Prolactin secretion in polycystic ovary syndrome (PCOS)

Hyperprolactinemia and polycystic ovary syndrome (PCOS) are on the list of the most frequent causes of female infertility. Both pathologies are characterized in common by several clinical features. At the same time, there are essential discrepancies in medical literature on mutual relations between PCOS and hyperprolactinemia. The objective of our study was to answer several questions, e.g. about frequency of hyperprolactinemia in PCOS patients, typical concentrations of prolactin (Prl) in PCOS patients vs women without polycystic ovaries and/or an assessment of circadian Prl level profiles vs single Prl sampling, as regards diagnostic usefulness.

The study was retrospective analysis of medical records of female patients in whom nine (9) points daily profile of prolactinemia had been performed.

Prl levels appeared to be slightly higher in women without PCOS but the difference did not reach a border of statistical significance. The incidence of elevated Prl concentrations in 8:00 AM and 11:00 AM samples was higher in women without PCOS than in PCOS patients (32.0% vs 16.3% - 8:00 AM, and 8.5% vs 4.6% - 11:00 AM, respectively). Also, elevated mean daily prolactinemia, assessed as area under the curve (AUC) of Prl concentrations, was more frequent in the group of women without PCOS than in those with PCOS (22.0% vs 13.9%).

Polycystic overy syndrome is not associated with higher levels of Prl, measured in daily profiles. Hyperprolactinemia does not seem to be more frequent in PCOS women than in healthy subjects and it should not be considered as characteristic feature of PCOS - both are distinct clinical entities. Prolactin concentrations should be assessed in each woman with PCOS suspicion because of certain common clinical signs in both disorders. Every woman diagnosed with PCOS and hyperprolactinemia should further be examined in terms of the actual causes of hyperprolactinemia because the coexistence of these two disease entities - as distinct - is also possible.