SAT-556 New Hypoglycemia In A Patient Who Has Been Treated With Hydroxychloroquine For 24 Years

Abstract Disclosure: Y. Esaki: None. I. Harbuz-Miller: None. Hydroxychloroquine-induced hypoglycemia has been reported in patients with and without diabetes. We describe a patient with systemic lupus erythematosus (SLE) on long-term hydroxychloroquine with new onset severe hypoglycemia. A 53-year-old woman with a past medical history of SLE treated with hydroxychloroquine since age 26, presented with recurrent hypoglycemia. Initial episode occurred three years prior to presentation with nocturnal diaphoresis associated with nausea, emesis, weakness, followed by loss of consciousness, requiring Emergency Medical Services. The fingerstick glucose was undetectable and improved with intravenous dextrose. Since then, she continued to have similar events with lowest glucose 44mg/dL which resolved with eating. She denied history of diabetes, bariatric surgery or access to diabetic medications. Continuous glucose monitor revealed several episodes of daytime and nocturnal hypoglycemia. A 72-hour supervised fasting test revealed hypoglycemia after 20 hours of fast with plasma glucose 49 mg/dl, with simultaneous C-peptide 0.3 ng/ml (1.1 - 4.4 ng/ml), insulin < 2 uIU/ml (3 - 25 uIU/ml), proinsulin < 2.0 pmol/L (</= 7.2 pmol/L) and beta-hydroxybutyrate 3.24 mmol/L (0.02 - 0.27 mol/L). The sulfonylurea screen was negative. A morning cortisol was 12 ug/dl. Glucagon treatment did not improve hypoglycemia. IGF-1 and IGF-2 were normal. Insulin antibody profile was negative. Cross-sectional images were unremarkable. Genetic evaluation for glycogen storage disease was negative. After weaning off hydroxychloroquine, the glucose improved and symptoms resolved until she had to restart hydroxychloroquine for lupus flare up. The hydroxychloroquine-induced hypoglycemia is poorly understood and suspect mechanisms include increased insulin secretion, decreased insulin degradation, increased glucose uptake by the peripheral tissue, and inhibition of gluconeogenesis. This case illustrates that hypoglycemia can develop after several years of treatment with hydroxychloroquine. Clinicians should monitor and educate patients about hypoglycemia as a potential adverse effect. Presentation: Saturday, July 12, 2025