SUN-122 Latent Autoimmune Diabetes in Adults Presenting in a Geriatric Patient with Autoimmune Hypothyroidism

Abstract

Objective We describe a case of a geriatric patient with autoimmune thyroid disease who at the age of 87 presented with Latent Autoimmune Diabetes in Adults (LADA) Case An 87-year-old Caucasian man with a history of HTN, HL, extensive CVD including CABG at age 39, multiple TIA/CVA’s, macular degeneration with legal blindness, hypothyroidism and tobacco dependence was referred to endocrine clinic for worsening diabetes. Two years prior to consultation, the patient had been diagnosed with diabetes based on a fasting blood glucose level of 156mg/dL (75-120 mg/dL) and an HbA1C of 6.7%. Patient was counseled on lifestyle modifications and started on metformin. Due to occasional episodes of hypoglycemia, with a repeat HbA1C of 6.4%, metformin was discontinued. Three months later, the patient presented with polyuria/polydipsia and unintentional weight loss, HbA1c 12.5%. The patient was started on a DDP-4 inhibitor and weight based insulin detemir and referred to endocrine clinic. At the time of encounter, the patient continued to report symptomatic hyperglycemia, but denied symptoms of stiff-man syndrome. He also denied prior hospitalizations for hyperglycemia or DKA and any family history of DM, thyroid or autoimmune diseases. Blood sugars at home were 300-400’s mg/dL. Physical exam was notable for a thin man (BMI 20). Blood tests included GAD65 autoantibody > 25,000 u/ml (0-5 u/ml), repeated and confirmed, insulin autoantibodies <5 uU/ml (<5 uU/ml) and negative anti-pancreatic islet cell antibodies (<1:1). Additional tests included anti-thyroglobulin >2250.0 IU/ml (0.0-0.9 IU/ml), TPO 272 IU/ml (0-34 IU/ml) and tissue transglutaminase IgA < 2 (0-3). The patient was diagnosed with LADA; oral antihyperglycemic agents were held and weight based mealtime insulin started. Four months later, a repeat HbA1c improved to 6.7%, however due to postprandial hypoglycemia, the patient stopped all insulin. Fasting blood labs were notable for plasma glucose 211 mg/dl with a preserved C-peptide 2.5ng/ml (1.1-4.4 ng/ml). Patient was advised to resume only the long acting insulin and to continue checking his blood sugars. Hypoglycemia resolved. Conclusion LADA is a subset of type 1 diabetes mellitus and is defined by adult age at diagnosis, the presence of diabetes-associated autoantibodies, and non-insulin requiring within the first 6 months of diagnosis. LADA is more prevalent in younger adults with a mean age of onset of 33.4 years and is a rare cause of diabetes in the elderly with the oldest reported case in a 94-year-old patient. Suspicion for LADA should be heightened among patients with a prior history of autoimmune disease, with Hashimoto’s thyroiditis being the most commonly associated. We report a case of a geriatric patient who based on his physical exam and known autoimmune thyroid disease prompted evaluation for LADA. Early identification can help direct timely therapies and improve glycemic control.