other - Doc Care Deputy EditorConsensus panel-liver health, screening early stage T1d, Technology in primary care; Current; American Diabetes Association. Advisory Panel; Current; Bayer AG, Boehringer Ingelheim International GmbH. Consultant; Ended; Corcept Therapeutics. Advisory Panel; Ended; Idorsia Pharmaceuticals Ltd. Advisory Panel; Current; Insulet Corporation. Advisory Panel; Ended; Madrigal Pharmaceuticals, Inc. Consultant; Current; Novo Nordisk, Sanofi. C.B. Manzano Salgado: Employee; Current; Sanofi. Employee; Ended; IQVIA Inc. M. Bonnemaire: Employee; Current; Sanofi. Stock/Shareholder; Current; Sanofi. L. Mk: None. A. Chopra: None. J. Dunne: Employee; Current; Sanofi-Aventis U.S. Employee; Ended; Novo Nordisk. L. Hao: Employee; Current; Sanofi. J. Pettus: None. P. Gottlieb: Consultant; Current; Eli Lilly and Company. Board Member; Current; IM Therapeutics. Other - CEO, CMO; Current; IM Therapeutics. Research Support; Current; Immune Tolerance Network, Nova Laboratories, National Institute of Diabetes and Digestive and Kidney Diseases. Advisory Panel; Current; Sanofi. Research Support; Current; Sanofi. Consultant; Current; SAB Biotherapeutics, Inc., Anaptys Bio, Cour, T1D Fund. Consultant; Ended; Imcyse, Viacyte, Abata.