Abstract 43: Age no bar for Type 1 diabetes mellitus

Introduction For a long time it has been thought that Type 1 Diabetes Mellitus (T1DM) occurs in children and young people, though no strict cut-off of age. Usually, T1DM diagnosis is thought only for patients <20-25 years. Now with the increasing obesity pandemic we see Type 2 Diabetes mellitus (T2DM) in adolescents as well but diagnosing T1DM in adults is uncommon. Here we describe our patient of 55 years having T1DM. Case history and examination 55 year post menopausal female presented with poorly controlled glycemia for 1 year. She was started on triple drug OHA combination as at diagnosis blood sugar was around 450 mg/dL. As blood sugars were not controlled other OHA was further added. Since the diagnosis, blood sugarwere uncontrolled so basal insulin was initiated. When she presented to us, glucometer reading was high with no ketosis and corresponding lab values was around 650 mg/dL. She was non-obese with BMI of 21.2 kg/m2 with no Acanthosis nigricans, no strie, no proximal muscle weakness and no h/o pancreatitis or steatorrhoea. She did not have any history of steroid abuse or any other alternate treatment. We ordered an Anti GAD antibody which came out to be very high > 600 IU/mL (N < 17). Differential diagnosis T2DM - Age of this patient favors the diagnosis of T2DM but acute onset and absence of signs of insulin resistance along with non responder to OHA were against T2DM. LADA - Presence of autoantibodies favors the diagnosis but LADA usually occurs in younger adults and does not require insulin for at least 6 months after diagnosis.[1] Diagnosis and treatment T1DM occurs due to beta cell destruction by autoantibody leading to severe insulin deficiency. A basal or stimulated C peptide is used for estimating the insulinopenic status in T1DM but sometimes it is low in poorly controlled diabetes.[2] So it was not done in our case. We proceeded to Anti GAD antibody titre which was very high, thus confirming the diagnosis. Patient was started on basal bolus therapy after insulin and hypoglycemia education. She is doing fine with insulin dose titration. Summary This case emphasizes the role of measuring GAD antibodies and suspecting T1DM in adults too. Infact misdiagnosis occurs in nearly half of adults with new T1DM.[3] The notion that T1DM is limited to children is not true. Anti-GAD Ab is the most prevalent autoantibody in adult T1DM, though this varies with genetic make up and population studied.[4] Higher number of antibodies increases the probability of T1DM. Diagnosis is important so that these patients are informed for life long insulin and OHA should not be tried. They should be screened for other autoimmune conditions as well.