Effects of metformin treatment on luteal phase progesterone concentration in polycystic ovary syndrome

Hotspots and frontiers in luteal phase defect research: An in-depth global trend bibliometric and visualization analysis over a 52-year period

Luteal phase defect (LPD) is a common female reproductive endocrine defect，which is associated not only with certain diseases but also with the menstrual cycle and fertility in women. With the development of assisted reproductive technology (ART) in recent years, the incidence of luteal phase defect is high among patients using assisted reproductive technology. The aim of this study was to evaluate worldwide research on luteal phase defects using bibliometric analysis. A total of 631 documents related to the study of luteal phase defect were identified over the last 52 years. The current status and trend of globalization can be comprehended by analyzing the annual number of publications, institutions, authors, countries and regions of corresponding authors, journals, influential luteal phase defect publications (which were highly cited), highly cited references in luteal phase defect publications (cocitation analysis) and keywords. The study results provide a comprehensive overview of the development of scientific literature and are of great significance for the future development of the field，especially infertility and early pregnancy loss.

Emerging Perspectives on the Impact of Diabetes Mellitus and Anti-Diabetic Drugs on Premenstrual Syndrome. A Narrative Review

Diabetes mellitus (DM) and premenstrual syndrome (PMS) are global health challenges. Both disorders are often linked to a range of physical and psychological symptoms that significantly impact the quality of life of many women. Yet, the exact relation between DM and PMS is not clear, and the management of both conditions poses a considerable challenge. In this review, we aimed to investigate the interplay between DM, anti-diabetic drugs, and the different theories and symptoms of PMS. Female sex hormones are implicated in the pathophysiology of PMS and can also impair blood glucose control. In addition, patients with diabetes face a higher susceptibility to anxiety and depression disorders, with a significant number of patients experiencing symptoms such as fatigue and difficulty concentrating, which are reported in patients with PMS as well. Complications related to diabetic medications, such as hypoglycemia (with sulfonylurea) and fluid retention (with thiazolidinediones) may also mediate PMS-like symptoms. DM can, in addition, disturb the normal gut microbiota (GM), with a consequent loss of beneficial GM metabolites that guard against PMS, particularly the short-chain fatty acids and serotonin. Among the several available anti-diabetic drugs, those (1) with an anti-inflammatory potential, (2) that can preserve the beneficial GM, and (3) possessing a lower risk for hypoglycemia, might have a favorable outcome in PMS women. Yet, well-designed clinical trials are needed to investigate the anti-diabetic drug(s) of choice for patients with diabetes and PMS.

An interplay of Progesterone, Leukemia Inhibitor Factor and Interleukin-6 in the window of implantation; Impact on fertility

BACKGROUND

The process of implantation is crucial for the initiation of conception and hence fertility. In addition to a number of factors, it is regulated by a cross talk of gonadotrophins [Luteinizing Hormone (LH), Follicle Stimulatory Hormone (FSH)], ovarian steroids [Estrogen (Et), Progesterone (Pt)] and cytokines [Leukemia inhibitory factor (LIF) and Interleukin 6 (IL6)]. These biomarkers are chief players of implantation.

OBJECTIVE

We aimed to explore the role of gonadotrophins (LH, FSH, LH/FSH ratio), ovarian steroids (Et, Pt) and cytokines (LIF, IL6) in the implantation process. This aim was achieved by comparing these hormones and cytokines in the fertile and infertile groups [Polycystic ovaries (PCOs), endometriosis, unexplained infertility (Uex-IF)] and finding their association in all study groups.

METHODS

A case control study conducted from October 2020-March 2023. A total of 135 infertile women (with PCOs, Uex-IF, and endometriosis) and 177 fertile women (matched for age and BMI) were selected. Levels of 'Et', 'Pt', 'LIF' and, 'IL6' were estimated using Enzyme Linked Immunosorbent Assay (ELISA). LH and FSH values were obtained from hospital desk records. The Independent Student'st-test was used to compare fertile and infertile groups. One-way ANOVA test was used to compare more than two groups, and Pearson's chi-square (χ2) test was employed to compare percentages of variables. Pearson correlation analysis was performed to assess the associations and correlations. A p value < 0.05 was considered statistically significant.

RESULTS

Significantly higher levels of LIF and IL6 were observed in fertile women compared to infertile women. Pt levels were significantly greater in the fertile group than in the infertile group. The FSH/LH ratio was significantly higher in the fertile group. Among infertile women, PCOs (71%) and Uex-IF (91%) exhibited lower Pt levels than the fertile controls (p < 0.01), but these levels remained within the reference range (RR). Among the fertile group (81%), levels of LIF within the RR were significantly higher compared to those with Uex-IF (49%) and females with endometriosis (37%). Moreover, the highest number of participants (57%) with Uex-IF exhibited IL6 levels significantly below the RR in comparison to the fertile group and infertile groups (PCOS and endometriosis). However, lower levels of IL6 were observed in women with Uex-IF. In the control group, LIF exhibited a significant positive correlation with IL6 (r = 0.370), Pt (r = 0.496), Et (r = 0.403), and LH (r = 0.428). Among women with PCOs, LIF showed a significant positive correlation with IL6 (r = 0.443), Pt (r = 0.607), and LH (r = 0.472). In cases of Uex-IF, LIF demonstrated a significant positive correlation with IL6 (r = 0.727). Females with endometriosis displayed a significant positive correlation between LIF and IL6 (r = 0.535) as well as Pt (r = 0.605). In fertile women, a positive correlation was observed between LH and IL6 (r = 0.197, p = 0.009), LIF (r = 0.428, p = 0.000), Pt (r = 0.238, p = 0.001), and Et (r = 0.356, p = 0.000). Furthermore, a positive correlation was found between LH and LIF (r = 0.472, p = 0.000) in women with PCOs.

CONCLUSION

Elevated levels of Pt were found to increase the production of LIF in fertile females. However, infertile females with PCOs and Uex-IF exhibited deficient levels of Pt, supporting its role as a biomarker for successful implantation in infertile women. These females showed decreased levels of gonadotropins as well as reduced LH/FSH ratio and diminished secretion of receptivity marker LIF, in addition to reduced Pt secretion. This suggests that reduced gonadotropin levels contribute to a lower LH/FSH ratio, resulting in decreased Pt secretion and ultimately leading to low levels of LIF, thereby causing impaired implantation in women with PCOs and Uex-IF. The exploration of low levels of LIF in patients with endometriosis requires further investigation. The significantly low levels of IL6 in the Uex-IF group elucidate the role of this cytokine in association with decreased Pt and LIF synthesis within this group.

Transcriptomic profile of GLCs of PCOS women highlights metabolic dysregulation as a plausible contributor to PCOS pathophysiology

Polycystic ovary syndrome (PCOS) is a complex heterogeneous disorder with reproductive and metabolic consequences whose aetiology is still elusive. To understand the cellular mechanisms that potentially govern follicular defect in women with PCOS, we performed transcriptomic profiles of granulosa-lutein cells (GLCs) by RNA-Seq analysis. We found differential expression of 876 genes in GLCs between PCOS and controls that belonged to various processes such as cell cycle, extracellular matrix organization, angiogenesis, oxidative stress, metabolism, etc. that support folliculogenesis, oocyte development, and maturation. The cross-talk between oocyte and GLCs is a fundamental cornerstone in determining oocyte quality and highly interlinked pathways of metabolism and redox homeostasis may influence this. We found several genes involved in the metabolism of carbohydrates, nucleotides, cholesterol, and lipids were dysregulated, which may impair the supply of metabolites to the growing oocyte, affecting oocyte development and competence. Additionally, high metabolic activity during folliculogenesis may augment oxidative damage to cells and macromolecules if not counter-balanced. We observed dysregulation of redox homeostasis and AGE-RAGE signalling in the follicular environment. Among the validated genes, prokineticin-1 and growth differentiation factor-15 were found to be negatively regulated, while, S100, calcium-binding protein A9 and angiomotin-like-2 were positively regulated in GLCs of women with PCOS. Comparing our data with previously published relevant transcriptomic studies showed metabolic, cytokine-cytokine receptor interaction, IL-17, and chemokine signalling pathways were most commonly affected in PCOS. Overall, this data can provide insights into mechanisms contributing to PCOS pathophysiology and can be explored as potential indicators for oocyte/embryo quality in IVF settings.

Correlations between salivary- and blood-derived gonadal hormone assessments and implications for inclusion of female participants in research studies

Even in the 21st century, female participants continue to be underrepresented in human physiology research. This underrepresentation is attributable in part to the perception that the inclusion of females is more time consuming, less convenient, and more expensive relative to males because of the need to account for the menstrual cycle in cardiovascular study designs. Accounting for menstrual cycle-induced fluctuations in gonadal hormones is important, given established roles in governing vascular function and evidence that failure to consider gonadal hormone fluctuations can result in misinterpretations of biomarkers of cardiovascular disease. Thus, for cardiovascular researchers, the inclusion of females in research studies implies a necessity to predict, quantify, and/or track indexes of menstrual cycle-induced changes in hormones. It is here that methodologies are lacking. Gold standard measurement requires venous blood samples, but this technique is invasive and can become both expensive and technically preclusive when serial measurements are required. To this end, saliva-derived measures of gonadal hormones provide a means of simple, noninvasive hormone tracking. To investigate the feasibility of this technique as a means of facilitating research designs that take the menstrual cycle into account, the purpose of this review was to examine literature comparing salivary and blood concentrations of the primary gonadal hormones that fluctuate across the menstrual cycle: estradiol and progesterone. The data indicate that there appear to be valid and promising applications of salivary gonadal hormone monitoring, which may aid in the inclusion of female participants in cardiovascular research studies.

Kelulut Honey Regulates Sex Steroid Receptors in a Polycystic Ovary Syndrome Rat Model

Reproductive and metabolic anomalies in polycystic ovary syndrome (PCOS) have been associated with the dysregulation of sex steroid receptors. Kelulut honey (KH) has been shown to be beneficial in PCOS-induced rats by regulating folliculogenesis and the oestrus cycle. However, no study has been conducted to evaluate KH's effect on sex steroid receptors in PCOS. Therefore, the current study examined the effects of KH, metformin, or clomiphene alone and in combination on the mRNA expression and protein distribution of androgen receptor (AR), oestrogen receptor α (ERα), oestrogen receptor β (ERβ), and progesterone receptor (PR) in PCOS-induced rats. The study used female Sprague-Dawley rats, which were treated orally with 1 mg/kg/day of letrozole for 21 days to develop PCOS. PCOS-induced rats were then divided and treated orally for 35 days with KH, metformin, clomiphene, KH + metformin, KH+ clomiphene and distilled water. In this study, we observed aberrant AR, ERα, ERβ and PR expression in PCOS-induced rats compared with the normal control rats. The effects of KH treatment were comparable with clomiphene and metformin in normalizing the expression of AR, ERα, and ERβ mRNA. However, KH, clomiphene and metformin did not affect PR mRNA expression and protein distribution. Hence, this study confirms the aberrant expression of sex steroid receptors in PCOS and demonstrates that KH treatment could normalise the sex steroid receptors profile. The findings provide a basis for future clinical trials to utilize KH as a regulator of sex steroid receptors in patients with PCOS.

An integrated in silico analysis highlighted angiogenesis regulating miRNA-mRNA network in PCOS pathophysiology

Background

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrinopathy and a leading cause of anovulatory infertility. Angiogenesis is vital for ovarian folliculogenesis. The expression of angiogenesis-associated genes/proteins is altered in the ovary of PCOS women. However, information on microRNAs (miRNAs) regulating their expression is limited. This study aims to identify dysregulated angiogenesis-related genes in the ovary of women with PCOS, to identify miRNAs regulating them, and to construct a miRNA-mRNA network associated with angiogenesis.

Methods

A comprehensive literature search and reanalysis of seven ovarian GEO microarray datasets were performed to identify differentially expressed angiogenesis-related genes in PCOS. These target genes were used to predict their regulating miRNAs by querying miRNA databases and their expression in the ovary was verified. Panther and STRING database were used for functional enrichment. Gene expression of shortlisted miRNAs was studied in granulosa cells using digital droplet PCR.

Results

The miRNAs expressed in the ovary and potentially targeting dysregulated angiogenesis-related genes in PCOS were identified and those enriched in angiogenesis-related pathways, like VEGF, FGF, PI3K/Akt, Notch signaling, and ECM interaction were shortlisted. Analysis showed PI3K/Akt signaling was the most enriched pathway. MiR-218-5p, miR-214-3p, miR-20a-5p, and miR-140-3p associated with the PI3K/Akt pathway were found to be up-regulated in granulosa cells of women with PCOS.

Conclusions

By in silico analysis, we identified crucial dysregulated angiogenesis-related genes, the miRNA-mRNA interactions, and signaling pathways involved in impaired follicular angiogenesis in PCOS. This work provides a novel insight into the mechanism of aberrant ovarian angiogenesis contributing to PCOS pathophysiology.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10815-022-02396-1.

The Role of Feed Restriction on DNA Methylation, Feed Efficiency, Metabolome, Biochemical Profile, and Progesterone Patterns in the Female Filial Generation (F1) Obtained From Early Feed Restricted Ewes (F0)

Deficient management of replacement animals in the farm during early developmental windows may promote adverse programming effects on reproductive traits and subsequent transmission to the next generation. In this sense, DNA methylation profiles allow researchers to decode epigenetic regulation mechanisms in mammals and identify novel candidate genes correlated with phenotype differences in both dams and offspring. Therefore, improving knowledge in the field of epigenetics and intergenerational effects caused by prenatal and postnatal early nutritional events (e.g., feed restriction) is crucial for refining strategies dedicated to animal breeding. In this study, we determined differences in the global blood methylation patterns, biochemical profile, and metabolome of ewe lambs (F1) born from either early feed restricted dams (F0-RES) or fed ad libitum (F0-ADL). Our data show that functional categories such as those related to cellular processes, phosphorylation, nervous system, immunity response, or reproductive function were enriched significantly in the F1-RES lambs due to differences in the methylation of genes in these categories. These F1-RES lambs did not show differences in feed efficiency during the replacement period but presented higher levels of insulin and triglycerides and reduced concentration of progesterone, whereas the metabolome profile demonstrated variations in the bile acid composition when compared with the F1-ADL lambs. Taken together, all these results suggest that intergenerational effects caused by early feed restriction of dams (F0) may persist in the F1 female lambs with negative consequences on genes involved in cellular processes and reproductive traits.

Molecular determination of progesterone receptor's PROGINS allele (Alu insertion) and its association with the predisposition and susceptibility to polycystic ovary syndrome (PCOS)

Polycystic ovary syndrome, previously known as Stein-Leventhal syndrome, is associated with altered reproductive endocrinology, predisposing a young woman towards the risk of PCOS. It has a prevalence of 6-20% among the reproductive-age women. Progesterone is a key hormone in the pathophysiology of PCOS and patients show diminished response (progesterone resistance), implicating the role of progesterone receptor (PR) as a factor in the disease etiology and prognosis. In this case-control study, we have used mutation-specific PCR (confirmed by Sanger sequencing) to detect the presence of a pathologically significant PR polymorphic variant called as PROGINS. The variant has an Alu insertion in intron G and has two SNPs in exon 4 and exon 5, with all the three aberrations in complete disequilibrium. Our results demonstrated a statistically significant difference in the frequencies of PROGINS between the PCOS patients and healthy controls (p = 0.047). The frequencies of the genotypes CC (A1/A1), CT (A1/A2), and TT (A2/A2) in patients were 74.50%, 20.58%, and 4.90%, and in healthy controls they were 87.28%, 11%, and 1.69%, respectively. Our results put forward two determining factors with regard to PCOS: (i) the frequency of PROGINS allele was significantly higher among PCOS patients compared to the healthy matched controls (0.15 vs 0.07) in the studied population, (ii) the PROGIN allele was significantly associated with the lower levels of serum progesterone in PCOS patients (p < 0.003). The findings are conspicuous as these relate the PROGINS variant to the increased susceptibility of PCOS and might explain the progesterone resistance in patients.

Role of 14-3-3β protein on ovarian folliculogenesis, steroidogenesis and its correlation in the pathogenesis of PCOS in mice

This study was designed to assess for the first time the circulating and ovarian level of 14-3-3β protein in the PCOS mice and the possible correlation between 14-3-3β protein with PCOS related increase in testosterone (HA), insulin levels (HI) and reduced insulin sensitivity in the ovary. PCOS was induced in mice using treatment of letrozole (by oral gavage) for 21 days. Immunohistochemical study showed increased expression of 14-3-3β protein in PCOS ovary compared to the control ovary. The circulating testosterone and insulin levels, together with circulating and ovarian levels of 14-3-3β protein also showed significant increase in PCOS mice compared to the control mice. An increase in 14-3-3β protein was observed positively correlated with circulating testosterone and insulin levels but showed a negative correlation with ovarian expression of insulin receptor protein in PCOS mice. The treatment of 14-3-3β protein in vitro to the normal ovary showed a significant increase in testosterone synthesis but a significant decline in insulin receptor protein expression compared to the vehicle-treated ovary of adult mice. The present study showed the direct role of 14-3-3β protein in increasing testosterone synthesis along with decreasing insulin sensitivity. Thus, 14-3-3β protein may be playing possible role in PCOS pathogenesis.

Alteration in angiogenic potential of granulosa-lutein cells and follicular fluid contributes to luteal defects in polycystic ovary syndrome

STUDY QUESTION

Is angiogenic potential of follicular fluid (FF) and granulosa-lutein cells (GLCs) altered in polycystic ovary syndrome (PCOS) and does it play a role in corpus luteum (CL) defect observed in them?

SUMMARY ANSWER

FF and GLCs of women with PCOS show reduced expression of pro-angiogenic factors compared to controls and exhibit a diminished capacity to induce angiogenesis.

WHAT IS KNOWN ALREADY

In women with PCOS, CL insufficiency and frequent miscarriage are reported, which may be due to defect in CL. The development of new blood vessels is essential to promote ovarian folliculogenesis and functional CL formation. The vasculature formation in CL which is important for its function is still unexplored in these women.

STUDY DESIGN, SIZE, DURATION

This case-control study was conducted in 30 healthy control women and 30 women with PCOS undergoing controlled ovarian hyperstimulation for IVF. The FF, GLCs and serum were collected from all participants during ovum pick up.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The capacity of FF to induce angiogenesis was assessed by measuring levels of pro-angiogenic factors vascular endothelial growth factor (VEGF) and fibroblast growth factor 2 (FGF2) and its tube formation and wound healing potential using human umbilical vein endothelial cells (HUVECs). We investigated the angiogenic potential and endothelial cell-like nature of GLCs using several approaches such as the expression of angiogenic genes by quantitative PCR, DiI-conjugated acetylated low-density lipoproteins (Dil-Ac-LDL) internalization assay, tube formation assay, expression of endothelial cell markers by immunofluorescence analysis. In addition, correlation of transcript levels of angiogenic genes with oocyte parameters was studied.

MAIN RESULTS AND THE ROLE OF CHANCE

FF and serum levels of VEGF and FGF2 were significantly higher and lower, respectively, in PCOS compared to controls. The tube formation and wound healing capacity of HUVECs was found to be reduced when measured after supplementation with FF of women with PCOS compared to controls. This suggests a decreased angiogenic capacity of FF in women with PCOS. Tube formation (P = 0.003) and Dil-Ac-LDL internalization (P = 0.03) ability of GLCs were significantly reduced in women with PCOS compared to controls. Protein expression levels of endothelial markers, vascular endothelial growth factor A (VEGFA) (P = 0.004), vascular endothelial growth factor receptor 2 (VEGFR2) (P = 0.011), TEK Receptor Tyrosine Kinase (Tie-2) (P = 0.026), fibroblast growth factor receptor 1 (FGFR1) (P = 0.026) and CD31 (P = 0.035) and transcript levels of angiogenic genes VEGFA (P = 0.042), hypoxia inducing factor 1A (HIF1A) (P = 0.025), FGF2 (P = 0.038), angiopoietin 1 (ANGPT1) (P = 0.028), heparin sulfate proteoglycan 2 (HSPG2) (P = 0.016), ADAM metallopeptidase with thrombospondin type1 motif, 1 (ADAMTS1) (P = 0.027) and fibronectin 1 (FN1) (P = 0.016) were found to be low in GLCs of PCOS compared to controls. Thus, the findings of this study indicate that endothelial cell-like characteristics of GLCs were significantly decreased in PCOS. Furthermore, transcript levels of VEGFA (r = 0.46, P = 0.009), ADAMTS1 (r = 0.55, P = 0.001), FGF2 (r = 0.42, P = 0.022) and ANGPT2 (r = 0.47, P = 0.008) showed a positive correlation with oocyte fertilization rate.

LIMITATIONS, REASONS FOR CAUTION

The vasculature formation in CL is not possible to study in women, but we explored the angiogenic characteristics of FF and GLC obtained from women with PCOS to speculate any vascularization defect of CL in these women. The FF and GLCs were obtained from the stimulated cycle during oocyte retrieval, which may not exactly mimic the in-vivo condition. The small sample size is another limitation of this study. Larger sample size and support by color Doppler studies on CL blood flow would help to strengthen our findings.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest that the altered angiogenic potential of FF and GLCs may affect vasculature development required for CL formation and function in PCOS. These findings pave the way to devise therapeutic strategies to support angiogenesis process in follicle of women with PCOS, which may improve CL insufficiency, progesterone levels and prevent frequent miscarriages in these women. Furthermore, our study also hypothesizes that the vascularization around the ovarian follicles is also compromised which may lead to the growth arrest of the follicles in PCOS, however, this needs thorough investigations.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by Grant BT/PR16524/MED/97/346/2016 from the Department of Biotechnology, Government of India. The authors have no conflicts of interest to disclose.

TRIAL REGISTRATION NUMBER

N/A.

Novel role of CXCL14 in modulating STAR expression in luteinized granulosa cells: implication for progesterone synthesis in PCOS patients

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in reproductive-age women. Reduced progesterone levels are associated with luteal phase deficiency in women with PCOS. The levels of C-X-C motif chemokine ligand-14 (CXCL14) were previously reported to be decreased in human-luteinized granulosa (hGL) cells derived from PCOS patients. However, the function of CXCL14 in hGL cells and whether CXCL14 affects the synthesis of progesterone in hGL cells remain unclear. In the present study, the levels of CXCL14 were reduced in follicular fluid and hGL cells in PCOS patients, accompanied by decreased progesterone levels in follicular fluid and decreased steroidogenic acute regulatory (STAR) expression in hGL cells. CXCL14 administration partially reversed the low progesterone production and STAR expression in hGL cells obtained from PCOS patients. In primary hGL cells, CXCL14 upregulated STAR expression and progesterone production. CXCL14 activated the phosphorylation of cyclic adenosine monophosphate response element-binding protein (CREB) and CREB inhibitor attenuated the modulation of StAR expression by CXCL14. P38 and Jun N-terminal kinase (JNK) pathways were also activated by CXCL14 and inhibition of p38 and JNK attenuated the increase of phosphorylation of CREB, STAR expression and progesterone production caused by CXCL14. Our findings revealed the novel role of CXCL14 in upregulation of STAR expression and progesterone synthesis through CREB phosphorylation via activation of p38 and JNK pathways in hGL cells. This is likely contributing to the dysfunction in steroidogenesis in granulosa cells from PCOS patients.

Epidemiology, pathogenesis, genetics & management of polycystic ovary syndrome in India

Polycystic ovary syndrome (PCOS) is a common endocrine disorder predominantly affecting women of reproductive age. Clinical manifestations are diverse including hyperandrogenism, anovulation, infertility and increased risk of metabolic diseases besides psychosocial dysfunction. This review provides information on the problem of PCOS in India, its pathophysiology, genetics and an overview of current management options to instigate further research in this field. Prevalence of PCOS in India ranges from 3.7 to 22.5 per cent depending on the population studied and the criteria used for diagnosis. Abnormalities in leptin-adiponectin (adipocyte biology), oxidative stress and autoimmunity are among the mechanisms studied regarding pathogenesis of PCOS. Many candidate gene studies have shown associations with PCOS in various studies. Studies have consistently demonstrated the relationship between the well-known manifestation of hyperandrogenism among Indian PCOS women and the metabolic morbidities including insulin resistance, glucose intolerance and cardiovascular risk. Management of individual components of PCOS can be achieved by medications or surgical methods, though further clarification regarding pathogenesis of PCOS is needed to sharpen our therapeutic armamentarium.

Systemic adiponectin treatment reverses polycystic ovary syndrome-like features in an animal model

The present study examined the efficacy of adiponectin for regulating the reproductive, metabolic and fertility status of mice with polycystic ovary syndrome (PCOS). PCOS was induced in prepubertal (21- to 22-day-old) mice using dehydroepiandrosterone (6mg 100g-1day-1 for 25days), after which mice were administered either a low or high dose of adiponectin (5 or 15µgmL-1, s.c., respectively). PCOS mice exhibited typical features, including the presence of numerous cystic follicles, increased circulating androgens, increased body mass, altered steroidogenesis, decreased insulin receptor expression and increased serum triglycerides, serum glucose, Toll-like receptor (TLR)-4 (a marker of inflammation) and vascular endothelial growth factor (VEGF; a marker of angiogenesis). These parameters were significantly correlated with a reduction in adiponectin in PCOS mice compared with vehicle-treated control mice. Exogenous adiponectin treatment of PCOS mice restored body mass and circulating androgen, triglyceride and glucose levels. Adiponectin also restored ovarian expression of steroidogenic markers (LH receptors, steroidogenic acute regulatory protein and 3β-hydroxysteroid dehydrogenase), insulin receptor, TLR-4 and VEGF levels in control mice. Adiponectin restored ovulation in PCOS mice, as indicated by the presence of a corpus luteum and attainment of pregnancy. These findings suggest that adiponectin effectively facilitates fertility in anovulatory PCOS. We hypothesise that systemic adiponectin treatment may be a promising therapeutic strategy for the management of PCOS.

Chronic hyperandrogenemia in the presence and absence of a western-style diet impairs ovarian and uterine structure/function in young adult rhesus monkeys

STUDY QUESTION

Does chronic hyperandrogenemia beginning at menarche, in the absence and presence of a western-style diet (WSD), alter ovarian and uterine structure-function in young adult rhesus monkeys?

SUMMARY ANSWER

Phenotypic alterations in ovarian and uterine structure/function were induced by exogenous testosterone (T), and compounded in the presence of a WSD (T+WSD).

WHAT IS KNOWN ALREADY

Hyperandrogenemia is a well-established component of PCOS and is observed in adolescent girls, indicating a potential pubertal onset of disease symptoms. Obesity is often associated with hyperandrogenemia and it is hypothesized that metabolic dysfunction exacerbates PCOS symptoms.

STUDY DESIGN, SIZE, DURATION

Macaque females (n = 40) near the onset of menarche (~2.5 years of age) were assigned to a 2 by 2 factorial cohort design. Effects on reproductive characteristics were evaluated after 3 years of treatment.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Rhesus macaques (Macaca mulatta) were fed either a normal balanced diet (n = 20) or a WSD (n = 20). Additionally, implants containing cholesterol (n = 20) or T (n = 20) were implanted subcutaneously to elevate serum T approximately 5-fold. This resulted in treatment groups of controls (C), T, WSD and T+WSD (n = 10/group). Vaginal swabbing was performed daily to detect menses. After 3 years of treatment, daily serum samples from one menstrual cycle were assayed for hormone levels. Ovarian structure was evaluated in the early follicular phase by 3D/4D ultrasound. Uterine endometrial size and ovarian/luteal vascular function was also evaluated in subgroups (n = 6/group) in the late follicular and mid-luteal phases by 3D/4D ultrasound and contrast-enhanced ultrasound, respectively. Expression of steroid hormone receptors and markers of decidualization and endometrial receptivity were assessed in endometrial biopsies at mid-luteal phase.

MAIN RESULTS AND THE ROLE OF CHANCE

Approximately 90% of menstrual cycles appeared ovulatory with no differences in frequency or duration between groups. Serum estradiol (E2) levels during the early follicular phase were greatest in the T alone group, but reduced in T+WSD (P < 0.02). Serum LH was elevated in the T group (P < 0.04); however, there were no differences among groups in FSH levels (P > 0.13). Ovarian size at menses tended to be greater in the WSD groups (P < 0.07) and antral follicles ≥1 mm were more numerous in the T+WSD group (P < 0.05). Also, females in T and T+WSD groups displayed polycystic ovarian morphology (PCOM) at greater frequency than C or WSD groups (P < 0.01). Progesterone (P4) levels during the luteal phase were reduced in the T+WSD group compared to C and T groups (P < 0.05). Blood volume (BV) and vascular flow (VF) within the corpus luteum was reduced in all treatment groups compared to C (P < 0.01, P = 0.03), with the WSD alone group displaying the slowest BV and VF (P < 0.05). C and WSD groups displayed endometrial glands at mid-luteal phase with low estrogen receptor 1 (ESR1) and progesterone receptor (PGR) mRNA and immunohistochemical staining in the functionalis zone, but appreciable PGR in the stroma. In contrast, T and T+WSD treatment resulted in glands with less secretory morphology, high ESR1 expression in the glandular epithelium and low PGR in the stroma. Endometrial levels of TIMP3 and MMP26 mRNA and immunostaining were also decreased in the T and T+WSD groups, whereas AR expression was unchanged.

LARGE SCALE DATA

None.

LIMITATIONS, REASONS FOR CAUTION

Females are young adults, so effects could change as they reach prime reproductive age. The T level generated for hyperandrogenemia may be somewhat greater than the 3-4-fold increase observed in adolescent girls, but markedly less than those observed in male monkeys or adolescent boys.

WIDER IMPLICATIONS OF THE FINDINGS

Alterations to ovarian and uterine structure-function observed in T and, in particular, T+WSD-treated female macaques are consistent with some of the features observed in women diagnosed with polycystic ovary syndrome (PCOS), and suggest impaired fertility.

STUDY FUNDING/COMPETING INTEREST(S)

Research reported in this publication was supported by the Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD) of the National Institutes of Health (NIH) under Award Number P50HD071836 (to RLS). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. Additional funding was provided by Office of the Director, NIH under Award Number P51OD011092 (Support for National Primate Research Center). Authors declare no competing interests.

A short course of metformin does not reduce OHSS in a GnRH antagonist cycle for women with PCOS undergoing IVF: a randomised placebo-controlled trial

STUDY QUESTION

Does 'metformin' reduce the incidence of ovarian hyperstimulation syndrome (OHSS) for women with polycystic ovary syndrome (PCOS) undergoing a GnRH antagonist assisted conception treatment cycle?

SUMMARY ANSWER

A short course of metformin does not reduce the incidence of OHSS for women with PCOS undergoing a GnRH antagonist treatment cycle.

WHAT IS KNOWN ALREADY

Metformin does reduce the incidence of OHSS in a GnRH-agonist treatment cycle.

STUDY DESIGN, SIZE, DURATION

A randomised placebo-controlled trial (RCT) using metformin or placebo. Randomisation was blinded to both patient and investigator, using a random permuted blocks method with a 50:50 allocation ratio. The study was completed over 5 years (2009-2014) with 153 randomised patients. A sample size calculation based on the incidence of OHSS was completed prospectively suggesting a minimum of 146 recruits was required for the trial with a power of 80% and a type 1 error of 0.05.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All patients met the Rotterdam criteria for PCOS and were treated with a standard GnRH antagonist IVF/ICSI treatment cycle in a tertiary infertility clinic. The study medication was started prior to stimulation and continued to oocyte retrieval. Of the 153 patients, 77 received metformin and 76 placebo.

MAIN RESULTS AND THE ROLE OF CHANCE

There was no reduction in the incidence of moderate-severe OHSS (Placebo (PLA) 12.2%, metformin (MET) = 16%, 95% CI -0.08-0.16, P = 0.66). There was no difference in total gonadotrophin dose (PLA = 1200, MET = 1200, 95% CI -118.67-118.67, P = 0.75), oocytes retrieved (PLA = 15, MET = 14, 95% CI -2.37-4.37, P = 0.66) or fertilisation rate (PLA = 60.7%, MET = 53.3%, 95% CI -0.96-14.94, P = 0.07). However, using metformin resulted in a reduced clinical pregnancy rate (CPR) per cycle started (PLA = 48.7%, MET = 28.6%, 95% CI 0.04-0.35, P = 0.02) and live birth rate (PLA = 51.6%, MET = 27.6%, 95% CI 0.05-0.40, P = 0.02). Furthermore, when ethnicity was taken into account there was a significant reduction in pregnancy outcome for the South Asian population irrespective of metformin or placebo use (CPR per cycle started, White Caucasian = 44.4%, South Asian = 19.4%; 95% CI 0.06-0.39, P = 0.01).

LIMITATIONS, REASONS FOR CAUTION

This study was only undertaken on an infertility population with PCOS with a limited duration of study medication use.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first adequately powered RCT to assess the impact of metformin on OHSS in a high-risk group (women with PCOS) undergoing a GnRH antagonist cycle. It does not support the empirical prescribing of metformin as an adjunct to a GnRH antagonist treatment cycle.

STUDY FUNDING/COMPETING INTERESTS

None.

TRIAL REGISTRATION NUMBER

EudraCT number 2009-010952-81.

TRIAL REGISTRATION DATE

21 September 2009.

DATE OF FIRST PATIENT'S ENROLMENT

30 October 2009.

Dual targeting of TNF-α and free radical toxic stress as a promising strategy to manage experimental polycystic ovary

CONTEXT

It is now clear that oxidative stress (OS) and chronic low-grade inflammation are two main pathways involved in polycystic ovary syndrome (PCOS) pathogenesis. Therefore, simultaneous targeting of these pathways by means of carvedilol and Semelil (ANGIPARS™), as established medicines with dual anti-cytokine and anti-oxidant potential may be a therapeutic alternative approach to the current treatments.

OBJECTIVE

The objective of this study is to study the protective effects of carvedilol and ANGIPARS™ on inflammatory and oxidative response in hyperandrogenism-induced polycystic ovary (PCO).

MATERIALS AND METHODS

The murine model of PCO was induced by letrozole (1 mg/kg/d; orally) and effective doses of carvedilol (10 mg/kg/d; orally) and ANGIPARS™ (2.1 mg/kg/d; orally) were administrated for 21 d in PCO and non-PCO healthy rats. Ovarian folliculogenesis, sex hormones concentrations, OS, inflammatory, and metabolic biomarkers were assessed in serum and ovaries.

RESULTS

PCO rats exhibited ovarian cystogenesis which was preserved by the application of carvedilol and ANGIPARS™. In comparison with controls, decreased level of the total antioxidant power (TAP) and higher levels of reactive oxygen species (ROS) and lipid peroxidation (LPO) in serum and ovaries (2.41 ± 0.67 versus 0.72 ± 0.11; and 0.17 ± 0.04 versus 0.05 ± 0.01; 5.48 ± 1.30 versus 10.56 ± 0.77; and 7.06 ± 1.94 versus 17.98 ± 0.98; p < 0.05, respectively) were detected in PCO rats. Moreover, the PCO rats exhibited hyperandrogenism due to a 3.7-fold increase in serum testosterone concentration (35.04 ± 3.17 versus 131.09 ± 13.24; p < 0.05) along with a 2.98-fold decrease in serum progesterone (6.19 ± 0.40 versus 18.50 ± 1.03; p < 0.05) and 5.2-fold decrease in serum estradiol (9.30 ± 0.61 versus 48.3 ± 2.10; p < 0.05) when compared with those of the control group. However, similar to the control group, normal levels of OS markers and sex hormones were detected in ANGIPARS™ and carvedilol co-treated PCO rats. Besides, when compared with controls, increased levels of TNF-α (770.75 ± 42.06 versus 477.14 ± 28.77; p < 0.05) and insulin (1.27 ± 0.10 versus 0.36 ± 0.05; p < 0.05) in PCO rats were significantly inhibited by carvedilol and ANGIPARS™ co-treatment.

DISCUSSION AND CONCLUSION

We evidenced the beneficial effects of carvedilol and ANGIPARS™ in PCO, which underpin the new alternative approach in using these kinds of medicines in female reproductive disorders.

ROLE OF INSULIN SENSITIZERS ON CARDIOVASCULAR RISK FACTORS IN POLYCYSTIC OVARIAN SYNDROME: A META-ANALYSIS

OBJECTIVE

Polycystic ovarian syndrome (PCOS) is associated with an increase in cardiovascular (CV) risk factors such as insulin resistance, with accompanying hyperinsulinemia and hyperlipidemia, which are predisposing factors for type 2 diabetes mellitus and CV disease. The aim of this meta-analysis is to examine the effect of insulin sensitizers on clinical and biochemical features of PCOS and risk factors for CV disease.

METHODS

A systematic literature review was conducted, and randomized controlled clinical trials were identified by a search of bibliographic databases: Medline database (from 1966 forward), EMBASE (January 1985 forward), and Cochrane Central Register of Controlled Trials. Reviews of reference lists further identified candidate trials. Data was independently abstracted in duplicate by 2 investigators using a standardized data-collection form. Articles without a comparison group and randomization allocation were excluded. Reviewers worked independently and in duplicate to determine the methodological quality of trials, then collected data on patient characteristics, interventions, and outcomes.

RESULTS

Of 455 studies, 44 trials were eligible. A random effects model was used. Significant unadjusted results favoring treatment with insulin sensitizers were obtained for body mass index (BMI) (effect size [ES] of 0.58), waist to hip ratio (WHR) (ES of 0.02), low-density-lipoprotein cholesterol (LDL-C) (ES of 0.11), fasting insulin (ES of 2.82), fasting glucose (ES of 0.10), free testosterone (ES of 1.88), and androstenedione level (ES of 0.76).

CONCLUSION

Treatment with insulin sensitizers in women with PCOS results in improvement in CV factors such as BMI, WHR, LDL-C, fasting insulin, glucose, free testosterone, and androstenedione.

Bone mineral density in women with polycystic ovary syndrome

PURPOSE

PCOS is a complex disorder and various features of this disorder may have great importance for bone metabolism. The aim of the study was to determine the relationship between existing hormonal disorders, and bone mineral density (BMD) in young women with PCOS.

METHODS

69 reproductive-aged PCOS women and 30 age-matched healthy controls were enrolled to the study women. In each individual we assessed the body mass index (BMI). We evaluated the serum concentrations of: gonadotropins, prolactin (PRL), estradiol (E2), dehydroepiandrosterone sulfate (DHEAS), testosterone (T), thyroid stimulating hormone (TSH), free thyroxine (fT4). We used the Homeostatic Model Assessment-Insulin Resistance Index (HOMA-IR) to diagnose insulin resistance. Bone mineral density in the lumbar spine was measured by dual-energy X-ray absorptiometry (DXA).

RESULTS

The PCOS women had lower BMD values as compared to the controls (1.057 ± 0.1260 vs. 1.210 ± 0.1805 g/cm(2), p < 0.0002). In the analysis of PCOS patients according to BMI, only in the subgroup of the normal weight PCOS we find significantly lower BMD in comparison to controls (p = 0.0049). In patients with PCOS, BMD was positively correlated with insulin concentration and HOMA-IR. In the controls Z-score values were positively correlated with insulin concentration and HOMA-IR.

CONCLUSIONS

The deleterious effect of estrogen deficiency on bones in PCOS is not balanced by androgen overproduction. Women with PCOS had significantly lower BMD of the lumbar spine compared to controls. Insulin seems to be one of the most important positive bone growth stimulators.

The effect of metformin treatment in vivo on acute and long-term energy metabolism and progesterone production in vitro by granulosa cells from women with polycystic ovary syndrome

STUDY QUESTION

What are the consequences of polycystic ovary syndrome (PCOS) pathology and metformin-pretreatment in vivo in women with PCOS on the metabolism and steroid production of follicular phenotype- and long-term cultured-granulosa cells (GC)?

SUMMARY ANSWER

PCOS pathology significantly compromised glucose metabolism and the progesterone synthetic capacity of follicular- and long-term cultured-GCs and the metabolic impact of PCOS on GC function was alleviated by metformin-pretreatment in vivo.

WHAT IS KNOWN ALREADY

Granulosa cells from women with PCOS have been shown to have an impaired insulin-stimulated glucose uptake and lactate production in vitro. However, these results were obtained by placing GCs in unphysiological conditions in culture medium containing high glucose and insulin concentrations. Moreover, existing data on insulin-responsive steroid production in vitro by PCOS GCs vary.

STUDY DESIGN, SIZE AND DURATION

Case-control experimental research comparing glucose uptake, pyruvate and lactate production and progesterone production in vitro by GCs from three aetiological groups, all undergoing IVF; healthy control women (Control, n = 12), women with PCOS treated with metformin in vivo (Metformin, n = 8) and women with PCOS not exposed to metformin (PCOS, n = 8). The study was conducted over a period of 3 years between 2007 and 2010.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Rotterdam criteria were used for the diagnosis of PCOS; all subjects were matched for age, BMI and baseline FSH. Individual patient cultures were undertaken with cells incubated in a validated, physiological, serum-free culture medium containing doses of 0–6 mM glucose and 0–100 ng/ml insulin for 6 h and 144 h to quantify the impact of treatments on acute and long-term metabolism, respectively, and progesterone production. The metabolite content of spent media was measured using spectrophotometric plate reader assay. The progesterone content of spent media was measured by enzyme-linked immunosorbent assay. Viable GC number was quantified after 144 h of culture by the vital dye Neutral Red uptake assay.

MAIN RESULTS AND THE ROLE OF CHANCE

Granulosa cells from women with PCOS pathology revealed reduced pyruvate production and preferential lactate production in addition to their reduced glucose uptake during cultures (P < 0.05). Metformin pretreatment alleviated this metabolic lesion (P < 0.05) and enhanced cell proliferation in vitro (P < 0.05), but cells retained a significantly reduced capacity for progesterone synthesis compared with controls (P < 0.05).

LIMITATIONS, REASONS FOR CAUTION

Although significant treatment effects were detected in this small cohort, further studies are required to underpin the molecular mechanisms of the effect of metformin on GCs.

WIDER IMPLICATIONS OF THE FINDINGS

The individual patient culture strategy combined with multifactorial experimental design strengthens the biological interpretation of the data. Collectively, these results support the notion that there is an inherent impairment in progesterone biosynthetic capacity of the GCs from women with PCOS. The positive, acute metabolic effect and the negative long-term steroidogenic effect on GCs following metformin exposure in vivo may have important implications for follicular development and luteinized GC function when the drug is used in clinical practice.

STUDY FUNDING/COMPETING INTEREST(S)

No competing interests. This work was supported by the UK Medical Research Council Grant Reference number G0800250.

Effects of hyperandrogenemia and increased adiposity on reproductive and metabolic parameters in young adult female monkeys

Many patients with hyperandrogenemia are overweight or obese, which exacerbates morbidities associated with polycystic ovary syndrome (PCOS). To examine the ability of testosterone (T) to generate PCOS-like symptoms, monkeys received T or cholesterol (control) implants (n = 6/group) beginning prepubertally. As previously reported, T-treated animals had increased neuroendocrine drive to the reproductive axis [increased luteinizing hormone (LH) pulse frequency] at 5 yr, without remarkable changes in ovarian or metabolic features. To examine the combined effects of T and obesity, at 5.5 yr (human equivalent age: 17 yr), monkeys were placed on a high-calorie, high-fat diet typical of Western cultures [Western style diet (WSD)], which increased body fat from <2% (pre-WSD) to 15-19% (14 mo WSD). By 6 mo on WSD, LH pulse frequency in the controls increased to that of T-treated animals, whereas LH pulse amplitude decreased in both groups and remained low. The numbers of antral follicles present during the early follicular phase increased in both groups on the WSD, but maximal follicular size decreased by 50%. During the late follicular phase, T-treated females had greater numbers of small antral follicles than controls. T-treated monkeys also had lower progesterone during the luteal phase of the menstrual cycle. Although fasting insulin did not vary between groups, T-treated animals had decreased insulin sensitivity after 1 yr on WSD. Thus, while WSD consumption alone led to some features characteristic of PCOS, T + WSD caused a more severe phenotype with regard to insulin insensitivity, increased numbers of antral follicles at midcycle, and decreased circulating luteal phase progesterone levels.

Genetic variants associated with insulin signaling and glucose homeostasis in the pathogenesis of insulin resistance in polycystic ovary syndrome: a systematic review

BACKGROUND

Polycystic ovary syndrome must be recognized as a serious issue due to its implication on long term health regardless of an individual's age. PCOS and insulin resistance are interlinked, as approximately 40 % of women with PCOS are insulin resistant. However, the detailed molecular basis for insulin resistance that is coupled with PCOS remains poorly understood.

OBJECTIVE

To review the published evidence that polymorphisms in genes that are involved in insulin secretion and action are associated with an increased risk of PCOS.

METHODS

We reviewed articles published through November 2012 which concerned polymorphisms of genes related to insulin signaling and glucose homeostasis as well as their associations with PCOS. The articles were identified via Medline searches.

CONCLUSIONS

No consistent evidence emerged of a strong association between the risk of PCOS and any known gene that is related to insulin signaling and glucose homeostasis. Moreover, recent genome-wide association studies are inconsistent in identifying the associations between PCOS and insulin metabolism genes. Many of the studies reviewed were limited by heterogeneity in the PCOS diagnosis and by not have having a sufficient number of study participants. Further studies are warranted to determine predisposing risk factors which could modify environmental factors and thus reduce the risk of PCOS. Large genome-wide association studies devoted solely to PCOS will be necessary to identify new candidate genes and proteins that are involved in PCOS risk.

Common pathophysiological mechanisms involved in luteal phase deficiency and polycystic ovary syndrome. Impact on fertility

Luteal phase deficiency (LPD) is a consequence of the corpus luteum (CL) inability to produce and preserve adequate levels of progesterone. This is clinically manifested by short menstrual cycles and infertility. Abnormal follicular development, defects in neo-angiogenesis or inadequate steroidogenesis in the lutein cells of the CL have been implicated in CL dysfunction and LPD. LPD and polycystic ovary syndrome (PCOS) are independent disorders sharing common pathophysiological profiles. Factors such as hyperinsulinemia, AMH excess, and defects in angiogenesis of CL are at the origin of both LPD and PCOS. In PCOS ovulatory cycles, infertility could result from dysfunctional CL. The aim of this review was to investigate common mechanisms of infertility in CL dysfunction and PCOS.

Mechanistic links between oxidative/nitrosative stress and tumor necrosis factor alpha in letrozole-induced murine polycystic ovary:

This study aimed to investigate the possible relationship between ovarian functionality and the oxidative response during cystogenesis induced by hyperandrogenization with letrozole and examine protective effect of the peroxisome proliferator-activated receptor gamma (PPAR-γ) agonist, pioglitazone (PIO), in polycystic ovary (PCO). Ovarian cysts were induced by oral administration of letrozol (1 mg/kg/day) for 21 consecutive days in the female rats. Effective dose of PIO (20 mg/kg/day) was administrated orally for 21 days. Serum estradiol (E), progesterone (P), testosterone (T), and the ovarian immunomodulator prostaglandin E (PGE) were analyzed as biomarkers of ovarian function. To determine the role of oxidative stress in PCO, the level of cellular lipid peroxidation (LPO), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and peroxynitrite (ONOO), and tumor necrosis factor alpha (TNF-α) as a marker of inflammation and apoptosis were measured in serum and the ovaries. Letrozole-induced PCO in rats exhibited a significant increase in LPO and ONOO in serum and ovary while significantly decreased serum and ovarian SOD, CAT, and GPx. Serum T and TNF-α, and ovarian PGE were increased in animals with cysts compared with healthy controls, while E and P diminished. When compared to control group, letrozole-treated group showed irregular sexual cycles, polycystic ovaries characterized by high incidence of sub-capsular ovarian cyst with diminished or scant granulosa cell layer, increased number of atretic pre-antral and antral follicles and absence of corpus luteum. There were almost no primary, secondary, and tertiary follicles observed in PCO rats. All measured parameters were improved by PIO and reached close to normal levels. The present study further supports the role of oxidative/nitrosative stress and infiammatory responses in the pathogenesis of letrozole-induced hyperandrogenic PCO rats. Results indicate that PIO is able to exert direct antioxidative and anti-inflammatory effects on the endocrine, biochemical, and pathological alterations independent of its possible effects mediated via increased insulin sensitivity in hyperandrogenized PCO.

Effect of DHEA and metformin on corpus luteum in mice

We evaluated the effect of hyperandrogenism in ovaries with functional and regressing corpora lutea (CL) and the action of metformin in preventing these possible alterations using a mouse model. To obtain a CL functional for 9+/-1 days, immature female mice of the BALB/c strain were injected i.p. with 10 IU/mouse of pregnant mare's serum gonadotropin (PMSG). DHEA (60 mg/kg body weight s.c., 24 and 48 h prior to kill) decreased both serum progesterone (P) and estradiol (E(2)) levels and increased the activity of superoxide dismutase (SOD) from ovaries with functional CL (on day 5 after PMSG). It increased P and E(2) and the activities of SOD and catalase (CAT) and decreased lipoperoxidation of ovaries with regressing CL (on day 9 after PMSG). Treatment with DHEA did not affect the production of prostaglandin F(2alpha) (PGF(2alpha)) or PGE by ovaries with functional CL, whereas DHEA decreased PGF(2alpha) and increased PGE production by ovaries with regressing CL. Metformin (50 mg/kg body weight, orally) given together with DHEA restored E(2) levels from mice with ovaries with functional CL and serum P, PGF(2alpha) and PGE levels, and oxidative balance in mice with ovaries with regressing CL. Metformin alone was able to modulate serum P and E(2) levels, lipoperoxidation, SOD and CAT, and the 5,5-dimethyl-1-pyrroline N-oxide/(*)OH signal. These findings suggest that hyperandrogenism is able to induce or to rescue CL from luteolysis and metformin treatment is able to prevent these effects.

Disruption in the expression and immunolocalisation of steroid receptors and steroidogenic enzymes in letrozole-induced polycystic ovaries in rat

The objective of the present study was to characterise the expression and tissue distribution of steroid receptors (oestrogen receptor-α and –β (ERα, ERβ), androgen receptor (AR) and progesterone receptor (PR)) and steroidogenic enzymes (P450 aromatase (P450arom), 3β-hydroxysteroid dehydrogenase (3β-HSD) and steroidogenic acute regulatory protein (StAR)) in letrozole-induced polycystic ovaries of rats. Changes in serum hormone levels, protein expression in whole ovaries by western blot analysis and protein localisation by immunohistochemistry were determined in female rats treated with the aromatase inhibitor letrozole and compared with controls in proestrous and diestrous rats. Increases in the serum LH, FSH and testosterone concentrations were observed in letrozole-treated rats whereas serum oestradiol and progesterone levels were reduced. Protein expression as analysed by western immunoblot was consistent with the immunohistochemical data. Letrozole treatment induced an increase in the expression of AR, StAR and 3β-HSD and a decrease in ERβ. ERα, PR and P450arom showed partial changes in relation to some cycle stages. These results indicate that cystogenesis in this experimental model is characterised by changes in steroid receptors and steroidogenic enzyme expression that may be essential to proper ovarian functioning and are in agreement with similar changes observed in women with PCOS.

Le syndrome des ovaires polykystiques (SOPK)

Polycystic ovaries syndrome (PCOS) is one of the most common female hormonal disorders. Its multiple components--reproductive, metabolic, neoplasic and cardiovascular--have a major impact on the public health. Androgen excess and resistance to insulin, probably from genetic origin, are responsible for most of the clinical symptomatology. Resistance to insulin seems to be accompanied by a greater risk of glucose intolerance, type 2 diabetes, lipidic anomalies and can involve the development of cardiovascular diseases. In addition, sleep apnea syndrome is more progressively described in PCOS. Infertility, menses disorders and hirsutism often push these patients to consult their physician. A better understanding of the physiopathological mechanisms led to the emergence of new therapeutic options increasing the sensitivity to insulin. Besides the pregnancy wishes, cares aim to attenuate the marks of the hyper-androgenism (hormonal treatment and cosmetic) and to correct cardiovascular, respiratory and gynaecological risk factors. In case of infertility by anovulation, cares must be performed by trained experts to minimize the risk of ovarian hyper-stimulation syndrome and multiple pregnancies. A gradation from loose weight to clomiphene citrate ovulation induction, ovarian drilling, low dose gonadotropin, in vitro fertilisation, or in vitro maturation of oocytes should bring back good reproduction potential.

A new rat model exhibiting both ovarian and metabolic characteristics of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder associated with ovulatory dysfunction, hyperandrogenism, abdominal obesity, and insulin resistance. However, its etiology is unclear, and its management is often unsatisfactory or requires a diversified approach. Here, we describe a new rat PCOS model, the first to exhibit both ovarian and metabolic characteristics of the syndrome. Female rats received the nonaromatizable androgen dihydrotestosterone (DHT) or the aromatase inhibitor letrozole by continuous administration, beginning before puberty, to activate androgen receptors. Adult DHT rats had irregular cycles, polycystic ovaries characterized by cysts formed from atretic follicles, and a diminished granulosa layer. They also displayed metabolic features, including increased body weight, increased body fat, and enlarged mesenteric adipocytes, as well as elevated leptin levels and insulin resistance. All letrozole rats were anovulatory and developed polycystic ovaries with structural changes strikingly similar to those in human PCOS. Our findings suggest that the formation of a "hyperplastic" theca interna reflects the inclusion of luteinized granulosa cells in the cyst wall rather than true hyperplasia. We conclude that the letrozole model is suitable for studies of the ovarian features of human PCOS, while the DHT model is suitable for studies of both ovarian and metabolic features of the syndrome.

Metformin reduces abortion in pregnant women with polycystic ovary syndrome

BACKGROUND

Women with polycystic ovary syndrome (PCOS) are considered to be at increased risk of miscarriage. Since metformin has beneficial effects on the risk factors contributing to first-trimester abortion in PCOS patients, we hypothesized that metformin - owing to its metabolic, endocrine, vascular and anti-inflammatory effects - may reduce the incidence of first-trimester abortion in PCOS women.

MATERIALS AND METHODS

A prospective cohort study was set up to determine the beneficial effects of metformin on PCOS patients during pregnancy. Two hundred non-diabetic PCOS patients were evaluated while undergoing assisted reproduction. One hundred and twenty patients became pregnant while taking metformin, and continued taking metformin at a dose of 1000-2000 mg daily throughout pregnancy. Eighty women who discontinued metformin use at the time of conception or during pregnancy comprised the control group.

RESULTS

Both groups were similar with respect to all background characteristics (age, body mass index, waist/hip ratio, follicle-stimulating hormone, luteinizing hormone, estradiol and dehydroepiandrosterone sulfate levels). Rates of early pregnancy loss in the metformin group were 11.6% compared with 36.3% in the control group (p < 0.0001; odds ratio = 0.23, 95% confidence interval 0.11-0.42).

CONCLUSIONS

Administration of metformin throughout pregnancy to women with PCOS was associated with a marked and significant reduction in the rate of early pregnancy loss.

Metformin prevents embryonic resorption induced by hyperandrogenisation with dehydroepiandrosterone in mice

The present study examined the mechanism by which metformin prevents dehydroepiandrosterone (DHEA)-induced embryonic resorption in mice. Treatment with DHEA (6 mg/100 g bodyweight, 24 and 48 h post implantation) induced 88 +/- 1 % embryonic resorption and the diminution of both serum oestradiol (E) and progesterone (P) levels. However, when metformin (50 mg/kg bodyweight) was given together with DHEA, embryo resorption (43 +/- 3% v. 35 +/- 5% in controls) and both serum E and P levels were not significantly different from controls. Glucose and insulin levels were increased in the DHEA-treated mice but when metformin was administered together with DHEA these parameters were similar to control values. Treatment with DHEA increased ovarian oxidative stress and diminished uterine nitric oxide synthase (NOS) activity; however, when metformin was administered together with DHEA, both ovarian oxidative stress and uterine NOS activity were not different from controls. Metformin treatment did not modify the percentage of CD4(+) and CD8(+) T cells from both axillar and retroperitoneal lymph nodes but prevented the increase of serum tumour necrosis factor +/- produced in DHEA-treated mice. These results show that metformin acts in DHEA-induced embryonic resorption in mice by modulating endocrine parameters, ovarian oxidative stress and uterine NOS activity.

Effects of metformin on the glycemic control, lipid profile, and arterial blood pressure of type 2 diabetic patients with metabolic syndrome already on insulin

Fifty-seven type 2 diabetic patients with metabolic syndrome and on insulin were assessed by a paired analysis before and 6 months after addition of metformin as combination therapy to evaluate the impact of the association on glycemic control, blood pressure, and lipid profile. This was a historical cohort study in which the files of type 2 diabetic patients with metabolic syndrome on insulin were reviewed. The body mass index (BMI), waist circumference, lipid profile, A1C level, fasting blood glucose level, daily dose of NPH insulin, systolic blood pressure, and diastolic blood pressure were assessed in each patient before the start of metformin and 6 months after the initiation of combination therapy. Glycemic control significantly improved (P < 0.001) after the addition of metformin (1404.4 +/- 565.5 mg/day), with 14% of the 57 patients reaching A1C levels up to 7%, and 53% reaching values up to 8%. There was a statistically significant reduction (P < 0.05) of total cholesterol (229.0 +/- 29.5 to 214.2 +/- 25.0 mg/dL), BMI (30.7 +/- 5.4 to 29.0 +/- 4.0 kg/m2), waist circumference (124.6 +/- 11.7 to 117.3 +/- 9.3 cm), and daily necessity of insulin. The reduction of total cholesterol occurred independently of the reductions of A1C (9.65 +/- 1.03 to 8.18 +/- 1.01%) and BMI and the reduction of BMI and WC did not interfere with the improvement of A1C. In conclusion, our study showed the efficacy of the administration of metformin and insulin simultaneously without negative effects. No changes were detected in HDL-cholesterol or blood pressure.