Metabolic and hormonal changes induced by pioglitazone in polycystic ovary syndrome: a randomized, placebo-controlled clinical trial

The Effect of Thiazolidinediones in Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

INTRODUCTION

Polycystic ovary syndrome (PCOS) is a complex endocrine condition affecting women of reproductive age. It is characterised by insulin resistance and is a risk for type 2 diabetes mellitus (T2DM). The aim of this study was to review the literature on the effect of pioglitazone and rosiglitazone in women with PCOS.

METHODS

We searched PubMed, MEDLINE, Scopus, Embase, Cochrane Library and the Web of Science in April 2020 and updated in March 2023. Studies were deemed eligible if they were randomised controlled trials (RCTs) reporting the effect of pioglitazone and rosiglitazone in PCOS. The study follows the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Two reviewers independently extracted data and assessed the risk of bias using the Cochrane risk of bias tool.

RESULTS

Out of 814 initially retrieved citations, 24 randomised clinical trials (RCTs) involving 976 participants were deemed eligible. Among women with PCOS, treatment with rosiglitazone compared to metformin resulted in a significant increase in the mean body weight (mean difference (MD) 1.95 kg; 95% CI 0.03-3.87, p = 0.05). Metformin treatment was associated with a reduction in mean body mass index (BMI) compared to pioglitazone (MD 0.85 kg/m2; 95% CI 0.13-1.57, p = 0.02). Both pioglitazone compared to placebo (MD 2.56 kg/m2; 95% CI 1.77-3.34, p < 0.00001) and rosiglitazone compared to metformin (MD 0.74 kg/m2; 95% CI 0.07-1.41, p = 0.03) were associated with a significant increase in BMI. Treatment with pioglitazone compared to placebo showed a significant reduction in triglycerides (MD - 0.20 mmol/L; 95% CI - 0.38 to - 0.03, p = 0.02) and fasting insulin levels (MD - 11.47 mmol/L; 95% CI - 20.20, - 2.27, p = 0.01). Rosiglitazone compared to metformin was marginally significantly associated with a reduction in the luteinising hormone (LH) (MD - 0.62; 95% CI - 1.25-0.00, p = 0.05).

CONCLUSION

Both pioglitazone and rosiglitazone were associated with significant increases in body weight and BMI when compared with metformin or placebo. Pioglitazone significantly reduced triglycerides and fasting insulin when compared with placebo while rosiglitazone showed a modest reduction of LH when compared with metformin.

PROSPERO REGISTRATION NO

CRD42020178783.

Adipose Tissue Dysfunction in Polycystic Ovary Syndrome

PURPOSE

Polycystic ovary syndrome (PCOS) is a complex genetic trait and the most common endocrine disorder of women, clinically evident in 5% to 15% of reproductive-aged women globally, with associated cardiometabolic dysfunction. Adipose tissue (AT) dysfunction appears to play an important role in the pathophysiology of PCOS even in patients who do not have excess adiposity.

METHODS

We undertook a systematic review concerning AT dysfunction in PCOS, and prioritized studies that assessed AT function directly. We also explored therapies that targeted AT dysfunction for the treatment of PCOS.

RESULTS

Various mechanisms of AT dysfunction in PCOS were identified including dysregulation in storage capacity, hypoxia, and hyperplasia; impaired adipogenesis; impaired insulin signaling and glucose transport; dysregulated lipolysis and nonesterified free fatty acids (NEFAs) kinetics; adipokine and cytokine dysregulation and subacute inflammation; epigenetic dysregulation; and mitochondrial dysfunction and endoplasmic reticulum and oxidative stress. Decreased glucose transporter-4 expression and content in adipocytes, leading to decreased insulin-mediated glucose transport in AT, was a consistent abnormality despite no alterations in insulin binding or in IRS/PI3K/Akt signaling. Adiponectin secretion in response to cytokines/chemokines is affected in PCOS compared to controls. Interestingly, epigenetic modulation via DNA methylation and microRNA regulation appears to be important mechanisms underlying AT dysfunction in PCOS.

CONCLUSION

AT dysfunction, more than AT distribution and excess adiposity, contributes to the metabolic and inflammation abnormalities of PCOS. Nonetheless, many studies provided contradictory, unclear, or limited data, highlighting the urgent need for additional research in this important field.

Impact of pharmacological interventions on anthropometric indices in women with polycystic ovary syndrome: A systematic review and meta-analysis of randomized controlled trials

CONTEXT

Polycystic ovary syndrome (PCOS) is a heterogeneous condition affecting women of reproductive age and is associated with increased body weight.

OBJECTIVE

To review the literature on the effect of different pharmacological interventions on the anthropometric indices in women with PCOS.

DATA SOURCES

We searched PubMed, MEDLINE, Scopus, Embase, Cochrane library, and the Web of Science in April 2020 with an update in PubMed in March 2021.

STUDY SELECTION

The study followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA)2020.

DATA EXTRACTION

Reviewers extracted data and assessed the risk of bias using the Cochrane risk of bias tool.

RESULTS

80 RCTs were included in the meta-analysis. Metformin vs placebo showed significant reduction in the mean body weight (MD: -3.13 kg; 95% confidence interval [CI]: -5.33 to -0.93, I² = 5%) and the mean body mass index (BMI) (MD: -0.75 kg/m² ; 95% CI: -1.15 to -0.36, I² = 0%). There was a significant reduction in the mean BMI with orlistat versus placebo (MD: -1.33 kg/m²; 95% CI: -2.16 to -0.66, I² = 0.0%), acarbose versus metformin (MD: -1.26 kg/m²; 95% CI: -2.13 to -0.38, I² = 0%), and metformin versus pioglitazone (MD: -0.91 kg/m²; 95% CI: -1.62 to -0.19, I² = 0%). A significant increase in the mean BMI was also observed in pioglitazone versus placebo (MD: + 2.59 kg/m²; 95% CI: 1.78-3.38, I² = 0%) and in rosiglitazone versus metformin (MD: + 0.80 kg/m²; 95% CI: 0.32-1.27, I² = 3%). There was a significant reduction in the mean waist circumference (WC) with metformin versus placebo (MD: -1.21 cm; 95% CI: -3.71 to 1.29, I² = 0%) while a significant increase in the mean WC with pioglitazone versus placebo (MD: + 5.45 cm; 95% CI: 2.18-8.71, I² = 0%).

CONCLUSION

Pharmacological interventions including metformin, sitagliptin, pioglitazone, rosiglitazone orlistat, and acarbose have significant effects on the anthropometric indices in women with PCOS.

Impact of pharmacological interventions on biochemical hyperandrogenemia in women with polycystic ovary syndrome: a systematic review and meta-analysis of randomised controlled trials

CONTEXT

Polycystic ovary syndrome (PCOS) is a complex endocrine disease that affects women of reproductive age and is characterised by biochemical and clinical androgen excess.

AIM

To evaluate the efficacy of pharmacological interventions used to decrease androgen hormones in women with PCOS.

DATA SOURCE

We searched PubMed, MEDLINE, Scopus, Embase, Cochrane library and the Web of Science from inception up to March 2021.

DATA SYNTHESIS

Two reviewers selected eligible studies and extracted data, and the review is reported according to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA).

RESULTS

Of the 814 randomised clinical trials (RCTs) located in the search, 92 met the eligibility criteria. There were significant reductions in total testosterone level with metformin versus (vs) placebo (SMD: - 0.33; 95% CI  - 0.49 to  - 0.17, p < 0.0001, moderate grade evidence) and dexamethasone vs placebo (MD:-0.86 nmol/L; 95% CI  - 1.34 to  - 0.39, p = 0.0004, very low-grade evidence). Significant reductions in the free testosterone with sitagliptin vs placebo (SMD:  - 0.47; 95% CI  - 0.97 to 0.04, p = 0.07, very low-grade evidence), in dehydroepiandrosterone sulphate (DHEAS) with flutamide vs finasteride (MD:  - 0.37 µg/dL; 95% CI  - 0.05 to  - 0.58, p = 0.02, very low-grade evidence), a significant reduction in androstenedione (A4) with rosiglitazone vs placebo (SMD:  - 1.67; 95% CI  - 2.27 to  - 1.06; 59 participants, p < 0.00001, very low-grade evidence), and a significant increase in sex hormone-binding globulin (SHBG) with oral contraceptive pill (OCP) (35 µg Ethinyl Estradiol (EE)/2 mg cyproterone acetate (CPA)) vs placebo (MD: 103.30 nmol/L; 95% CI 55.54-151.05, p < 0.0001, very low-grade evidence) were observed.

CONCLUSION

Metformin, OCP, dexamethasone, flutamide, and rosiglitazone use were associated with a significant reduction in biochemical hyperandrogenemia in women with PCOS, though their individual use may be limited due to their side effects.

PROSPERO REGISTRATION NO

CRD42020178783.

Markers of insulin resistance in Polycystic ovary syndrome women: An update

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders, affecting 5%-10% of women of reproductive age. The importance of this syndrome lies in the magnitude of associated comorbidities: infertility, metabolic dysfunction, cardiovascular disease (CVD), plus psychological and oncological complications. Insulin resistance (IR) is a prominent feature of PCOS with a prevalence of 35%-80%. Without adequate management, IR with compensatory hyperinsulinemia contributes directly to reproductive dysfunction in women with PCOS. Furthermore, epidemiological data shows compelling evidence that PCOS is associated with an increased risk of impaired glucose tolerance, gestational diabetes mellitus and type 2 diabetes. In addition, metabolic dysfunction leads to a risk for CVD that increases with aging in women with PCOS. Indeed, the severity of IR in women with PCOS is associated with the amount of abdominal obesity, even in lean women with PCOS. Given these drastic implications, it is important to diagnose and treat insulin resistance as early as possible. Many markers have been proposed. However, quantitative assessment of IR in clinical practice remains a major challenge. The gold standard method for assessing insulin sensitivity is the hyperinsulinemic euglycemic glucose clamp. However, it is not used routinely because of the complexity of its procedure. Consequently, there has been an urgent need for surrogate markers of IR that are more applicable in large population-based epidemiological investigations. Despite this, many of them are either difficult to apply in routine clinical practice or useless for women with PCOS. Considering this difficulty, there is still a need for an accurate marker for easy, early detection and assessment of IR in women with PCOS. This review highlights markers of IR already used in women with PCOS, including new markers recently reported in literature, and it establishes a new classification for these markers.

Impact of pharmacological interventions on insulin resistance in women with polycystic ovary syndrome: A systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

Polycystic ovary syndrome (PCOS) is a complex endocrine condition affecting women of reproductive age. It is characterized by insulin resistance and is a major risk factor for type 2 diabetes mellitus (T2DM). The objective was to review the literature on the effect of different pharmacological interventions on insulin resistance in women with PCOS.

DESIGN

We searched PubMed, MEDLINE, Scopus, Embase, Cochrane library and the Web of Science in April 2020 and updated in March 2021. The study follows the 2020 Preferred Reporting Items for Systematic reviews and Meta-ana. Reviwers extracted data and assessed the risk of bias using the Cochrane risk of bias tool.

RESULTS

In 58 randomized controlled trials there were significant reductions in the fasting blood glucose (FBG) with metformin versus placebo (standardized mean difference [SMD]: -0.23; 95% confidence interval [CI]: -0.40, -0.06; I² = 0%, low-grade evidence), and acarbose versus metformin (mean difference [MD]: -10.50 mg/dl; 95% CI: -15.76, -5.24; I² = 0%, low-grade evidence). Significant reductions in fasting insulin (FI) with pioglitazone versus placebo (SMD: -0.55; 95% CI: -1.03, -0.07; I² = 37%; p = .02, very-low-grade evidence). A significant reduction in homoeostatic model assessment of insulin resistance (HOMA-IR) was seen with exenatide versus metformin (MD: -0.34; 95% CI: -0.65, -0.03; I² = 0%, low-grade evidence). No effect on homoeostatic model assessment of beta cells (HOMA-B) was observed.

CONCLUSIONS

Pharmacological interventions, including metformin, acarbose, pioglitazone and exenatide have significant effects on FBG, FI, HOMA-IR but not on HOMA-B.

The comparative effectiveness of 55 interventions in obese patients with polycystic ovary syndrome: A network meta-analysis of 101 randomized trials

BACKGROUND

Polycystic ovary syndrome (PCOS) affects up to 18% of reproductive-age females. The prevalence of obesity in PCOS patients reaches up to 80%, which is 2-fold higher than the general population.

OBJECTIVE

The present study aimed to compare the effectiveness of 55 pharmacological interventions across 17 different outcomes in overweight/obese PCOS patients with hyperandrogenism manifestations for both short- and long-term follow-ups. A comprehensive literature search was performed on PubMed, Scopus, Embase, Science Direct, Web of Science, and Cochrane CENTRAL for randomized controlled trials comparing any conventional pharmacological intervention as a monotherapy or a combination in overweight/obese patients with polycystic ovary syndrome and hyperandrogenism manifestations. Extracted data included three main parameters; I. Anthropometric parameters (BMI, Waist and Hip circumferences, and Waist/HIP ratio), II. Hormonal parameters (FSH, LH, FSG, SHBG, Estradiol, Total Testosterone, Free testosterone, DHEAS, Androstenedione), and III. Metabolic parameters (Total Cholesterol, LDL-C, HDL-C, Triglycerides, Fasting glucose, Fasting glucose, HOMA-IR). Critical appraisal and risk of bias assessments were performed using the modified Jadad scale, and the overall quality of this network meta-analysis was evaluated according to the CINeMA framework. We performed both a pairwise meta-analysis and a network meta-analysis to evaluate the effect sizes with 95% CI, and we calculated the surface under the cumulative ranking curve (SUCRA) for each intervention.

RESULTS

Our final search on May 15th 2021 retrieved 23,305 unique citations from searching six electronic databases. Eventually, 101 RCTs of 108 reports with a total of 8,765 patients were included in our systematic review and multi-treatments meta-analysis. 55 different interventions were included: 22 monotherapies, and 33 combinations. The two-dimensional cluster ranking of the average SUCRA values for metabolic and hormonal parameters with significant estimates revealed flutamide (77.5%, 70%; respectively) as the highest and rosiglitazone (38.2%, 26.3%; respectively) as the lowest, in terms of the overall efficacy in reducing weight and hyperandrogenism. However, cyproterone-acetate+ethinylestradiol exhibited a higher ranking in improving hormonal parameters (71.1%), but even a lower-ranking regarding metabolic parameters (34.5%).

CONCLUSIONS AND RELEVANCE

Current evidence demonstrated the superiority of flutamide in improving both metabolic and hormonal parameters, and the higher efficacy of cyproterone-acetate+ethinylestradiol only in improving hormonal parameters. Nearly all interventions were comparable in female hormones, FGS, HDL, glucose, and insulin levels improvements.

Resistance to the Insulin and Elevated Level of Androgen: A Major Cause of Polycystic Ovary Syndrome

PCOS has a wide range of negative impacts on women's health and is one of the most frequent reproductive systemic endocrine disorders. PCOS has complex characteristics and symptom heterogeneity due to the several pathways that are involved in the infection and the absence of a comm14on cause. A recent study has shown that the main etiology and endocrine aspects of PCOS are the increased level of androgen, which is also known as "hyperandrogenemia (HA)" and secondly the "insulin resistance (IR)". The major underlying cause of the polycystic ovary is these two IR and HA, by initiating the disease and its severity or duration. As a consequence, study on Pathogenesis is crucial to understand the effect of "HA" and "IR" on the pathophysiology of numerous symptoms linked to PCOS. A deep understanding of the pattern of the growth in PCOS for HA and IR can help ameliorate the condition, along with adjustments in nutrition and life, as well as the discovery of new medicinal products. However, further research is required to clarify the mutual role of IR and HA on PCOS development.

Circulating sex hormone binding globulin levels are modified with intensive lifestyle intervention, but their changes did not independently predict diabetes risk in the Diabetes Prevention Program

INTRODUCTION

Sex hormone binding globulin (SHBG) levels are reported to be inversely associated with diabetes risk. It is unknown whether diabetes prevention interventions increase SHBG and whether resultant changes in SHBG affect diabetes risk. The purpose of this analysis was to determine whether intensive lifestyle intervention (ILS) or metformin changed circulating SHBG and if resultant changes influenced diabetes risk in the Diabetes Prevention Program (DPP).

RESEARCH DESIGN AND METHODS

This is a secondary analysis from the DPP (1996-2001), a randomized trial of ILS or metformin versus placebo on diabetes risk over a mean follow-up of 3.2 years. The DPP was conducted across 27 academic study centers in the USA. Men, premenopausal and postmenopausal women without hormone use in the DPP were evaluated. The DPP included overweight/obese persons with elevated fasting glucose and impaired glucose tolerance. Main outcomes measures were changes in SHBG levels at 1 year and risk of diabetes over 3 years.

RESULTS

ILS resulted in significantly higher increases (postmenopausal women: p<0.01) or smaller decrements (men: p<0.05; premenopausal women: p<0.01) in SHBG compared with placebo or metformin. Changes in SHBG were primarily attributable to changes in adiposity. There were no consistent associations of change in SHBG with the risk of diabetes by treatment arm or participant group.

CONCLUSIONS

Lifestyle intervention may be associated with favorable changes in circulating SHBG, which is largely due to changes in adiposity. Changes in circulating SHBG do not independently predict reductions in diabetes incidence.

Current treatment for polycystic ovary syndrome: focus on adolescence

Polycystic ovary syndrome (PCOS) is the most frequent endocrine disorder in women and it is associated with an increased rate of infertility. Its etiology remains largely unknown, although both genetic and environmental factors play a role. PCOS is characterized by insulin resistance, metabolic disorders and low-grade chronic inflammation. To date, the treatment of PCOS is mainly symptomatic and aimed at reducing clinical signs of hyperandrogenism (hirsutism and acne), at improving menstrual cyclicity and at favoring ovulation. Since PCOS pathophysiology is still largely unknown, the therapeutic interventions currently in place are rarely cause-specific. In such cases, the therapy is mainly directed at improving hormonal and metabolic dysregulations typical of this condition. Diet and exercise represent the main environmental factors influencing PCOS. Thus, therapeutic lifestyle changes represent the first line of intervention, which, in combination with oral contraceptives, represent the customary treatment. Insulin resistance is becoming an increasingly studied target for therapy, most evidence stemming from the time-honored metformin use. Relatively novel strategies also include the use of thiazolidinediones and GLP1-receptor agonists. In recent years, a nutraceutical approach has been added to the therapeutic toolkit targeting insulin resistance. Indeed, emerging data support inositol and alpha-lipoic acid as alternative compounds, alone or in combination with the aforementioned strategies, with favorable effects on ovulation, insulin resistance and inflammation. Nevertheless, additional studies are required in adolescents, in order to assess the effectiveness of diet supplements in preventing negative impacts of PCOS on fertility in adult age. This review focuses on the main therapeutic options for PCOS to date.

Apolipoprotein J is a hepatokine regulating muscle glucose metabolism and insulin sensitivity

Crosstalk between liver and skeletal muscle is vital for glucose homeostasis. Hepatokines, liver-derived proteins that play an important role in regulating muscle metabolism, are important to this communication. Here we identify apolipoprotein J (ApoJ) as a novel hepatokine targeting muscle glucose metabolism and insulin sensitivity through a low-density lipoprotein receptor-related protein-2 (LRP2)-dependent mechanism, coupled with the insulin receptor (IR) signaling cascade. In muscle, LRP2 is necessary for insulin-dependent IR internalization, an initial trigger for insulin signaling, that is crucial in regulating downstream signaling and glucose uptake. Of physiologic significance, deletion of hepatic ApoJ or muscle LRP2 causes insulin resistance and glucose intolerance. In patients with polycystic ovary syndrome and insulin resistance, pioglitazone-induced improvement of insulin action is associated with an increase in muscle ApoJ and LRP2 expression. Thus, the ApoJ-LRP2 axis is a novel endocrine circuit that is central to the maintenance of normal glucose homeostasis and insulin sensitivity.

Hepatokines are proteins secreted by the liver that can regulate whole body metabolism. Here the authors identify apolipoprotein J as a hepatokine that regulates muscle glucose metabolism and insulin resistance through a low-density lipoprotein receptor-related protein−2 mediated mechanism in mice.

From Prediabetes to Type 2 Diabetes Mellitus in Women with Polycystic Ovary Syndrome: Lifestyle and Pharmacological Management

AIMS

Despite the very clear association between polycystic ovary syndrome (PCOS) and dysglycemia, few studies have explored the continuum of glycemic alterations leading from minor glucose abnormalities to overt diabetes. The purpose of this review is to trace the natural history of glycemic alteration in women with PCOS.

METHODS

We performed a literature review without time limit until August 2019. Inclusion criteria were studies addressing the association between impaired glucose tolerance or impaired fasting glucose or type 2 diabetes (T2D) and PCOS with at least an English abstract. The exclusion criteria were no PCOS or impaired glucose tolerance or impaired fasting glucose or T2D as outcome. The outcomes of interest were the onset of impaired glucose tolerance, impaired fasting glucose, T2D, and the progression from impaired glucose tolerance or impaired fasting glucose to T2D.

RESULTS

Healthy diet and physical activity are the first-line therapy for PCOS. Treatment with metformin was associated with significant lower 2-hour postload glucose levels and with reduction in fasting glucose when compared to placebo. Thiazolidinediones were more effective in reducing fasting glucose levels compared to placebo. Metformin and pioglitazone treatments showed similar effects on fasting glucose levels. The sodium-glucose cotransporter-2 inhibitor empagliflozin did not show differences in metabolic parameters when compared to metformin. The combination therapy with metformin plus the glucagon-like peptide-1 receptor agonist liraglutide was associated with significant improvements in basal and postload glucose levels compared with only liraglutide. Likewise, a combination therapy with the dipeptidyl peptidase-4 inhibitor saxagliptin and metformin demonstrated superiority versus metformin in fasting glucose and oral glucose tolerance test normalization. Myo-inositol supplementation was associated with lower insulin levels, glucose levels, and insulin resistance when compared with placebo, metformin, or estrogen treatments.

CONCLUSIONS

The use of insulin-sensitizing agents, such as metformin and inositols, along with lifestyle interventions may improve the metabolic profile in PCOS women.

Insulin-sensitising drugs (metformin, rosiglitazone, pioglitazone, D-chiro-inositol) for women with polycystic ovary syndrome, oligo amenorrhoea and subfertility

BACKGROUND

Polycystic ovary syndrome (PCOS) is characterised by infrequent or absent ovulation, and high levels of androgens and insulin (hyperinsulinaemia). Hyperinsulinaemia occurs secondary to insulin resistance and is associated with increased risk of cardiovascular disease and diabetes mellitus. Insulin-sensitising agents such as metformin may be effective in treating PCOS-related anovulation.

OBJECTIVES

To evaluate the effectiveness and safety of insulin-sensitising drugs in improving reproductive and metabolic outcomes for women with PCOS undergoing ovulation induction.

SEARCH METHODS

We searched the following databases from inception to January 2017: Cochrane Gynaecology and Fertility Group Specialised Register, CENTRAL, MEDLINE, Embase, PsycINFO and CINAHL. We searched registers of ongoing trials and reference lists from relevant studies.

SELECTION CRITERIA

We included randomised controlled trials of insulin-sensitising drugs compared with placebo, no treatment, or an ovulation-induction agent for women with oligo and anovulatory PCOS.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for eligibility and bias. Primary outcomes were live birth rate and gastrointestinal adverse effects. Secondary outcomes included other pregnancy outcomes, menstrual frequency and metabolic effects. We combined data to calculate pooled odds ratios (ORs) and 95% confidence intervals (CIs). We assessed statistical heterogeneity using the I2 statistic and reported quality of the evidence for primary outcomes using GRADE methodology.

MAIN RESULTS

We assessed the interventions metformin, clomiphene citrate, metformin plus clomiphene citrate, D-chiro-inositol, rosiglitazone and pioglitazone. We compared these with each other, placebo or no treatment. We included 48 studies (4451 women), 42 of which investigated metformin (4024 women). Evidence quality ranged from very low to moderate. Limitations were risk of bias (poor reporting of methodology and incomplete outcome data), imprecision and inconsistency. Metformin versus placebo or no treatmentThe evidence suggests that metformin may improve live birth rates compared with placebo (OR 1.59, 95% CI 1.00 to 2.51, 4 studies, 435 women, I2 = 0%, low-quality evidence). The metformin group experienced more gastrointestinal side effects (OR 4.76, 95% CI 3.06 to 7.41, 7 studies, 670 women, I2 = 61%, moderate-quality evidence) but had higher rates of clinical pregnancy (OR 1.93, 95% CI 1.42 to 2.64, 9 studies, 1027 women, I2 = 43%, moderate-quality evidence), ovulation (OR 2.55, 95% CI 1.81 to 3.59, 14 studies, 701 women, I2 = 58%, moderate-quality evidence) and menstrual frequency (OR 1.72, 95% CI 1.14 to 2.61, 7 studies, 427 women, I2 = 54%, low-quality evidence). There was no clear evidence of a difference in miscarriage rates (OR 1.08, 95% CI 0.50 to 2.35, 4 studies, 748 women, I2 = 0%, low-quality evidence). Metformin plus clomiphene citrate versus clomiphene citrate alone There was no conclusive evidence of a difference between the groups in live birth rates (OR 1.21, 95% CI 0.92 to 1.59, 9 studies, 1079 women, I2 = 20%, low-quality evidence), but gastrointestinal side effects were more common with combined therapy (OR 3.97, 95% CI 2.59 to 6.08, 3 studies, 591 women, I2 = 47%, moderate-quality evidence). However, the combined therapy group had higher rates of clinical pregnancy (OR 1.59, 95% CI 1.27 to 1.99, 16 studies, 1529 women, I2 = 33%, moderate-quality evidence) and ovulation (OR 1.57, 95% CI 1.28 to 1.92, 21 studies, 1624 women, I2 = 64%, moderate-quality evidence). There was a statistically significant difference in miscarriage rate per woman, with higher rates in the combined therapy group (OR 1.59, 95% CI 1.03 to 2.46, 9 studies, 1096 women, I2 = 0%, low-quality evidence) but this is of uncertain clinical significance due to low-quality evidence, and no clear difference between groups when we analysed miscarriage per pregnancy (OR 1.30, 95% CI 0.80 to 2.12, 8 studies; 400 pregnancies, I2 = 0%, low-quality evidence). Metformin versus clomiphene citrateWhen all studies were combined, findings for live birth were inconclusive and inconsistent (OR 0.71, 95% CI 0.49 to 1.01, 5 studies, 741 women, I2 = 86%, very low-quality evidence). In subgroup analysis by obesity status, obese women had a lower birth rate in the metformin group (OR 0.30, 95% CI 0.17 to 0.52, 2 studies, 500 women, I2 = 0%, very low-quality evidence), while data from the non-obese group showed a possible benefit from metformin, with high heterogeneity (OR 1.71, 95% CI 1.00 to 2.94, 3 studies, 241 women, I2 = 78%, very low-quality evidence). Similarly, among obese women taking metformin there were lower rates of clinical pregnancy (OR 0.34, 95% CI 0.21 to 0.55, 2 studies, 500 women, I2 = 0%, very low-quality evidence) and ovulation (OR 0.29, 95% CI 0.20 to 0.43 2 studies, 500 women, I2 = 0%, low-quality evidence) while among non-obese women, the metformin group had more pregnancies (OR 1.56, 95% CI 1.05 to 2.33, 5 studies, 490 women, I2 = 41%, very low-quality evidence) and no clear difference in ovulation rates (OR 0.81, 95% CI 0.51 to 1.28, 4 studies, 312 women, low-quality evidence, I2=0%). There was no clear evidence of a difference in miscarriage rates (overall: OR 0.92, 95% CI 0.50 to 1.67, 5 studies, 741 women, I2 = 52%, very low-quality evidence). D-chiro-inositol (2 studies), rosiglitazone (1 study) or pioglitazone (1 study) versus placebo or no treatmentWe were unable to draw conclusions regarding other insulin-sensitising drugs as no studies reported primary outcomes.

AUTHORS' CONCLUSIONS

Our updated review suggests that metformin alone may be beneficial over placebo for live birth, although the evidence quality was low. When metformin was compared with clomiphene citrate, data for live birth were inconclusive, and our findings were limited by lack of evidence. Results differed by body mass index (BMI), emphasising the importance of stratifying results by BMI. An improvement in clinical pregnancy and ovulation suggests that clomiphene citrate remains preferable to metformin for ovulation induction in obese women with PCOS.An improved clinical pregnancy and ovulation rate with metformin and clomiphene citrate versus clomiphene citrate alone suggests that combined therapy may be useful although we do not know whether this translates into increased live births. Women taking metformin alone or with combined therapy should be advised that there is no evidence of increased miscarriages, but gastrointestinal side effects are more likely.

Add on DPP-4 inhibitor alogliptin alone or in combination with pioglitazone improved β-cell function and insulin sensitivity in metformin treated PCOS

PURPOSE

Impaired β-cell function remains unaddressed in PCOS. The aim of the study was to evaluate whether dipeptidyl peptidase-4 (DPP-4) inhibitor alogliptin (ALO) alone or in combination with pioglitazone (PIO) improves β-cell function along with insulin resistance (IR) in metformin (MET) treated obese women with PCOS with persistent IR.

MATERIALS AND METHODS

In 12-week randomized study, ALO 25 mg QD (n=15) or ALO 25 mg QD and PIO 30 mg QD (n=15) was added to MET 1000 mg BID in PCOS women (aged 34.4 ± 6.5 years, BMI 39.0 ± 4.9 kg/m², HOMA-IR 4.82 ± 2.52, mean ± SD). Model derived parameters of glucose homeostasis from the meal tolerance test (MTT) were determined. The ability of the β-cell function was assessed by the adaptation index (AI).

RESULTS

MET-ALO and MET-ALO-PIO resulted in a significant decrease of HOMA-IR (by 1.6±2.3 (p=0.039) and 2.9±3.3 (p=0.001), respectively) and an increase in insulin sensitivity (IS) after meal ingestion (oral glucose IS) by 31.4±97.5 ml·min^-1·m^-2 (p=0.007) vs 39.0±58.1 ml·min^-1·m^-2 (p=0.039), respectively. AI across the entire group was significantly improved from 329.6±200.6 to 442.5±303.9 (p=0.048).

CONCLUSIONS

ALO alone and in combination with PIO improved IR along with dynamic IS and meal related β-cell function when added to MET treated PCOS.

Evaluating the effect of insulin sensitizers metformin and pioglitazone alone and in combination on women with polycystic ovary syndrome: An RCT

BACKGROUND

Insulin resistance and hyperinsulinemia may play a role in pathogenesis of PCOS. One of the common therapeutic methods is using insulin-sensitizing drugs such as metformin and thiazolidinediones.

OBJECTIVE

The purpose was to determine the effect of metformin and pioglitazone on clinical, hormonal and metabolic parameters in women with PCOS.

MATERIALS AND METHODS

Eighty four women randomly received one of the following for 3 months: metformin (n=28) (500 mg three times a day), pioglitazone (30 mg daily) (n=28) and combination of both metformin and pioglitazone (n=28) (30 mg/day pioglitazone plus 500 mg metformin three times a day). Hormonal profile, fasting serum insulin, body weight, body mass index, menstrual status and waist to hip ratio were evaluated before and after treatment.

RESULTS

Metformin and pioglitazone and combination therapy induced favorable changes in fasting serum insulin, HOMA-IR index, QUICKI, fasting glucose to insulin ratio in women with PCOS. Body weight, BMI, and waist to hip ratio increased significantly after treatment with pioglitazone but the data were similar after administration of metformin or combination therapy. Total testosterone level decreased significantly only after treatment with metformin. After 3 months in patients who received pioglitazone or combination therapy, menstrual cycles became regular in 71.4% and 73.9% respectively. While menstrual improvement happened only in 36.4% of the patients treated with metformin.

CONCLUSION

These findings suggest that insulin-sensitizing drugs induce beneficial effect in insulin resistance and menstrual cyclicity but only metformin ameliorated hyperandrogenemia in women with PCOS. Treatment with combination of metformin and pioglitazone did not show more benefit than monotherapy with each drug alone.

Serum adiponectin is independently associated with the metabolic syndrome in Hong Kong, Chinese women with polycystic ovary syndrome

OBJECTIVE

To evaluate the association of serum adiponectin level with the metabolic syndrome in Chinese women with polycystic ovary syndrome (PCOS).

METHODS

This was a cross-sectional study carried out in Hong Kong Chinese women with PCOS at a university-affiliated tertiary hospital between January 2010 and January 2011. Clinical and biochemical parameters of the women were analysed. Prediction of the metabolic syndrome was determined by receiver-operator characteristic (ROC) curves, univariate and multivariate logistic regression analyses.

RESULTS

A total of 116 women diagnosed to have PCOS were analysed. The area under the ROC curve of adiponectin for the prediction of metabolic syndrome was 0.820, 95% confidence interval (CI) 0.737-0.886. Univariate binary logistic regression showed that testosterone, sex hormone-binding globulin (SHBG), free androgen index (FAI), waist circumference, body mass index (BMI), quantitative insulin-sensitivity check index (QUICKI), homeostasis model assessment of insulin resistance (HOMA-IR) and adiponectin were significantly associated with the metabolic syndrome. On multivariate logistic regression analysis, adiponectin (p =  0.020), HOMA-IR, age (p =  0.011) and BMI (p =  0.019) were independently associated with the metabolic syndrome, but not FAI (p =  0.256).

CONCLUSIONS

Serum adiponectin is independently associated with the metabolic syndrome in Chinese women with PCOS. Further longitudinal follow-up studies are needed to determine whether serum adiponectin adds to the prediction of long-term cardiometabolic morbidity conferred by age, BMI and measures of insulin resistance.

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.

Activation of G proteins by GIV-GEF is a pivot point for insulin resistance and sensitivity

A long-held tenet in the field of diabetes is that the tipping point between insulin sensitivity and resistance resides at the level of insulin receptor/insulin receptor substrate–adaptor complexes. Here it is shown that activation of Gαi by GIV/Girdin is a decisive event within the metabolic insulin signaling cascade that reversibly orchestrates insulin sensitivity or resistance.

Insulin resistance (IR) is a metabolic disorder characterized by impaired insulin signaling and cellular glucose uptake. The current paradigm for insulin signaling centers upon the insulin receptor (InsR) and its substrate IRS1; the latter is believed to be the sole conduit for postreceptor signaling. Here we challenge that paradigm and show that GIV/Girdin, a guanidine exchange factor (GEF) for the trimeric G protein Gαi, is another major hierarchical conduit for the metabolic insulin response. By virtue of its ability to directly bind InsR, IRS1, and phosphoinositide 3-kinase, GIV serves as a key hub in the immediate postreceptor level, which coordinately enhances the metabolic insulin response and glucose uptake in myotubes via its GEF function. Site-directed mutagenesis or phosphoinhibition of GIV-GEF by the fatty acid/protein kinase C-theta pathway triggers IR. Insulin sensitizers reverse phosphoinhibition of GIV and reinstate insulin sensitivity. We also provide evidence for such reversible regulation of GIV-GEF in skeletal muscles from patients with IR. Thus GIV is an essential upstream component that couples InsR to G-protein signaling to enhance the metabolic insulin response, and impairment of such coupling triggers IR. We also provide evidence that GIV-GEF serves as therapeutic target for exogenous manipulation of physiological insulin response and reversal of IR in skeletal muscles.

Pioglitazone increases whole body insulin sensitivity in obese, insulin-resistant rhesus monkeys

Hyperinsulinemic-euglycemic clamps are considered the "gold standard" for assessing whole body insulin sensitivity. When used in combination with tracer dilution techniques and physiological insulin concentrations, insulin sensitization can be dissected and attributed to hepatic and peripheral (primarily muscle) effects. Non-human primates (NHPs), such as rhesus monkeys, are the closest pre-clinical species to humans, and thus serve as an ideal model for testing of compound efficacy to support translation to human efficacy. We determined insulin infusion rates that resulted in high physiological insulin concentrations that elicited maximal pharmacodynamic responses during hyperinsulinemic-euglycemic clamps. These rates were then used with [U-¹³C]-D-glucose, to assess and document the degrees of hepatic and peripheral insulin resistance between healthy and insulin-resistant, dysmetabolic NHPs. Next, dysmetabolic NHPs were treated for 28 days with pioglitazone (3 mg/kg) and again had their insulin sensitivity assessed, illustrating a significant improvement in hepatic and peripheral insulin sensitivity. This coincided with a significant increase in insulin clearance, and normalization of circulating adiponectin. In conclusion, we have determined a physiological clamp paradigm (similar to humans) for assessing glucose turnover in NHPs. We have also demonstrated that insulin-resistant, dysmetabolic NHPs respond to the established insulin sensitizer, pioglitazone, thus confirming their use as an ideal pre-clinical translational model to assess insulin sensitizing compounds.

The Role of Metformin in Metabolic Disturbances during Pregnancy: Polycystic Ovary Syndrome and Gestational Diabetes Mellitus

Maintenance of gestation implicates complex function of multiple endocrine mechanisms, and disruptions of the global metabolic environment prompt profound consequences on fetomaternal well-being during pregnancy and postpartum. Polycystic Ovary Syndrome (PCOS) and gestational diabetes mellitus (GDM) are very frequent conditions which increase risk for pregnancy complications, including early pregnancy loss, pregnancy-induced hypertensive disorders, and preterm labor, among many others. Insulin resistance (IR) plays a pivotal role in the pathogenesis of both PCOS and GDM, representing an important therapeutic target, with metformin being the most widely prescribed insulin-sensitizing antidiabetic drug. Although traditional views neglect use of oral antidiabetic agents during pregnancy, increasing evidence of safety during gestation has led to metformin now being recognized as a valuable tool in prevention of IR-related pregnancy complications and management of GDM. Metformin has been demonstrated to reduce rates of early pregnancy loss and onset of GDM in women with PCOS, and it appears to offer better metabolic control than insulin and other oral antidiabetic drugs during pregnancy. This review aims to summarize key aspects of current evidence concerning molecular and epidemiological knowledge on metformin use during pregnancy in the setting of PCOS and GDM.

Hirsutism: an evidence-based treatment update

BACKGROUND

Hirsutism has a relatively high prevalence among women. Depending upon societal and ethnic norms, it can cause significant psychosocial distress. Importantly, hirsutism may be associated with underlying disorders and co-morbidities. Hirsutism should not simply be looked upon as an issue of cosmesis. Patients require appropriate evaluation so that underlying etiologies and associated sequelae are recognized and managed. Treatment of hirsutism often requires a multidisciplinary approach, and a variety of physical or pharmacologic modalities can be employed. Efficacy of these therapies is varied and depends, among other things, upon patient factors including the underlying etiology, hormonal drive, and local tissue sensitivity to androgens.

OBJECTIVE

The objective of this paper is to review and summarize current evidence evaluating the efficacy of various treatment modalities for hirsutism in premenopausal women.

METHODS

Online databases were searched to identify all relevant prior systematic reviews and meta-analyses as well as recently published (2012-present) randomized controlled trials (RCTs) on hirsutism treatment.

RESULTS

Four recently published RCTs met criteria for inclusion in our review. In addition, one meta-analysis and one systematic review/treatment guideline were identified in the recent literature. Physical modalities and oral contraceptive pills (OCPs) remain first-line treatments. Evidence supports the use of electrolysis for permanent hair removal in localized areas and lasers (particularly alexandrite and diode lasers) for permanent hair reduction. Topical eflornithine can be used as monotherapy for mild hirsutism and as an adjunct therapy with lasers or pharmacotherapy in more severe cases. Combined OCPs as a class are superior to placebo; however, antiandrogenic and low-dose neutral OCPs may be slightly more efficacious in improving hirsutism compared with other types of OCPs. Antiandrogens are indicated for moderate to severe hirsutism, with spironolactone being the first-line antiandrogen and finasteride and cyproterone acetate being second-line antiandrogens. Due to its risk for hepatotoxicity, flutamide is not considered a first-line therapy. If used, the lowest effective dose should be administered with careful monitoring of liver enzymes. Monotherapy with an insulin sensitizer does not significantly improve hirsutism. While insulin sensitizers improve important metabolic and endocrine aberrations in polycystic ovary syndrome, they are not recommended when hirsutism is the sole indication for use. Lifestyle modification counseling is recommended. Gonadotropin-releasing hormone analogs and glucocorticoids are only recommended in specific circumstances. Additional therapies without sufficient supportive evidence of efficacy are ovarian surgery, statins (HMG-CoA reductase inhibitors), and vitamin D supplementation.

LIMITATIONS

In general, most therapies garner recommendations that are weak (where the estimates of benefits versus risks of therapy are either closely balanced or uncertain) and are based on low- to moderate-quality evidence.

CONCLUSIONS

Risks and benefits of treatment must be carefully considered and discussed with the patient. Expectations for efficacy should be appropriately set. A minimum of 6 months is required to see benefit from pharmacotherapy and lifelong treatment is often necessary for sustained benefit.

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.

Inflammatory cytokines and chemokines, skeletal muscle and polycystic ovary syndrome: effects of pioglitazone and metformin treatment

OBJECTIVE

Chronic low-grade inflammation is a common feature of insulin resistant states, including obesity and type 2 diabetes. Less is known about inflammation in Polycystic Ovary Syndrome (PCOS). Thus we evaluated the impact of PCOS on circulating cytokine levels and the effects of anti-diabetic therapies on insulin action, cytokine and chemokine levels and inflammatory signaling in skeletal muscle.

METHODS

Twenty subjects with PCOS and 12 healthy normal cycling (NC) subjects of similar body mass index were studied. PCOS subjects received oral placebo or pioglitazone, 45 mg/d, for 6 months. All PCOS subjects then had metformin, 2 g/day, added to their treatment. Circulating levels of cytokines, chemokines, and adiponectin, skeletal muscle markers of inflammation and phosphorylation of signaling proteins, insulin action evaluated by the hyperinsulinemic/euglycemic clamp procedure and Homeostasis Model Assessment of Insulin Resistance were measured.

RESULTS

Circulating levels of a number of cytokines and chemokines were generally similar between PCOS and NC subjects. Levels in PCOS subjects were not altered by pioglitazone or metformin treatment, even though whole body insulin action and adiponectin levels increased with pioglitazone. In spite of the lack of change in levels of cytokines and chemokines, several markers of inflammation in skeletal muscle were improved with Pio treatment.

CONCLUSIONS

PCOS may represent a state of elevated sensitivity of inflammatory cells in skeletal muscle to cytokines and chemokines, a property that could be reversed by pioglitazone treatment together with improved insulin action.

Pioglitazone counteracts the tumor necrosis factor-α inhibition of follicle-stimulating hormone-induced follicular development and estradiol production in an in vitro mouse preantral follicle culture system

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of reproductive age and is characterized by chronic anovulation. Insulin resistance may be a key component of the pathogenesis of this disorder. Pioglitazone is a thiazolidinedione derivative that acts by improving insulin resistance via the peroxisome proliferator-activated receptor-γ (PPAR-γ) pathway. Reportedly, pioglitazone improves the anovulation status in patients with PCOS. In the present study, we examined whether pioglitazone directly affects ovarian follicular development and steroidogenesis using in vitro mouse preantral follicle culture system.

METHODS

An isolated individual in vitro mouse preantral follicle culture was used to test the effects of pioglitazone on the follicle development and steroidogenesis. Tumor necrosis factor-α (TNF-α), which plays a role in insulin resistance, has been reported to inhibit the follicle stimulating hormone (FSH)-induced follicular development and steroidogenesis in an in vitro mouse preantral follicle culture system. Therefore, we examined whether pioglitazone counteracts these effects by TNF-α. We assessed the follicle diameter and follicle survival and antral-like cavity formation rates, the 17β-estradiol (E2) levels in the culture medium, and the ovulation rate using the in vitro preantral follicle culture.

RESULTS

Pioglitazone treatment counteracted the inhibition of TNF-α in FSH-induced follicle development in a dose-dependent manner. Pioglitazone, at a concentration of 5 μM, which was the minimum effective concentration, significantly counteracted the inhibition of TNF-α in FSH-induced follicle survival (29 versus 56%, P < 0.05), antral-like cavity formation (29 versus 48%, P < 0.05), E2 concentration in the culture medium (mean ± SEM = 21 ± 1 versus mean ± SEM = 27 ± 1 pg/mL, P < 0.05), and human chorionic gonadotropin-induced ovulation rate (9 versus 28%, P < 0.05).

CONCLUSIONS

Pioglitazone counteracted the inhibition by TNF-α on FSH-induced follicle development and steroidogenesis in the in vitro mouse preantral follicle culture. The results suggest that pioglitazone may directly affect the follicular development and steroidogenesis.

Metabolic and other effects of pioglitazone as an add-on therapy to metformin in the treatment of polycystic ovary syndrome (PCOS)

Insulin resistance is a key pathogenic defect of the clustered metabolic disturbances seen in polycystic ovary syndrome (PCOS). Metformin is an insulin sensitizer acting in the liver and the peripheral tissues that ameliorates the metabolic and reproductive defects in PCOS. In addition, pioglitazone is an insulin sensitizer used in diabetes mellitus type 2 (T2DM), improving insulin resistance (IR) in adipose tissue and muscles. In T2DM, these drugs are also used as a combined treatment due to their "add-on effect" on insulin resistance. Although the beneficial role of troglitazone (a member of the thiazolidinediones (TZDs) family) in PCOS has been shown in the past, currently only pioglitazone is available in the market. A few small randomized controlled trials have directly compared the effectiveness of pioglitazone in women with PCOS, while there are a limited number of small studies that support the beneficial metabolic add-on effect of pioglitazone on metformin-treated PCOS women as compared to metformin or pioglitazone monotherapy. These findings suggest a potentially promising role for combined pioglitazone/metformin treatment in the management of PCOS in metformin-resistant patients. In view of recent concerns regarding pioglitazone usage and its associated health risk, we aim to compare the pros and cons of each drug regarding their metabolic and other hormonal effects in women with PCOS and to explore the possible beneficial effect of combined therapy in certain cases, taking into consideration the teratogenic effect of pioglitazone. Finally, we discuss the need for a randomized controlled trial that will evaluate the metabolic and other hormonal effects of combined metformin/pioglitazone treatment in PCOS with selective treatment targets.

Effects of insulin-sensitizing agents and insulin resistance in women with polycystic ovary syndrome

Objective

The aim of this study was to investigate the effect of insulin sensitizing agents on hormonal and metabolic parameters as well as menstrual patterns in women with polycystic ovary syndrome (PCOS).

Methods

One hundred and twenty-three patients with PCOS were included. Metformin was administered to patients at 1,500 mg or 1,700 mg daily for 3 months. If the patients had no improvement of the menstrual cycle or metformin-related adverse effects developed, the patients changed medication to a daily dose of either 15 mg pioglitazone or up to 45 mg. Then resumption of a regular menstrual cycle or recovery of ovulation was evaluated. Hormonal and metabolic profiles were compared between the response and non-response group to insulin sensitizing agents.

Results

One hundred and five patients with PCOS were treated with metformin for 3 months. Forty-eight patients (45.7%) showed improvement of menstrual cycle regularity after 3 months of metformin use, whereas 57 patients (54.3%) had no change. The mean free testosterone measured after 3 months of treatment was significantly lower in metformin responders than in non-responders. The other parameters did not differ between the groups. Of the 23 patients who used pioglitazone for 3 to 6 months, 19 patients (82.6%) showed improvement in their menstrual cycles.

Conclusion

Metformin treatment seems to be effective for the improvement of menstrual cyclicity irrespective of insulin resistance in women with PCOS. When metformin related adverse effect occurred, pioglitazone would be effective for aiding the resumption of the menstrual cycle.

Does pioglitazone improve depression through insulin-sensitization? Results of a randomized double-blind metformin-controlled trial in patients with polycystic ovarian syndrome and comorbid depression

Thiazolidinediones have shown beneficial effects in short-term treatment of depression. However, it is unclear whether the antidepressant efficacy of these agents is related to their insulin-sensitizing action. We conducted the present study to compare the antidepressant efficacy of pioglitazone with another insulin-sensitizer, metformin, in obese patients with concomitant polycystic ovarian syndrome (PCOS) and major depressive disorder (MDD). In a six-week double-blind study, 50 patients with PCOS and MDD (DSM-IV-TR criteria) with Hamilton depression rating scale (HDRS) score of <20, randomly received pioglitazone (15 mg twice daily; PO) or metformin (750 mg twice daily; PO). Assessment was done using HDRS (weeks 0, 3, 6) together with fasting Insulin, glucose, and lipid profile, liver enzymes, homeostatic model assessment of insulin resistance (HOMA-IR), anthropometric measures, and serum androgens (weeks 0 and 6). Pioglitazone was superior to metformin in reducing HDRS scores at the end of the study [38.3% versus 8.3% reduction from baseline scores, F(1, 37) = 73.513, P<0.001]. Changes from baseline in HOMA-IR values at week 6 were not significantly different between the two groups (P = 0.888). Baseline (but not follow-up) HDRS and HOMA-IR values were significantly correlated (r = 0.393, P = 0.012). In multiple regression analysis, treatment with pioglitazone independent of HOMA-IR values predicted greater score reduction on HDRS at week 6 (standardized beta = 0.801, P<0.001). Biochemical and hormonal profile did not differ between the two groups at week 6. Metformin was associated with higher frequency of gastrointestinal side effects (P = 0.014). In summary, we showed that pioglitazone improved depression with mechanisms largely unrelated to its insulin-sensitizing action (registration number: IRCT201106081556N23).

The future of thiazolidinedione therapy in the management of type 2 diabetes mellitus

Since their approval, thiazolidinediones (TZDs) have been used extensively as insulin-sensitizers for the management of type 2 diabetes mellitus (T2DM). Activation of peroxisomal proliferator-activated receptor gamma (PPARγ) nuclear receptors by TZDs leads to a vast spectrum of metabolic and antiinflammatory effects. In the past decade, clinicians and scientists across the fields of metabolism, diabetes, liver disease (NAFLD), atherosclerosis, inflammation, infertility, and even cancer have had high hopes about the potential for TZDs to treat many of these diseases. However, an increasing awareness about undesirable "off-target" effects of TZDs have made us rethink their role and be more cautious about the long-term benefits and risks related to their use. This review examines the most relevant work on the benefits and risks associated with TZD treatment, with a focus on the only PPARγ agonist currently available (pioglitazone), aiming to offer the reader a balanced overview about the current and future role of TZDs in the management of insulin-resistant states and T2DM.

Free carnitine and acylcarnitines in obese patients with polycystic ovary syndrome and effects of pioglitazone treatment

OBJECTIVE

To determine fasting and insulin-stimulated levels of carnitine precursors, total and free carnitine, and acylcarnitines, and evaluate the impact of pioglitazone treatment in obese patients with polycystic ovary syndrome (PCOS).

DESIGN

The present study is a secondary analysis of a previously published case-control study, followed by a double-blind randomized clinical trial.

SETTING

Academic tertiary care medical center.

PATIENT(S)

Thirty obese premenopausal patients with PCOS and 14 healthy women.

INTERVENTION(S)

Sixteen weeks of blinded treatment with pioglitazone (30 mg/d) or placebo.

MAIN OUTCOME MEASURE(S)

Total and free carnitine and acylcarnitines.

RESULT(S)

Contrary to controls, patients with PCOS were characterized with slightly lower levels of fasting total and free carnitine, its precursors, and derivatives. Total and free carnitine correlated inversely to sex hormone-binding globulin (SHBG) in patients with PCOS, whereas no associations were found between acylcarnitines and androgenes. Insulin stimulation-induced changes in the levels of total and free carnitine, carnitine precursors, and acylcarnitines in the PCOS group followed the same trends as in the control group. Pioglitazone treatment significantly increased fasting levels of serum-free carnitine, propionyl carnitine, and total carnitine. The analysis of between group differences revealed significant changes in the isovaleryl carnitine levels and lipid oxidation rates after pioglitazone treatment compared with placebo.

CONCLUSION(S)

Acute insulin stimulation was associated with increased serum levels of free carnitine in both patients and healthy controls. Treatment with pioglitazone is able to redistribute free fatty acids from insulin-sensitive tissues, diminish demand for carnitine, and influence the overall carnitine turnover.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00145340.

Effects of thiazolidinediones on polycystic ovary syndrome: a meta-analysis of randomized placebo-controlled trials

INTRODUCTION

Thiazolidinedione (TZD) is one of the therapy options for polycystic ovary syndrome (PCOS) patients; however, the effectiveness of TZD in the treatment of PCOS remains controversial. The aim of this metaanalysis was to clarify the role that TZDs play in the treatment of PCOS.

METHODS

The authors searched the following databases for any date up to June 2012 for randomized controlled trials on PCOS treatment in which interventions for the experimental and control groups were TZDs and placebo, respectively: Medline, Embase, and the Cochrane library.

RESULTS

The search strategy identified 173 potential publications, eight of which were included. In the treatment of PCOS, the insulin-lowering effects of TZDs were superior to placebo (95% CI -1.50 to -0.12; P=0.021), and the lowering of fasting blood glucose was superior to placebo (95% CI -1.06 to -0.05; P=0.031). There was no difference in reduction of the Ferriman-Gallwey scores or the androgen levels between TZDs and placebo (95% CI -0.57 to 0.10; P=0.169 and 95% CI -0.64 to 0.09; P=0.141, respectively). The effects of TZDs on body weight reduction were inferior to placebo (95% CI 0.13 to 0.66; P=0.003). Significant between-study heterogeneity was detected for several variables assessed.

CONCLUSION

This is the first meta-analysis to evaluate the role that TZDs plays in the treatment of PCOS compared with placebo. The currently available data showed that TZDs can effectively reduce insulin and fasting blood glucose levels in patients with PCOS, but TZDs may not effectively reduce the Ferriman-Gallwey score or androgen levels and may increase body weight.

Insulin-sensitising drugs (metformin, rosiglitazone, pioglitazone, D-chiro-inositol) for women with polycystic ovary syndrome, oligo amenorrhoea and subfertility

BACKGROUND

Polycystic ovary syndrome (PCOS) is characterised by infrequent or absent ovulation (anovulation), high levels of male hormones (hyperandrogenaemia) and high levels of insulin (hyperinsulinaemia secondary to increased insulin resistance). Hyperinsulinaemia is associated with an increase in cardiovascular risk and the development of diabetes mellitus. Insulin-sensitising agents such as metformin may be effective in treating the features of PCOS, including anovulation.

OBJECTIVES

To assess the effectiveness of insulin-sensitising drugs in improving reproductive outcomes and metabolic parameters for women with PCOS.

SEARCH METHODS

We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register (October 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 3rd Quarter 2011), CINAHL (October 2011), MEDLINE (January 1966 to October 2011), and EMBASE (January 1985 to October 2011).

SELECTION CRITERIA

Randomised controlled trials of insulin sensitising drugs compared with either placebo, no treatment, or an ovulation induction agent for women with PCOS, menstrual disturbance and subfertility.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion and trial quality, and extracted data.  

MAIN RESULTS

Forty-four trials (3992 women) were included for analysis, 38 of them using metformin and involving 3495 women.There was no evidence that metformin improved live birth rates, whether it was used alone (pooled OR 1.80, 95% CI 0.52 to 6.16, 3 trials, 115 women) or in combination with clomiphene (pooled OR 1.16, 95% CI 0.85 to 1.56, 7 trials, 907 women). However, clinical pregnancy rates were improved for metformin versus placebo (pooled OR 2.31, 95% CI 1.52 to 3.51, 8 trials, 707 women) and for metformin and clomiphene versus clomiphene alone (pooled OR 1.51, 95% CI 1.17 to 1.96, 11 trials, 1208 women). In the studies that compared metformin and clomiphene alone, there was evidence of an improved live birth rate (pooled OR 0.3, 95% CI 0.17 to 0.52, 2 trials, 500 women) and clinical pregnancy rate (pooled OR 0.34, 95% 0.21 to 0.55, 2 trials, 500 women) in the group of obese women who took clomiphene.Metformin was also associated with a significantly higher incidence of gastrointestinal disturbances than placebo (pooled OR 4.27, 95% CI 2.4 to 7.59, 5 trials, 318 women) but no serious adverse effects were reported.

AUTHORS' CONCLUSIONS

In agreement with the previous review, metformin was associated with improved clinical pregnancy but there was no evidence that metformin improves live birth rates whether it is used alone or in combination with clomiphene, or when compared with clomiphene. Therefore, the role of metformin in improving reproductive outcomes in women with PCOS appears to be limited.

A systematic review and meta-analysis of randomized controlled trials comparing pioglitazone versus metformin in the treatment of polycystic ovary syndrome

OBJECTIVE

Evidence indicates that metformin and pioglitazone both improve insulin resistance and hirsutism among patient with polycystic ovarian syndrome (PCOS). However, the effectiveness of pioglitazone versus metformin in the treatment of PCOS remains controversial. To summarize the relative efficacy of pioglitazone and metformin in PCOS patients, a systematic review and meta-analysis of randomized controlled trials (RCTs) was performed.

METHODS

The authors searched MEDLINE, EMBASE, CNKI and WANFANG DATA for articles published up to November 2011 to identify those comparing pioglitazone versus metformin as a treatment for PCOS.

RESULTS

Of the 161 studies retrieved, six trials were included in this analysis, including a total of 278 women with PCOS. Pioglitazone was found to be significantly more effective than metformin at reducing fasting insulin level (P = 0.002, standardized mean differences [SMD] = -0.37, 95% confidence interval [CI] [-0.61, -0.13]). Similarly, pioglitazone was found to be significantly more effective than metformin at improving the HOMA-IR index (P = 0.014, SMD = -0.32, 95% CI [-0.57, -0.06]). However, pioglitazone was significantly less effective than metformin at reducing body mass index (BMI; P = 0.038, SMD = 0.25, 95% CI [0.01, 0.49]). The effect of pioglitazone on fasting glucose levels, testosterone levels, and Ferriman-Gallwey scores was not significantly different from that of metformin (P greater than 0.05 for all).

CONCLUSION

This systematic review and meta-analysis suggests that pioglitazone was more suitable for treating hyperinsulinemia and insulin resistance among PCOS patients, while metformin was more effective in reducing body weight. Well designed RCTs are needed to provide better evidence.

Medical management of metabolic dysfunction in PCOS

Polycystic ovary syndrome (PCOS) is associated with metabolic derangements including insulin resistance, dyslipidemia, systemic inflammation and endothelial dysfunction. There is a growing need to develop pharmacologic interventions to improve metabolic function in women with PCOS. Medications that have been tested in patients with PCOS include metformin, thiazolidinediones, acarbose, naltrexone, orlistat, vitamin D and statins. Metformin decreases hepatic gluconeogenesis and free fatty acid oxidation while increasing peripheral glucose uptake. Early studies in PCOS suggested that metformin indirectly reduces insulin level, dyslipidemia and systemic inflammation; however, recent placebo-controlled trials failed to demonstrate significant metabolic benefit. Thiazolidinediones act primarily by increasing peripheral glucose uptake. Most studies in PCOS have demonstrated that thiazolidinediones reduce insulin resistance; however, effects on dyslipidemia were disappointing. Use of thiazolidinediones is associated with weight gain and major complications. Acarbose reduces digestion of polysaccharides. Studies in PCOS yielded inconsistent effects of acarbose on insulin sensitivity and no significant improvement of dyslipidemia. Naltrexone reduces appetite and modulates insulin release; its use in PCOS may reduce hyperinsulinemia. Orlistat decreases absorption of dietary fats; studies in PCOS suggest beneficial effects on insulin sensitivity. Vitamin D may improve insulin sensitivity but mixed results on lipid profile in PCOS have been reported. Statins are competitive inhibitors of the key enzyme regulating the mevalonate pathway; their effects are related to reduced cholesterol production as well as anti-inflammatory and anti-oxidant properties. In women with PCOS, statins reduce hyperandrogenism, improve lipid profile and reduce systemic inflammation while the effects on insulin sensitivity are variable. Use of statins is contraindicated in pregnancy.

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.

Epidemiology, diagnosis and management of hirsutism: a consensus statement by the Androgen Excess and Polycystic Ovary Syndrome Society

BACKGROUND

Hirsutism, defined by the presence of excessive terminal hair in androgen-sensitive areas of the female body, is one of the most common disorders in women during reproductive age.

METHODS

We conducted a systematic review and critical assessment of the available evidence pertaining to the epidemiology, pathophysiology, diagnosis and management of hirsutism.

RESULTS

The prevalence of hirsutism is ~10% in most populations, with the important exception of Far-East Asian women who present hirsutism less frequently. Although usually caused by relatively benign functional conditions, with the polycystic ovary syndrome leading the list of the most frequent etiologies, hirsutism may be the presenting symptom of a life-threatening tumor requiring immediate intervention.

CONCLUSIONS

Following evidence-based diagnostic and treatment strategies that address not only the amelioration of hirsutism but also the treatment of the underlying etiology is essential for the proper management of affected women, especially considering that hirsutism is, in most cases, a chronic disorder needing long-term follow-up. Accordingly, we provide evidence-based guidelines for the etiological diagnosis and for the management of this frequent medical complaint.

Drospirenone/ethinyl estradiol versus rosiglitazone treatment in overweight adolescents with polycystic ovary syndrome: comparison of metabolic, hormonal, and cardiovascular risk factors

CONTEXT

Adolescents with polycystic ovary syndrome (PCOS) have insulin resistance and higher rates of the metabolic syndrome.

OBJECTIVE

Our objective was to compare the effects of 6 months treatment with drospirenone/ethinyl estradiol (EE) (3 mg/30 μg) vs. rosiglitazone (4 mg) daily on the hormonal and cardiometabolic profiles of overweight/obese adolescents with PCOS.

DESIGN

We conducted a randomized, double-blinded, parallel clinical trial in an academic hospital, with n = 46 patients.

OUTCOME MEASURES

The primary outcome measure was insulin sensitivity, hepatic with [6,6-(2)H(2)]glucose and peripheral with a 3-h hyperinsulinemic-euglycemic clamp. Other outcome measures included plasma androgen profile and response to ACTH stimulation, glucose and insulin response to oral glucose tolerance test, insulin secretion with a 2-h hyperglycemic clamp, fasting lipid profile, inflammatory markers, intima media thickness, aortic pulse wave velocity, body composition by dual-energy x-ray absorptiometry, and abdominal adiposity by computed tomography scan.

RESULTS

Drospirenone/EE resulted in greater reductions in androgenemia. Neither treatment led to change in weight or body mass index, but rosiglitazone led to a significant decrease in visceral adiposity. Compared with drospirenone/EE, treatment with rosiglitazone improved hepatic and peripheral insulin sensitivity and lowered fasting and stimulated insulin levels during the oral glucose tolerance test. Treatment with drospirenone/EE was associated with elevations in total cholesterol, high-sensitivity C-reactive protein and leptin concentrations, whereas treatment with rosiglitazone led to lower triglycerides and higher adiponectin concentrations. Neither treatment affected intima media thickness or pulse wave velocity.

CONCLUSIONS

In overweight/obese adolescents with PCOS, 6 months treatment with rosiglitazone was superior to drospirenone/EE in improving the cardiometabolic risk profile, and effective but inferior in attenuating hyperandrogenemia. Additional studies are needed to test insulin sensitizers in the treatment of the reproductive and cardiometabolic aspects of PCOS.

Assessing and treating insulin resistance in women with polycystic ovarian syndrome

Polycystic ovarian syndrome (PCOS) is a highly prevalent hormonal and metabolic disorder among reproductive aged women worldwide. Women with PCOS have widely varying phenotypes and seek medical care for differing reasons. In addition to concern for menstrual cycle function, ovulation, hirsutism and acne, many PCOS women have abnormal glucose metabolism. While diabetes mellitus and impaired glucose tolerance are easily diagnosed, the diagnosis of and concern for insulin resistance as a precursor disorder is underappreciated. Insulin resistance may be the first important marker of metabolic disease in PCOS women at risk for metabolic syndrome and coronary artery disease.

Metformin vs thiazolidinediones for treatment of clinical, hormonal and metabolic characteristics of polycystic ovary syndrome: a meta-analysis

OBJECTIVES

Insulin-sensitizing drugs (ISDs) have been advocated for the long-term treatment of polycystic ovary syndrome (PCOS). It is therefore important to compare the efficacy and safety of ISDs such as metformin and thiazolidinediones (TZDs) for the treatment of this syndrome.

METHODS

A meta-analysis to assess the effectiveness and safety of metformin vs TZDs (including pioglitazone and rosiglitazone) in the treatment of PCOS was conducted, using MEDLINE (1966-May 2010) and EMBASE (1988-May 2010) to select randomized controlled trials comparing clinical, hormonal and metabolic results.

RESULTS

Ten trials were included. TZDs were superior to metformin in reducing serum levels of free testosterone (P=0.03) and dehydroepiandrosterone sulfate (DHEA) (P=0.002) after 3 months treatment. Decreases in triglyceride levels were more pronounced with metformin after 6 months (P<0.0001). Decreases in body mass index (BMI) were greater with metformin treatment as assessed at 3 and 6 months (P<0.00001). There were no significant between-group differences concerning improvements in ovulation, pregnancy rate, menstrual patterns or insulin sensitivity, or changes in serum levels of androstenedione, luteinizing hormone, follicle-stimulating hormone, total cholesterol, low-density lipoprotein C or insulin. Metformin caused a significantly higher incidence of side effects such as nausea, diarrhoea and abdominal cramping (P<0.00001). Significant between-study heterogeneity was detected for several variables assessed.

CONCLUSIONS

The findings from this meta-analysis do not indicate that metformin is superior to TZD's for the treatment of PCOS or vice versa. Between studies, heterogeneity was a major confounder. A large scale, well-designed, randomized, controlled trial is needed to further address this issue.

Polycystic Ovary Syndrome

Polycystic ovary syndrome is the most common endocrine disorder in women of reproductive age. It affects 6% to 7% of the population and is characterized by hyperandrogenism and ovarian dysfunction. Women with the disorder often present with insulin resistance and obesity, making it importance for health care providers to monitor closely for signs and symptoms of metabolic syndrome and type 2 diabetes. Treatments are targeted toward improving insulin tolerance, reducing signs and symptoms of hyperandrogenism (hirsutism, anovulation, etc), restoring normal menstrual cycle function, and restoring fertility. Major treatment should include weight management through diet and exercise, regardless of body mass index and might include concurrent drug therapy. It is important that pharmacists understand the underlying pathophysiology of the disease and the available treatments, in addition to the importance of reducing risk of metabolic syndrome/type 2 diabetes, and cardiovascular disease in these patients.

Thiazolinedione treatment in PCOS--an update

Polycystic ovary syndrome (PCOS) is characterised by anovulation, hyperandrogenism, and polycystic ovaries. Fifty percent of patients fulfil the criteria for the metabolic syndrome. The pathogenesis of PCOS may be looked as a vicious cycle involving hyperandrogenemia, central obesity, and insulin resistance and medical treatment should aim at breaking this cycle. Lifestyle intervention, oral contraceptives, and insulin sensitises such as metformin are the most commonly used treatment modalities. The thiazolidinediones rosiglitazone and pioglitazone were recently applied as insulin sensitising treatment in patients with PCOS. Thiazolidinediones activate the transcription of genes that affect glucose and lipid metabolism mediating decreased free fatty acid levels and decreased visceral fat mass. In the present article, we give an overview of the diverse effects of glitazone treatment in patients with PCOS. We review the studies comparing glitazone versus metformin and oral contraceptive treatment and recommend which patients should be treated with glitazones in daily praxis.

Insulin and hyperandrogenism in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a very common endocrine disorder characterized by chronic anovulation, clinical and/or biochemical hyperandrogenism, and/or polycystic ovaries. But most experts consider that hyperandrogenism is the main characteristic of PCOS. Several theories propose different mechanisms to explain PCOS manifestations: (1) a primary enzymatic default in the ovarian and/or adrenal steroidogenesis; (2) an impairment in gonadotropin releasing hormone (GnRH) secretion that promotes luteal hormone (LH) secretion; or (3) alterations in insulin actions that lead to insulin resistance with compensatory hyperinsulinemia. However, in the past 20 years there has been growing evidence supporting that defects in insulin actions or in the insulin signalling pathways are central in the pathogenesis of the syndrome. Indeed, most women with PCOS are metabolically insulin resistant, in part due to genetic predisposition and in part secondary to obesity. But some women with typical PCOS do not display insulin resistance, which supports the hypothesis of a genetic predisposition specific to PCOS that would be revealed by the development of insulin resistance and compensatory hyperinsulinemia in most, but not all, women with PCOS. However, these hypotheses are not yet appropriately confirmed, and more research is still needed to unravel the true pathogenesis underlying this syndrome. The present review thus aims at discussing new concepts and findings regarding insulin actions in PCOS women and how it is related to hyperandrogenemia.

Peroxisome proliferator-activated receptor-(gamma) receptor ligand partially prevents the development of endometrial explants in baboons: a prospective, randomized, placebo-controlled study

A prospective, randomized, placebo-controlled study was conducted in a baboon model to determine if a thiazolidinedione agonist of peroxisome proliferator-activated receptor-gamma, pioglitazone, can impede the development of endometriosis. Endometriosis was induced using laparoscopic, intrapelvic injection of eutopic menstrual endometrium, previously incubated with placebo or pioglitazone for 30 min, in 12 female baboons with a normal pelvis that had undergone at least one menstrual cycle since the time of captivity. At this point, the 12 baboons were randomized into two groups and treated from the day of induction. They received either PBS tablets (n = 6, placebo control, placebo tablets once a day by mouth) or pioglitazone (n = 6, test drug, 7.5 mg by mouth each day). A second and final laparoscopy was performed in the baboons to record the extent of endometriotic lesions between 24 and 42 d after induction (no difference in length of treatment between the two groups, P = 0.38). A videolaparoscopy was performed to document the number and surface area of endometriotic lesions. The surface area and volume of endometriotic lesions were significantly lower in pioglitazone treated baboons than the placebo group (surface area, 48.6 vs. 159.0 mm(2), respectively, P = 0.049; vol, 23.7 vs. 131.8 mm(3), respectively, P = 0.041). The surface area (3.5 vs. 17.8 mm(2), P = 0.017, pioglizatone vs. placebo) and overall number (1.5 vs. 9.5, P = 0.007, pioglizatone vs. placebo) of red lesions were lower in the pioglitazone group. A peroxisome proliferator-activated receptor-gamma ligand, pioglitazone, effectively reduced the initiation of endometriotic disease in the baboon endometriosis model. Using this animal model, we have shown that thiazolidinedione is a promising drug for preventive treatment of endometriosis.

Insulin-sensitising drugs (metformin, rosiglitazone, pioglitazone, D-chiro-inositol) for women with polycystic ovary syndrome, oligo amenorrhoea and subfertility

BACKGROUND

Polycystic ovary syndrome (PCOS) is characterised by anovulation, hyperandrogaenemia and insulin resistance. Hyperinsulinaemia is associated with an increase in cardiovascular risk and the development of diabetes mellitus. If insulin sensitising agents such as metformin are effective in treating features of PCOS, then they could have wider health benefits than just treating the symptoms of the syndrome.

OBJECTIVES

To assess the effectiveness of insulin sensitising drugs in improving reproductive outcomes and metabolic parameters for women with PCOS and menstrual disturbance.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders & Subfertility Group trials register (searched September 2008), the Cochrane Central Register of Controlled Trials (Cochrane Library, third Quarter 2008), CINAHL (searched September 2008), MEDLINE (January 1966 to September 2008), and EMBASE (January 1985 to September 2008). All searches were rerun 13 August 2009 17 RCTs were located and await classification.

SELECTION CRITERIA

Randomised controlled trials which investigated the effect of insulin sensitising drugs compared with either placebo or no treatment, or compared with an ovulation induction agent.

DATA COLLECTION AND ANALYSIS

Thirty one trials (2537 women) were included for analysis, 27 of them using metformin and involving 2150 women.

MAIN RESULTS

There is no evidence that metformin improves live birth rates whether it is used alone (Pooled OR = 1.00, 95% CI 0.16 to 6.39) or in combination with clomiphene (Pooled OR = 1.48, 95% CI 1.12 to 1.95). However, clinical pregnancy rates are improved for metformin versus placebo (Pooled OR = OR 3.86, 95% C.I. 2.18 to 6.84) and for metformin and clomiphene versus clomiphene alone (Pooled OR =1.48, 95% C.I. 1.12 to 1.95) ). In the studies that compared metformin and clomiphene alone, there was no evidence of an improved live birth rate (OR= 0.67, 95% CI 0.44 to 1.02) but the pooled OR resulted in improved clinical pregnancy rate in in the clomiphene group (OR = 0.63 , 95% 0.43 to 0.92), although there was significant heterogeneity.There is also evidence that ovulation rates are improved with metformin in women with PCOS for metformin versus placebo (Pooled OR 2.12, 95% CI 1.50 to 3.0) and for metformin and clomiphene versus clomiphene alone (Pooled OR = 3.46, 95% CI 1.97 to 6.07).Metformin was also associated with a significantly higher incidence of gastrointestinal disturbance, but no serious adverse effects were reported.

AUTHORS' CONCLUSIONS

In agreement with the previous review, metformin is still of benefit in improving clinical pregnancy and ovulation rates. However, there is no evidence that metformin improves live birth rates whether it is used alone or in combination with clomiphene, or when compared with clomiphene. Therefore, the use of metformin in improving reproductive outcomes in women with PCOS appears to be limited.