Effect of Superovulation with Human Menopausal Gonadotropins on Growth Hormone Levels in Women*

Abstract

GH synthesis and secretion are influenced by several factors, including age, body weight, and sex steroid hormones. Endogenous and exogenous estrogens influence the circulating levels of GH. The purpose of the present investigation was to define the relationship between serum GH and estradiol levels during the follicular phase in women with normal ovulatory menstrual cycles compared with that in women undergoing superovulation with human menopausal gonadotropins (hMG) alone or hMG plus GnRH agonists during treatment for infertility. Serum GH and estradiol levels were determined by immunoassay in eight women during the follicular phase of a spontaneous natural cycle (group I). Thirty women underwent ovulation induction with hMG alone (group II), and 30 women received GnRH agonists followed by hMG (group III). During the follicular phase estradiol levels increased gradually in group I and reached a peak estradiol level of 1.19 +/- 0.2 nmol/L (mean +/- SEM). As expected, estradiol levels rose faster and reached higher levels in groups II and III (5.44 +/- 0.62 and 8.73 +/- 0.91 nmol/L, respectively). Whereas serum GH levels increased minimally in group I, reaching a peak level of 2.54 +/- 1.15 nmol/L, serum GH concentrations increased markedly after day 8 in groups II and III, reaching peak levels of 8.70 +/- 1.58 and 7.54 +/- 1.12 nmol/L, respectively (P less than 0.01). Basal to peak GH levels were higher in groups II and III than in group I. In summary, there are modest increases in GH levels during the follicular phase of the normal menstrual cycle, but the levels are markedly increased during superovulation with hMG or hMG plus GnRH agonists, and parallel increases in estradiol levels.

Oral Estradiol Administration Modulates Continuous Intravenous Growth Hormone (GH)-Releasing Peptide-2-Driven GH Secretion in Postmenopausal Women1

“…Serum E 2 concentrations approximate those observed in the late follicular or preovulatory phase of the normal menstrual cycle (4,6,(41)(42)(43), but are less than values achieved in typical ovulation-induction regimens (42). In both contexts, serum GH concentrations rise to the degree recorded here.…”

Growth Hormone Secretory Dynamics Over the Menstrual Cycle.

“…Superovulation with resultant grossly elevated serum estrogen levels results in a two-to four-fold increase in mean daily GH concentration [25,26] . Serum IGF-I also falls during superovulation.…”

“…Only women with regular spontaneous menstrual cycles as confirmed by menstrual diary for at least two months prior to the study were included. Women were studied during the early follicular (EF) phase of the cycle (days 2-5 after the onset of menstrual bleeding), periovulatory phase (P0, 16 to 14 days prior to next expected menses) and luteal phase (days [24][25][26].…”

Pituitary Growth Hormone Secretion and Cell Growth Hormone Production: Regulation of Their Secretion and Their Signaling Pathways

“…But this can change throughout the menstrual cycle, as described before. Pulsatile GH release in women is doubled in the late follicular stage [138], and when estrogens are administered for superovulation, GH release is significantly increased [139]. Moreover, treatment of men with diethylstilbestrol (a potent estrogen) induces a change in the pulsatile pattern of GH release similar to that commonly seen in females [140].…”