Endocrine Abstracts

Introduction: Adult-onset autoimmune diabetes (AID) has two different phenotypes: classic type 1 diabetes mellitus (T1DM), with insulin requirement just after diagnosis, and latent autoimmune diabetes in adults (LADA). According to the Immunology of Diabetes Society, LADA diagnostic criteria are: age of onset of 30 years or more, any islet autoantibody, absence of insulin requirement for at least 6 months. The purpose of this study is to characterize patients with AID followed on a tertiary centre, comparing classic T1DM and LADA.

Methods: We collected data from patients with diabetes and positive islet autoantibodies, with at least 30 years at diagnosis. We classified patients who started insulin in the first 6 months as T1DM and patients with no insulin requirements in the first 6 months as LADA. Data regarding presentation, autoantibodies, A1C and C-peptide at diagnosis, therapeutics and complications were analysed with SPSS.

Results: Ninety-two patients included, 46 with T1DM and 46 with LADA. In T1DM group, 50% female, in LADA 52.1%. The median age at diagnosis was 38 years in T1DM group and 42 years in LADA group. The median follow-up time after diabetes diagnosis was 8 years in T1DM and 11 years in LADA (P=0.023). The median time between diagnosis of diabetes and diagnosis of autoimmune cause was 0 months in T1DM and 60 months in LADA (P<0.001). The mean BMI at diagnosis was 23.52 kg/m² in T1DM and 26.07 kg/m² in LADA (P=0.023). The median number of positive autoantibodies was 2 in T1DM and 1 in LADA (P=0.013). There was no statistical difference between both groups in what concerns to title of GAD autoantibodies, A1C and C-peptide at diagnosis of autoimmune aetiology. The presence of symptoms at diagnosis was associated with T1DM group (P<0.001). There was no difference between both groups in A1C, lipid profile, glomerular filtration rate and BMI at the last evaluation. LADA group was associated with macroalbuminuria (P=0.042). The median daily insulin dose was 40U for T1DM and 33.5U for LADA. Patients in LADA group used more often non insulin antidiabetic drugs (P=0.001). There were no differences on other diabetes complications.

Conclusion: Patients with classic T1DM presented more often with symptoms at diagnosis, lower BMI and higher number of autoantibodies, which may be related to a more aggressive autoimmune process. Patients with LADA were associated with macroalbuminuria and were more often under non insulin antidiabetic drugs. The ideal treatment of LADA is yet to be identified.