Effects of insulin-like growth factor I and growth hormone in cultured human granulosa cells

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

CONTEXT:

Insulin-like growth factor-1 (IGF-1) has been reported to play a role in human follicular and embryonic development. However, earlier studies carried out mostly in animal models or in culture mediums supplemented with IGF-1 have been unable to directly link IGF-1 with embryo quality. Results correlating IGF-1 with pregnancy outcome have also been ambiguous so far.

AIM:

The aim of this study is to find if in situ follicular-fluid level of IGF-1 is predictive of embryo quality and implantation rates in in vitro fertilization (IVF) cycles.

SETTINGS AND DESIGN:

Prospective study involving 120 cycles of conventional IVF-embryo transfer in infertile women.

SUBJECTS AND METHODS:

IGF-1 concentrations were estimated in pooled follicular-fluid on the day of oocyte-pickup. Embryo quality was assessed daily at different developmental stages. Cycles were sorted into low and high follicular fluid insulin-like growth factor-1 (FF IGF-1) groups according to the median value of measurement. Embryo quality, clinical pregnancy and implantation rate were the main outcome measures.

STATISTICAL ANALYSIS:

Graph-pad Prism 5 statistical package.

RESULTS:

FF IGF-1 correlates with embryo quality (Pearson r = 0.3894, r² = 0.1516, P > 0.0001) and clinical pregnancy (Pearson r = 0.5972, r² = 0.36, P > 0.0001). High FF IGF-1 group shows significantly higher rates of fertilization, cleavage, blastocyst formation and top grade embryos compared with low FF IGF-1 group. Clinical pregnancy rates (38.33 vs. 20%, P = 0.0272) and embryo implantation rates (21.6 vs. 10.32%, P = 0.0152) are also significantly higher in the high versus low FF IGF-1 group. Threshold value of FF IGF-1 for clinical pregnancy is <58.50 ng/mg protein (receiver operating characteristics _AUC : 0.85 ± 0.03, 95% CI: 0.78-0.91).

CONCLUSION:

FF IGF-1 is a plausible biochemical marker of embryo quality and implantation rate and correlates with clinical pregnancy rates in conventional IVF cycles.

Polycystic ovary syndrome in adolescents

BACKGROUND

Polycystic ovary syndrome (PCOS) is the commonest endocrine disorder in women and typically presents during adolescence. The clinical and biochemical presentation is heterogeneous, but elevated serum concentrations of androgens are the most consistent biochemical abnormality and may be considered to be the hallmark of the syndrome. Many women with PCOS also have insulin resistance and hyperinsulinaemia, which may contribute to the clinical and endocrine abnormalities. The aetiology of PCOS is not clear but studies in the Rhesus monkey suggest that exposure to excess androgen during intrauterine life results in many of the features of human PCOS, including ovarian dysfunction, abnormal LH secretion and insulin resistance.

OBJECTIVE

To review the studies from the literature, including those of the author, regarding aetiology, presentation and management of PCOS in adolescents.

RESULTS AND CONCLUSIONS

We have proposed that PCOS in adolescents arises as a result of a genetically determined disorder of ovarian function that results in hyper-secretion of androgens, possibly during fetal life and also during physiological activation of the hypothalamic-pituitary-ovarian in infancy and at the onset of puberty. There is plentiful evidence for a genetic basis for PCOS (it appears to be a complex endocrine disorder resulting from the effects of a several genes), but environmental factors, notably nutrition, influence the clinical and biochemical phenotype. Obesity unmasks or amplifies symptoms, endocrine and metabolic abnormalities. The increasing incidence of childhood obesity has resulted in an alarming Increase not only in distressing symptoms but also impaired glucose tolerance and even diabetes among adolescent girls with PCOS. The search for PCOS genes in this condition, that is not only heterogeneous but also presents only in women of reproductive age, is not straightforward and has produced few convincing candidates so far. In due course, however, identification of the major susceptibility loci is likely to provide key insight into the aetiology of the syndrome and improve diagnosis and management.

Apoptosis of cultured granulosa-lutein cells is reduced by insulin-like growth factor I and may correlate with embryo fragmentation and pregnancy rate

OBJECTIVE

To correlate apoptosis of cultured human granulosa-lutein cells (GL cells) with the outcome of IVF (embryo fragmentation and pregnancy rate) and to study the effect of insulin and insulin-like growth factor I (IGF-I) on apoptosis.

DESIGN

In vitro assays.

SETTING

University laboratory and private IVF center.

PATIENT(S)

Eighty-one women undergoing IVF.

INTERVENTION(S)

Purified human GL cells from pooled follicles were cultured for 48 hours in serum-free media with or without insulin and IGF-I. Cumulus cells and mural GL cells were evaluated separately.

MAIN OUTCOME MEASURE(S)

Detection of apoptosis by using caspACE FITC-VAD-FMK, a fluorescent in situ marker for activated caspases; embryo fragmentation; and pregnancy.

RESULT(S)

Age younger than 38 years and successful pregnancy were associated with less apoptosis (33.0% +/- 17.2% vs. 43.2% +/- 18.0% and 30.2% +/- 14.0% vs. 40.4% +/- 19.5%, respectively). There was a linear correlation between embryo fragmentation and GL cell apoptosis. Insulin-like growth factor I decreased apoptosis in a dose-dependent fashion. A statistically significant effect (17% decrease) was reached at a dose of 10 nM. Insulin (10 nM) caused a small (8%) decrease in apoptosis, but this effect did not reach statistical significance. Cumulus cells consistently had <3% apoptosis.

CONCLUSION(S)

[1] Apoptosis of cultured GL cells may be associated with IVF outcome and ovarian reserve and [2] IGF-I decreases apoptosis of cultured GL cells.