[Antidiuretic hormone levels (arginine-vasopressin) in cases of peripheral hypothyroidism. 26 cases].

Plasma arginine-vasopressin (AVP) levels were measured by radioimmunoassay in 26 untreated myxoedematous patients and 27 healthy subjects. In 22 patients, in spite low osmolality AVP values were not significantly different from those found in controls, but they were considerably increased in 4 patients with severe myxoedema and very low osmolality. Statistical analysis showed negative correlation between AVP values and osmolality in the patients. On the other hand, no correlation was found between AVP values and aldosterone or plasma renin activity values. These results suggest inappropriate secretion of antidiuretic hormone in myxoedema.