Frequency of Adrenal Insufficiency in Patients With Hypoglycemia in an Emergency Department: A Cross-sectional Study

Context: In most patients presenting with hypoglycemia in emergency departments, the etiology of hypoglycemia is identified. However, it cannot be determined in approximately 10% of cases. Objective: We aimed to identify the causes of unknown hypoglycemia, especially adrenal insufficiency. Methods: In this cross-sectional study, we evaluated the etiology of hypoglycemia among patients in our emergency department with hypoglycemia (plasma glucose level < 70 mg/dL (3.9 mmol/L)] between April 1, 2016 and March 31, 2021 using a rapid adrenocorticotropic hormone (ACTH) test. Results: There were 528 cases with hypoglycemia included [52.1% male; median age 62 years (range 19-92)]. The majority [389 (73.7%)] of patients were using antidiabetes drugs. Additionally, 33 (6.3%) consumed alcohol; 17 (3.2%) had malnutrition; 13 (2.5%), liver dysfunction; 12 (2.3%), severe infectious disease; 11 (2.1%), malignancy; 9 (1.7%), heart failure; 4 (0.8%), insulin autoimmune syndrome; 3 (0.6%), insulinoma; 2 (0.4%) were using hypoglycemia-relevant drugs; and 1 (0.2%) suffered from non-islet cell tumor. Rapid ACTH tests revealed adrenal insufficiency in 32 (6.1%). In those patients, serum sodium levels were lower (132 vs 139 mEq/L, P < 0.01), eosinophil counts were higher (14 vs 8%, P < 0.01), and systolic blood pressure was lower (120 vs 128 mmHg, P < 0.05) at baseline than in patients with the other etiologies. Conclusion: The frequency of adrenal insufficiency as a cause of hypoglycemia was much higher than what we anticipated. When protracted hypoglycemia of unknown etiology is recognized, we recommend that the patient is checked for adrenal function using a rapid ACTH test.