9390 Does Znt8a Have An Association With The Duration Of Diabetes? Case Series And Literature Review

Abstract

Abstract Disclosure: N.M. Rivera Vargas: None. C.S. Botero Suarez: None. S.K. Suryanarayanan: None. S. Saad-Omer: None. Context: Latent autoimmune Diabetes of adults (LADA) is a form of autoimmune diabetes with features of Type 2 Diabetes but positive autoantibodies resembling Type 1 Diabetes. Latent autoimmune diabetes in adults (LADA), has a mixed phenotype with positive islet-cell antibodies (ICA), glutamic acid decarboxylase autoantibodies (GADA), protein tyrosine phosphatase autoantibodies (IA2A), insulin autoantibodies (IAA), or zinc transporter-8 autoantibodies (ZnT8A). Since the discovery of ZnT8A, the relevance and clinical utility of this marker has sparked interest. Although ZnT8A is used as a complementary diagnostic aid in children, its utility in adults seems to be unclear. Objective: We report a case series of 26 subjects referred to the Orlando VA Endocrine clinic with measured ZnT8A. We hypothesize that higher ZnT8A will be found in adult autoimmune diabetes with newly diagnosed diabetes rather than those with a longer duration of diabetes. We also explore the association between ZnT8A and family history, duration of diabetes, diabetes complications, and C-peptide levels. Method: A case series of 26 adult patients with diabetes mellitus with a positive ZnT8A (≥15 U/mL). We reviewed medical records of these cases to include ZnT8A levels, years of diabetes diagnosis, C-peptide levels, and diabetes complications. Patients were classified into subgroups based on ZnT8A levels into < 350 U/mL or ≥ 350 U/mL. Results: The 26 patients reviewed had a mean (SD) age of 46 (13) years. The mean (SD) duration of diabetes was 16 (12) years, and HbA1C was 8.4 (1.1) %. Poisson regression analysis showed a statistically significant inverse relationship between ZnT8A and years of diabetes (regression coefficient: -0.028; 95% confidence interval: -0.03 to -0.25; p-value <0.001). Diabetic ketoacidosis was present in 35% of subjects, while diabetic neuropathy was noted in 58% of subjects with positive ZnT8A. Patients with a high ZnT8Ab above 350 U/mL displayed a weak trend towards a lower C-peptide mean (p-value 0.42), and lower prevalence of DKA (p-value 0.42) which was not statistically significant. Conclusion: In this case series of patients with adult-onset diabetes, there seems to be a statistically significant inverse relationship between ZnT8A levels and duration of diabetes suggesting a reduction of ZnT8A levels over time. Although limited by a small number of subjects, this may suggest the need for screening with autoantibodies in the setting of diabetes earlier in the disease process. Presentation: 6/2/2024