Metformin versus flutamide in the treatment of metabolic consequences of non-obese young women with polycystic ovary syndrome: a randomized prospective study

Updates on Molecular Targets and Epigenetic-Based Therapies for PCOS

Polycystic ovarian syndrome (PCOS) can cause infertility in females due to hyperandrogenism and neuroendocrine abnormalities. The aim of this study is to decipher the impact of endocrine variables, hyperandogenism, insulin resistance, oxidative stress, and dietary conditions in PCOS conditions, subsequently to depict the role of epigenetic factors relative to phenotypic manifestations in PCOS conditions. We have reviewed several metabolic milieus pertinent to PCOS conditions. Comparative efficacies of various PCOS therapies, and recent clinical recommendations for the effective management of PCOS and role of metabolic/endocrine variables in PCOS conditions were described. Comparative therapeutic effects were vividly delineated according to the variable pathophysiology and internal variables during PCOS syndrome on the female body through the formation of cascade of endocrine pathology, which affects working capacity and fosters redox stress-induced cardiovascular, neural, and liver abnormalities. GLP-1 agonists, insulin sensitizers (metformin), and diet and exercise regimens efficacy were explained in enhancing the fertility outcomes among the overweight or obese females with PCOS. Comprehensive appraisal of DNA methylation as epigenetic changes and the manifestations of methylated genes in PCOS conditions were discussed particularly to screen novel molecular targets for developing efficient diagnostic indicators for predicting PCOS risk or its progression. Due to the reversible nature of epigenetic modifications, it is possible to screen the "druggable" regions to target or to correct abnormalities in the gene expression subsequently to develop chromatin-modifying therapies against PCOS.

Menstrual dysfunction in polycystic ovary syndrome: association with dynamic state insulin resistance rather than hyperandrogenism

OBJECTIVE

To examine the relation of menstrual cyclicity abnormalities to hyperandrogenism (HA) and dynamic state insulin resistance (IR) in oligo-ovulatory women with polycystic ovary syndrome (PCOS).

DESIGN

Prospective cross-sectional study.

SETTING

Tertiary-care academic center.

PATIENT(S)

Fifty-seven women with PCOS (1990 National Institutes of Health criteria) and 57 healthy control women matched by body mass index (BMI).

INTERVENTION(S)

Short insulin tolerance test (ITT).

MAIN OUTCOME MEASURE(S)

Menstrual cyclicity, sex hormone-binding globulin (SHBG), measures of HA (i.e., modified Ferriman-Gallwey score, total and free testosterone, dehydroepiandrosterone sulfate), and the rate constant for plasma glucose disappearance (kITT) derived from the short ITT.

RESULT(S)

Adjusting for age, BMI, and ethnicity, the mean androgen measures were higher and SHBG trended lower, kITT was lower, and the prevalence of IR was higher in PCOS than in controls, independent of menstrual cyclicity. The optimal cutoff point for IR was set at kITT value of 3.57%/minute or lower. Overall, 79% of the women with PCOS had IR. To control further for the effect of ethnicity, a subgroup of 46 non-Hispanic white PCOS participants were studied; those who exhibited amenorrhea (n = 15) or oligomenorrhea (n = 19) had or tended toward having a lower kITT and a higher prevalence of IR than the women with PCOS and oligo-ovulatory eumenorrhea (n = 12). The kITT trended lower and the prevalence of IR trended higher in women with PCOS and amenorrhea than those with oligomenorrhea. The measures of SHBG and HA were similar across the three menstrual groups.

CONCLUSION(S)

Oligo-ovulatory women with PCOS and overt oligo/amenorrhea have greater degrees of IR but not HA when compared with oligo-ovulatory eumenorrheic women with PCOS, suggesting that IR and hyperinsulinemia but not HA play a role in determining the degree of menstrual dysfunction, which can be used as a clinical marker for the degree of IR in oligo-ovulatory PCOS.

Pharmacological Approaches to Controlling Cardiometabolic Risk in Women with PCOS

Polycystic ovary syndrome (PCOS) is characterized by elevated androgen production and subclinical changes in cardiovascular and metabolic risk markers. Total cholesterol, high-density lipoprotein (HDL) cholesterol, fasting glucose, and fasting insulin appear to increase specifically in PCOS compared with fertile women. PCOS also confers an increased risk of cardiometabolic disease in later life. Novel biomarkers such as serum’s cholesterol efflux capacity and blood-derived macrophage activation profile may assist in more accurately defining the cardiometabolic risk profile in these women. Aldosterone antagonists, androgen receptor antagonists, 5α-reductase inhibitors, and synthetic progestogens are used to reduce hyperandrogenism. Because increased insulin secretion enhances ovarian androgen production, short-term treatment with metformin and other hypoglycemic agents results in significant weight loss, favorable metabolic changes, and testosterone reduction. The naturally occurring inositols display insulin-sensitizing effects and may be also used in this context because of their safety profile. Combined oral contraceptives represent the drug of choice for correction of androgen-related symptoms. Overall, PCOS management remains focused on specific targets including assessment and treatment of cardiometabolic risk, according to disease phenotypes. While new options are adding to established therapeutic approaches, a sometimes difficult balance between efficacy and safety of available medications has to be found in individual women.

Effect of metformin and flutamide on insulin, lipogenic and androgen-estrogen signaling, and cardiometabolic risk in a PCOS-prone metabolic syndrome rodent model

Polycystic ovary syndrome (PCOS) is highly associated with cardiometabolic risk and the metabolic syndrome (MetS), predisposing women to increased risk of developing type 2 diabetes and cardiovascular disease. Metformin is commonly used to treat insulin resistance-glucose intolerance, and flutamide, an androgen receptor (AR) antagonist, is used to target hyperandrogenemia and dyslipidemia. Currently, the physiological mechanism of action of these treatments on androgen, lipidogenic, and insulin signaling pathways remains unclear in PCOS. The aim of this study was to investigate the effects and mechanisms of action of metformin and flutamide on plasma lipid-apolipoprotein (Apo)B-lipoprotein and insulin-glucose metabolism, and endocrine-reproductive indices in a PCOS-prone MetS rodent model. PCOS-prone rodents were treated with metformin (300 mg/kg body wt), flutamide (30 mg/kg body wt), or metformin + flutamide combination treatment for 6 wk. Metformin was shown to improve fasting insulin and HOMA-IR, whereas flutamide and combination treatment were shown to reduce plasma triglycerides, ApoB48, and ApoB100, and this was associated with decreased intestinal secretion of ApoB48/triglyceride. Flutamide and metformin were shown to reduce plasma androgen indices and to improve ovarian primary and preovulatory follicle frequency. Metformin treatment increased hepatic estrogen receptor (ER)α, and metformin-flutamide decreased intestinal AR and increased ERα mRNA expression. Metformin-flutamide treatment upregulated hepatic and intestinal insulin signaling, including insulin receptor, MAPK1, and AKT2. In conclusion, cardiometabolic risk factors, in particular ApoB-hypertriglyceridemia, are independently modulated via the AR, and understanding the contribution of AR and insulin-signaling pathways further may facilitate the development of targeted interventions in high-risk women with PCOS and MetS.

Screening for insulin-independent pathways that modulate glucose homeostasis identifies androgen receptor antagonists

Pathways modulating glucose homeostasis independently of insulin would open new avenues to combat insulin resistance and diabetes. Here, we report the establishment, characterization, and use of a vertebrate ‘insulin-free’ model to identify insulin-independent modulators of glucose metabolism. insulin knockout zebrafish recapitulate core characteristics of diabetes and survive only up to larval stages. Utilizing a highly efficient endoderm transplant technique, we generated viable chimeric adults that provide the large numbers of insulin mutant larvae required for our screening platform. Using glucose as a disease-relevant readout, we screened 2233 molecules and identified three that consistently reduced glucose levels in insulin mutants. Most significantly, we uncovered an insulin-independent beneficial role for androgen receptor antagonism in hyperglycemia, mostly by reducing fasting glucose levels. Our study proposes therapeutic roles for androgen signaling in diabetes and, more broadly, offers a novel in vivo model for rapid screening and decoupling of insulin-dependent and -independent mechanisms.

Diabetes is a disease that affects the ability of the body to control the level of sugar in the blood. Individuals with diabetes are unable to make a hormone called insulin – which normally stimulates certain cells to absorb sugar from the blood – or their cells are less able to respond to this hormone. Most treatments for diabetes involve replacing the lost insulin or boosting the hormone’s activity in the body. However, these treatments can also cause individuals to gain weight or become more resistant to insulin, making it harder to control blood sugar levels.

In addition to insulin, several other factors regulate the levels of sugar in the blood and some of them may operate independently of insulin. However, little is known about such factors because it is impractical to carry out large-scale screens to identify drugs that target them in humans or mice, which are often used as experimental models for human biology.

To overcome this challenge, Mullapudi et al. turned to another animal known as the zebrafish and generated mutant fish that lack insulin. The mutant zebrafish had similar problems with regulating sugar levels as those observed in humans and mice with diabetes. This observation suggests that insulin is just as important in zebrafish as it is in humans and other mammals.

The mutant zebrafish did not survive into adulthood, and so Mullapudi et al. transplanted healthy tissue into the zebrafish to allow them to produce enough insulin to survive. These adult zebrafish produced many offspring that still carried the insulin mutation. Mullapudi et al. used these mutant offspring to screen over 2,000 drugs for their ability to decrease blood sugar levels in the absence of insulin. The screen identified three promising candidate drugs, including a molecule that interferes with a receptor for a signal known as androgen.

These findings will help researchers investigate new ways to treat diabetes. In the future, the screening approach developed by Mullapudi et al. could be adapted to search for new drugs to treat other human metabolic conditions.

Combined oral contraceptives and/or antiandrogens versus insulin sensitizers for polycystic ovary syndrome: a systematic review and meta-analysis

BACKGROUND

Androgen excess is a key pathogenetic mechanism in polycystic ovary syndrome (PCOS), although hyperinsulinism also contributes to androgen secretion. Therapeutic approaches for adult patients not seeking fertility include combined oral contraceptives (COC), antiandrogens (AA) and/or insulin sensitizers, although these practices are supported by limited high-quality evidence.

OBJECTIVE AND RATIONALE

We aimed to assess the efficacy and safety of these common treatments for PCOS by conducting a meta-analysis of RCTs with the following review questions: Which is the more appropriate therapeutic approach for hyperandrogenic symptoms, hyperandrogenemia, and ovulatory dysfunction in adult women with PCOS not seeking fertility; What is the impact on classic cardiometabolic risk factors of the more common treatments used in those women; Does the combination of the antiandrogenic therapy plus metformin have any impact on efficacy or cardiometabolic profile?

SEARCH METHODS

We searched PubMed and EMBASE for articles published up to 16 September 2017. After deleting duplicates, the abstracts of 1522 articles were analysed. We subsequently excluded 1446 articles leaving 76 studies for full-text assessment of eligibility. Of them, 43 articles were excluded. Hence, 33 studies and 1521 women were included in the quantitative synthesis and in the meta-analyses. Meta-analyses calculated mean differences (MD), standardized mean differences (SMD), odds ratio (OR) and 95% CIs. Heterogeneity and inconsistency across studies was assessed by χ2 test and Higgins's I2 statistics. Quality and risk of bias of individual studies were assessed according to the Cochrane Handbook for Systematic Reviews of Interventions 5.1.0. We then used the approach recommended by the Grading of Recommendations, Assessments, Development, and Evaluation (GRADE) group to indicate the global quality of evidence for a selection of primary outcomes.

OUTCOMES

Regarding efficacy, the MD in hirsutism score between COC and/or AA and metformin were not significant. The exclusion of one single study including most women with severe hirsutism yielded a significant effect in favour of COC and/or AA. When only those studies including an AA were compared with metformin, there were significant differences favouring antiandrogenic therapy. The combination of COC and/or AA with metformin was similar to COC and/or AA therapy alone in the whole group of patients. Post-intervention OR for the presence of regular menses favoured COC therapy. In terms of cardiometabolic impact, the MD in BMI were in favour of metformin. The negative effect of COC therapy on BMI was blunted by its combination with metformin. The MD in homoeostasis model assessment of insulin resistance (HOMA-IR) were also in favour of metformin therapy compared to COC and/or AA. The combination of COC and/or AA and metformin decreased MD in HOMA with respect to antiandrogenic therapy alone. There were no significant post-intervention SMD in circulating glucose levels between COC and/or AA and metformin. However, adding metformin to COC and/or AA yielded a beneficial effect on fasting glucose levels. Post-intervention OR for abnormal glucose tolerance showed no significant differences between COC and/or AA and metformin, although after excluding studies including an AA as a comparator (without COC) a significant effect in favour of metformin therapy was observed. There were no significant differences among therapies in lipid profile, blood pressure or prevalence of hypertension. The global quality of evidence was very low when addressing the impact of the treatments explored on prevalence of hypertension and lipid profiles, low in the case of hirsutism, BMI and blood pressure values, and high for endometrial protection and glucose tolerance.

WIDER IMPLICATIONS

These data provide further scientific evidence for the choice of treatment of women with PCOS. COC and AA are more effective than metformin for hyperandrogenic symptoms and endometrial protection. Their combination with metformin adds a positive effect on BMI and glucose tolerance.

PROSPERO CRD REGISTRATION NUMBER

CRD42016053457.

COMPARISON OF FINASTERIDE, METFORMIN, AND FINASTERIDE PLUS METFORMIN IN PCOS

The effects of finasteride on insulin resistance and of metformin on hyperandrogenism in patients with polycystic ovary syndrome (PCOS) are not clear. This study therefore compared the effects of finasteride, metformin, and finasteride plus metformin treatments on hormone levels, insulin resistance, and hirsutism score in women with PCOS. Fifty-two patients with PCOS were randomly assigned to receive finasteride 5 mg/day, metformin 1700 mg/day or finasteride plus metformin for 12 months. Body mass index (BMI), Ferriman Gallway score (FGS), serum concentrations of estradiol, sex hormone-binding globulin, free testosterone, dehydroepiandrosterone sulfate (DHEAS), androstenedione, and homeostasis model assessment of insulin resistance (HOMA-IR) index and areas under the curve (AUC) for insulin and glucose were evaluated before and after 12 months of treatment. Reductions in FGS, free testosterone, DHEAS, androstenedione, HOMA-IR, AUC-insulin, and AUC-glucose were significant within each group, whereas BMI and estradiol were not. Comparisons of changes in parameters in the 3 groups did not clearly show the superiority of any treatment modality. The treatment with finasteride alone significantly reduced both androgen levels and parameters of insulin resistance. In addition, metformin alone was effective, and not inferior to finasteride, in the treatment of hyperandrogenism.

Hereditary cancer syndromes as model systems for chemopreventive agent development

Research in chemoprevention has undergone a shift in emphasis for pragmatic reasons from large, phase III randomized studies to earlier phase studies focused on safety, mechanisms, and utilization of surrogate endpoints such as biomarkers instead of cancer incidence. This transition permits trials to be conducted in smaller populations and at substantially reduced costs while still yielding valuable information. This article will summarize some of the current chemoprevention challenges and the justification for the use of animal models to facilitate identification and testing of chemopreventive agents as illustrated though four inherited cancer syndromes. Preclinical models of inherited cancer syndromes serve as prototypical systems in which chemopreventive agents can be developed for ultimate application to both the sporadic and inherited cancer settings.

Regulation of Androgen Receptor Expression Alters AMPK Phosphorylation in the Endometrium: In Vivo and In Vitro Studies in Women with Polycystic Ovary Syndrome

The failure of reproductive success in polycystic ovary syndrome (PCOS) patients could be in part due to endometrial dysfunction. However, no studies have investigated any causality between androgen, androgen receptor (AR) expression, and adenosine monophosphate activated protein kinase (AMPK) activation in the endometrium under physiological and pathological conditions. In the present study, we show that 1) endometrial AR expression levels fluctuate in non-PCOS and PCOS patients during the menstrual cycle; 2) the menstrual phase-dependent alteration of p-AMPKα expression occurs in non-PCOS patients but not in PCOS patients; 3) AR expression is higher in PCOS patients than non-PCOS patients during hyperplasia while AMPKα activation (indicated by the ratio of p-AMPKα to AMPKα); and 4) co-localization of AR and Ki-67 in epithelial cell nuclei is observed in endometrial hyperplasia. Importantly, using in vitro human tissue culture and an in vivo 5α-dihydrotestosterone-treated rat model, we show that the action of androgen on AMPKα activation is likely mediated through nuclear AR, especially in epithelial cells. Collectively, we present evidence that AR expression and AMPKα activation depend on menstrual cycle phase and the presence of PCOS, and the data suggest that AR-mediated regulation of AMPKα activation might play a role in the development of endometrial hyperplasia.

Hyperandrogenism and Insulin Resistance, Not Changes in Body Weight, Mediate the Development of Endothelial Dysfunction in a Female Rat Model of Polycystic Ovary Syndrome (PCOS)

This study was designed to differentiate the contributions of hyperandrogenism, insulin resistance (IR), and body weight to the development of endothelial dysfunction in polycystic ovary syndrome and determine the effectiveness of insulin sensitization and antiandrogenic therapy after the establishment of vascular and metabolic dysfunction using a rat model of polycystic ovary syndrome. We hypothesized that the observed endothelial dysfunction was a direct steroidal effect, as opposed to changes in insulin sensitivity or body weight. Prepubertal female rats were randomized to the implantation of a pellet containing DHT or sham procedure. In phase 1, DHT-exposed animals were randomized to pair feeding to prevent weight gain or metformin, an insulin-sensitizing agent, from 5 to 14 weeks. In phase 2, DHT-exposed animals were randomized to treatment with metformin or flutamide, a nonsteroidal androgen receptor blocker from 12 to 16 weeks. Endothelial function was assessed by the vasodilatory response of preconstricted arteries to acetylcholine. Serum steroid levels were analyzed in phase 1 animals. Fasting blood glucose and plasma insulin were analyzed and homeostasis model assessment index calculated in all animals. Our data confirm the presence of endothelial dysfunction as well as increased body weight, hypertension, hyperinsulinemia, and greater IR among DHT-treated animals. Even when normal weight was maintained through pair feeding, endothelial dysfunction, hyperinsulinemia, and IR still developed. Furthermore, despite weight gain, treatment with metformin and flutamide improved insulin sensitivity and blood pressure and restored normal endothelial function. Therefore, the observed endothelial dysfunction is most likely a direct result of hyperandrogenism-induced reductions in insulin sensitivity, as opposed to weight gain.

Polycystic ovary syndrome: chemical pharmacotherapy

INTRODUCTION

Polycystic ovary syndrome (PCOS) is the most common reproductive endocrine disease among women of childbearing age. The clinical features are heterogeneous and vary in intensity. Hirsutism, menstrual disorders and infertility are the most frequent conditions observed; however, long-term complications (dyslipidemia, hypertension, cardiovascular disease, type 2 diabetes mellitus, endometrial cancer) are also often described. Each disorder may be managed by tailored strategies, employing sequential or combined pharmacological and/or non-pharmacological treatment.

AREAS COVERED

The authors review the drugs used for PCOS management and discuss new approaches. A systematic MEDLINE search regarding the randomized controlled trials, retrospective and observational studies about medical treatments of PCOS, the Cochrane library for reviews and also search for registered trials on ClinicalTrials.gov is performed.

EXPERT OPINION

A uniform treatment for PCOS patients does not exist. Clinicians should perform an accurate evaluation of patients' characteristics, identifying the phenotypic target and, subsequently, the best-tailored treatment to manage one or more clinical issues. Lifestyle intervention should always be the first recommended approach unless other issues indicate that drug or hormonal interventions are superior.

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.

No metabolic impact of surgical normalization of hyperandrogenism in postmenopausal women with ovarian androgen-secreting tumours

AIM

To examine the impact of surgical normalization of testosterone on body weight and on glucose and lipid metabolism and insulin sensitivity in a group of hyperandrogenic women with ovarian androgen-secreting tumours (OAST).

METHODS

Five consecutive postmenopausal hyperandrogenic patients (aged 63 ± 5 years) with a diagnosis of OAST were prospectively evaluated. Clinical signs, symptoms and metabolic and hormonal parameters were collected at the time of the diagnosis and at follow-up, 12 months after surgical oophorectomy. A group of 15 age-matched and body mass index-matched postmenopausal control women served as a reference group.

RESULTS

At baseline, patients with OAST had very high testosterone levels and inappropriately low gonadotrophin levels for their menopausal status. All the women were overweight or obese, and one had a history of polycystic ovary syndrome and Type 2 diabetes. Twelve months after surgical oophorectomy, testosterone and gonadotrophin levels returned to appropriate values for menopausal status in all patients; however, no change in body weight was found. Fasting glucose levels slightly increased (P < 0·05) without any significant change in other metabolic parameters. In the woman with diabetes, a moderate decrease in haemoglobin A1c occurred. Red blood cell count and haematocrit values were normalized (P < 0·05, respectively).

CONCLUSION

Normalization of androgen levels achieved after surgical oophorectomy did not cause any significant change in body weight and insulin sensitivity. These findings may offer a different perspective on the impact of hyperandrogenaemia on metabolism.

State of the Art Review: Emerging Therapies: The Use of Insulin Sensitizers in the Treatment of Adolescents with Polycystic Ovary Syndrome (PCOS)

PCOS, a heterogeneous disorder characterized by cystic ovarian morphology, androgen excess, and/or irregular periods, emerges during or shortly after puberty. Peri- and post-pubertal obesity, insulin resistance and consequent hyperinsulinemia are highly prevalent co-morbidities of PCOS and promote an ongoing state of excess androgen. Given the relationship of insulin to androgen excess, reduction of insulin secretion and/or improvement of its action at target tissues offer the possibility of improving the physical stigmata of androgen excess by correction of the reproductive dysfunction and preventing metabolic derangements from becoming entrenched. While lifestyle changes that concentrate on behavioral, dietary and exercise regimens should be considered as first line therapy for weight reduction and normalization of insulin levels in adolescents with PCOS, several therapeutic options are available and in wide use, including oral contraceptives, metformin, thiazolidenediones and spironolactone. Overwhelmingly, the data on the safety and efficacy of these medications derive from the adult PCOS literature. Despite the paucity of randomized control trials to adequately evaluate these modalities in adolescents, their use, particularly that of metformin, has gained popularity in the pediatric endocrine community. In this article, we present an overview of the use of insulin sensitizing medications in PCOS and review both the adult and (where available) adolescent literature, focusing specifically on the use of metformin in both mono- and combination therapy.

Type 2 diabetes and cardiovascular disease in polycystic ovary syndrome: what are the risks and can they be reduced?

Polycystic ovary syndrome (PCOS) is a risk factor for Type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD), but these risks are poorly defined. This study aimed to evaluate the evidence for these risks and whether screening and risk reduction are feasible. Medline reviews and data quality analysis were used using standard tools. Results showed that (i) polycystic ovary syndrome is a risk factor forT2DM but the magnitude of risk is uncertain, (ii) fasting plasma glucose is an inadequate screening test forT2DM in this population and the oral glucose tolerance test is superior, (iii) the identification of women with PCOS for diabetes screening is constrained by current diagnostic criteria for PCOS; however, women with oligomenorrhoea and those with diagnosed PCOS and obesity or a family history of T2DM are at highest risk, (iv) risk factors for T2DM are improved by weight loss interventions and by metformin. However, no studies have determined whether T2DM incidence is reduced, (v) polycystic ovary syndrome is associated with cardiovascular disease (CVD) risk factors but data on CVD incidence are weak, (vi) risk factors for CVD are improved by the same interventions and statins and (vi) no studies have evaluated whether CVD incidence is reduced. While PCOS has important metabolic associations, and short-term interventions reduce risk factors for T2DM and CVD, data on prevalence and incidence of T2DM and particularly CVD are poor. There is a need for a clear definition of PCOS, for diabetes screening protocols and for long-term studies to determine whether risks can be reduced.

Evidence-based and potential benefits of metformin in the polycystic ovary syndrome: a comprehensive review

Metformin is an insulin sensitizer widely used for the treatment of patients affected by type 2 diabetes mellitus. Because many women with polycystic ovary syndrome (PCOS) are insulin resistant, metformin was introduced in clinical practice to treat these patients also. Moreover, metformin's effect has other targets beside its insulin-sensitizing action. The present review was aimed at describing all evidence-based and potential uses of metformin in PCOS patients. In particular, we will analyze the uses of metformin not only for the treatment of all PCOS-related disturbances such as menstrual disorders, anovulatory infertility, increased abortion, or complicated pregnancy risk, hyperandrogenism, endometrial, metabolic and cardiovascular abnormalities, but also for the prevention of the syndrome.

Use of metformin in polycystic ovary syndrome

Women with polycystic ovary syndrome (PCOS) have a myriad of phenotypic and clinical features that may guide therapeutic options for metabolic protection and ovulation induction. The use of metformin may prove beneficial in a subset of the population of women with PCOS. Hyperinsulinemia, as demonstrated by elevated insulin levels on a 2-hour 75-g load glucose tolerance test, is an important parameter in deciding whether or not to initiate metformin therapy to women with PCOS with the hope of preventing or delaying the onset of type 2 diabetes mellitus (DM). Cardiovascular risk factors including markers of subclinical inflammation, and dyslipidemia may also be improved by metformin therapy. For ovulation induction, metformin is not as effective as clomiphene citrate as first-line therapy for women with PCOS. There are no clear data to suggest that metformin reduces pregnancy loss or improves pregnancy outcome in PCOS, and it is currently recommended that metformin be discontinued with the first positive pregnancy test result, unless there are other medical indications (eg, type 2 DM). This review addresses practical management guidelines for the uses of metformin in women with PCOS.

Effects of androgens on insulin action in women: is androgen excess a component of female metabolic syndrome?

Hyperinsulinemia as a consequence of insulin resistance causes hyperandrogenemia in women. The objective was to review evidence for the converse situation, i.e. whether androgens adversely influence insulin action. Androgen excess could potentially contribute to the pathogenesis of insulin resistance in women with polycystic ovary syndrome (PCOS), metabolic syndrome/type 2 diabetes, and in obese peripubertal girls. An Entrez-PubMed search was conducted to identify studies addressing the relationship of androgens with metabolic syndrome/type 2 diabetes in women. Studies reporting outcomes of androgen administration, interventions to reduce androgen effects in hyperandrogenemic women, and basic studies investigating androgen effects on insulin target tissues were reviewed. Multiple studies showed associations between serum testosterone and insulin resistance or metabolic syndrome/type 2 diabetes risk in women, but their cross-sectional nature did not allow conclusions about causality. Androgen administration to healthy women was associated with development of insulin resistance. Intervention studies in women with hyperandrogenism were limited by small subject numbers and use of indirect methods for assessing insulin sensitivity. However, in three of the seven studies using euglycemic hyperinsulinemic clamps, reduction of androgen levels or blockade of androgen action improved insulin sensitivity. Testosterone administration to female rats caused skeletal muscle insulin resistance. Testosterone induced insulin resistance in adipocytes of women in vitro. In conclusion, the metabolic consequences of androgen excess in women have been under-researched. Studies of long-term interventions that lower androgen levels or block androgen effects in young women with hyperandrogenism are needed to determine whether these might protect against metabolic syndrome/type 2 diabetes in later life.

Polycystic ovarian syndrome: pathophysiology, molecular aspects and clinical implications

Polycystic ovarian syndrome (PCOS) is universally recognised as the commonest endocrinopathy of women. The definition and the aetiological hypotheses of PCOS are continuously evolving to accommodate expanding knowledge on the syndrome, which is now known to be more complex than purely a reproductive disorder. Increased androgen synthesis, disrupted folliculogenesis and insulin resistance lie at the pathophysiological core of PCOS. An intriguing concept involves the perpetuation of a vicious circle with endocrine/reproductive and metabolic components. An unfavourable metabolic environment may unmask genetic traits of ovarian dysfunction, and the unfolding endocrine derangement could further aggravate the metabolic disarray. This article reviews the molecular mechanisms known to underlie the ovarian and metabolic abnormalities characterising PCOS. The putative interdependence between reproductive and metabolic aspects of PCOS, and therapeutic implications for the management of PCOS, are also discussed.

Metformin and polycystic ovary syndrome

PURPOSE OF REVIEW

The aim of this article is to describe the role of insulin resistance in the etiology of polycystic ovary syndrome and to review the results of treatment with the insulin sensitizing drug metformin.

RECENT FINDINGS

Polycystic ovary syndrome is a heterogeneous combination of clinical, hormonal, and reproductive abnormalities associated with insulin resistance and increased cardiovascular risk factors. Reduction of hyperinsulinism and improvement of insulin sensitivity with metformin has been reported to ameliorate these abnormalities in many, but not all studies, with few adverse effects.

SUMMARY

Metformin may be the drug of first choice for most, if not all women with polycystic ovarian syndrome, either alone or in combination with other treatments. Further investigation is necessary to determine the optimal dose and duration of treatment necessary to maximize response.

Sustainability of 8% weight loss, reduction of insulin resistance, and amelioration of atherogenic-metabolic risk factors over 4 years by metformin-diet in women with polycystic ovary syndrome

In 74 women with polycystic ovary syndrome, treated for 4 years with metformin (MET) and diet, we prospectively assessed whether, and to what degree, weight loss, reduction of insulin resistance, and amelioration of coronary heart disease risk factors could be sustained. We hypothesized that response to MET-diet would not differ by pretreatment body mass index (BMI) classes <25 (normal), > or =25 to <30 (overweight), > or =30 to <40 (obese), and > or =40 (extremely obese). [table: see text] Metformin-diet was successful in producing stable approximately 8% weight reduction for all 4 years (trend P < .0001). Percentage of reductions in weight on MET-diet was significant (P < .05) and did not differ among the 3 highest BMI categories (> or =40, > or =30 to <40, > or =25 to <30), but were not significant in the normal-weight category (BMI, <25). On MET-diet, median homeostasis model assessment of insulin resistance (HOMA-IR) was 33% lower than entry at 1 year, 50% at 2 years, 51% at 3 years, and 50% at 4 years (trend, P < .0001). On MET-diet, median low-density lipoprotein cholesterol (LDL-C) was 6% lower than entry at year 1, 6% at year 2, 7% at year 3, and 11% at year 4 (trend P < .0001). On MET-diet, median high-density lipoprotein cholesterol (HDL-C) was 3% higher than entry at year 2, 8% higher at year 3, and 11% higher at year 4 (trend P < .0001). Percentage of reductions in HOMA-IR, LDL-C, triglyceride, and systolic blood pressure, and increments in HDL-C did not differ (P > .1) in the 4 BMI categories. By stepwise regression, weight loss was a significant (P < or = .01) positive explanatory variable for reduction in HOMA-IR for all 4 follow-up years. Metformin-diet in women with polycystic ovary syndrome effectively and safely reduces weight and LDL-C while raising HDL-C, and maintains these outcomes stable over 4 years.

Chromium picolinate improves insulin sensitivity in obese subjects with polycystic ovary syndrome

Trivalent chromium (1000 microg), as chromium picolinate, given without change in diet or activity level, caused a 38% mean improvement in glucose disposal rate in five obese subjects with polycystic ovary syndrome who were tested with a euglycemic hyperinsulinemic clamp technique. This suggests that chromium picolinate, an over-the-counter dietary product, may be useful as an insulin sensitizer in the treatment of polycystic ovary syndrome.

Low-dose flutamide-metformin therapy for hyperinsulinemic hyperandrogenism in non-obese adolescents and women

Polycystic ovary syndrome (PCOS) is a variable disorder that is characterized in adolescents and young women by a broad spectrum of anomalies, including hyperandrogenemia, insulin resistance, dyslipidemia, body adiposity and low-grade inflammation. At present, there is no approved therapy for PCOS. Recent studies indicate that a low-dose combination of flutamide (Flu; a generic androgen-receptor blocker) and metformin (Met; a generic insulin-sensitizer) normalizes the adolescent PCOS spectrum more than an oral contraceptive (OC); in young women, the PCOS spectrum was found to be more normalized by OC plus Flu-Met than by OC alone. Within the pathophysiological cascade of PCOS, Flu-Met seems to counter upstream anomalies like hyperinsulinemia or hyperandrogenism, thereby preventing or reversing downstream effects. In contrast, an OC essentially masks downstream symptoms like hirsutism, acne or irregular menses, whereas the upstream aberrations remain unaltered or may even be worsened. The available experience with Flu-Met is limited but promising. We emphasize that Flu-Met may (as part of its efficacy) induce ovulation but is contra-indicated post-conception because of potential embryotoxicity; therefore, it seems wise to combine Flu-Met with an oral or a transdermal oestro-progestagen or with a non-endocrine method of contraception. May this update prompt further research into Flu-Met's therapeutic potential in patients with PCOS. Until the abovementioned effects have been broadly confirmed, Flu-Met should not be regarded as a standard therapy for widespread clinical practice.

Use of metformin for prevention of ovarian hyperstimulation syndrome: a novel approach

In the present study, which includes 287 participants, metformin has been used by women undergoing IVF/intracytoplasmic sperm injection for more than 5 weeks before and during treatment and during luteal phase. There was no significant difference in number of gonadotrophins used, days of stimulation, number of oocytes retrieved, and number of embryos replaced. There was no significant difference in clinical pregnancy rate between both groups but there was significant reduction in the incidence of ovarian hyperstimulation syndrome (OHSS) in the group taking metformin. Metformin is a safe, cheap drug that can help in prevention of OHSS.