THU367 Hyperosmolar Hyperglycemic State In A Middle-old Male With Primary Hyperparathyroidism

Disclosure: D.M. Dimayuga: None. M.C. Isidro: None. A 79-year-old male was brought to our hospital for drowsiness. He had low-grade fever with associated cough and anorexia 1 week prior. He had a previous history of hypertension and primary hyperparathyroidism (PHPT) maintained on cinacalcet. He did not have a history of diabetes and a family history of diabetes, and his HbA1c was 5.4% three months before. On admission, the results of his physical examination and vital signs were as follows: height, 152cm; weight, 56.0 kg; BMI, 24.2 kg/m(2); temperature, 36.5C; heart rate, 85 beats/min; SpO2, 98% (on room air); respiratory rate, 22 breaths/min; and blood pressure, 115/60 mm Hg. His blood glucose level was 966 mg/dL, HbA1c 13.4%, and serum osmolality 324 mOsm/kg. Serum ketones were 15 mg/dL and blood gas analysis was normal. He was diagnosed with hyperglycemic hyperosmolar state (HHS) and infusion of insulin and saline was subsequently initiated. With clinical suspicion of chronic pancreatitis given the patient’s history of PHPT, serum lipase was checked, 105 U/L (NV: 12-53 U/L). Ionized calcium was 1.36 mmol/L. On CT scan of abdomen, there was no evidence of duct dilatation and calcification, and instead, “features of diffuse fatty atrophy of the pancreas” were seen. His endogenous insulin secretory capacity was sufficient (serum C-peptide: 2.76 ng/mL, NV: 0.78-5.19 ng/mL). Eventually, the patient’s level of consciousness improved and glycemic control was achieved. Soon after, insulin was shifted to basal-bolus regimen. On the 7th day of hospitalization, patient was discharged with minimal insulin requirements. Two weeks later, on follow up, his blood glucose levels were found to be stable. It was not clear whether our patient had new-onset autoimmune or type 2 diabetes. Although autoimmune diabetes generally occurs when about 90% of the pancreatic beta cells have been destroyed, the patient could have been in the honeymoon period wherein beta cell activity was transiently regained after commencement of insulin therapy. Our plan is to monitor his C-peptide titers and test his insulin antibodies. Evidence suggests that PHPT may cause insulin resistance and glucose intolerance. The rise in free intracellular calcium may reduce glucose transport in insulin-stimulated glucose transporters, increasing the need for insulin. This could be the case in our patient hence we diagnosed him with type 2 diabetes. To the best of our knowledge, this is the first case demonstrating the co-occurrence of HHS and PHPT. Presentation: Thursday, June 15, 2023