Normal ACTH levels in saltlosing congenital adrenal hyperplasia (CAH) with elevated plasma renin concentration (PRC). The effect of mineralocorticoid treatment

Abstract

Eleven patients with salt losing CAH (21 OH deficiency), aged 5-19 years were treated with cortisone 20-55 mg/m²/24 h in 3 divided doses and supplementary salt. Normal (< 60 m.i.u./1) and moderately raised (133, 140 m.i.u./1) PRC values in 4 patients were compatible with good control - normal excretion of pregnanetriol (Ptriol). High PRC values (153-522 m.i.u./1) were found in connection with high values of Ptriol (6.5-34.8 μmol/24 h). Plasma Aldosterone (PA) was 3-11 (control values <18) ng/100 ml. Normal ACTH values (11-82 pg/ml) were found in all patients - in one pt. with high PRC (522 m.i.u./1) ACTH was 99 pg/ml.

During maintenance of cortisone therapy, mineralocorticoid (Florinef^(R) was added to the treatment. The dose was gradually increased over a period (median 15 months) up to 1-4 μg/kg/24 h (2 doses) and normal PRC values were established. PA decreased significantly to values below 4 ng/100 ml. Ptriol excretion decreased markedly (to 0.4 -69 μmol/24 h). ACTH values were still in the normal range. During the observation period no change in growth velocity could be demonstrated.