Plasma aldosterone concentrations related to 17alpha-hydroxyprogesterone in congenital adrenal hyperplasia

Plasma aldosterone and 17alpha-hydroxyprogesterone (17-OHP) concentrations were measured in 35 patients with congenital adrenal hyperplasia resulting from 21-hydroxylase deficiency. Ten patients had never been treated and among them were 4 salt-losing infants. Both aldosterone and 17-OHP were high in the 6 untreated non salt-losers. The values ranged respectively from 110 to 376 pg/ml and from 150 to 292 ng/ml. Results were variable in the 4 salt-losers. Three out of 5 untreated non salt-losers who were submitted to a low sodium diet, responded by doubling their aldosterone levels. When plasma 17-OHP concentrations were less than 30 ng/ml, the mean aldosterone level in the treated non salt-losers (n=6) was 15.3 pg/ml +/- 4.3 (SE). This value was not different from the mean level found in the control children (n=7), 18.8 pg/ml +/- 3.2. In the treated salt-losers (n=9), the measured aldosterone levels were less than or equal to 10 pg/ml 7 times out of 9. When the treated patients exhibited plasma 17-OHP concentrations greater than 30 ng/ml, the salt-losers (n=11) were distinguished from the non salt-losers (n=8) in that they showed as significantly lower aldosterone mean level, 24.6 pg/ml +/- 4.3 against 69 pg/ml +/- 13.4 found in the non salt-losers. The salt-losers displayed no aldosterone increases to synthetic ACTH stimulation under treatment or at the withdrawal of treatment, while positive aldosterone responses were often observed in the non salt-losers. In the latter group, studied under different conditions (with and without therapy, on low sodium diet, after ACTH test) a significant correlation was found between aldosterone and 17-OHP levels expressed in log. values, (n=38, r=0.80, P less than 0.001). The relationship could also be established with the values obtained from all the salt-losers, but it was less significant, (n=35, r=0.46, P less than 0.02).