The effect of myo-inositol/di-chiro-inositol on markers of ovarian reserve in women with PCOS undergoing IVF/ICSI: A systematic review and meta-analysis

Myo-Inositol and Its Derivatives: Their Roles in the Challenges of Infertility

Myo-inositol (MYO) and D-chiro-inositol (DCI) are the two most significant isomeric forms of inositol, playing a critical role in intracellular signaling. MYO is the most abundant form of inositol in nature; DCI is produced from MYO through epimerization by an insulin-dependent enzyme. Recently, it has been demonstrated that inositol may influence oocyte maturation and improve intracellular Ca2+ oscillation in the oocytes, and it has been proposed as a potential intervention for restoring spontaneous ovulation. The MYO concentration in human follicular fluid is considered a bioindicator of oocyte quality. In the ovary, DCI modulates the activity of aromatase, thus regulating androgen synthesis. Under physiological conditions, the MYO/DCI ratio is maintained at 40:1 in plasma. In women with PCOS, the MYO/DCI ratio is lowered to 0:2:1, contributing to elevated androgen production. By regulating FSH signaling, MYO administration increases the number of high-quality embryos available for transfer in poor responder patients. Finally, by acting downstream to insulin signaling, inositol administration during pregnancy may represent a novel strategy for counteracting gestational diabetes. These findings show that diet supplementation with inositol may be a promising strategy to address female infertility and sustain a healthy pregnancy.

Inositols and female reproduction disorders: a consensus statement from the working group of the Club of the Italian Society of Endocrinology (SIE)-Women's Endocrinology

PURPOSE

To provide the latest scientific knowledge on the efficacy of inositols for improving reproductive disorders in women with and without polycystic ovary syndrome (PCOS) and to reach a consensus on their potential use through a Delphi-like process.

METHODS

A panel of 17 endocrinologists and 1 gynecologist discussed 4 key domains: menses irregularity and anovulation, fertility, pregnancy outcomes, and neonatal outcomes.

RESULTS

A total of eight consensus statements were drafted. Myo-inositol (Myo) supplementation can be used to improve menses irregularities and anovulation in PCOS. Myo supplementation can be used in subfertile women with or without PCOS to reduce the dose of r-FSH for ovarian stimulation during IVF, but it should not be used to increase the clinical pregnancy rate or live birth rate. Myo supplementation can be used in the primary prevention of gestational diabetes mellitus (GDM), but should not be used to improve pregnancy outcomes in women with GDM. Myo can be preconceptionally added to folic acid in women with a previous neural tube defects (NTD)-complicated pregnancy to reduce the risk of NTDs in newborns. Myo can be used during pregnancy to reduce the risk of macrosomia and neonatal hypoglycemia in mothers at risk of GDM.

CONCLUSION

This consensus statement provides recommendations aimed at guiding healthcare practitioners in the use of inositols for the treatment or prevention of female reproductive disorders. More evidence-based data are needed to definitively establish the usefulness of Myo, the appropriate dosage, and to support the use of D-chiro-inositol (DCI) or a definitive Myo/DCI ratio.

Effectiveness of Myo-Inositol on Oocyte and Embryo Quality in Assisted Reproduction: Systematic Review and Meta-Analysis of Randomized Clinical Trials

INTRODUCTION

We sought to conduct a systematic review and meta-analysis of randomized clinical trials (RCTs) to evaluate the impact of myo-inositol on oocyte and embryo quality in women undergoing assisted reproduction.

METHODS

The systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 checklist (registration number: CRD42023433328). Studies were identified by searching PubMed, Cochrane Library, Google Scholar, Scopus, Embase, and ClinicalTrials databases.

RESULTS

Eight RCTs were included for qualitative analysis reporting on 820 participants. Four meta-analyses were performed. Numbers of retrieved oocytes in comparison of intervention and control group were higher in inositol group (mean difference [MD] = 0.41, 95% CI: 0.05-0.77, p = 0.02). Meta-analysis of two studies comparing numbers of oocytes among poor ovarian responder patients showed no significant difference between intervention and control group (MD = 0.50, 95% CI: 0.57-1.58, p = 0.36). Miscarriage rate has no statistically significant difference between the treatment and control groups (risk ratios [RRs] = 0.81, 95% CI: 0.20-3.32, p = 0.77). Inositol played no role in improving clinical pregnancy rates; there was no significant difference between the intervention group and the control group (RR = 1.41, 95% CI: 0.88-2.25, p = 0.15).

CONCLUSION

Thus, we did not find any benefits of using myo-inositol on oocyte and embryo quality in women undergoing reproductive technologies. Further studies are needed to assess efficacy, safety, and high compliance by female patients.

A Literature Review and a Proposed Classification of the Relationships between Ovulatory Infertility and Lifestyle Factors Based on the Three Groups of Ovulation Disorders Classified by WHO

Ovulatory infertility is a serious clinical problem whose direct causes are still largely unknown. In addition to pathologies that make it impossible for a couple to establish a pregnancy, there are a number of other factors that have a bearing on fertility, including lifestyle factors, and particularly diet. Although numerous studies have been performed linking such factors to ovulatory infertility, most of them lack the necessary clinical significance, instead focusing on observational data and suggesting or establishing associative relationships. This article consists of a literature review focusing on connections between lifestyle factors such as diet, physical exercise, oxidative stress, sleep, and supplementation, and ovulatory infertility. Special emphasis was given to issues such as obesity and insulin resistance and their mutual relationship with other factors linked to ovulatory infertility. In addition, based on the conclusions of the literature review, the authors have proposed a classification of relationships between ovulation disorders and lifestyle factors in ovulatory infertility within the framework of the WHO classification of ovulation disorders. Furthermore, areas that merit further research have been indicated as well as those that do not. WHO Group II disorders gained prominence in the results of the study as the number of links with lifestyle factors and ovulatory infertility found in the course of the review greatly exceeded those for Groups I and III. The data presented in the article show that the issues of proper diet and physical exercise are those that could benefit from robust clinical studies focused specifically on ovulation infertility, while studies concerning the relationship between oxidative stress, sleep, and supplementation and ovulatory infertility do not seem to be promising directions as far as clinical significance is concerned.

Effects of nutrition on metabolic and endocrine outcomes in women with polycystic ovary syndrome: an umbrella review of meta-analyses of randomized controlled trials

CONTEXT

Numerous meta-analyses have been conducted on the effects of nutritional interventions on various health outcomes in women with polycystic ovary syndrome (PCOS). However, the strength of the evidence and its clinical significance are unclear.

OBJECTIVE

This umbrella review aimed to summarize the effects of nutritional interventions on women with PCOS and assess the strength of the evidence.

DATA SOURCES

PubMed, Scopus, and Web of Science were searched from inception until March 17, 2021.

DATA EXTRACTION

Meta-analyses of randomized clinical trials (RCTs) that examined the impact of dietary modifications or supplementations on women with PCOS were selected. Data extraction, quality assessments of the meta-analyses, and evaluation of the strength of the evidence were conducted independently by 2 investigators and confirmed by a third.

DATA ANALYSIS

Twenty-eight RCT meta-analyses were included, reporting 40 different outcomes. Lower carbohydrate, Dietary Approaches to Stop Hypertension, or lower glycemic index/load diets in women with PCOS significantly improved some anthropometric and metabolic characteristics (with very low to low certainty). Probiotics/synbiotics reduced fasting plasma glucose, fasting insulin (FI), and homeostasis model assessment-estimated insulin resistance (HOMA-IR) (with moderate to high certainty). Curcumin supplementation decreased fasting plasma glucose, FI, and HOMA-IR (with moderate certainty). Fish oil supplementation decreased FI and HOMA-IR, and omega-3 reduced triglycerides (with moderate certainty). There were also improvements in FI after taking vitamin D or inositol supplements (with moderate certainty). Supplementation with fish oil increased adiponectin (with high certainty), and probiotics/synbiotics reduced total testosterone (with moderate certainty). In subfertile women with PCOS, inositol increased the ovulation rates (with moderate certainty).

CONCLUSION

There was no high-certainty evidence that diets alone in women with PCOS improved health or reproductive outcomes. Supplementation with vitamin D, probiotics/synbiotics, omega-3, inositol, and curcumin showed favorable effects on some metabolic outcomes. Probiotics/synbiotics possibly reduces total testosterone, and inositol stimulates ovulation in women with PCOS.

REGISTRATION

PROSPERO registration no. CRD42021251496.

Efficacy of Myo-inositol on Anthropometric, Metabolic, and Endocrine Outcomes in PCOS Patients: a Meta-analysis of Randomized Controlled Trial

Polycystic ovary syndrome (PCOS) is a common cause of female infertility, affecting 5-10% of women of reproductive age. Many studies have reported improvement in insulin resistance and thereby intracellular glucose uptake after myo-inositol treatment in PCOS patients, but these studies have a small sample size, varying methodology, and outcome analysis. Therefore, we designed a present meta-analysis of randomized controlled trials to explore the effect of myo-inositol supplementation on anthropometric, metabolic, and endocrine outcomes in PCOS patients. Randomized controlled trials assessing the effectiveness of myo-inositol were identified in electronic databases like PubMed, Cochrane, Embase, MEDLINE, CINAHL, and AMED. Listed references and citations of related articles were also screened manually to identify additional studies. Research papers for which full-text copies were not available on scientific databases were procured from respective authors. Thereafter, data were extracted from included studies and analyzed using RevMan 5.3 of the Cochrane Collaboration. A total of 17 randomized controlled trials with 1083 PCOS patients were included in this meta-analysis. Among the 17 trials, 7 trials compared myo-inositol with folic acid, 8 trials compared myo-inositol with metformin, and 2 trials compared myo-inositol with oral contraceptives. No significant improvement in body mass index, waist-to-hip ratio, fasting insulin, fasting glucose, HOMA, LH, FSH, estradiol, sex hormone-binding globulin, dehydroepiandrosterone, and total testosterone levels were observed after myo-inositol treatment in PCOS patients except androstenedione and prolactin levels. Clinically significant improvement was not observed in anthropometric, metabolic, and endocrine outcomes after myo-inositol treatment in PCOS patients. However, heterogeneity between studies was high.

Transcriptomic landscape of granulosa cells and peripheral blood mononuclear cells in women with PCOS compared to young poor responders and women with normal response

STUDY QUESTION

Are transcriptomic profiles altered in ovarian granulosa cells (GCs) and peripheral blood mononuclear cells (PBMNCs) of women with polycystic ovary syndrome (PCOS) compared to young poor responders (YPR) and women with normal response to ovarian stimulation?

SUMMARY ANSWER

RNA expression profiles in ovarian GCs and PBMNCs were significantly altered in patients with PCOS compared with normoresponder controls (CONT) and YPR.

WHAT IS KNOWN ALREADY

PCOS is characterised by a higher number of follicles at all developmental stages. During controlled ovarian hyperstimulation, PCOS women develop a larger number of follicles as a result of an exacerbated response, with an increased risk of ovarian hyperstimulation syndrome. Despite the number of developing follicles, they are often heterogeneous in both size and maturation stage, with compromised quality and retrieval of immature oocytes. Women with PCOS appear to have a longer reproductive lifespan, with a slightly higher menopausal age than the general population, in addition to having a higher antral follicular count. As a result, the ovarian follicular dynamics appear to differ significantly from those observed in women with poor ovarian response (POR) or diminished ovarian reserve.

STUDY DESIGN, SIZE, DURATION

Transcriptomic profiling with RNA-sequencing and validation using quantitative reverse transcription PCR (qRT-PCR). Women with PCOS (N = 20), YPR (N = 20) and CONT (N = 20). Five patients for each group were used for sequencing and 15 samples per group were used for validation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

PCOS was defined using the revised Rotterdam diagnostic criteria for PCOS. The YPR group included women <35 years old with <4 mature follicles (at least 15 mm) on the day of the trigger. According to internal data, this group represented the bottom 15th percentile of patients' responses in this age group. It was consistent with Patient-Oriented Strategies Encompassing Individualize D Oocyte Number (POSEIDON) criteria for POR (Group 3). The young CONT group included women <35 years without PCOS or anovulation, who developed >14 mature follicles (at least 15 mm on transvaginal ultrasound). According to internal data, a threshold of >14 mature follicles was established to represent the top 25% of patients in this age group in this clinic.

Overall, n = 60 GCs and PBMNCs samples were collected and processed for total RNA extraction. To define the transcriptomic cargo of GCs and PBMNCs, RNA-seq libraries were successfully prepared from samples and analysed by RNA-seq analysis. Differential gene expression analysis was used to compare RNA-seq results between different groups of samples. Ingenuity pathway analysis was used to perform Gene Ontology and pathways analyses.

MAIN RESULTS AND THE ROLE OF CHANCE

In PBMNCs of PCOS, there were 65 differentially expressed genes (DEGs) compared to CONT, and 16 compared to YPR. In GCs of PCOS, 4 genes showed decreased expression compared to CONT, while 58 genes were differentially expressed compared to YPR. qRT-PCR analysis confirmed the findings of the RNA-seq. The functional enrichment analysis performed revealed that DEGs in GCs of PCOS compared to CONT and YPR were prevalently involved in protein ubiquitination, oxidative phosphorylation, mitochondrial dysfunction and sirtuin signaling pathways.

LARGE SCALE DATA

The data used in this study is partially available at Gene Ontology database.

LIMITATIONS, REASONS FOR CAUTION

The analysis in PBMNCs could be uninformative due to inter-individual variability among patients in the same study groups. Despite the fact that we considered this was the best approach for our study's novel, exploratory nature.

WIDER IMPLICATIONS OF THE FINDINGS

RNA expression profiles in ovarian GCs and PBMNCs were altered in patients with PCOS compared with CONT and YPR. GCs of PCOS patients showed altered expression of several genes involved in oxidative phosphorylation, mitochondrial function and sirtuin signaling pathways. This is the first study to show that the transcriptomic landscape in GCs is altered in PCOS compared to CONT and YPR.

STUDY FUNDING/COMPETING INTEREST(S)

This study was partially supported by grant PI18/00322 from Instituto de Salud Carlos III, and European Regional Development Fund (FEDER), ‘A way to make Europe’ awarded to S.H. M.C., S.H., S.T., L.R., M.R., I.R., A.P. and R.C. declare no conflict of interests concerning this research. E.S. is a consultant for and receives research funding from the Foundation for Embryonic Competence.

TRIAL REGISTRATION NUMBER

N/A.

Myoinositol versus metformin pretreatment in GnRH-antagonist cycle for women with PCOS undergoing IVF: a double-blinded randomized controlled study

OBJECTIVE

To study the effects of myoinositol (Myo) in comparison to metformin (Met), in reducing the risk of OHSS and improving ART outcome in PCOS women undergoing IVF.

DESIGN

Double-blinded randomized controlled trial (CTRI/2018/05/014196).

SETTING

ART Clinic, AIIMS, New Delhi patients: 102 infertile PCOS women undergoing IVF cycles were enrolled after evaluating for eligibility and allotted as 50 in group 1 (Myo) and 52 in group 2 (Met) after randomization.

INTERVENTIONS

Recruited patients received Myo 2 g twice daily (group 1) and Met 850 mg twice daily (group 2). Pre- and post-treatment clinical (menstrual pattern, BMI), hormonal profile (LH, FSH, testosterone, prolactin [PRL], and AMH), biochemical parameters (HOMA IR, fasting glucose, and insulin), ovarian with antral follicle count (AFC) and side effect profile were assessed. After 3 months of therapy, patients were recruited for IVF cycle by antagonist protocol was involving controlled ovarian stimulation, cycle monitoring, oocyte recovery, insemination of oocytes and follow up with fertilization, cleavage, transfer of good grade cleavage embryos, or blastocysts pregnancy outcomes and OHSS incidence and medications was continued until the day of OPU.

MAIN OUTCOME MEASURES

Primary outcome was OHSS and clinical pregnancy rate including spontaneous, IVF, and cumulative pregnancy rate including FET. Secondary outcome was ART outcomes and the change in biochemistry and hormonal profile between groups and inter group after medications at 12 weeks.

RESULTS

Incidence of OHSS (Myo 5 (10.0) (n = 50), Met 10 (20.0) (n = 50) p .07) was not statistically different between groups. Clinical pregnancy rate (Myo 18 (36.0) (n = 50), Met 9 (18.0) (n = 50) p .04) cumulative pregnancy rate including FET (Myo 16 (43.2) (n = 37) vs. Met 10) 22.7) (n = 44) p .05) and spontaneous conception (prior to IVF) Myo 13 (26.0) (n = 50), Met 6 (12.0) (n = 50) p .07) was significantly high in Myo group. No between group difference in ovarian stimulation outcomes including duration and dosage of gonadotropins, E2, P4 levels, number of follicles >14 mm on day of trigger. Number of oocytes retrieved and grade of maturity were similar between groups. Fertilization, cleavage and number of good grade embryos were significantly higher in Myo group. However, implantation rate and number of embryos for freezing were similar between groups. Myo had improvement in fasting insulin, HOMA, Sr.AMH, and SHBG suggesting decreased insulin resistance.

CONCLUSIONS

Myo is equally beneficial as Met in reducing the risk of OHSS and has better ART outcome in PCOS women undergoing antagonist cycles.

The Optimal Number of Oocytes Retrieved From PCOS Patients Receiving IVF to Obtain Associated With Maximum Cumulative Live Birth Rate and Live Birth After Fresh Embryo Transfer

AIMS

This study aims to determine the optimal number of oocytes retrieved so that patients with polycystic ovary syndrome (PCOS) receiving in vitro fertilization (IVF) can obtain the best cumulative live birth rate (CLBR) and live birth after fresh embryo transfer.

METHODS

This is a retrospective study of 1,419 patients with PCOS who underwent their first IVF cycle at the Second Hospital of Hebei Medical University from January 2014 to December 2021. Multivariable regression analysis was performed to adjust for factors known to independently affect cumulative live birth aspiration. The number of oocytes retrieved to obtain the best cumulative live birth rate was explored through curve fitting and threshold effect analysis. The decision tree method was used to explore the best number of oocytes retrieved to achieve live birth in the shortest time.

RESULTS

(1) The number of oocytes retrieved was found to be an independent protective factor for the cumulative live birth rate (OR = 1.09 (95% CI: 1.06, 1.12)). When the number of oocytes retrieved was less than 15, CLBR increased by 16% with each increase in the number of oocytes retrieved (OR = 1.16 (95% CI: 1.11, 1.22)); and when more than 15, CLBR tended to be stable. (2) Live birth after the first fresh embryo transfer was analyzed through a classification decision tree. For patients younger than 35 years old, those with less than 6 oocytes and those with 7-16 oocytes had a similar proportion of live births with fresh embryo transfer but higher than 16 oocytes (53.7% vs. 53.8% vs. 18.4%). Patients older than 35 years old had a similar proportion of live births with fresh embryo transfer (35.7% vs. 39.0%) to those younger than 35 years old, but the proportion of no live births after using up all embryos was higher than those younger than 35 years old (39.3% vs. 19.2%).

CONCLUSIONS

In PCOS patients, high CLBR can be obtained when the number of oocytes retrieved was 15 or more. The number of oocytes retrieved from 7 to 16 could achieve more chance of live birth after fresh embryo transfer.

Impact of myo-inositol treatment in women with polycystic ovary syndrome in assisted reproductive technologies

Polycystic ovary syndrome (PCOS) is marked in 30 to 40% by insulin resistance and hyperandrogenism. Myo-inositol (MI) increases insulin sensitivity, decreases hyperandrogenism and improves the menstrual cycle. Its effect during assisted reproductive technologies (ART) has been studied by many authors. We conducted a review of the literature on the impact of MI administration in PCOS women in assisted reproductive technologies. Myo-inositol is effective in normalizing ovarian function, improving oocyte and embryo quality in PCOS, however further evaluations by large multicentre randomized controlled trials are needed to assess the clinical pregnancy and live birth rates in ART.

Decreased Insulin Resistance by Myo-Inositol Is Associated with Suppressed Interleukin 6/Phospho-STAT3 Signaling in a Rat Polycystic Ovary Syndrome Model

Myo-inositol supplementation may reduce insulin resistance (IR) with few serious side effects in patients with polycystic ovary syndrome (PCOS). To explore the mechanism of this action in an animal model, a PCOS-IR rat model was generated. Enzyme-linked immunosorbent assay was used to assess changes in ovulation function during treatment with a myo-inositol supplement, and Western blotting, real-time polymerase chain reaction, and immunohistochemistry were performed to investigate the underlying molecular mechanisms. The results showed that the myo-inositol supplement decreased the homeostatic model assessment of insulin resistance (HOMA-IR) index and significantly decreased the serum levels of luteinizing hormone (LH), LH/follicle-stimulating hormone ratio, and testosterone, while increasing the serum level of estradiol. Upregulation of interleukin 6 (IL-6), phospho-STAT3 (p-STAT3), Mir-21, and Mir-155 and significant downregulation of PPAR-γ and GLUT4 were detected in the untreated PCOS-IR rat model. However, downregulation of IL-6, p-STAT3, miR-21, and miR-155 and significant upregulation of PPAR-γ and GLUT4 were detected with myo-inositol supplementation. Thus, myo-inositol supplementation may reduce Mir-21 and Mir-155 levels by downregulating IL-6 and p-STAT3 and, subsequently, reverse the expression of PPAR-γ and GLUT4, leading to a decreased HOMA-IR index. In conclusion, the identification of an IL-6/p-STAT3/Mir-155/Mir-21/PPAR-γ/GLUT4 system in the PCOS-IR rat model provides insight into the pathogenesis of PCOS and may indicate a possible therapeutic strategy. Amelioration of the basal serum glucose levels and of the HOMA/HOMA-IR index may be achieved by the reversal of the expression of PPAR-γ and GLUT4 through the downregulation of IL-6, p-STAT3, miR-21, and miR-155 with myo-inositol supplementation.