Salt Wasting, Hydro-sodium Balance and Fludrocortisone Requirement in Congenital Adrenal Hyperplasia

Congenital adrenal hyperplasia (CAH) in its classic neonatal form with severe salt-wasting represents a challenge for pediatric endocrinologists in order to maintain sodium balance, especially as the physiopathology and optimal therapeutic management of this urinary salt loss remain poorly studied, particularly during the neonatal period. The human kidney presents the characteristic of being immature at birth with a functional tubulopathy associating sodium wasting and difficulty to concentrate urine, in connection with a transient renal resistance to aldosterone action, which is exacerbated in case of CAH by insufficiency of aldosterone production. The objective of project is therefore to study the secretion profiles of plasma and urinary steroids in neonates with classical salt-wasting form of CAH before treatment and under treatment with Fludrocortisone and Hydrocortisone during the first months of life, using an advanced technology: LC-MSMS (Liquid chromatography coupled with tandem mass spectrometry). The study of the existence of a correlation between plasma and urinary steroid profiles will also make it possible to subsequently consider simplified medical follow-up for these patients. This project will lead to a better understanding of sodium handling and steroid secretion and excretion profiles in CAH neonates, in order to improve the therapeutic management of mineralocorticoid replacement in these patients.