THU364 A Rare Case Of Concurrent Diabetic Ketoacidosis And Grave’s Thyrotoxicosis

Disclosure: A.D. Teixeira: None. E. Ukponmwan: None. P. Kachhadia: None. S. Aldasouqi: None. A. Abu Limon: None. Introduction: Type 1 Diabetes Mellitus (T1DM) is marked by deranged glycemic control due to the autoimmune destruction of insulin producing β cells in the pancreas. It affects 1.5 million adults in the United States. Approximately one-third of these patients may develop autoimmune polyglandular syndrome (APS). Autoimmune Thyroid Disease (AITD) is the most commonly associated autoimmune disease, with Hashimoto’s Thyroiditis more commonly observed than Graves Disease (GD). Patients with AITD and T1DM meet criteria for APS type 3A. Here, we present a case of a patient hospitalized for T1DM with diabetic ketoacidosis (DKA) who was also found to have concurrent GD. Case Presentation: Our patient was a 50 year old male who presented to the hospital with complaints of nausea and vomiting for a two day duration. He had symptoms of unintentional weight loss, polyuria and polydipsia for about two months prior to presentation. He was found to have blood sugar level of 438 mg/dL, with pH of 7.05 (7.35-7.45), anion gap of 30, bicarbonate level of 7.0 mmol/L (20-30 mmol/L), Beta-hydroxybutyrate level of 82mg/dL (n<4.10 mg/dL). Hemoglobin A1C was 15.1% . EKG revealed atrial fibrillation with RVR, and therefore thyroid function tests (TFTs) were ordered and showed a thyroid stimulating hormone (TSH) level of 0.01uIU/mL (0.35-4 uIU/mL), free thyroxine (FT4) of 1.29 ng/dL (0.61-1.37 ng/dL) and free triiodothyronine (FT3) levels of 4.4 pg/mL (2.8-4.4 pg/mL). Endocrinology evaluation of the patient’s Thyroid US showed some mild vascularity. Cardiac evaluation of patient’s atrial fibrillation did not reveal any other causes of arrythmia. Further labs showed TSI of 2.6 (n<1.3 TSI index) with normal TRAb and TPO levels. T1DM antibody testing revealed GAD-65 antibody (Ab) level of 51.3 nmol/L (n <0.02 nmol/L), Zinc Transporter 8 Ab level of >500 U/mL (n<15 U/mL). He was started on methimazole with good tolerance and was discharged upon resolution of his DKA with multiple daily injections of insulin. Discussion: AITD is the most prevalent autoimmune disease associated with T1DM, with GD being a less common association compared to Hashimoto’s thyroiditis. Many patients diagnosed with T1DM may develop other autoimmune conditions. On rare occasions these diseases can present concurrently, as it did with our patient. Recognition and awareness of APS types helps physicians recognize and screen for other autoimmune conditions that have previously been seen together. Literature search shows very few cases with both diseases presenting at the same time on hospitalization. However, with the recent COVID-19 pandemic, 5 cases were reported of simultaneous disease following vaccination. Our patient had no known exposure to COVID-19 virus or vaccine when he developed symptoms. Presentation: Thursday, June 15, 2023