The ratio of androstenedione:11 beta-hydroxyandrostenedione is an important marker of adrenal androgen excess in women.

To determine if the ratio of serum androstenedione (A):11 beta-hydroxyandrostenedione (OHA) would be helpful in differentiating adrenal from ovarian hyperandrogenism. Prospective study of outpatients being evaluated for hyperandrogenism. Normal women (n = 27), those with hyperandrogenic chronic anovulation (n = 25), and 7 with adult onset of congenital adrenal hyperplasia (CAH) because of 21-hydroxylase deficiency. Fasting serum between 8:00 A.M. and 9:00 A.M. Patients with hyperandrogenic chronic anovulation and CAH received dexamethasone (DEX) 2 mg for 7 days. Serum testosterone (T), unbound T, dehydroepiandrosterone sulfate (DHEAS), A, and 11 beta-OHA by radioimmunoassay. Serum 11 beta-OHA and DHEAS were elevated in 52% and 40% of patients with hyperandrogenic chronic anovulation and in 7 of 7 and 1 of 7 patients with CAH. The ratio of A:11 beta-OHA was significantly higher (P less than 0.05) in hyperandrogenic chronic anovulation and significantly lower (P less than 0.05) in CAH compared with controls. Serum A:11 beta-OHA correlated with T (r = 0.58, P less than 0.05). The ratios of A:11 beta-OHA were similar and significantly lower in CAH and hyperandrogenic chronic anovulation patients who were DEX sensitive compared with those who were not DEX sensitive. The ratio correlated with the percentage suppression of T, unbound T, and A after DEX (P less than 0.01). There were no differences with measurements of DHEAS and 11 beta-OHA. Using the mean ratio of controls (1.3) as a cutoff value, the sensitivity of the A:11 beta-OHA in detecting adrenal hyperandrogenism, as assessed by DEX sensitivity, was 100%, the specificity was 84%, and the predictive value was 67%. The ratio of A:11 beta-OHA appears to be an excellent marker for identifying patients with adrenal hyperandrogenism and CAH.