RESUMEN
HISTORY: A 59-year-old woman presented for an endocrinological evaluation of recurrent spontaneous hypoglycemia. The complaints always regressed after carbohydrate intake. Due to classic congenital adrenal hyperplasia, the patient received substitution therapy with hydrocortisone for decades. FINDINGS AND DIAGNOSIS: The patient was in good general condition and slightly overweight. The blood glucose at the time of admission was 87âmg/dl. The cortisol and adrenocorticotropic hormone (ACTH) under substitution with delayed-release hydrocortisone were unremarkable. The mixed-meal tolerance test (MMTT, standardized breakfast test) showed no reactive hypoglycemia. In the subsequent 72-hour fast, symptomatic hypoglycemia of 46âmg/dl was demonstrated after 36 hours. The insulin secretion was suppressed. The low cortisol as well as the high ACTH indicated an undersupply of hydrocortisone at this time. THERAPY AND COURSE: Initially, the morning dose of delayed-release hydrocortisone was increased. However, this had no effect on blood glucose. Therefore, hydrocortisone was also prescribed at night. CONCLUSION: In addition to endogenous hyperinsulinism, a disturbance of the contrainsulinergic hormones can also be responsible for spontaneous hypoglycemia.The MMTT and the 72-hour fast test should be used for diagnosis. It is important to ensure that hormone analysis is carried out immediately in hypoglycemia. The ratio of insulin, C-peptide and proinsulin to blood glucose and the constellation of counter-regulatory hormones such as cortisol, ACTH, growth hormone, Insulin-like growth factor 1 (IGF-1) and catecholamines can provide information about the etiology of hypoglycemia.