Efficacy of thyroxine treatment in women with reproductive disorders and hyperprolactinemia developed on the background of primary hypothyroidism and correlations between prolactin and thyroid hormones

Abstract

Background: Determination of the efficacy of treatment of hyperprolactinemia developed on the background of primary hypothyroidism in women with reproductive disorders is of great medical importance.

Aim: To determine effectiveness of performed treatment with thyroxine in women with hyperprolactinemia developed on the background of primary hypothyroidism and determination of correlations between prolactin and other hormones before and after treatment in women with hyperprolactinemia developed on the background of primary hypothyroidism.  

Methods: Prospective cohort study was conducted at the Center for Reproductive Medicine "Universe" and the clinic ‘’Medhealth’’ during 2016-2018. Study involved 52 untreated women with hyperprolactinemia developed on the background of primary hypothyroidism. Medical history was analyzed with each of them. Objective investigations were conducted. Prolactin (PRL), thyroid stimulating hormone (TSH), free thyroxine (FT4), anti–thyroid peroxidase (anti-TPO), follicle stimulating hormone(FSH), luteinizing hormone (LH), estradiol (E2), total testosterone (TT), free testosterone (FT) and progesterone were studied in blood serum in dynamics with immunoassay analysis (ELISA) method. Ultrasound examination of pelvic organs and thyroid gland was performed. In all cases, L-thyroxine was used continuously to treat hyperprolactinemia with dose adjustment in dynamics. In patients with whom despite stable compensation of hypothyroidism, prolactin levels were not normalized, dopamine agonist (bromocriptine) was included in the treatment along with continued thyroxine administration.

Results:The mean levels of PRL and TSH before treatment were significantly high compared to the reference indicators (p<0.05). Anti-TPO mean levels (p <0.05) were also significantly high compared to the reference rates, while the E2 and progesterone mean levels were significantly lower (p <0.05). Prior to treatment, there was no significant difference between mean FT4, FSH, LH, TT, FT and reference rates (p> 0.05). After the treatment PRL, TSH, and anti-TPO significantly reduced;  E2, progesteron significantly increased; FT4, FSH, LH, TT, FT remained within reference rates.

Conclusions: Continuous treatment with thyroxine normalized prolactin levels, regulated the menstrual cycle and restored ovulation in patients with mild hyperprolactinemia developed on the  background of primary hypothyroidism, which accounted for 88.9% of the women involved in the study. Despite stable compensation of hypothyroidism achieved with thyroxine replacement therapy, no normalization of prolactin levels was observed in 11.1% of patients with moderate hyperprolactinemia developed on the background of primary hypothyroidism and a dopamine agonist was included in the treatment, after which the prolactin level normalized, menstrual cycle regulated and ovulation restored. Prior to treatment, significant positive correlation of prolactin with TSH and significant negative correlation with E2 and Progesterone was detected in women with hyperprolactinemia developed on the background of primary hypothyroidism. Significant correlation of prolactin with FT4, anti-TPO, FSH, LH, TT and FT was not detected. After the treatment significant correlation was determined only between prolactin and TSH.