1442-P: Type 1 Diabetes (T1D) Clusters in the SEARCH for Diabetes in Youth Study

Objective: Youth with T1D are heterogeneous for β-cell insufficiency, insulin sensitivity, autoantibody profile, risk alleles, and inflammatory markers. It is unknown whether subtypes of T1D exist. Such clusters might aid in the identification of youth at increased risk for poor outcomes. Methods: SEARCH is a population-based observational cohort of youth (< 20 years) with diabetes conducted from 2002 - 2012. Youth with T1D (n=1107) were clustered by inflammatory status and insulin secretion and sensitivity using hierarchical clustering (hclust, R 4.3.1) with C-reactive protein (CRP), C-peptide, and body mass index Z-score (< 1 year since diagnosis). Demographics were compared across clusters. Results: We found 6 clusters (Table). Youth in clusters 1 and 5 were more likely to be White and younger at diagnosis, with lower C-peptide, BMI Z-score, waist circumference, CRP, and IL-6. Youth in cluster 2 had high prevalence of positive GAD65 antibodies, CRP, and IL-6. Youth in cluster 3 had high prevalence of IA2 antibodies. Youth in cluster 6 were more likely to be Black or Hispanic and older at diagnosis, with higher C-peptide, BMI Z-score, waist circumference, triglycerides, and leptin. Conclusion: We observed distinct clusters among youth with T1D of short duration. Future studies should examine whether T1D clusters are associated with diabetes outcomes and how T1D clusters compare to conventional risk scores for diabetes complications. K.K. Harrall: None. S.M. Bird: None. C. Kim: None. M.J. Redondo: None. D. Dabelea: None. National Institutes of Health (U18DP006517); National Institutes of Health (R21HD108508)