SAT036 Chlorthalidone Implicated In The Development Of DKA HHS Overlap In A Patient With Type II Diabetes Mellitus

Disclosure: R.T. Hilder: None. Introduction: Thiazide diuretics are routinely used in the management of hypertension and impaired glucose tolerance is a well-known side effect of these medications. This case reports on a patient with type II Diabetes Mellitus newly initiated on Chlorthalidone, presenting with complications of profound hyperglycemia consistent with an overlap of HHS (Hyperglycemic hyperosmolar state) and DKA (Diabetic ketoacidosis). Case: A 61-year-old Hispanic male with history of Hypertension, Hyperlipidemia, Left Cerebellar Hemorrhage and Type II Diabetes Mellitus on Metformin 500mg twice daily, presented with a 2-month history of fatigue, polyuria and polydipsia. Lab work was significant for blood glucose 908 mg/dl, pH 7.28, HCO3 15, Anion Gap 25 and elevated beta-hydroxybutyrate of 10.82 mmol/l. HbA1c was 12.7%, up from 8.8% three weeks prior. C-peptide 0.7 ng/ml and GAD-65 Ab <5 IU/ml. For hypertension, the patient was adherent with titrated doses of Amlodipine, Benazepril and Hydralazine and newly initiated on Chlorthalidone 25mg daily, 2 weeks prior. There were no infectious signs or symptoms nor alternative precipitant for the hyperglycemia identified. The patient was admitted to the ICU for an overlap of DKA and HHS. The anion gap closed, and acidosis resolved within 24 hours with IV fluid resuscitation and Insulin drip on DKA protocol. He was discharged on Glargine 30 units daily, Lispro 8 units three times daily with meals and Metformin 500mg BID. Discussion: This patient’s presentation of hyperglycemia and ketosis in the absence of profound acidosis is suggestive of HHS, consistent with his protracted course preceding admission. His elevated beta-hydroxybutyrate however is more typically associated with DKA. With no other precipitant for the severe hyperglycemia and rapid rise in HbA1c identified, Chlorthalidone is the likely trigger. Thiazide diuretics are recognized to cause impaired glucose tolerance but there are few case reports on the development of HHS/DKA. The severity of this presentation in a patient otherwise routinely prescribed Chlorthalidone as an outpatient, without indication for blood glucose monitoring, highlights the need for greater research and awareness for this potentially fatal complication. Presentation: Saturday, June 17, 2023