Diabetes insipidus in children. I. Arginine-vasopressin determination in plasma during short dehydration test.

Plasma vasopressin as well as plasma and urinary osmolality are measured during an overnight dehydration test in vasopressin is undetectable. It is present in plasma from patients with partial diabetes insipidus but the level is not appropriate for plasma osmolality. In patients with polyuria of renal origin plasma vasopressin was significantly higher than in patients with neurogenic diabetes insipidus. Plasma vasopressin measurement is of diagnostic values in partial neurogenic diabetes insipidus and may be of considerable help to distinguish this group of patients from children with polyuria of renal origin.