Isolated corticotropin deficiency in chronic alcoholism

Three patients who chronically abused alcohol were found to be hyponatraemic with normal plasma potassium. The first had been admitted with confusion and weight loss, the second with hypotension and sepsis, and the third with confusion and hypoglycaemia-induced seizures. All three patients had a subnormal cortisol response in the short synacthen test; however, the plasma cortisol after three days of tetracosactrin administration was greater than 550 nmol/L. Baseline corticotropin levels were less than 10 pg/mL in all three. No structural lesions of the hypothalamo-pituitary tract were found and there was no evidence of other endocrinopathies. Glucocorticoid replacement therapy led to the resolution of hyponatraemia and hypoglycaemia, where present, and to clinical improvement. The two surviving patients remained hypocortisolaemic in the long term, without recurrence of hyponatraemia or hypoglycaemia. The features of isolated corticotropin deficiency are easily confused with other effects of chronic alcohol abuse. In alcoholic patients with unexplained hyponatraemia, hypoglycaemia or haemodynamic instability, a short tetracosactrin test is advisable.