Increased androgen secretion in patients with prolactinomas: the impact of altered HPA function

Earlier studies suggested that hyperprolactinemia was associated with elevated serum DHEA-S levels. The importance of DHEA-S measurements in the diagnosis of adrenal insufficiency prompted us to assess adrenal androgen levels in hyperprolactinemic subjects with normal or impaired function.

Prospective study including 122 medically treated and 26 surgically patients with prolactinomas. Serum PRL, DHEA and DHEA-S levels were measured before and repeatedly after cabergoline therapy and also in the perioperative period of surgically treated patients.

Serum PRL levels decreased (P < 0.001) in all 101 medically treated patients with normal HPA function from 728.3 ± 1507 reaching 29.1 ± 39 and 14.9 ± 24.4 µg/L at 3 and 12 months, respectively. Concurrently serum DHEA-S levels decreased (P < 0.001) from 245.9 ± 196 to 216.2 ± 203.3 and to 169.7 ± 121.1 µg/dl at 3 and 12 months, respectively. These effects were reversed in 19 patients who discontinued treatment and were re-demonstrated after therapy resumption. Among the 22 surgically treated patients with normal HPA, peri-operative PRL levels decreased rapidly (P < 0.001) with a parallel decline in serum DHEA-S levels (P = 0.03). Strong correlations were noted between PRL and DHEA-S decrements observed with medical or surgical therapy. Medically (n = 21) and surgically (n = 4) patients with impaired HPA function had very low DHEA-S values that were unchanged despite marked reductions in PRL secretion.

Hyperprolactinemia is associated with a reproducible and reversible increase in serum DHEA-S that was observed in medically- and surgically-treated patients with normal HPA function. Thus, a normal age- and gender-adjusted serum DHEA-S level continues to imply normal HPA function even among hyperprolactinemic subjects.