SUN-542 Identifying Late Autoimmune Diabetes in Older Adults: Implications for Diagnosis and Management

Abstract Disclosure: B.A. Bradley: None. M.K. Williams: None. P. Madhavan: None. Background: Latent autoimmune diabetes of adulthood (LADA) is a form of diabetes mellitus (DM) that shares characteristics of both type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM). LADA is marked by islet β-cell autoimmunity and insulin resistance, with an estimated prevalence of 5.1% of adults with T2DM, and typically presents between ages 30 and 50. Most patients are positive for a single islet autoantibody, with GAD being the most predominant. Risk factors include a personal or family history of autoimmune disease, low birth weight, and history of smoking. Clinical Case: A 71-year-old Caucasian male with a history of hyperlipidemia and diabetes mellitus presented to the endocrine team for evaluation of worsening blood sugars. He was previously managed with Metformin 2000 mg daily and Semaglutide po 7 mg daily with good control of his sugars. During the previous 4 months his HbA1c increased from 6.7 to 8.0%. Family history was significant for DM, in his father who was diagnosed in his 60s and his sister who was diagnosed in her late 20s with T1DM. Vitals were stable with blood pressure of 133/85 mm Hg, heart rate of 58 bpm, BMI of 23.56 kg/m2. Physical exam was significant for evidence of mild neuropathy. Laboratory tests revealed GAD antibodies levels greater than 250 (< 5 IU/mL), and a fructosamine level of 350 (205-285 µmol/L). Islet cell antibody screening was negative, glucose was 147 mg/dL (65-99 mg/dL), and C-peptide was 0.92 ng/mL (0.80-3.85 ng/mL). CT abdomen with and without contrast revealed a normal pancreas without focal masses. Evaluation for Cushing’s syndrome was also negative. Due to worsening glycemic control on oral agents, the patient was switched to basal bolus insulin which then improved his glycemic control. Conclusion: This case highlights the importance of considering LADA even in elderly patients who present with unexplained worsening of diabetes. Given LADA’s potential for atypical presentation, clinicians should maintain a high level of clinical suspicion in patients who exceed the typical age of presentation. Presentation: Sunday, July 13, 2025