Clinical Characteristics and Predictors of Glycemic Control During the First 24 Months After Diagnosis of Type 1 Diabetes

<b>Background</b>: Long-term glycemic control in type 1 diabetes (T1D) varies substantially among affected individuals, but the role of baseline characteristics at diagnosis and their association with later glycemic control remain incompletely understood. Identifying early predictors of glycemic control may facilitate timely, individualized therapeutic interventions. <b>Methods</b>: We retrospectively analyzed electronic health records of individuals with newly diagnosed T1D between 2001 and 2022 to assess anthropometric and metabolic parameters at the first presentation of the condition across age groups and determine predictors of glycated hemoglobin (HbA_1c) trajectories over 24 months. The multicentric cohort, which comprised people who were diagnosed with T1D in the Austrian federal state of Styria, was classified as children (<10 years), adolescents (10-18 years) or adults (≥18 years). Variables of interest included demographic and anthropometric data, positivity and titers of diabetes-specific autoantibodies, treatment setting (inpatient/outpatient), and presence and severity of diabetic ketoacidosis (DKA). <b>Results</b>: The cohort consisted of 281 individuals (23.1% were children, 41.3% were adolescents, and 35.6% were adults at T1D diagnosis; 46.6% were female). In the unadjusted analyses, younger age (age < 18 years), female sex, and receiving treatment in a general ward were associated with higher HbA_1c levels over 24 months. However, after adjustment for important covariates, only younger age remained a significant predictor of inferior glycemic control over 24 months, emphasizing the importance of structured, age-appropriate follow-up care. <b>Conclusions</b>: Younger age at T1D diagnosis independently predicts suboptimal glycemic trajectories over the first two years after T1D onset. Early identification may enable targeted, age-specific interventions to improve long-term outcomes.