Prolactin and Prostate Hypertrophy: A Pilot Observational, Prospective, Case-Control Study in Men with Prolactinoma

Abstract

In experimental models, prolactin (PRL) displays independent hypertrophic effects on the prostate. To investigate whether hyperprolactinemia is associated with prostate enlargement in humans, we designed this open, prospective, case-control study enrolling 20 men with prolactinoma (aged 34 +/- 10 yr) and 20 age-matched healthy men. The endocrine profile and prostate transrectal ultrasonography were performed before and after 12 and 24 months of cabergoline treatment in the patients and at study entry and after 24 months in the controls. The patients had lower serum testosterone, dihydrotestosterone (DHT), and IGF-I levels and prostate volume (15.4 +/- 3.5 vs. 19.6 +/- 5.1 ml; P < 0.001) and higher PRL levels and prostate-specific antigen density than controls. There was no difference in prostate and transitional zone volumes between patients with normoandrogenemia (n = 8) or hypoandrogenemia (n = 12). After 12 and 24 months of treatment, PRL, testosterone, and DHT levels were normal in all cases, as were IGF-I and IGF-binding protein-3 levels. After 24 months, prostate volume was comparable to that in controls (21.7 +/- 4.5 vs. 22.5 +/- 4.7 ml). There were no changes in prostate structure throughout the study period in either the patients or the controls. In conclusion, in young men with prolactinoma PRL excess is unlikely to have effects on the prostate per se, because it is accompanied by low testosterone and DHT levels that produce the major effects.

PRL Secreting Adenomas in Male Patients

“…Recently Colao et al have evaluated the effects of hyperprolactinaemia and its control by dopamine agonist cabergoline on prostate structure in young men with prolactinoma [20]. We found, as expected, lower serum testosterone and dihydrotestosterone (DHT), and higher PRL levels in the patients than in the controls, but, surprisingly, the prostate volume was lower in hyperprolactinemic men than in normal subjects [20].…”

Cancer risk in hyperprolactinemia patients: a population-based cohort study

“…Furthermore, the effect of hyperprolactinemia on human prostate was evaluated in 20 men with prolactinomas, demonstrating a reduced prostate size compared with controls (31). The authors speculate that this finding is probably due to reduced testosterone and dihydrotestosterone levels found in the prolactinoma patients (31). This study is the first to report a reduced risk of prostate cancer in hyperprolactinemia patients.…”

“…In a prospective case-control study, PRL levels were measured in 144 men with prostate cancer and 289 male controls, where no association was found between PRL levels and prostate cancer (16). Furthermore, the effect of hyperprolactinemia on human prostate was evaluated in 20 men with prolactinomas, demonstrating a reduced prostate size compared with controls (31). The authors speculate that this finding is probably due to reduced testosterone and dihydrotestosterone levels found in the prolactinoma patients (31).…”

The effect of oral administration of aqueous extract of Newbouldia laevis leaves on fertility hormones of male albino rats.

“…This condition is typically manifest in males as failure in production of normal numbers of sperm. In the male, LH acts upon the Leydig cells of the testis and is responsible for the production of testosterone, an androgen that exerts both endocrine activity and intra-testicular activity on spermatogenesis (Glazener et al, 1987;Colao et al, 2004). The result shows that the aqueous extract of Newbouldia laevis boosted the FSH and LH levels in the experimental animals as represented in Table 1.…”