SUN-412 Endocrine Tug-of-War: Navigating Autoimmune Polyglandular Syndrome Type II

Abstract Disclosure: C.B. Hurd: None. A.Z. Nasir: None. C.A. Soubliere: None. Introduction: Autoimmune Polyglandular Syndrome Type II (APS-II) is a rare autoimmune disorder in which primary adrenal insufficiency (Addison's disease) coexists with autoimmune thyroid disease (e.g., Hashimoto's thyroiditis) and type 1 diabetes mellitus. APS-II affects approximately 1 in 20,000 individuals, with a higher prevalence in women, typically presenting in the third to fourth decades of life. Managing APS-II is challenging due to the risk that one endocrine treatment may exacerbate another. Case Presentation A 33-year-old male with APS-II presented with a 2-day history of abdominal pain, nausea, vomiting, and poorly controlled blood glucose. He had increased his corticosteroid dose due to vomiting, fearing adrenal crisis. Despite this, his blood glucose remained high, peaking at 550 mg/dL, and laboratory results showed diabetic ketoacidosis (DKA) with an anion gap of 17 and beta-hydroxybutyrate of 5.2 mmol/L. The patient was admitted and received an insulin infusion along with corticosteroid management. DKA resolved overnight, and glycemic control improved. His insulin regimen was adjusted, and he was discharged with a steroid taper and follow-up with endocrinology. Discussion: This case highlights the complexities of managing APS-II, where corticosteroid treatment to prevent adrenal crisis can worsen hyperglycemia, precipitating DKA. The interaction between corticosteroid therapy and insulin requires careful monitoring and individualized treatment plans to balance adrenal insufficiency and glycemic instability. Clinicians must recognize these interactions and adjust therapy to avoid adverse outcomes. Conclusion Managing APS-II requires an understanding of the interactions between coexisting endocrine disorders. This case emphasizes the importance of individualized treatment, vigilant monitoring, and multidisciplinary collaboration to optimize outcomes for APS-II patients. Presentation: Sunday, July 13, 2025