Plasma Aldosterone, Renin Activity, and 17α-Hydroyprogesterone in Salt-Losing Congential Adrenal Hyperplasia. I. Response to ACTH in Hydrocortisone Treated Patients and Effect of 9α-Fluorotisol

Abstract

Plasma aldosterone (PA), renin activity (PRA), and 17-OH-progesterone (17-OH P) were measured in a group of 11 salt-losers with congenital adrenal hyperplasia (21-OH-deficiency) aged 5–20 years, treated with oral hydrocortisone and under a constant sodium diet. A group of 7 non salt-losers and 10 normal children were evaluated for comparison. Salt-losers had mean baseline concentrations of PA, PRA, and 17-OH P that were significantly higher (P < 0.02, P < 0.05, and P < 0.001, respectively) than in normal controls, but comparable to non salt-loser levels. In salt-losers, a positive correlation (P = 0.01) was found when PA was plotted against chronological age. ACTH was unable to raise PA in salt-losers, but there was a normal rise in non salt-losers. The addition of 9α-fluorocortisol (9α-FF) (100 μg/ 24 h for 7–13 months) succeeded in lowering mean PA and PRA to normal levels in 8 salt-losing patients. The same was observed in 4 non salt-losers, with, in addition, a blunted PA response to ACTH. In the two patient groups, the mean basal 17-OH P value was lowered and a similar decreased response to ACTH was observed. These data indicate that: 1) there is an increased secretion of aldosterone suggesting an increase in adrenal activity closeto or during puberty in salt-losers which parallels that of non salt-losers, 2) this increased PA could play a role in the apparent remission of salt-loss in patients off mineralocortdcoid treatment, but it is not capable of preventing saltlosing crises as reflected by the impaired post-ACTH PA response, and 3) blunted PA and 17-OH P responses to ACTH were observed during 9α-FF administration. (J Clin Endocrinol Metob45: 551, 1977)