Should plasma prolactin assay be routinely performed in the assessment of erectile insufficiency? Report of a series of 445 patients and review of the literature

Objective : To define the value of plasma prolactin assay in the assessment of erectile insufficiency. Material and Methods : Plasma prolactin assay (radioimmunoassay) was perfor med in 445 patients presenting, with erectile insufficiency (mean age 52.5 years). Results : 9 patients (2%) presented plasma prolactin levels greater than 25 ng/ml and 4 (0.9%) of them had levels higher than 35 ng/ml. Eight of these 9 patients were taking hyperprolactinaemic drugs. The aetiology remained u nclear in 1 patient, but the pituitary gland was normal on CT scan. Review of the literature : In the population of men with erectile insuffici ency, 2.7% of subjects have plasma prolactin levels greater ter than 20 or 25 ng/ml. 1.3% have levels greater than 35 or 40 ng/ml and 0.6% present pit uitary tumours. In the case of pituitary tumours responsible hyperprolactin amia and erectile insufficiency : 1) plasma prolactin is greater than 30 ng /ml in 90% of cases and greater than 50 ng/ml in 83% of cases; 2) total pla sma testosterone is less than 3 ng/ml ii? 88% of cases and less than 4 ng/m l in 96% of cases; 3) libido is decreased in 90% of cases. Conclusion : The prevalence of hyperprolactinemia and pituitary tumours in the population of men with erectile insufficiency is low. Moreover, certain criteria are suggestive of hyperprolactinemia especially when it is second ary to a pituitary tumour. Consequently routine plasma prolactin assay is n ot justified. This assay should only be performed when libido is impaired, total plasma testosterone is decreased or when the patient presents certain signs such as headache, gynaecomastia or visual disturbances.