Insulin and insulin-like growth factor I in follicular fluid after induction of ovulation in women undergoing in vitro fertilization

Abstract

This study was undertaken to evaluate the relationship between concentrations of insulin and insulin-like growth factor I (IGF-I) in follicular fluid and fertilization and cleavage of human oocytes fertilized in vitro. The concentration of oestradiol, progesterone, luteinizing hormone, follicle-stimulating hormone, testosterone, insulin and IGF-I was determined in 36 follicular fluids, free of visible blood contamination and containing mature oocyte-corona-cumulus complexes, obtained from 12 women undergoing in vitro fertilization. Follicular development was induced by clomiphene citrate and human menopausal gonadotrophin, and follicular aspiration was performed 35 h after an ovulatory dose of human chorionic gonadotrophin. Concentrations of IGF-I were significantly higher in follicular fluids associated with mature oocytes that fertilized and cleaved, than in follicular fluid associated with mature oocytes that did not fertilize (P < 0.001). There was no difference in the concentration of insulin between follicular fluids from which fertilized oocytes were obtained and those with oocytes that remained unfertilized. No significant correlations were found between rates of embryo cleavage, concentrations of insulin and IGF-I. Multiple linear regression analysis demonstrated that the concentrations of IGF-I in follicular fluid were predicted statistically by a negative regression coefficient for the concentration of testosterone, and by a positive regression coefficient for the concentration of progesterone in follicular fluid. No candidate variable was included in the model to predict concentrations of insulin. These data suggest an important role for IGF-I in the mature follicle.

Follicular fluid insulin like growth factor-1 (FF IGF-1) is a biochemical marker of embryo quality and implantation rates in in vitro fertilization cycles

“…Two earlier studies,[2627] had linked FF IGF-1 with follicular development and oocyte maturation but found no significant correlation with embryo cleavage rates. Bencomo et al (2006)[28] reported a dose dependent decrease in the rate of apoptosis of human granulosa lutein (GL) cells and embryo fragmentation rates.…”

“…[192021] Human studies with IGF-1 have mostly employed in vitro cell culture techniques,[222324] with exogenous supplementation instead of its estimation in in situ sources like FF. [25] A definitive role of IGF-1 in FF has not yet been established or is poorly understood with conflicting reports,[2627282930] on its predictive values. Moreover, no approach has yet been made to directly correlate FF IGF-1 with embryo quality.…”

Efficacy of ER-α Polymorphisms and the Intrafollicular IGF System for Predicting Pregnancy in IVF-ET Patients

“…A study on FF markers to predict an implantation potential of embryos showed that mean intrafollicular concentrations of IGF-I were significantly higher in patients who became pregnant versus those who failed to establish a pregnancy [16] . Moreover, higher FF IGF-I concentrations were associated with mature oocytes that would be fertilized and cleaved, which might indicate an important role for IGF-I in the mature follicle [20] . In addition, FF IGF-I concentrations were found to be significantly correlated with increasing follicular size and were significantly higher in follicles with mature oocytes than in follicles with atretic oocytes [21] .…”

“…Moreover, mean FF concentrations of IGF-I and IGFBP-1 were significantly lower in those with a reduced ovarian reserve with no change in E 2 or IGF-II levels [18] . The ratio of IGF-I/ IGFBP-1 in FF was found to be correlated with pregnancy rates, indicating that both IGF-I and IGFBP-1 could be used as indicators of oocyte quality and oocyte maturity [17,[19][20][21] .…”

Chemotactic Effect of Hormones in Mouse Spermatozoa

“…The role of insulin in synthesis of oxytocin in granulosa cells has been studied in recent years [17]. However, very little is known about the relationship between concentrations of insulin and oxytocin in follicular fluid and parameters of oocyte quality and roles of these hormones in the fertilization process [20].…”