Reference values for renal concentrating capacity in children by the desmopressin test.

Reference values are reported for maximal renal concentrating capacity in children using intranasally administered desmopressin. The report is based on 591 tests in 473 healthy children aged 0.5-13 years. The concentrating capacity increased markedly during the first years of life and reached a plateau at the age of 3 years. The mean value minus two standard deviations was 525 mosmol/kg at 1 year of age and 825 mosmol/kg at 3 years of age.