Metformin administration is more effective when non-obese patients with polycystic ovary syndrome show both hyperandrogenism and hyperinsulinemia

Polycystic Ovary Syndrome as Metabolic Disease: New Insights on Insulin Resistance

Polycystic ovary syndrome (PCOS) is a very frequent disease that affects reproductive ability and menstrual regularity. Other than the criteria established at the Rotterdam consensus, in these last few years a new issue, insulin resistance, has been found frequently, and at a very high grade, in patients with PCOS. Insulin resistance occurs for several factors, such as overweight and obesity, but it is now clear that it occurs in patients with PCOS with normal weight, thus supporting the hypothesis that insulin resistance is independent of body weight. Evidence shows that a complex pathophysiological situation occurs that impairs post-receptor insulin signalling, especially in patients with PCOS and familial diabetes. In addition, patients with PCOS have a high incidence of non-alcoholic fatty liver disease related to the hyperinsulinaemia. This narrative review focuses on the recent new insights about insulin resistance in patients with PCOS, to better understand the metabolic impairment accounting for most of the clinical signs/symptoms of PCOS.

PCOS and Assisted Reproduction Technique: Role and Relevance of Inositols

Polycystic ovary syndrome is an endocrine disorder often characterized by insulin resistance and hyperinsulinemia, especially in overweight/obese women. Among insulin sensitizers, the positive role of inositols has been increasingly established in recent years. The action of inositols not only concerns the metabolic parameters of these patients, but also the hormonal profile, resulting in beneficial effects on ovarian function. For this reason, many studies have tried to recognize their role in PCOS infertile women who underwent in vitro fertilization (IVF) procedures.

Effects of L-carnitine on Polycystic Ovary Syndrome

Objective:

Polycystic ovary syndrome (PCOS) is a common disorder in women of reproductive age. This study investigated the effects of L-carnitine on the clinical and laboratory findings of women with PCOS.

Methods:

Eighty women diagnosed with PCOS between 2017 and 2018 by the Rotterdam Criteria were enrolled in the study; six were lost during the study. The participants were given L-carnitine 3 g daily (Pursinapharma, Iran) for three months. Blood samples were taken after overnight fasting at baseline and three months into the study to assess the levels of fasting glucose, insulin, triglycerides, high-density lipoprotein (HDL), low-density lipoprotein (LDL), free testosterone, dehydroepiandrosterone (DHEA), and the insulin resistance index (HOMA-IR). The patients were weighed before and after treatment and had their body mass index (BMI) calculated. Menstrual cycles and manifestations of hirsutism were also assessed.

Results:

The data showed a significant improvement in insulin sensitivity and decreases in serum LDL levels and the BMI after three months of treatment. There was a significant increase in serum HDL levels. More regular menstrual cycles and decreased hirsutism were also observed.

Conclusion:

It appears that treatment with L-carnitine might decrease the risk of cardiovascular events by normalizing metabolic profiles and the BMI.

Defective insulin signaling and the protective effects of dimethyldiguanide during follicular development in the ovaries of polycystic ovary syndrome

It is established that the physiological effects of insulin are primarily mediated by the insulin signaling pathway. However, a defective insulin signaling is closely associated with the clinical manifestations of polycystic ovary syndrome (PCOS), which include excess androgen levels, insulin resistance and anovulation, and is involved in the pathophysiology of PCOS at the molecular level. Dimethyldiguanide (DMBG) has been widely employed to alleviate reproduction dysfunction in women with PCOS, however, the exact mechanism of this effect remains unclear. The objective of the present study was to investigate the effects of DMBG on the expression of the insulin signaling pathway in the ovaries of rats with PCOS, and to identify the potential underlying molecular mechanisms of these effects in PCOS. In the present study, a PCOS rat model was induced by letrozole, and successful establishment of the model was confirmed by examining ovarian histology and determining serum testosterone levels, by hematoxylin and eosin staining and ELISA, respectively. Subsequently, the expression of two key elements of insulin signaling, insulin receptor substrate (IRS)‑2 and phosphatidylinositol 3‑kinase (PI3K), was determined by immunohistochemistry and western blot analysis. The results demonstrated that IRS‑2 and PI3K expression was markedly decreased in PCOS ovaries, which was rescued by DMBG treatment. These results indicate that IRS‑2/PI3K signaling may be involved in the development of PCOS and the therapeutic effects of DMBG on PCOS. To further confirm the effects of DMBG on insulin signaling expression during this process, the expression of an additional two downstream proteins, phosphoinositide‑dependent kinase‑1 (PDK‑1) and the mammalian target of rapamycin (mTOR), was also investigated in the present study, and the results demonstrated that the expression of PDK‑1 and mTOR was significantly reduced in PCOS ovaries and increased following DMBG treatment, further indicating that altered insulin signaling may have an important role in the development and treatment of PCOS. In conclusion, the results of the present study indicate that the reduced expression of proteins involved in insulin signaling may contribute to the development of the clinical features of PCOS, and DMBG reverses reduced expression of insulin signaling components, by a mechanism that is yet to be determined, to attenuate certain symptoms of PCOS, such as obesity. To the best of our knowledge, the present study is the first to provide data regarding the detailed changes of insulin signaling during the development and treatment of PCOS, and may provide an important reference for clinical PCOS treatment.

Ovulation induction by metformin among obese versus non-obese women with polycystic ovary syndrome

OBJECTIVES

There is some evidence that the efficacy of metformin as an ovulation stimulation agent depends on the body mass index (BMI) of the treated anovulatory women with polycystic ovary syndrome (PCOS). The aim of this study was to examine the likelihood of successful ovulation among obese (BMI ⩾30 kg/m²) versus non-obese (BMI <30 kg/m²) women with PCOS.

METHODS

A total of 243 medical charts of women with PCOS who visited King Khaled University Hospital (KKUH) in Riyadh, Saudi Arabia, between 2006 and 2012 were reviewed. Patients' sociodemographic, laboratory, and medical data were collected. Descriptive statistics and multiple logistic regression analyses were performed to compare the patients' baseline data and successful ovulation among the obese and non-obese anovulatory women with PCOS, respectively.

RESULTS

One hundred and nine women with PCOS who were prescribed metformin for ⩾3 months were included in the study. Almost 60% of the women who were included in the study were obese. The likelihood of ovulation among obese women with PCOS was 77.9% (odds ratio = 0.221, 95% CI 0.052-0.947, P = 0.042) less than that in their non-obese counterparts.

CONCLUSION

The findings of this study suggest that metformin is more effective as an ovulation stimulation agent when administered to non-obese women with PCOS. Lifestyle modifications such as diet and exercise should be emphasized upon as an integral part of any treatment plan for PCOS.

Inositol and In Vitro Fertilization with Embryo Transfer

Recently, studies on inositol supplementation during in vitro fertilization program (IVF) have gained particular importance due to the effect of this molecule on reducing insulin resistance improving ovarian function, oocyte quality, and embryo and pregnancy rates and reducing gonadotropin amount during stimulation. Inositol and its isoforms, especially myoinositol (MYO), are often used as prestimulation therapy in infertile patients undergoing IVF cycle. Inositol supplementation started three months before ovarian stimulation, resulting in significant improvements in hormonal responses, reducing the amount of FSH necessary for optimal follicle development and serum levels of 17beta-estradiol measured the day of hCG injection. As shown by growing number of trials, MYO supplementation improves oocyte quality by reducing the number of degenerated and immature oocytes, in this way increasing the quality of embryos produced. Inositol can also improve the quality of sperm parameters in those patients affected by oligoasthenoteratozoospermia.

Combining treatment with myo-inositol and D-chiro-inositol (40:1) is effective in restoring ovary function and metabolic balance in PCOS patients

Polycystic ovary syndrome (PCOS), a relevant cause of infertility, is a heterogeneous, endocrine disorder affecting up to 10-15% of women in reproductive age. Besides hyperandrogenism, insulin resistance (IR) plays a key role in such syndrome. Insulin-sensitizing drugs, such as Metformin, are effective in treating hyper-insulinemic PCOS patients. Recently, inositols - myo-inositol (MI) and D-chiro-inositol (DCI) - have shown to be an efficient and safe alternative in PCOS management, as both inositol isoforms are able to counteract downstream consequences of insulin resistance. Yet, whereas DCI contributes in mediating insulin activity mainly on non-ovarian tissues, MI displays specific effects on ovary, chiefly by modulating glucose metabolism and FSH-signaling. Moreover, MI may also improve ovarian functions by modulating steroid metabolism through non-insulin-dependent pathways. As DCI and MI activity likely involves different biological mechanisms, both inositol isoforms can be synergistically integrated according to a multitargeted design, by combining MI and DCI in a ratio corresponding to their physiological plasma relative amount (40:1). New experimental and clinical evidence with MI plus DCI evidenced the suitability of such integrated approach, and provided promising results. Further studies need to investigate thoroughly the molecular mechanism and confirm such preliminary data.

Metformin improved health-related quality of life in ethnic Chinese women with polycystic ovary syndrome

Background

Few studies have assessed whether the amelioration of the clinical signs of polycystic ovary syndrome (PCOS) achieved by treatment leads to improvement in the health-related quality of life (HRQoL) of patients. This study was aimed to examine the HRQoL of ethnic Chinese women with PCOS who received metformin treatment.

Methods

This prospective study was conducted at a medical center in Taiwan. Study participants aged 18–45 years were diagnosed as having PCOS according to the Rotterdam criteria, and all received metformin treatment. Their HRQoL was assessed using generic (WHOQOL-Bref) and PCOS-specific (Chi-PCOSQ) instruments. Mixed effect models were used to examine the effects of metformin on repeatedly measured HRQoL. Additional analyses using stratified patients characteristics (overweight vs. normal; hyperandrogenism vs. non-hyperandrogenism) were done.

Results

We recruited 109 participants (56 % were overweight, 80 % had hyperandrogenism). Among the domain scores of WHOQOL-Bref, the psychological domain score was the lowest one (12.64 ± 2.2, range 4–20). Weight (3.25 ± 1.59, range 1–7) and infertility (3.38 ± 1.93, range 1–7) domain scores were relatively low among the domain scores of Chi-PCOSQ. Overweight and hyperandrogenic patients had significantly lower HRQoL as compared with those of normal weight and non-hyperandrogenic patients, respectively. Metformin significantly improved the physical domain of WHOQOL-Bref (p = 0.01), and the infertility (p = 0.043) and acne and hair loss aspects (p = 0.008) of PCOS-specific HRQoL. In the subgroup analysis, significantly improved HRQoL following metformin treatment appeared for only overweight and hyperandrogenism subgroups.

Conclusions

Metformin might improve health-related quality of life of polycystic ovary syndrome women by ameliorating psychological disturbances due to acne, hair loss and infertility problems, especially for overweight and hyperandrogenic patients.

Reflections on inositol(s) for PCOS therapy: steps toward success

In polycystic ovary syndrome (PCOS) pathogenesis, both the insulin resistance and the related compensatory hyperinsulinemia are involved. Despite their similarities, Myo-inositol (MI) and d-chiro-inositol (DCI) play different roles in PCOS etiology and therapy. Indeed, in tissue such as the liver both molecules are involved in the insulin signaling, i.e. MI promotes glucose uptake and DCI glycogen synthesis. In reproductive tissue such as the ovary, MI regulates glucose uptake and follicle stimulating hormone (FSH) signaling, whereas DCI is devoted to the insulin-mediated androgen production. The new hypothesis on "DCI paradox" in the ovary has provided the key for a better understanding. Unlike other tissues, ovary is not insulin resistant, indeed because the epimerase enzyme, which converts MI to DCI, is insulin dependent, the "DCI paradox" hypothesis suggests that in the ovary of PCOS women, an increased epimerase activity leads to a DCI overproduction and MI depletion. This imbalance could be the cause of the poor oocyte quality and the impairment in the FSH signaling. Owing to this situation, the focal point is the administration of both MI and DCI in a proper ratio for treating PCOS. This topic, with several other "hot" issues, was the driving thread in the discussion between the two scientists.

Modulatory role of D-chiro-inositol (DCI) on LH and insulin secretion in obese PCOS patients

Polycystic ovary syndrome (PCOS) is a common endocrine condition that affects fertility through oligo-ovulation, hyperandrogenism and polycystic morphology of the ovaries. Since it has been demonstrated a high incidence of insulin resistance in PCOS patients, our study aimed to evaluate the efficacy of the integrative treatment with D-chiro-inositol (DCI) (500 mg die, per os, for 12 weeks) on hormonal parameters and insulin sensitivity in a group of overweight/obese PCOS patients (body mass index; BMI > 26). After the treatment, interval several endocrine parameters improved (luteinizing hormone [LH], LH/follicle stimulating hormone [FSH], androstenedione and insulin), insulin response to oral glucose tolerance test reported the significant improvement of insulin sensitivity as well as the gonadotropin-releasing hormone (GnRH)-induced (10 µg, in bolus) LH response. BMI decreased, though no lifestyle modification was requested. When data were analyzed according to the presence or absence of first-grade diabetic relatives, PCOS patients with diabetic relatives showed greater improvement after DCI administration. In conclusion DCI administration is effective in restoring better insulin sensitivity and an improved hormonal pattern in obese hyperinsulinemic PCOS patients, in particular, in hyperinsulinemic PCOS patients who have diabetic relatives.

Effects of the insulin sensitizer pioglitazone on menstrual irregularity, insulin resistance and hyperandrogenism in young women with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common endocrine cause of menstrual irregularities, hirsutism and acne. Women with PCOS present elevated plasma insulin levels, both fasting and after a glucose load, as an indirect evidence of insulin resistance. PCOS women may also present hypertension, low levels of HDL cholesterol, hypertriglyceridemia, visceral obesity and a higher level of CRP and fibrinogen that can predict an atherosclerotic risk.

METHODS

This study was carried out on 15 young women with PCOS selected according to the 2003 diagnostic criteria of The Rotterdam Consensus Statement and 15 Control women. PCOS women were treated with pioglitazone 30 mg/day and at the beginning and after 6 months of treatment were evaluated: menstrual cycle trend, hirsutism and acne, total cholesterolemia and HDL, triglyceridemia, fibrinogenemia, C-reactive protein, oral glucose tolerance test, glycated hemoglobin, FSH, LH, 17OH-progesterone, 17β-estradiol, free and total testosterone, SHBG, DHEA-S, Δ4-androstenedione and adiponectin.

RESULTS AND DISCUSSION

Treatment with pioglitazone improves the irregularities of menses and hirsutism. Six months of treatment modify other parameters linked with a higher risk of type 2 diabetes mellitus and cardiovascular diseases: adiponectin increased with reduction of insulin resistance while fibrinogen and CRP levels decreased.

Myo-inositol modulates insulin and luteinizing hormone secretion in normal weight patients with polycystic ovary syndrome

AIM

To investigate hormonal dynamics in a group of non-obese polycystic ovary syndrome (PCOS) patients under myo-inositol (MYO) administration.

METHODS

Hormonal profiles, insulin response to oral glucose tolerance test (OGTT) and luteinizing hormone (LH) response to gonadotropin-releasing hormone (GnRH) stimulation test before and after the administration of a preparation of MYO (3 g p.o. daily) mixed with lactoferrin and bromelin, in a group (n = 24) of normal weight PCOS patients.

RESULTS

After the treatment interval, body mass index (BMI) did not change while LH, LH/follicle-stimulating hormone, 17-hydroxy-progesterone and androstenedione decreased significantly. Insulin response to OGTT was significantly reduced after the treatment interval (P < 0.05) as well as GnRH-induced LH response (P < 0.05). High-sensitivity C-reactive protein decreased significantly after the treatment interval.

CONCLUSION

MYO administration positively modulates insulin sensitivity in non-obese PCOS patients without compensatory hyperinsulinemia, improving hormonal parameters. The presence of bromelin in the formulation modulated the pro-inflammatory state that characterizes PCOS, independently of BMI.

Endocrine and clinical effects of myo-inositol administration in polycystic ovary syndrome. A randomized study

OBJECTIVE

To evaluate the effects the administration of myo-inositol (MYO) on hormonal parameters in a group of polycystic ovary syndrome (PCOS) patients.

DESIGN

Controlled clinical study.

SETTING

PCOS patients in a clinical research environment.

PATIENTS

50 overweight PCOS patients were enrolled after informed consent.

INTERVENTIONS

All patients underwent hormonal evaluations and an oral glucose tolerance test (OGTT) before and after 12 weeks of therapy (Group A (n¼10): MYO 2 g plus folic acid 200 mg every day; Group B (n¼10): folic acid 200 mg every day). Ultrasound examinations and Ferriman-Gallwey score were also performed.

MAIN OUTCOME MEASURES

Plasma LH, FSH, PRL, E2, 17OHP, A, T, glucose, insulin, C peptide concentrations, BMI, HOMA index and glucose-to-insulin ratio.

RESULTS

After 12 weeks of MYO administration plasma LH, PRL, T, insulin levels and LH/FSH resulted significantly reduced. Insulin sensitivity, expressed as glucose-to-insulin ratio and HOMA index resulted significantly improved after 12 weeks of treatment. Menstrual cyclicity was restored in all amenorrheic and oligomenorrheic subjects. No changes occurred in the patients treated with folic acid.

CONCLUSIONS

MYO administration improves reproductive axis functioning in PCOS patients reducing the hyperinsulinemic state that affects LH secretion.

Differential insulin response to myo-inositol administration in obese polycystic ovary syndrome patients

Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism, chronic anovulation, polycystic ovaries at ultrasound evaluation, and quite frequently by insulin resistance or compensatory hyperinsulinemia. Attention has been given to the role of inositol-phosphoglycan (IPG) mediators of insulin action and growing evidences suggest that a deficiency of D-chiro-inositol (DCI) containing IPG might be at the basis of insulin resistance, frequent in PCOS patients. On such basis, we investigated the efficacy on insulin sensitivity and hormonal parameters of 8 weeks treatment with myo-inositol (MYO) (Inofert, ItalPharmaco, Milano, Italy) at the dosage of 2 g day in a group (n = 42) of obese PCOS patients,. After the treatment interval body mass index (BMI) and insulin resistance decreased together with luteinizing hormone (LH), LH/FSH and insulin. When subdividing the patients according to their fasting insulin levels, Group A (n = 15) insulin below 12 µU/ml and Group B (n = 27) insulin above 12 µU/ml, MYO treatment induced similar changes in both groups but only patients of Group B showed the significant decrease of both fasting insulin plasma levels (from 20.3 ± 1.8 to 12.9 ± 1.8 µU/ml, p < 0.00001) and of area under the curve (AUC) of insulin under oral glucose tolerance test (OGTT). In conclusion, our study supports the hypothesis that MYO administration is more effective in obese patients with high fasting insulin plasma levels.

Effects of myo-inositol in women with PCOS: a systematic review of randomized controlled trials

Polycystic ovary syndrome (PCOS) affects 5%-10% of women in reproductive age, and it is the most common cause of infertility due to ovarian dysfunction and menstrual irregularity. Several studies have reported that insulin resistance is common in PCOS women, regardless of the body mass index. The importance of insulin resistance in PCOS is also suggested by the fact that insulin-sensitizing compounds have been proposed as putative treatments to solve the hyperinsulinemia-induced dysfunction of ovarian response to endogenous gonadotropins. Rescuing the ovarian response to endogenous gonadotropins reduces hyperandrogenemia and re-establishes menstrual cyclicity and ovulation, increasing the chance of a spontaneous pregnancy. Among the insulin-sensitizing compounds, there is myo-inosiol (MYO). Previous studies have demonstrated that MYO is capable of restoring spontaneous ovarian activity, and consequently fertility, in most patients with PCOS. With the present review, we aim to provide an overview on the clinical outcomes of the MYO use as a treatment to improve ovarian function and metabolic and hormonal parameters in women with PCOS.

Use of metformin in the treatment of polycystic ovary syndrome

Metformin is quite an old drug, but it is optimal for the control of glycemia in Type 2 diabetes. It was reported, 15 years ago, that insulin resistance was abnormally high in most polycystic ovary syndrome (PCOS) patients. Starting from that moment, increasing numbers of studies were performed to demonstrate the efficacy of metformin in controlling and/or modulating several aspects of PCOS, which is the most common cause of menstrual irregularity, inesthetisms and infertility. Metformin induces higher glucose uptake, thus inducing a lower synthesis/secretion of insulin. Such an effect permits the possible restoration of the normal biological functions that are severely affected by the compensatory hyperinsulinemia reactive to the increased peripheral insulin resistance. These are the basis of the many positive effects of this drug, such as the restoration of menstrual cyclicity, ovulatory cycles and fertility, because abnormal insulin levels affect the hypothalamus-pituitary-ovarian function, as well as the use of glucose in peripheral tissues. Metformin improves the impairments typically observed in hyperinsulinemic PCOS patients, reducing the possible evolution towards metabolic syndrome and Type 2 diabetes; and when pregnancy occurs, it consistently reduces the risk of gestational diabetes, eclampsia and hypertension. PCOS seems to be the perfect physiopathological condition that might have higher benefits from metformin administration, obviously after Type 2 diabetes. This review focuses on the many aspects of PCOS and on the possible issues of this disease for which metformin might be a putative optimal treatment.

Prenatal androgenization of female mice programs an increase in firing activity of gonadotropin-releasing hormone (GnRH) neurons that is reversed by metformin treatment in adulthood

Prenatal androgenization (PNA) of female mice with dihydrotestosterone programs reproductive dysfunction in adulthood, characterized by elevated luteinizing hormone levels, irregular estrous cycles, and central abnormalities. Here, we evaluated activity of GnRH neurons from PNA mice and the effects of in vivo treatment with metformin, an activator of AMP-activated protein kinase (AMPK) that is commonly used to treat the fertility disorder polycystic ovary syndrome. Estrous cycles were monitored in PNA and control mice before and after metformin administration. Before metformin, cycles were longer in PNA mice and percent time in estrus lower; metformin normalized cycles in PNA mice. Extracellular recordings were used to monitor GnRH neuron firing activity in brain slices from diestrous mice. Firing rate was higher and quiescence lower in GnRH neurons from PNA mice, demonstrating increased GnRH neuron activity. Metformin treatment of PNA mice restored firing activity and LH to control levels. To assess whether AMPK activation contributed to the metformin-induced reduction in GnRH neuron activity, the AMPK antagonist compound C was acutely applied to cells. Compound C stimulated cells from metformin-treated, but not untreated, mice, suggesting that AMPK was activated in GnRH neurons, or afferent neurons, in the former group. GnRH neurons from metformin-treated mice also showed a reduced inhibitory response to low glucose. These studies indicate that PNA causes enhanced firing activity of GnRH neurons and elevated LH that are reversible by metformin, raising the possibility that central AMPK activation by metformin may play a role in its restoration of reproductive cycles in polycystic ovary syndrome.

Polycystic ovary syndrome: challenges in adolescence

Polycystic ovary syndrome (PCOS) is one of the most common endocrine diseases in women of reproductive age. PCOS typically develops during adolescence and is a heterogeneous syndrome classically characterized by features of anovulation combined with signs of androgen excess (hirsutism, acne). Increasing obesity in adolescents probably exacerbates signs of PCOS, contributing to its earlier recognition. Recognizing the features of this syndrome can be very challenging in adolescence. Although adolescents' concerns are often cosmetic, if left untreated these girls are at risk for diabetes, metabolic syndrome, and infertility as they mature. Efforts should be made to diagnose and treat PCOS to minimize the development of symptoms and prevent the onset of cardiovascular and metabolic disturbances.

Angiotensin converting enzyme gene insertion/deletion polymorphism in patients with polycystic ovary syndrome

OBJECTIVE

The aim of this study is to investigate the relevance of polymorphism in angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism to the pathophysiology of polycystic ovary syndrome (PCOS).

SUBJECTS AND METHODS

Thirty patients with PCOS by Rotterdam consensus criteria and 33 control subjects were prospectively investigated. ACE gene amplification of DNA was performed by polymerase chain reaction. Homeostatic model assessment (HOMA-IR) was applied.

RESULTS

Compared to controls, ACE gene DD genotype and D allele were observed more frequently in PCOS (63% vs. 46% for DD genotype and 75% vs. 67% for D allele) (p > 0.05). Body mass index, fasting glucose and insulin levels, HOMA-IR index and total testosterone levels were higher in PCOS group (p < 0.05). The frequencies of D and I alleles were 45 (75%) and 15 (25%) for PCOS group and 44 (67%) and 22 (33%) for control group (p > 0.05). No significant differences were observed in the genotype and allele distributions between cases and control groups. HOMA-IR index was significantly higher in patients with PCOS with DD genotype than those with II genotype (p < 0.05).

CONCLUSION

The ACE gene polymorphism was not associated with PCOS. However, the presence of D allele was associated with higher rate of insulin resistance in patients with PCOS.

Metformin administration was associated with a modification of LH, prolactin and insulin secretion dynamics in women with polycystic ovarian syndrome

AIM. To elucidate the dynamics of FSH, LH, prolactin (PRL), TSH and insulin secretion in women with polycystic ovarian syndrome (PCOS) treated with metformin (MET).

PATIENTS AND METHODS

In a prospective, controlled and randomised trial, 32 women with PCOS and 32 with normal cycle were recruited to receive MET (850 mg b.i.d.) or placebo (n: 16 for each subgroup) for an average of 40 days. Pituitary function and insulin secretion were assessed before and after intervention by GnRH-TRH tests and oral glucose tolerance test induced insulin response.

RESULTS

Basal and area under the response curve (AURC) LH values were higher in PCOS than in normal controls before MET and declined following treatment in the former group (P < 0.05). Ovulatory PCOS responders had lower basal LH, AURC(LH) and AURC(PRL) values during MET than anovulatory cases (P < 0.05 for all) and AURCins was lower in ovulatory than anovulatory PCOS before and on MET (P < 0.02-P < 0.05), with a rise of QUICKY index in the former group during MET treatment (P < 0.05). FSH and TSH were similar.

CONCLUSIONS

MET administration lowered LH activity in all PCOS women and in ovulatory responders and also compromised PRL stimulated secretion in the latter cases. These findings were indicative of an effect of MET on pituitary activity.

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 metformin and ethinyl estradiol-cyproterone acetate on clinical, endocrine and metabolic factors in women with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is a major endocrine abnormality that affects women of reproductive age. Oral contraceptive pills are usually the first choice of treatment for PCOS when fertility is not desired. Metformin, an insulin-sensitizing drug, has been shown to improve such metabolic abnormality. Aim. To compare the effects of a contraceptive pill in combination with metformin on the clinical, endocrine and metabolic parameters in obese and non-obese patients with PCOS.

METHODS

Sixty PCOS patients (25 obese, 35 non-obese) were enrolled in this prospective clinical study. PCOS was defined according to the Rotterdam criteria. Patients were randomized to oral treatment with Diane35 (35 microg ethinyl estradiol plus 2 mg cyproterone acetate), metformin or a combination of Diane35/metformin for 3 months. Body mass index (BMI), waist-to-hip ratio (WHR), Ferriman-Gallwey (FG) score, leuteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, fasting insulin and glucose/insulin ratio were measured at baseline and at the end of treatment.

RESULTS

Diane35 resulted in a higher reduction of FG score in both obese and non-obese PCOS patients compared with metformin. Menstrual regularity was restored in all PCOS patients treated with Diane35 compared with only 28% of those receiving metformin. Metformin significantly decreased BMI and WHR in obese patients (p < 0.05). Testosterone levels decreased in all three groups. LH levels and LH/FSH ratio decreased with Diane35 and Diane35/metformin in both obese and non-obese patients. Metformin significantly decreased fasting insulin concentrations (p < 0.05 and p < 0.01) and increased the insulin sensitivity (p < 0.05) in both obese and non-obese PCOS patients, while no significant changes were observed in the Diane35 group. In addition, insulin levels also decreased (p < 0.05) in the Diane35/metformin group.

CONCLUSIONS

Our data show that a combination of metformin and contraceptive pill may be more effective in suppressing the hyperandrogenemia of obese and non-obese PCOS patients than metformin alone and may reduce insulin levels more than contraceptive pill alone. Hence, combined treatment may become a more effective therapeutic option for PCOS.

Abnormal response of insulin to glucose loading and assessment of insulin resistance in non-obese patients with polycystic ovary syndrome

OBJECTIVES

To investigate the insulin response to glucose loading and to determine which method is best in order to evaluate insulin resistance in women with polycystic ovary syndrome (PCOS).

METHODS

In order to eliminate the influence of obesity on the variables, all subjects were non-obese. Standard oral glucose tolerance tests were performed in 23 normal women and 21 patients with PCOS. Insulin resistance was evaluated by the homeostasis model assessment insulin resistance index (HOMA-IR), homeostasis model assessment for beta-cell function (HOMA-%B), the quantitative insulin-sensitivity check index (QUICKI) and area under the curve for glucose (AUC(glucose)) and insulin (AUC(insulin)).

RESULTS

The mean values of HOMA-IR, AUC(insulin) and AUC(glucose) in the PCOS group were significantly higher than in the BMI-matched normal control group (p < 0.05, p < 0.01 and p < 0.01, respectively). There were significant positive correlations between AUC(insulin) and AUC(glucose) and androgens or luteinizing hormone in all subjects (p < 0.001). However, HOMA-IR and fasting insulin were significantly correlated only with total testosterone (p < 0.05). AUC(insulin) and AUC(glucose) values were elevated in more than 50% of PCOS patients with normal values of HOMA indices.

CONCLUSION

In the PCOS group, the abnormal response of insulin to glucose loading was suggested. AUC(insulin) may be a better index than others to evaluate insulin resistance in non-obese PCOS patients.

Metformin decreases the adipokine vaspin in overweight women with polycystic ovary syndrome concomitant with improvement in insulin sensitivity and a decrease in insulin resistance

OBJECTIVE

Polycystic ovary syndrome (PCOS) is associated with insulin resistance and obesity. Vaspin (visceral adipose tissue-derived serine protease inhibitor) levels increase with hyperinsulinemia and obesity. Currently, no data exists on vaspin in PCOS women. We therefore assessed mRNA and protein levels of vaspin, including circulating vaspin, from subcutaneous and omental adipose tissue of PCOS women and matched control subjects. Ex vivo regulation of adipose tissue vaspin and the effects of metformin treatment on circulating vaspin levels in PCOS subjects were also studied.

RESEARCH DESIGN AND METHODS

Real-time RT-PCR and Western blotting were used to assess mRNA and protein expression of vaspin. Serum vaspin was quantified by enzyme-linked immunosorbent assay. The effects of d-glucose, insulin, and gonadal and adrenal steroids on adipose tissue vaspin were analyzed ex vivo.

RESULTS

There were significantly higher levels of circulating vaspin (P < 0.05), vaspin mRNA (P < 0.05), and protein (P < 0.05) in omental adipose tissue of PCOS women. Interestingly, in omental adipose tissue explants, glucose significantly increased vaspin protein levels and secretion into conditioned media (P < 0.001). Also, after 6 months of metformin treatment, there was a significant decrease in serum vaspin levels in PCOS women (P < 0.001). Furthermore, multivariate regression analysis revealed that following metformin therapy, changes in circulating glucose levels were predictive of changes in serum vaspin levels (P = 0.014).

CONCLUSIONS

We report, for the first time, elevated serum and omental adipose tissue levels of vaspin in overweight PCOS women and ex vivo regulation of vaspin, predominantly by glucose. More importantly, metformin treatment decreases serum vaspin levels, a novel observation.

The serine phosphorylation hypothesis of polycystic ovary syndrome: a unifying mechanism for hyperandrogenemia and insulin resistance

Polycystic ovary syndrome (PCOS) is a common endocrinopathy affecting 4%-8% of reproductive-aged women. The syndrome is characterized by hyperandrogenemia and disordered gonadotropin secretion and is often associated with insulin resistance. However, rather than being one disease entity caused by a single molecular defect, PCOS under its current diagnostic criteria most likely includes a number of distinct disease processes with similar clinical phenotypes but different pathophysiologic mechanisms. The serine phosphorylation hypothesis can potentially explain two major features of PCOS--hyperandrogenemia and insulin resistance. Further defining the molecular mechanisms regulating androgen biosynthesis and insulin action in PCOS patients will permit a better understanding of the syndrome and may lead to the generation of novel specific pharmacologic therapies.

Myo-inositol administration positively affects hyperinsulinemia and hormonal parameters in overweight patients with polycystic ovary syndrome

OBJECTIVE

To evaluate the effects the administration of myo-inositol (MYO) on hormonal parameters in a group of PCOS patients.

DESIGN

Controlled clinical study.

SETTING

PCOS patients in a clinical research environment.

PATIENTS

20 overweight PCOS patients were enrolled after informed consent.

INTERVENTIONS

All patients underwent hormonal evaluations and an oral glucose tollerance test (OGTT) before and after 12 weeks of therapy (Group A (n = 10): myo-inositol 2 gr. plus folic acid 200 mug every day; Group B (n = 10): folic acid 200 mug every day). Ultrasound examinations and Ferriman-Gallwey score were also performed.

MAIN OUTCOME MEASURES

Plasma LH, FSH, PRL, E2, 17OHP, A, T, glucose, insulin, C peptide concentrations, BMI, HOMA index and glucose-to-insulin ratio.

RESULTS

After 12 weeks of MYO administration plasma LH, PRL, T, insulin levels and LH/FSH resulted significantly reduced. Insulin sensitivity, expressed as glucose-to-insulin ratio and HOMA index resulted significantly improved after 12 weeks of treatment. Menstrual cyclicity was restored in all amenorrheic and oligomenorrheic subjects. No changes occurred in the patients treated with folic acid.

CONCLUSIONS

Myo-inositol administration improves reproductive axis functioning in PCOS patients reducing the hyperinsulinemic state that affects LH secretion.

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.