Sleep-dependent hyperprolactinemia and Corpus luteum pathogenesis

The results obtained in wake and sleep conditions by PRL determinations performed in 6 normoprolactinemic infertile women with luteal phase deficiency (LPD) are reported. Infertility was apparently due to LPD. PRL levels were determined by RIA in blood samples collected at 20-min intervals from 18(00) to 08(00). LPD has been previously demonstrated by endometrial biopsy, basal temperature and circulating progesterone determinations. PRL levels were also determined in 5 normal women used as control subjects under the same experimental conditions. The results obtained, expressed as means +/- SD of LPD vs. control group, were 15.9 +/- 4.6 vs. 11.6 +/- 3.3 ng/ml (p greater than 0.1) in wake conditions and 31.9 +/- 5.9 vs. 21.4 +/- 5.7 ng/ml (p less than 0.01) in sleep conditions. PRL values during the highest pulse (HP) in sleep and wake conditions were 20.9 +/- 5.2 vs. 17.0 +/- 3.3 ng/ml (p less than 0.1) and 51.1 +/- 17.1 vs. 34.3 +/- 2.4 ng/ml (p less than 0.01), respectively. In 2 out of the 6 patients mean PRL values were 22.0 and 26.5 ng/ml during sleep, and 26.0 and 33.0 ng/ml during HP. These values were not statistically significant when compared with those obtained in the control group. The results obtained show that 4 out of the 6 patients with LPD and normal PRL levels in wake conditions had sleep-dependent hyperprolactinemia due to the pulses with a more significant amplitude. These findings suggest that in some cases sleep-induced hyperprolactinemia might be involved in LPD pathogenesis.