Intrafollicular and Circulating Concentrations of Leptin Do Not Predict the Outcome in IVF-ICSI Cycles

The follicular levels of adipokines and their ratio as the prognostic markers of in vitro fertilization outcomes

INTRODUCTION

Adipokines are involved in the regulation of the female reproductive system. The purpose was to study the possibility of using adipokines levels in the follicular fluid to predict IVF efficiency.

MATERIALS AND METHODS

Four groups of women were studied: pregnant during IVF, with normal (PN, n = 9) and increased (BMI > 25 kg/m²) body weight (BW) (PI, n = 7), and nonpregnant during IVF, with normal (nPN, n = 16) and increased BW (nPI, n = 21).

RESULTS

In PN group, leptin level was higher than in nPN group (p < .05). In the PI and nPI groups, it did not differ, but was higher than in women with normal BW. In PN group, ghrelin level was lower than in nPN group (p < .05), while in the PI and nPI groups it was comparable. The leptin/ghrelin ratio in PN group was higher than in nPN group (18.10 ± 3.38 vs. 3.93 ± 0.60, p < .05), but lower than in the PI (31.70 ± 15.38) and nPI (24.30 ± 3.45) groups. The leptin/adiponectin ratio in PN group was also higher than in nPN group (6.97 ± 0.64 vs. 2.95 ± 0.39, p < .05), but lower than in the PI (13.60 ± 1.59) and nPI (10.86 ± 0.87) groups. Adiponectin levels differed only between the nPN and nPI groups. In women with normal BW, odds ratio showed that the leptin/ghrelin ratio has the greatest prognostic value for predicting the success of IVF outcomes (OR: 29.53; CI: 1.53-570.83, p =.025) among other indicators. In women with increased BW, none of the indicators had predictive value.

CONCLUSION

The follicular leptin/ghrelin ratio is a suitable indicator for predicting IVF outcomes in women with normal BW.

Association of serum and follicular fluid leptin and in vitro Fertilization/ ICSI outcome: A systematic review and meta-analysis

There are conflicting reports regarding circulating leptin and its relationship between pregnancy outcomes in infertile women undergoing in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). We performed a systematic review and meta-analysis to assess the association between serum or follicular fluid (FF) leptin concentrations reported for infertile women and their IVF outcome. A systematic search was undertaken in available databases (PubMed, Scopus, Web of Science, The Cochrane Library and Embase) to find studies published up to Aug 2020 and the standardized mean difference with 95 % confidence interval was taken from 14 eligible studies. Both graphical (funnel plots) and test methods (Egger's regression test and the Begg) assessed the presence of publication bias. Subgroup analysis was used to investigate the source of heterogeneity. Pooled effect sizes based on the eligible papers indicated that of there is no statistically significant correlation between leptin levels in follicular fluid and serum on the day of ovum pick-up (OPU) and day of HCG (human chorionic gonadotrophin) administration in pregnant and non-pregnant women who underwent IVF/ICSI cycles. However, combination of leptin in serum and/or FF with other parameters may be a useful marker to predict IVF outcome.

Follicular fluid leptin as a marker for pregnancy outcomes in women undergoing IVF treatment: a systematic review and meta-analysis

Leptin is a hormone secreted mainly by the adipocytes with an essential role in the regulation of body weight. It acts on the reproductive axis at different sites, with stimulatory effects at the hypothalamus and pituitary and inhibitory interactions at the gonads. To investigate the influence of leptin on pregnancy outcomes in women undergoing IVF, we undertook a systematic review. A search of PubMed from 1966 to 2018 identified ten studies meeting the inclusion criteria. Outcomes were BMI, serum leptin level at hCG injection, serum and follicular fluid leptin level at the oocyte pick up, and serum 17β-oestradiol level at oocyte pick up time, oocytes retrieved and embryo transfer number. Results indicated that follicular fluid leptin concentrations at the oocyte pick up were significantly lower in women who became pregnant compared to those who did not (MD = -4.53 (ng/ml); 95% CI: -7.78, -1.78; p value < 0.006). In conclusion, elevated leptin concentrations in follicular fluid at oocyte pick up time is significantly associated with an adverse pregnancy outcome in women undergoing an IVF programme.

Leptin and its potential interest in assisted reproduction cycles

BACKGROUND

Leptin, an adipose hormone, has been shown to control energy homeostasis and food intake, and exert many actions on female reproductive function. Consequently, this adipokine is a pivotal factor in studies conducted on animal models and humans to decipher the mechanisms behind the infertility often observed in obese women.

METHODS

A systematic PubMed search was conducted on all articles, published up to January 2015 and related to leptin and its actions on energy balance and reproduction, using the following key words: leptin, reproduction, infertility, IVF and controlled ovarian stimulation. The available literature was reviewed in order to provide an overview of the current knowledge on the physiological roles of leptin, its involvement in female reproductive function and its potential interest as a prognostic marker in IVF cycles.

RESULTS

Animal and human studies show that leptin communicates nutritional status to the central nervous system and emerging evidence has demonstrated that leptin is involved in the control of reproductive functions by acting both directly on the ovaries and indirectly on the central nervous system. With respect to the clinical use of leptin as a biomarker in IVF cycles, a systematic review of the literature suggested its potential interest as a predictor of IVF outcome, as high serum and/or follicular fluid leptin concentrations have correlated negatively with cycle outcome. However, these preliminary results remain to be confirmed.

CONCLUSION

Leptin regulates energy balance and female reproductive function, mainly through its action on hypothalamic-pituitary-ovarian function, whose molecular and cellular aspects are progressively being deciphered. Preliminary studies evaluating leptin as a biomarker in human IVF seem promising but need further confirmation.

In Vitro Fertilization, Levels of Pro-Inflammatory Factors and Lipid Peroxidation

BACKGROUND

Infertility is a problem concerning 10-15% of the individuals in the fertile period. This study investigated effects of proinflammatory factors as well as lipid hydroperoxides (LPO) levels upon in vitro fertilization (IVF) success.

MATERIALS AND METHODS

In this prospective, non-randomized, controlled clinical study, sera obtained from 26 fertile (group-1), 26 infertile women before (group-2) and after (group-3) IVF treatment were analyzed. Leptin, leptin receptor, resistin, tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP) were analyzed using enzyme-linked immunosorbent assay (ELISA). LPO was determined spectrophotometrically. Mann- Whitney U test, paired samples t test, Wilcoxon signed-rank test as well as Pearson correlation analysis by SPSS were performed for statistical analysis.

RESULTS

TNF-α, resistin and LPO levels increased (P=0.020, P=0.003, P=0.001, respectively) in group-3 compared to group-2. A significant increase in LPO was noted both in group-2 and -3 compared to controls (P=0.000). LPO were higher in non-pregnants than pregnants in group-2. For pregnants, significant correlations were observed between leptin and resistin in group-2 and TNF-α and leptin in group-3. None of these correlations were found for the women, who could not conceive.

CONCLUSION

LPO, leptin-resistin correlation, associations with TNF-α may be helpful during the interpretation of IVF success rates.

Assessment of follicular fluid leptin levels and insulin resistance as outcome predictors in women undergoing in vitro fertilization-intracytoplasmic sperm injection

OBJECTIVE

To analyze follicular fluid leptin (FFL) levels, abdominal obesity, and insulin resistance as predictors of in vitro fertilization (IVF)-intracytoplasmic sperm injection (ICSI) outcome.

DESIGN

Observational study.

SETTING

Academic medical center.

PATIENT(S)

A sample of 130 infertile women aged 26-40 years without polycystic ovary syndrome.

INTERVENTION(S)

Measurement of FFL levels in controlled ovarian hyperstimulation cycles with an antagonist and agonist protocol for IVF-ICSI.

MAIN OUTCOME MEASURE(S)

Live birth rate.

RESULT(S)

Mean FFL values were significantly higher in pregnancies not ending in a live birth, even after adjustment for waist circumference and insulin resistance. A multivariable model obtained with the use of logistic binary regression analysis showed that waist circumference and insulin resistance had no influence over IVF-ICSI outcomes, but a higher number of follicles, lower serum progesterone levels on the day before α-hCG administration, and lower FFL concentrations were significantly associated with a higher probability of having a live birth. The multivariate model reached a sensitivity of 87% and a specificity of 71% for predicting the possibility of pregnancy ending in a live birth.

CONCLUSION(S)

High FFL levels were associated with abdominal obesity, insulin resistance, and a lower live birth rate after IVF-ICSI. Further investigations are warranted to define the precise roles of leptin, obesity, and insulin resistance on IVF-ICSI outcomes.

Relationship between follicular fluid adipocytokines and the quality of the oocyte and corresponding embryo development from a single dominant follicle in in vitro fertilization/intracytoplasmic sperm injection cycles

OBJECTIVE

To investigate the association of individual follicular fluid (FF) leptin and adiponectin levels with the quality of the corresponding oocyte and embryo.

METHODS

We prospectively enrolled 67 women who underwent controlled ovarian hyperstimulation with 89 FF samples. FF and the corresponding oocyte was obtained from a single dominant preovulatory follicle at the time of oocyte retrieval. Concentrations of leptin and adiponectin were measured by enzyme-linked immunosorbent assay in an individual follicle. The oocyte quality, fertilization rate, and corresponding embryo development were assessed.

RESULTS

The FF level of leptin was significantly associated with body mass index (r=0.334, p<0.01). The FF adiponectin level was significantly higher in the normal fertilization group than the abnormal fertilization group (p=0.009) in the non-obese women. A lower FF leptin level was associated with a trend toward mature oocytes, normal fertilization, and good embryo quality, although these relationships were not statistically significant. The leptin:adiponectin ratio of FF did not differ significantly according to oocyte and embryo quality. The quality of the oocyte and embryo was not associated with the FF leptin level tertile. However, the normal fertilization rate was positively associated with FF adiponectin level tertile. There was a trend towards improved oocytes and normal fertilization rates with the lowest tertile of the FF leptin:adiponectin ratio, but this difference was not statistically significant.

CONCLUSION

Our results suggest that a high FF adiponectin concentration could be a predictor of normal fertilization. However, the FF leptin concentration and leptin:adiponectin ratio is not significantly related to oocyte maturity and corresponding embryo development.

The effects of GnRH analogs on serum and follicular fluid leptin levels and pregnancy outcomes in short protocols of assisted reproductive technology

OBJECTIVE

To determine serum and follicular leptin levels in patients using gonadotropin releasing hormone agonist and antagonist in Assisted Reproductive Technology short protocol cycles and to evaluate pregnancy outcomes.

MATERIAL AND METHODS

Patients randomly selected to join assisted reproductive technology cycles during February 2004-July 2004 were enrolled in this study. Group 1 consisted of 21 patients receiving r FSH+ GnRH agonists, whereas Group 2 consisted of 34 patients who received r FSH +GnRH antagonists. During the ovulation induction period 5 serum samples were collected (induction day 1, day 3 or antagonist starting day, human chorionic hormone day, oocyte pickup day, and twelfth day of embryo transfer). Follicular fluid samples were collected to be evaluated for leptin, estradiol, prolactin and luteinizing hormone.

RESULTS

There was no difference in age, basal FSH, basal LH, and basal E2 between groups. Serum leptin levels were similar in both groups. Also, when each group's serum leptin levels were evaluated according to the presence of pregnancy, there was no significant difference in both groups. When follicle leptin levels were evaluated according to the existence of pregnancy, in both groups the follicle leptin levels were lower in pregnant participants but this difference was not statistically significant. When obesity is defined as body mass index over 26.5, there is a correlation between obesity and leptin levels in Group 2.

CONCLUSION

Our results have shown that both agonists and antagonists have similar efficacy and effect in poor responder women. Leptin levels in either groups, whether pregnant or non-pregnant were not statistically different. This result shows the need for more studies on leptin in infertility.

Intrafollicular and serum levels of leptin during in vitro fertilization cycles: comparison between the effects of recombinant follicle-stimulating hormones and human menopausal gonadotrophin

OBJECTIVES

To compare the effect of recombinant follicle-stimulating hormones (r-FSH) and human menopausal gonadotrophin (hMG) on leptin levels in serum and follicular fluid (FF) during in vitro fertilization IVF/ET treatment, and to investigate whether leptin levels in the follicular fluid and/or serum are correlated with IVF success.

METHODS

Sixty-three patients undergoing IVF cycle were subdivided into two groups. r-FSH was used to for controlled ovarian hyperstimulation in 29 patients (Group A) while, hMG was used in 34 patients (Group B). Our main outcomes were serum and FF leptin on the day of oocyte collection.

RESULT(S)

The two groups were comparable in age, body mass index (BMI), indications for IVF/ET, E2 level on human chorionic gonadotrophin day, number of retrieved oocytes, fertilization rate, number of transferred embryos and pregnancy rate. Serum and FF leptin levels were similar between the two study groups. Additionally, no correlation was found between levels of leptin in either serum or FF and cycle results such as: number of retrieved oocytes, fertilization rate and pregnancy rate.

CONCLUSIONS

r-FSH and hMG have been found to have comparable effects on leptin levels in the serum and the FF of patients undergoing IVF/ET. Additionally, leptin levels in both serum and FF on day of retrieval have no correlation to IVF/ET outcome.

Expression of leptin receptor mRNA in cumulus cells is correlated with expression of PTX3

This study investigated the role of the leptin system in human oocyte maturation and its prognostic value for IVF outcome. The protein concentrations of leptin and soluble leptin receptor in follicular fluid were determined and the free leptin index (FLI) were established. Additionally, mRNA expression levels of different leptin receptor (ObR) isoforms and of PTX3 and HAS2 in cumulus cells were quantified, mutually compared and analysed relative to FLI, body mass index, age and number of retrieved oocytes. Expression of all target genes was detected in the cumulus cells, with relatively low concentrations of ObR-Long. Strong mutual correlations were found between mRNA expression levels of leptin receptor isoforms (P < 0.001) and also between the short isoforms of the leptin receptor and PTX3 (P < 0.001). Although the mean values of the pregnant and non-pregnant groups did not differ significantly for any of the variables, the chance that treatment resulted in ongoing pregnancy was higher with leptin 0.5 ng/mg protein compared with concentrations >0.5 ng/mg protein (P < 0.05). It is concluded that the leptin system appears to play a role in the IVF protocol, whereby signal transduction in cumulus cells occurs predominantly via the short isoforms of ObR.