[Hyponatremia, a frequent, and at times a major and indicative sign in anterior pituitary insufficiency].

Thirty five patients with hypopituitarism have been studied. Nine had a mild hyponatremia (126-137 mEq/l) and five a profound hyponatremia (105-124 mEq/l). None of them had hemodilution (plasma protein, potassium were normal). Hyponatremia was present even in the absence of deficit in GH and/or TSH, and/or FSH-LH. All the pateints had a complete ACTH deficiency. There was a negative correlation between age and natremia (r = -0,39; p0.02). 2/5 patients with severe hyponatremia had mental confusion. These two patients had a complete TSH deficiency. Natremia increased with cortisone therapy in all cases but reached the normal range only in one case. Mental confusion disappeared and natremia became normal in all patients with therapy with cortisone and thyroid hormones.