The effects of rosiglitazone and metformin on insulin resistance and serum androgen levels in obese and lean patients with polycystic ovary syndrome

Research Progress of Metformin in the Treatment of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is one of the most common malignancies and has a high mortality, posing a great threat to both human physical and mental health. With the advancement of scientific research, a variety of cancer therapies have been used for OSCC treatment. However, the prognosis of OSCC shows no significant improvement. Metformin has been recognized as the first-line drug for the treatment of diabetes, and recent studies have shown that metformin has a remarkable suppressive effect on tumor progression. Metformin can not only affect the energy metabolism of tumor cells but also play an antitumor role by modulating the tumor microenvironment and cancer stem cells. In this review, the molecular mechanism of metformin and its anticancer mechanism in OSCC are summarized. In addition, this article summarizes the side effects of metformin and the future prospects of its application in the treatment of OSCC.

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.

Insulin Sensitizers for Improving the Endocrine and Metabolic Profile in Overweight Women With PCOS

OBJECTIVE

To evaluate the efficacy of insulin sensitizers on menstrual frequency, sex hormone, and metabolic parameters in overweight women with polycystic ovary syndrome (PCOS).

METHODS

We searched multiple databases from inception to September 2019 for randomized controlled trials. Network meta-analysis was conducted using multivariate random effects method.

RESULTS

Fourteen trials reporting on 619 women were included. Compared with metformin, metformin + thiazolidinediones (TZDs) was more superior in menstrual recovery (weighted mean difference [WMD] 3.68; 95% credibility interval [CrI], 1.65 to 8.20), metformin +  glucagon-like peptide-1 (GLP-1) receptor agonists was more effective in decreasing androstenedione (WMD -2.53; 95% CrI, -3.96 to -1.09), both metformin + GLP-1 receptor agonists (WMD 9.22; 95% CrI, 5.46 to 12.98) and metformin + TZDs (WMD 4.30; 95% CrI, 0.78 to 7.82) were more effective in increasing sex hormone-binding globulin (SHBG), while TZDs were less effective in decreasing body mass index (BMI) (WMD 1.69; 95% CrI, 0.72 to 2.66). Compared with GLP-1 receptor agonists, metformin + GLP-1 receptor agonists was associated with higher SHBG (WMD 7.80; 95% CrI, 4.75 to 10.85), lower free testosterone (WMD -1.77; 95% CrI, -3.25 to -0.29), lower androstenedione (WMD -2.70; 95% CrI, -3.91 to -1.50) and lower fasting blood glucose (WMD -0.41; 95% CrI, -0.73 to -0.08).

CONCLUSION

For overweight women with PCOS, both metformin combined with GLP-1 receptor agonists and metformin combined with TZDs appear superior to monotherapy in improving hyperandrogenemia. Metformin combined with TZDs could be particularly effective in promoting the recovery of menstruation. Metformin combined with GLP-1 receptor agonists has the additional advantage of improving fasting glucose when compared with GLP-1 receptor agonists alone. TZDs are inferior to metformin in decreasing BMI.

A prospective pilot study of the effect of acupuncture on insulin sensitivity in women with polycystic ovary syndrome and insulin resistance

OBJECTIVE

To test the hypothesis that acupuncture improves insulin sensitivity in women with polycystic ovary syndrome (PCOS) and insulin resistance (IR).

DESIGN

Prospective pilot study.

SETTING

Guangzhou, China, 2014-2016.

PARTICIPANTS

Eighty women with PCOS aged 18-40 years with body mass index (BMI) above 18.5 kg/m² and with homeostatic model assessment for insulin resistance (HOMA-IR) index ⩾2.14.

INTERVENTIONS

Subjects received acupuncture with combined manual and low-frequency electrical stimulation of the needles three times per week for 6 months.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the change in HOMA-IR after 6 months of acupuncture relative to baseline. Secondary outcomes included changes after 6 months of acupuncture and at 3 months of follow-up (both relative to baseline) in oral glucose tolerance test (OGTT) parameters (glucose and insulin levels), anthropometric measurements, and circulating metabolic and endocrine variables.

RESULTS

HOMA-IR and fasting plasma glucose and insulin levels were significantly decreased after 6 months of acupuncture, and both HOMA-IR and fasting insulin remained significantly decreased at 3 months of follow-up. In a subgroup analysis of normal-weight and overweight/obese women, HOMA-IR was reduced after 6 months of acupuncture in both subgroups, but there was no significant difference between the two groups.

CONCLUSIONS

Acupuncture treatment in Chinese women with PCOS and IR was associated with an encouraging improvement in insulin sensitivity. Further randomized controlled studies are required to confirm the efficacy of acupuncture for this indication.

Effects of vitamin D on steroidogenesis, reactive oxygen species production, and enzymatic antioxidant defense in human granulosa cells of normal and polycystic ovaries

Polycystic ovary syndrome (PCOS) is accompanied with many disturbances in hormone synthesis and antioxidant defense. Previous reports have indicated that Vitamin D (vit.D) affects gene expression and have roles in normal follicular development. Therefore, we investigated the effects of vit.D on steroidogenesis, apoptosis, reactive oxygen species (ROS) production, and antioxidant defenses of human normal granulosa cells (N-GCs) and granulosa cells from polycystic ovaries (PCO-GCs). Ovarian GCs were obtained during oocyte retrieval procedure from 120 women with PCOS and from 100 healthy women who referred to Shiraz Fertility Center. The isolated GCs were cultured in the presence or absence of vit.D (100 nM), for 48 h. Concentration of sex steroids was measured by ELISA. Glutathione peroxidase (GPx) and superoxide dismutase (SOD) expression and activities were assessed by q-PCR and photometric methods, respectively. The amount of ROS production was estimated using chemiluminescence and fluorescence methods. Cell viability and apoptosis were detected by Annexin-V/propidium iodide detection kit. Basal estrone and progesterone secretion by N-GCs was significantly higher than that of PCO-GCs. Vit.D significantly increased aromatase and 3β-hydroxysteroid dehydrogenase activity in N-GCs and PCO-GCs. Basal expression and activity of GPx, in PCO-GCs were significantly lower than those of N-GCs. Treatment with vit.D significantly increased genes expression and enzyme activities in both groups. Basal ROS in PCO-GCs was markedly greater than that of N-GCs, which was attenuated by vit.D treatment. Cell apoptosis was directly correlated with ROS levels. We conclude that vit.D improved N-GCs and PCO-GCs functions through affecting steroidogenesis and enzymatic antioxidant defense. Under vit.D treatment, PCO-GCs could act more similar to N-GCs.

Comparing the individual effects of metformin and rosiglitazone and their combination in obese women with polycystic ovary syndrome: a randomized controlled trial

OBJECTIVE

To compare the effects of metformin, rosiglitazone, and their combination in obese polycystic ovary syndrome (PCOS) patients with insulin resistance.

DESIGN

Prospective randomized controlled trail.

SETTING

Tertiary teaching hospital.

PATIENT(S)

Obese Chinese women (body mass index [BMI] ≥25 kg/m²) with insulin resistance who fulfilled the Rotterdam criteria of PCOS.

INTERVENTION(S)

In group 1, 68 patients administered metformin (1,500 mg/day); in group 2, 67 patients administered rosiglitazone (4 mg/day); in group 3, 69 patients administered metformin (1,000 mg/day) and rosiglitazone (4 mg/day) for 6 months, all with the same diet and regular exercise lifestyle recommendation.

MAIN OUTCOME MEASURE(S)

Average menstrual interval, anthropometric measurements, androgen-related parameters, and metabolic features of insulin, carbohydrates, and lipids, with intention-to-treat analysis.

RESULT(S)

The baseline parameters showed no statistically significant differences. After the 6-month treatment, most participants showed an improved menstrual pattern. There were statistically significant decreases in acne scores, weight, BMI, waist circumference, waist-to-hip ratio, and serum testosterone. The metabolic indexes of insulin, carbohydrates, and lipids were improved obviously compared with the baseline in each group. Among the three groups, the patients administered 1,500 mg/day metformin experienced greater reductions in weight. However, the rosiglitazone users (alone or combined with metformin) showed a more notable decline in total cholesterol and triglyceride levels.

CONCLUSION(S)

Considering the benefits of metformin on weight loss, high-dose metformin (1,500 mg/day) along with lifestyle modification should be recommended for obese, insulin-resistant women with PCOS. Rosiglitazone alone or combined with low-dosage metformin plus lifestyle modification should be considered for the women with abnormal lipid profiles.

CLINICAL TRIAL REGISTRATION NUMBER

ChiCTR-TRC-13003642 (Chinese Clinical Trial Registry).

Bitter Taste Receptor Ligand Improves Metabolic and Reproductive Functions in a Murine Model of PCOS

Polycystic ovary syndrome (PCOS) results from functional ovarian hyperandrogenism due to dysregulation of androgen secretion. Cultured theca cells from polycystic ovaries of women with the most common form of PCOS overexpress most androgen producing enzymes, particularly CYP450c17. In this study, a murine model was used of PCOS induced by chronic feeding with a high-fat diet that exhibits the reproductive, hyperandrogenic, and metabolic constellation of PCOS symptoms seen in women. Oral administration of KDT501, a hops-derived bitter taste receptor (Tas2R 108) isohumulone ligand resulted in resolution of PCOS-associated endocrine and metabolic disturbances and restored reproductive function. Pioglitazone, a PPARγ agonist, also improved metabolic and reproductive function, though not to the same degree as KDT501. Specifically, treatment of the murine PCOS model with KDT501 resulted in reduced testosterone and androstenedione levels in the absence of significant changes in LH or FSH, improved glucose tolerance and lipid metabolism, and reduced hepatic lipid infiltration and adiposity. There was significant improvement in estrous cyclicity and an increase in the number of ovarian corpora lutea, indicative of improved reproductive function after exposure to KDT501. Finally, ex vivo exposure of murine ovaries to KDT501 attenuated androgen production and ovarian expression of CYP450c17. Interestingly, the ovaries expressed Tas2R 108, suggesting a potential regulation of ovarian steroidogenesis through this chemosensory receptor family. In summary, a therapeutic strategy for PCOS possibly could include direct influences on ovarian steroidogenesis that are independent of gonadotrophic hormone regulation.

Polycystic Ovary Syndrome: Implication for Drug Metabolism on Assisted Reproductive Techniques-A Literature Review

Polycystic ovary syndrome (PCOS) affects 6–10% of women and could be considered one of the most common endocrine alterations in women of reproductive age. The syndrome is characterized by several hormonal and metabolic alterations, including insulin resistance and hyperandrogenism, which play a severe detrimental role in the patient’s fertility. We aimed to offer an overview about drug metabolism in the PCOS population. Nevertheless, we did not find any study that directly compared drug metabolism between PCOS and healthy women. We therefore decided to summarize briefly how hormonal and insulin sensitizer drugs act differently in healthy and PCOS women, who show altered steroidogenesis by theca cells and metabolic imbalance, focusing especially on assisted reproductive techniques. To date, data about drug metabolism in the PCOS population appears to be extremely limited. This important gap could have significant implications for therapeutic approaches and future perspectives: the dosage of drugs commonly used for the treatment of PCOS women should be tailored according to each patient’s characteristics; we should implement new clinical trials in order to identify the best pharmacologic strategy for PCOS patients undergoing in vitro fertilization (IVF); it would be advisable to create an international expert panel to investigate the drug metabolism in the PCOS population.

Why AMPK agonists not known to be stressors may surprisingly contribute to miscarriage or hinder IVF/ART

Here we examine recent evidence suggesting that many drugs and diet supplements (DS), experimental AMP-activated protein kinase (AMPK) agonists as well as energy-depleting stress, lead to decreases in anabolism, growth or proliferation, and potency of cultured oocytes, embryos, and stem cells in an AMPK-dependent manner. Surprising data for DS and drugs that have some activity as AMPK agonists in in vitro experiments show possible toxicity. This needs to be balanced against a preponderance of evidence in vivo that these drugs and DS are beneficial for reproduction. We here discuss and analyze data that leads to two possible conclusions: First, although DS and drugs that have some of their therapeutic mechanisms mediated by AMPK activity associated with low ATP levels, some of the associated health problems in vivo and in vitro fertilization/assisted reproductive technologies (IVF/ART) may be better-treated by increasing ATP production using CoQ10 (Ben-Meir et al., Aging Cell 14:887-895, 2015). This enables high developmental trajectories simultaneous with solving stress by energy-requiring responses. In IVF/ART, it is ultimately best to maintain handling and culture of gametes and embryos in the quietest state with low metabolic activity (Leese et al., Mol Hum Reprod 14:667-672, 2008; Leese, Bioessays 24 (9):845-849, 2002) using back-to-nature or simplex algorithms to identify optima (Biggers, Reprod Biomed Online 4 Suppl 1:30-38, 2002). Stress markers, such as checkpoint proteins like TRP53 (aka p53) (Ganeshan et al., Exp Cell Res 358:227-233, 2017); Ganeshan et al., Biol Reprod 83:958-964, 2010) and a small set of kinases from the protein kinome that mediate enzymatic stress responses, can also be used to define optima. But, some gametes or embryos may have been stressed in vivo prior to IVF/ART or IVF/ART optimized for one outcome may be suboptimal for another. Increasing nutrition or adding CoQ10 to increase ATP production (Yang et al., Stem Cell Rev 13:454-464, 2017), managing stress enzyme levels with inhibitors (Xie et al., Mol Hum Reprod 12:217-224, 2006), or adding growth factors such as GM-CSF (Robertson et al., J Reprod Immunol 125:80-88, 2018); Chin et al., Hum Reprod 24:2997-3009, 2009) may increase survival and health of cultured embryos during different stress exposure contexts (Puscheck et al., Adv Exp Med Biol 843:77-128, 2015). We define "stress" as negative stimuli which decrease normal magnitude and speed of development, and these can be stress hormones, reactive oxygen species, inflammatory cytokines, or physical stimuli such as hypoxia. AMPK is normally activated by high AMP, commensurate with low ATP, but it was recently shown that if glucose is present inside the cell, AMPK activation by low ATP/high AMP is suppressed (Zhang et al., Nature 548:112-116, 2017). As we discuss in more detail below, this may also lead to greater AMPK agonist toxicity observed in two-cell embryos that do not import glucose. Stress in embryos and stem cells increases AMPK in large stimulation indexes but also direness indexes; the fastest AMPK activation occurs when stem cells are shifted from optimal oxygen to lower or high levels (Yang et al., J Reprod Dev 63:87-94, 2017). CoQ10 use may be better than risking AMPK-dependent metabolic and developmental toxicity when ATP is depleted and AMPK activated. Second, the use of AMPK agonists, DS, and drugs may best be rationalized when insulin resistance or obesity leads to aberrant hyperglycemia and hypertriglyceridemia, and obesity that negatively affect fertility. Under these conditions, beneficial effects of AMPK on increasing triglyceride and fatty acid and glucose uptake are important, as long as AMPK agonist exposures are not too high or do not occur during developmental windows of sensitivity. During these windows of sensitivity suppression of anabolism, proliferation, and stemness/potency due to AMPK activity, or overexposure may stunt or kill embryos or cause deleterious epigenetic changes.

Menstrual Dysfunction in Girls From the Treatment Options for Type 2 Diabetes in Adolescents and Youth (TODAY) Study

CONTEXT

Little is known about reproductive function in girls with youth-onset type 2 diabetes.

OBJECTIVES

To characterize girls with irregular menses and effects of glycemic treatments on menses and sex steroids in the Treatment Options for Type 2 Diabetes in Youth (TODAY) study.

DESIGN

Differences in demographic, metabolic, and hormonal characteristics between regular- vs irregular-menses groups were tested; treatment group (metformin with or without rosiglitazone, metformin plus lifestyle) effect on menses and sex steroids over time in the study was assessed. This is a secondary analysis of TODAY data.

SETTING

Multicenter study in an academic setting.

PATIENTS

TODAY girls not receiving hormonal contraception and those at least 1-year postmenarche were included. Irregular menses was defined as three or fewer periods in the prior 6 months.

RESULTS

Of eligible participants with serum measurement of sex steroids (n = 190; mean age, 14 years), 21% had irregular menses. Those with irregular vs regular menses had higher body mass index (BMI) (P = 0.001), aspartate aminotransferase (AST) (P = 0.001), free androgen index (P = 0.0003), and total testosterone (P = 0.01) and lower sex hormone-binding globulin (SHBG) (P = 0.004) and estradiol (P = 0.01). Differences remained after adjustment for BMI. There was no treatment group effect on menses or sex steroids at 12 or 24 months, and no association of sex steroids was seen with measures of insulin sensitivity or secretion.

CONCLUSIONS

Menstrual dysfunction is common in girls with recently diagnosed type 2 diabetes and associated with alterations in sex steroids, SHBG, and AST but not with alteration in insulin sensitivity or β-cell function and did not improve with 2 years of antihyperglycemic treatment.

Clinical outcome of various metformin treatments for women with polycystic ovary syndrome

Aim

Polycystic ovary syndrome (PCOS) is an ovulatory disorder and insulin resistance and diabetes are involved in its pathophysiology. Metformin, an anti-diabetic agent, has been reported to be useful to induce ovulation.

Methods

Metformin treatment was classified into four types: (1) clomiphene-metformin combination treatment for clomiphene-resistant patients; (2) clomiphene-metformin combination for clomiphene-sensitive patients; (3) clomiphene-metformin combination for naïve patients; and (4) metformin monotherapy. The patients underwent physical, endocrinological, and clinical examinations for their ovulation rates, pregnancy rates, and follicular development.

Results

The ovulation rates, pregnancy rates, and single follicular development were not significantly different among the clomiphene-metformin combination treatment groups. In the Body Mass Index (BMI) subanalysis, the pregnancy rate was higher in the BMI≥30 kg/m2 group than in the other three groups with a BMI of ≤30 kg/m2 in both cycles and cases. The ovulation rates and pregnancy rates were significantly higher in the group with a fasting insulin of ≥15 μU/mL than in the groups with a fasting insulin of <15 μU/mL in both cycles and cases.

Conclusion

Clomiphene-metformin combination treatment appears to be useful, at least for clomiphene-resistant patients, and a BMI of >30 kg/m2 and a fasting insulin of ≥15 μU/mL appear to be predictors of a good result with this treatment.

High-fat diets exaggerate endocrine and metabolic phenotypes in a rat model of DHEA-induced PCOS

Polycystic ovary syndrome (PCOS) is a complex endocrine and metabolic disorder with unclear etiology and unsatisfactory management. Effects of diets on the phenotype of PCOS were not fully understood. In the present study, we applied 45 and 60% high-fat diets (HFDs) on a rat model of PCOS induced by postnatal DHEA injection. We found that both DHEA and DHEA+HFDs rats exhibited reproductive abnormalities, including hyperandrogenism, irregular cycles and polycystic ovaries. The addition of HFDs, especially 60% HFDs, exaggerated morphological changes of ovaries and a number of metabolic changes, including increased body weight and body fat content, impaired glucose tolerance and increased serum insulin levels. Results from qPCR showed that DHEA-induced increased expression of hypothalamic androgen receptor and LH receptor were reversed by the addition of 60% HFDs. In contrast, the ovarian expression of LH receptor and insulin receptor mRNA was upregulated only with the addition of 60% HFDs. These findings indicated that DHEA and DHEA+HFDs might influence PCOS phenotypes through distinct mechanisms: DHEA affects the normal function of hypothalamus-pituitary-ovarian axis through LH, whereas the addition of HFDs exaggerated endocrine and metabolic dysfunction through ovarian responses to insulin-related mechanisms. We concluded that the addition of HFDs yielded distinct phenotypes of DHEA-induced PCOS and could be used for studies on both reproductive and metabolic features of the syndrome.

Genetic Rodent Models of Obesity-Associated Ovarian Dysfunction and Subfertility: Insights into Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy affecting women and a leading cause of female infertility worldwide. Defined clinically by the presence of hyperandrogenemia and oligomenorrhoea, PCOS represents a state of hormonal dysregulation, disrupted ovarian follicle dynamics, and subsequent oligo- or anovulation. The syndrome's prevalence is attributed, at least partly, to a well-established association with obesity and insulin resistance (IR). Indeed, the presence of severe PCOS in human genetic obesity and IR syndromes supports a causal role for IR in the pathogenesis of PCOS. However, the molecular mechanisms underlying this causality, as well as the important role of hyperandrogenemia, remain poorly elucidated. As such, treatment of PCOS is necessarily empirical, focusing on symptom alleviation. The generation of knockout and transgenic rodent models of obesity and IR offers a promising platform in which to address mechanistic questions about reproductive dysfunction in the context of metabolic disease. Similarly, the impact of primary perturbations in rodent gonadotrophin or androgen signaling has been interrogated. However, the insights gained from such models have been limited by the relatively poor fidelity of rodent models to human PCOS. In this mini review, we evaluate the ovarian phenotypes associated with rodent models of obesity and IR, including the extent of endocrine disturbance, ovarian dysmorphology, and subfertility. We compare them to both human PCOS and other animal models of the syndrome (genetic and hormonal), explore reasons for their discordance, and consider the new opportunities that are emerging to better understand and treat this important condition.

Insulin resistance in nonobese Japanese women with polycystic ovary syndrome is associated with poorer glucose tolerance, delayed insulin secretion, and enhanced insulin response

Purpose

To determine the prevalence of insulin resistance (IR) and impaired glucose tolerance (IGT) in PCOS patients, the optimal screening method, and to compare our findings between nonobese and obese Japanese women with PCOS.

Methods

Ninety-eight PCOS patients were included in this research from 2006 to 2013. Glucose tolerance test (OGTT) was performed. Serum glucose and insulin concentration were assayed before and 30, 60, and 120 min after taking 75 g of glucose.

Results

All examined metabolic parameters were significantly favorable in the nonobese subjects, below 25 kg/m². HOMA-IR, fasting insulin, glucose₁₂₀, and insulin₁₂₀ showed strong correlations with BMI. A total of 1.4 % of nonobese women had IR based on fasting insulin or HOMA-IR. However, 15.5 % (11/71) of nonobese women had IR as determined by a continuous increase of serum insulin level in OGTT. In comparison, the prevalence of IR among the obese women ranged from 41 to 59 %. AUC_glucose, glucose₆₀, glucose₁₂₀, and insulin₁₂₀ in nonobese women with a continuous insulin increase were higher than those without such a continuous increase.

Conclusions

All examined metabolic parameters were significantly correlated with BMI. As the presence of a continuous increase of insulin level reflects to some degree poorer glucose tolerance, delayed insulin secretion, and enhanced insulin response compared with non-continuous insulin increase, OGTT might not been excluded to determine IR and IGT for nonobese women with PCOS.

Similar causes of various reproductive disorders in early life

During the past few decades, scientific evidence has been accumulated concerning the possible adverse effects of the exposure to environmental chemicals on the well-being of wildlife and human populations. One large and growing group of such compounds of anthropogenic or natural origin is referred to as endocrine-disrupting chemicals (EDCs), due to their deleterious action on the endocrine system. This concern was first focused on the control of reproductive function particularly in males, but has later been expanded to include all possible endocrine functions. The present review describes the underlying physiology behind the cascade of developmental events that occur during sexual differentiation of males and the specific role of androgen in the masculinization process and proper organogenesis of the external male genitalia. The impact of the genetic background, environmental exposures and lifestyle factors in the etiology of hypospadias, cryptorchidism and testicular cancer are reviewed and the possible role of EDCs in the development of these reproductive disorders is discussed critically. Finally, the possible direct and programming effects of exposures in utero to widely use therapeutic compounds, environmental estrogens and other chemicals on the incidence of reproductive abnormalities and poor semen quality in humans are also highlighted.

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.

Effects of caloric intake timing on insulin resistance and hyperandrogenism in lean women with polycystic ovary syndrome

In women with PCOS (polycystic ovary syndrome), hyperinsulinaemia stimulates ovarian cytochrome P450c17α activity that, in turn, stimulates ovarian androgen production. Our objective was to compare whether timed caloric intake differentially influences insulin resistance and hyperandrogenism in lean PCOS women. A total of 60 lean PCOS women [BMI (body mass index), 23.7±0.2 kg/m2] were randomized into two isocaloric (~1800 kcal; where 1 kcal≈4.184 J) maintenance diets with different meal timing distribution: a BF (breakfast diet) (980 kcal breakfast, 640 kcal lunch and 190 kcal dinner) or a D (dinner diet) group (190 kcal breakfast, 640 kcal lunch and 980 kcal dinner) for 90 days. In the BF group, a significant decrease was observed in both AUCglucose (glucose area under the curve) and AUCinsulin (insulin area under the curve) by 7 and 54% respectively. In the BF group, free testosterone decreased by 50% and SHBG (sex hormone-binding globulin) increased by 105%. GnRH (gonadotropin-releasing hormone)-stimulated peak serum 17OHP (17α-hydroxyprogesterone) decreased by 39%. No change in these parameters was observed in the D group. In addition, women in the BF group had an increased ovulation rate. In lean PCOS women, a high caloric intake at breakfast with reduced intake at dinner results in improved insulin sensitivity indices and reduced cytochrome P450c17α activity, which ameliorates hyperandrogenism and improves ovulation rate. Meal timing and distribution should be considered as a therapeutic option for women with PCOS.

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

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

PPAR Gamma: Coordinating Metabolic and Immune Contributions to Female Fertility

Peroxisome proliferator-activated receptor gamma (PPARG) regulates cellular functions such as adipogenesis and immune cell activation. However, new information has indicated additional roles of PPARG directing the cyclic changes that occur within ovarian tissue of female mammals, including those that facilitate the release of oocytes each estrous cycle. In addition to ovarian PPARG expression and function, many PPARG actions within adipocytes and macrophages have additional direct and indirect implications for ovarian function and female fertility. This encompasses the regulation of lipid uptake and transport, insulin sensitivity, glucose metabolism, and the regulation of inflammatory mediator synthesis and release. This review discusses the developing links between PPARG activity and female reproductive function, and highlights several mechanisms that may facilitate such a relationship.

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.

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.

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.

Developmental programming: insulin sensitizer treatment improves reproductive function in prenatal testosterone-treated female sheep

Prenatal testosterone (T) excess causes reproductive and metabolic disruptions including insulin resistance, attributes of women with polycystic ovary syndrome. This study tested the hypothesis that insulin resistance contributes toward severity of reproductive disruptions in prenatally T-treated females. Pregnant sheep were injected im with 100 mg of T-propionate semiweekly from d 30-90 of gestation. Immediately after the first breeding season, a subset of controls and prenatal T-treated (TR) sheep were administered an insulin sensitizer (rosiglitazone; 8 mg/d) orally for 8 months. Untreated control and prenatal T-treated females (T group) were studied in parallel. Biochemical analyses revealed rosiglitazone to be safe for use in sheep. Glucose tolerance tests performed before and after the insulin sensitizer treatment found that insulin sensitizer decreased cumulative insulin, cumulative insulin/glucose ratio, and insulin area under the curve by about 50% and increased the insulin sensitivity index by about 70% in the TR compared with the T group. Twenty percent of TR females showed a reduced number of cycles in the second relative to first breeding season as opposed to 80% of T group females showing such deterioration. Insulin sensitizer treatment also decreased the number of aberrant cycles (>/=18 d) during the second breeding season in the TR group relative to the first as opposed to the T group females showing an increase in the second breeding season relative to the first. These findings provide evidence that insulin sensitizer treatment prevents further deterioration of the reproductive axis in prenatal T-treated sheep, a finding of translational relevance to women with polycystic ovary syndrome.

Women's perceptions of polycystic ovary syndrome following participation in a clinical research study: implications for knowledge, feelings, and daily health practices

OBJECTIVE

Polycystic ovary syndrome (PCOS) is a complex endocrine disorder that affects 6% to 10% of reproductive aged women. It is a poorly understood and often undiagnosed condition that has implications for the health of affected women. We assessed changes in knowledge, feelings, and daily health practices related to PCOS in clinical research study participants.

METHODS

Sixty-eight women who had received counselling and education about PCOS while participating in a clinical research study were invited to complete an online survey that assessed levels of concern, knowledge, healthy dieting, active living, and health care satisfaction before and after the study. Differences and associations between scores were analyzed by paired t tests and Pearson correlation.

RESULTS

Forty-three women (63%) completed the survey. After taking part in a clinical research study, participants believed they had increased knowledge of (P < 0.001) and concern about (P = 0.029) the etiology and health consequences of PCOS, better lifestyle practices (P < 0.001), and improved health care satisfaction (P = 0.045). Enhanced knowledge of PCOS was positively associated with changes in concern (P = 0.045), healthy dietary habits (P = 0.04), activity levels (P = 0.003), and health care satisfaction (P < 0.001). After the study, women felt empowered to participate in the management of their condition and communicate with their primary care providers.

CONCLUSION

Women with PCOS felt that they had more knowledge and motivation to implement preventive health strategies after participating in a clinical research study. Education about how PCOS affects their immediate and long-term health enabled women with PCOS to feel physical and psychological benefits and to engage more with their health care providers.

Radiolabeling, biodistribution and gamma scintigraphy of noscapine hydrochloride in normal and polycystic ovary induced rats

BACKGROUND

Noscapine, an alkaloid from Papaver somniferum, widely used as an antitussive, is being clinically studied in the treatment of polycystic ovary syndrome (PCOS) and a few other cancers primarily because of its anti-angiogenesis properties. With the advent of diverse application of noscapine, we sought to determine whether the radiolabeling method can be useful in studying uptake and kinetics of the molecule in-vivo. Specific objectives of this study were to radiolabel noscapine with Technetium-99m (Tc-99m), to determine its organ biodistribution in rat model and study its uptake kinetics in PCOS model.

METHODS

A method for radiolabeling noscapine with Tc-99m was standardized using stannous reduction method and its in vitro and in vivo stability parameters were studied. The radiopharmaceutical was also evaluated for blood kinetics and biodistribution profile. An animal model of PCOS was created by using antiprogesterone RU486 and uptake of 99mTc-noscapine in normal and PCOS ovaries was compared using gamma scintigraphy.

RESULTS

Noscapine hydrochloride was successfully radiolabeled with Tc-99m with high labeling efficiency and in vitro stability. Most of the blood clearance of the drug (80%) took place in first hour after intravascular injection with maximum accumulation being observed in liver, spleen, kidney followed by the ovary. At 4 hours post injection, radiolabeled complex accumulation doubled in PCOS ovaries in rats (0.9 +/- 0.03% ID/whole organ) compared to normal cyclic rats (0.53 +/- 0.01% ID/whole organ). This observation was further strengthened by scintigraphic images of rats taken at different time intervals (1 h, 2 h, 4 h, and 24 h) where SPECT images suggested discrete accumulation in the PCOS ovaries.

CONCLUSION

Through our study we report direct radiolabeling of noscapine and its biodistribution in various organs and specific uptake in PCOS that may show its utility for imaging ovarian pathology. The increased ovarian uptake in PCOS may be related to its receptor binding suggesting possible role of 99mTc-noscapine in PCOS diagnostics and therapeutics.

Dehydroepiandrosterone to induce murine models for the study of polycystic ovary syndrome

During the last decade a battery of animal models used for the study of polycystic ovary syndrome (PCOS) have allowed a focus on different aspects of the pathology. Since dehydroepiandrosterone (DHEA) was found to be one of the most abundant circulating androgens in women with PCOS, a rodent model showing the salient features found in women with PCOS was developed by the injection of DHEA. Although insulin-sensitizing agents, such as biguanides, are clinically used in the treatment of diabetes and PCOS, the complete understanding of their mechanisms of action remains unknown. The present review discusses the molecular mechanisms involved in the development of PCOS by using the DHEA-PCOS murine model and analyzes the role of the biguanide metformin as treatment.

Steroidogenesis in the fetal testis and its susceptibility to disruption by exogenous compounds

Masculinization depends on adequate production of testosterone by the fetal testis within a specific "masculinization programming window." Disorders resulting from subtle deficiencies in this process are common in humans, and environmental exposures/lifestyle could contribute causally because common therapeutic and environmental compounds can affect steroidogenesis. This evidence derives mainly from rodent studies, but because there are major species differences in regulation of steroidogenesis in the fetal testis, this may not always be a guide to potential effects in the human. In addition to direct study of the effects of compounds on steroidogenesis, information also derives from study of masculinization disorders that result from mutations in genes in pathways regulating steroidogenesis. This review addresses this issue by critically reviewing the comparative timing of production and regulation of steroidogenesis in the fetal testis of humans and of rodents and its susceptibility to disruption; where there is limited information for the fetus, evidence from effects on steroidogenesis in the adult testis is considered. There are a number of fundamental regulatory differences between the human and rodent fetal testis, most notably in the importance of paracrine vs. endocrine drives during masculinization such that inactivating LH receptor mutations block masculinization in humans but not in rodents. Other large differences involve the steroidogenic response to estrogens and GnRH analogs and possibly phthalates, whereas for other compounds there may be differences in sensitivity to disruption (ketoconazole). This comparison identifies steroidogenic targets that are either vulnerable (mitochondrial cholesterol transport, CYP11A, CYP17) or not (cholesterol uptake) to chemical interference.

Targeting insulin sensitivity in the treatment of polycystic ovary syndrome

Targeting insulin resistance may result in a list of benefits for women with PCOS, including hormonal, metabolic and ovulatory (and fertility) improvements. The therapeutic strategy to treat PCOS should however depend on the clinical situation, the phenotype, the degree of androgen excess, age, the presence of infertility and the woman's desire to conceive, the presence of obesity and, finally, the spectrum of metabolic abnormalities and the need to treat or prevent long-term associated comorbidities. According to the needs, therapeutic options include, alone or in combination, lifestyle management, particularly in the presence of obesity, the use of insulin sensitizers, metformin and thiazolidinediones, antiandrogens or estro-progestins.

Relevance of an opioid, noscapine in reducing cystogeneses in rat experimental model of polycystic ovary syndrome

AIM

Owing to grave socio-medical consequences, polycystic ovary syndrome (PCOS) is a highly alarming endocrinopathy. For searching better therapeutics for PCOS, we present a rat model for PCOS using antiprogestin RU486 and evaluate the efficacy of noscapine for its treatment.

MATERIAL AND METHODS

Female Wistar rats weighing 200+/-10 g bwt, exhibiting regular estrous cycle were administered an oral dose of RU486 [20 mg/kg body weight (bwt)/day] in olive oil for 13 consecutive days and compared with controls receiving 0.1 ml olive oil/100 g bwt/day. PCOS induced rats were administered varying dosing regimens of noscapine and were further compared with flutamide, the conventional drug for PCOS. Consecutively, vaginal smears and ovulation was noted and rats from all the groups were sacrificed and serum hormone levels for LH, FSH, PRL, estradiol, and testosterone were measured by enzyme-linked immunosorbent assay. Uteri and ovaries were excised free of adjacent tissue, weighed and further recruited for ascertaining ovary histologic parameters.

RESULTS

Our data go in accordance with previous studies where RU486 administered rats mimicked classical PCOS parameters seen in women. PCOS induced rats with ovulation blockade, persistent estrus and polycystic ovary resumed estrous cycle in 3-4 days post noscapine administration (120 mg/kg bwt/day). Folliculogenesis was followed by ovulation with reduced cystic manifestation and restored ovary and uterus weight. Biochemically, serum LH, PRL, estradiol, and testosterone concentration showed reduction while FSH and progesterone concentration increased significantly when compared with the conventional drug flutamide.

DISCUSSION

The amelioration of PCOS by noscapine is a novel observation that makes it a potential candidate for being a better therapeutic modality.

Could oxidative stress influence the in-vitro maturation of oocytes?

In the efforts aimed at improving the quality of in-vitro-matured human oocytes, the dynamic balance and roles of pro-/antioxidants merit further consideration. In-vitro maturation (IVM) is emerging as a popular technology at the forefront of fertility treatment and preservation. However, standard in-vitro culture conditions exert oxidative stress or an imbalance between oxidants and antioxidants. Reactive oxygen species (ROS) are oxygen-derived molecules formed as intermediary products of cellular metabolism. By acting as powerful oxidants, ROS can oxidatively modify any molecule, resulting in structural and functional alterations. ROS are neutralized by an elaborate defence system consisting of enzymatic and nonenzymatic antioxidants. This review captures the inherent and external factors that may modulate the oxidative stress status of oocytes. It discusses the suspected impacts of oxidative stress on the gamut of events associated with IVM, including prematuration arrest, meiotic progression, chromosomal segregation, cytoskeletal architecture and gene expression. In-vivo and in-vitro strategies that may overcome the potential influences of oxidative stress on oocyte IVM are presented. Future studies profiling the oxidative stress status of the oocyte may permit not only the formulation of a superior IVM medium that maintains an adequate pro-/antioxidant balance, but also the identification of predictors of oocyte quality.

In polycystic ovary syndrome, adrenal steroids are regulated differently in the morning versus in response to nutrient intake

OBJECTIVE

To investigate adrenal steroid regulation in polycystic ovary syndrome.

DESIGN

Five-hour oral glucose tolerance test (OGTT) and frequently sampled-intravenous gluclose tolerance test.

SETTING

University research center.

PATIENT(S)

Thirty patients.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Anthropometrics, leptin, cortisol, DHEAS, glucose, insulin.

RESULT(S)

Morning cortisol correlated with sensitivity index (SI, r = .540), DHEAS correlated inversely with age (r = -.6359), body mass index (BMI, r = -.6199), fat mass (r = -0.630), and leptin (r = -0.5676). Between the second and fourth hour of OGTT, cortisol changes (Delta) exhibited three patterns: I, responders (n = 9, Delta: 10.7 +/- 1.0 microg/dL); II, nonresponders (n = 10, Delta: -3.5 +/- 0.6 microg/dL); III, intermediates (n = 11, Delta: 4.3 +/- 1.0 microg/dL). Compared with nonresponders, responders were more obese (BMI: 37.0 +/- 1.6 vs. 31.7 +/- 1.8 kg/m(2)); had higher leptin (28.9 +/- 1.7 vs. 24.1 +/- 1.1 ng/mL), and lower DHEAS (133 +/- 12 vs. 236 +/- 32 ng/mL), higher glucose at 1 h of OGTT (195 +/- 13 vs. 131 +/- 12 mg/dL), higher area under the curve (AUC)(Glucose) (332 +/- 20 vs. 265 +/- 17 mg/dL), higher AUC(Insulin) (244 +/- 50 vs. 125 +/- 30 muU/mL), and lower nadir glucose (61 +/- 2 vs. 70 +/- 2 mg/dL).

CONCLUSION(S)

Obesity and insulin resistance are associated with lower morning cortisol and DHEAS but increased cortisol and DHEA responses after glucose ingestion. Morning steroid levels may not reflect the day-long exposure.

Rosiglitazone as treatment for clomiphene citrate-resistant polycystic ovary syndrome: factors associated with clinical response

PURPOSE

To identify the various clinical, biochemical, and ultrasonographic factors that determine clinical response to rosiglitazone as a first-line therapy in a series of women with newly diagnosed clomiphene citrate (CC)-resistant polycystic ovary syndrome (PCOS).

METHODS

This retrospective analysis included 200 women with newly diagnosed CC-resistant PCOS who received rosiglitazone as a first-line therapy between 2001 and 2006. The effect of clinical and biochemical characteristics on the ovulation and pregnancy rates during rosiglitazone therapy was evaluated. Women were divided into three categories according to the severity of clinical and biochemical parameters of PCOS. The success rates were compared among the categories using contingency table analysis. Multiple regression analysis was used to identify independent predictors of success of rosiglitazone therapy.

RESULTS

Body mass index (BMI) > or = 35 kg/m(2), serum testosterone concentration > or = 4.5 nmol/L, free androgen index (FAI) > or = 15, and with duration of infertility > 3 years were associated with poor response to rosiglitazone therapy. In rosiglitazone responders, women with lower pretreatment serum luteinizing hormone (LH) concentrations or a lower LH/follicle-stimulating hormone (FSH) ratio are more likely to have a sustained beneficial effect.

CONCLUSIONS

Marked obesity, marked hyperandrogenism, and long duration of infertility in women with newly diagnosed CC-resistant PCOS were predictors of resistance to rosiglitazone therapy as a first-line treatment.

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

CONTEXT

Polycystic ovary syndrome (PCOS) is characterized by insulin resistance, compensatory hyperinsulinemia, increased prevalence of impaired glucose tolerance, and increased ovarian androgen biosynthesis.

OBJECTIVE

The aim of the study was to evaluate effects of pioglitazone on whole body insulin action and ovarian androgen biosynthesis in PCOS.

DESIGN

We performed a randomized placebo-controlled trial.

SETTING

The study was conducted at the Special Diagnostic and Treatment Unit of the Veterans Affairs Medical Center, San Diego, and the University of California, San Diego, General Clinical Research Center.

PATIENTS OR OTHER PARTICIPANTS

A total of 23 subjects with PCOS were evaluated at baseline and end of treatment. Six age- and body mass index-matched women without PCOS were normal controls for baseline evaluation.

INTERVENTION

Subjects with PCOS were randomized to oral placebo or pioglitazone 45 mg daily for 6 months.

MAIN OUTCOME MEASURE(S)

The primary outcome measures were whole body insulin action as measured by hyperinsulinemic euglycemic clamp and ovarian androgen biosynthesis as measured by leuprolide-stimulated production of 17-hydroxyprogesterone (17-OHP).

RESULTS

Compared with placebo, pioglitazone treatment significantly improved multiple measures of insulin action, including glucose disposal rate (P < 0.01), 2-h glucose during 75-g oral glucose tolerance test (P < 0.01), area under the curve glucose during oral glucose tolerance test (P < 0.01), serum adiponectin (P < 0.01), and fasting hyperinsulinemia (P < 0.01). Compared to placebo, pioglitazone treatment reduced the increment of leuprolide-stimulated 17-OHP (P < 0.02). Improvements in glucose disposal rate correlated with reductions in 17-OHP stimulation (P < 0.02).

CONCLUSIONS

Compared to placebo, pioglitazone treatment in PCOS was associated with improvements in insulin action and glucose homeostasis and ameliorated the hyperandrogenic ovarian response.

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.

Basic infertility including polycystic ovary syndrome

Infertility in women has many possible causes and must be approached systematically. The most common cause of medically treatable infertility is the polycystic ovary syndrome (PCOS). This syndrome is common in young women and is the cause of anovulatory infertility in 70% of cases. It is therefore an important condition to screen and manage in primary care medical settings. In the past 10 years, insulin sensitization with weight loss or metformin has been shown to be a safe and effective treatment for PCOS infertility that eliminates the risk of multiple pregnancy and may reduce the risk of early pregnancy loss as compared with ovulation-inductor drugs. The authors believe metformin should be considered as first-line therapy because it has the advantage to allow for normal single ovulation, for reduced early pregnancy loss, and, most importantly, lifestyle modifications and weight loss before pregnancy. Losing weight not only improves fertility but also reduces adverse pregnancy outcomes associated with obesity.

Dysglycemia and a history of reproductive risk factors

OBJECTIVE

The purpose of this study was to identify reproductive risk factors associated with dysglycemia (diabetes, impaired glucose tolerance, and impaired fasting glucose) in a contemporary multiethnic population.

RESEARCH DESIGN AND METHODS

We studied 14,661 women screened with an oral glucose tolerance test for the Diabetes Reduction Assessment with Ramipril and Rosiglitazone Medication (DREAM) trial. Reproductive risk factors were compared in normoglycemic and dysglycemic women.

RESULTS

Dysglycemia was significantly associated with the number of children born (odds ratio 1.03 per child [95% CI 1.01-1.05]), age (1.05 per year [1.04-1.05]), non-European ancestry (1.09 [1.01-1.17]), preeclampsia/eclampsia (1.14 [1.02-1.27]), irregular periods (1.21 [1.07-1.36]), and gestational diabetes mellitus (GDM) (1.53 [1.35-1.74]). The relationship between GDM and dysglycemia did not differ across BMI tertiles (P = 0.84) nor did the relationships of other risk factors.

CONCLUSIONS

Reproductive factors, particularly GDM, are associated with dysglycemia in middle-aged women from many ethnicities. Reproductive factors can be used to counsel young women about their future risk of dysglycemia, whereas in middle age they may help screen for dysglycemia.

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.

Hirsutism

Hirsutism is defined as the excessive growth of terminal hair on the face and body of a female in a typical male pattern distribution. Hirsutism is a common clinical problem in women and the treatment depends on the cause of hirsutism. Untreated hirsutism can be associated with considerable loss of self-esteem and psychological morbidity. Hyperandrogenemia is the key trigger for excess hair growth. Polycystic ovary syndrome and idiopathic hirsutism are the most common cause of hirsutism. As with all medical problems, investigation begins with a careful history, examination and then investigation directed at the possible cause. A raised serum testosterone level of > 150 ng/dl (5.2 nmol/l) should prompt further investigations to exclude an underlying androgen-secreting tumour. The treatment of hirsutism is most effective using combination therapy, including lifestyle therapies, androgen suppression, peripheral androgen blockage and cosmetic treatments. Women should be warned not to expect improvement or at least 3-6 months after therapy is begun and lifelong therapy may be needed to prevent recurrence. The current review discusses definition, pathogenesis, differential diagnosis, diagnostic strategies, management, guidelines and the authors' recommendations about hirsutism.

Metformin and oral contraceptive treatments reduced circulating asymmetric dimethylarginine (ADMA) levels in patients with polycystic ovary syndrome (PCOS)

There is a little information in literature about circulating asymmetric dimethylarginine (ADMA) concentrations in polycystic ovary syndrome (PCOS) and the results reported are discrepant. In this study, therefore, we aimed (1) to determine the circulating ADMA concentrations in 44 women with PCOS and 22 age- and BMI-matched healthy controls, (2) to evaluate its correlations with insulin resistance, gonadotrophins, and androgen secretion, and (3) to compare effects of metformin and ethinyl estradiol-cyproterone acetate (EE/CPA) treatments on circulating ADMA concentrations. In conclusion, our data indicate that circulating ADMA concentrations in non-obese, non-hypertensive and young women with PCOS are significantly higher than healthy controls and they improved by a 3-month course of metformin and oral contraceptive treatments.

Decreased androgen levels and improved menstrual pattern after angiotensin II receptor antagonist telmisartan treatment in four hypertensive patients with polycystic ovary syndrome: case series

We describe 4 consecutive hypertensive women with polycystic ovary syndrome, classified according to the National Institute of Child Health and Human Development (NICHD) criteria, treated with telmisartan 40 mg/d for six months. Blood pressure, menstrual pattern, body mass index (BMI), homeostasis model assessment of insulin resistance, testosterone, dehydroepiandrosterone sulfate (DHEAS), and androstenedione were recorded and measured before and after telmisartan treatment. Obese hypertensive polycystic ovary syndrome patients had a decrease in systolic blood pressure. Marked drop-off in serum androgen concentrations was observed in all four patients. Three patients improved their menstrual cyclicity. The improvements were independent of changes in weight. The reduction of androgen concentrations and improvement in menstrual pattern was achieved despite a non-significant change of fasting insulin levels in patients, who were not considered severely insulin resistant at baseline. These findings may provide a new basis for a proper choice of the antihypertensive drug in hypertensive women with polycystic ovary syndrome.

Peroxisome proliferator-activated receptors: new players in the field of reproduction

Peroxisome proliferator-activated receptors (PPAR) are members of the nuclear hormone receptor superfamily. Synthetic ligands to one family member, PPARgamma, are currently widely used as treatment for chronic diseases such as diabetes type II and other insulin resistances, e.g. as seen in polycystic ovary syndrome (PCOS). Moreover, novel approaches employing knock-out mice demonstrated that PPARgamma seems to play a key role in placental and fetal development. This review describes recent insights into the role of PPARs in human reproduction with specific reference to infertility, placental maturation and fetal development as well as disturbed pregnancy. Further, we highlight the current knowledge on synthetic ligands to PPARgamma used as a treatment in women with PCOS.

Metformin improves polycystic ovary syndrome symptoms irrespective of pre-treatment insulin resistance

OBJECTIVE

Insulin resistance (IR) and obesity are common features of the polycystic ovary syndrome (PCOS). Insulin-sensitizing agents have been shown to improve both reproductive and metabolic aspects of PCOS, but it remains unclear whether it is also beneficial in lean patients without pre-treatment IR. The aim of this study was to determine the influence of metformin on the clinical and biochemical parameters of PCOS irrespective of the presence of basal obesity and IR.

DESIGN

The effect of 6 months of metformin treatment was prospectively assessed in 188 PCOS patients, divided into three groups according to body mass index (BMI; lean: BMI<25 kg/m2, overweight: BMI 25-29 kg/m2, and obese: BMI30 kg/m2). Outcome parameters, which were also assessed in 102 healthy controls, included body weight, homeostasis model assessment for IR (HOMA-IR), fasting glucose and insulin levels, area under the curve of insulin response (AUCI), hyperandrogenism, and menstrual irregularities.

RESULTS

In comparison with the respective BMI-appropriate control groups, only obese but not lean and overweight PCOS patients showed differences in fasting insulin and HOMA-IR. Metformin therapy significantly improved all outcome parameters except fasting glucose levels. Subgroup analyses revealed that in the group of lean PCOS patients without pre-treatment IR, metformin significantly improved HOMA-IR (1.7+/-1.0 vs 1.1+/-0.7 micromol/lxmmol/l2) and fasting insulin levels (7.7+/-4.2 vs 5.4+/-3.9 mU/l), in addition to testosterone levels (2.6+/-0.9 vs 1.8+/-0.7 nmol/l), anovulation rate (2.3 vs 59.5%), and acne (31.8 vs 11.6%; all P<0.017). In the overweight and obese PCOS groups, metformin also showed the expected beneficial effects.

CONCLUSION

Metformin improves parameters of IR, hyperandrogenemia, anovulation, and acne in PCOS irrespective of pre-treatment IR or obesity.

AMP kinase activation increases glucose uptake, decreases apoptosis, and improves pregnancy outcome in embryos exposed to high IGF-I concentrations

Women with polycystic ovarian syndrome are at increased risk of miscarriage. Although evidence exists that metformin reduces this risk, the mechanism is unknown. This study tests the hypothesis that AMP kinase (AMPK) activation with metformin directly improves insulin signaling within the blastocyst, leading to improved pregnancy outcomes. Murine embryos were exposed to 200 nmol/l IGF-I, similar to the concentrations that can occur during polycystic ovary syndrome (PCOS). Resulting blastocysts were compared with embryos cocultured with excess IGF-I plus metformin and embryos cultured in control medium for the following: AMPK phosphorylation, insulin-stimulated glucose uptake, and apoptosis. Study and control blastocysts were also transferred into control animals. On embryonic day (E) 14.5, resulting fetuses were examined for size and rates of fetal implantation and resorption. Compared with control blastocysts, blastocysts exposed to high concentrations of IGF-I showed a decrease in AMPK activation and insulin-stimulated glucose uptake and an increase in the number of apoptotic nuclei. Blastocysts cocultured in metformin and excess IGF-I performed as well as controls in all studies. 5-Aminoimidazole-4-carboxamide 1-beta-d-ribofuranoside, another AMPK activator, also prevented the effects of excess IGF-I on blastocysts. Implantation rates and fetal size at day 14.5 were significantly lower among IGF-I-exposed embryos transferred into control mothers compared with control embryos transferred into control mothers. Both of these parameters were reversed by co-incubation with metformin and IGF-I before transfer. Activation of embryonic AMPK may be the mechanism responsible for the improved pregnancy outcomes seen in PCOS patients taking metformin.

The effects of metformin and rosiglitazone, alone and in combination, on the ovary and endometrium in polycystic ovary syndrome

OBJECTIVE

To examine the effects of metformin and rosiglitazone, alone and in combination, on endometrial histology and ovarian steroid production.

STUDY DESIGN

Randomized open-label study of metformin and rosiglitazone in 16 women with polycystic ovary syndrome (PCOS) performed at a single academic health center. The study consisted of a 6-week baseline observation period, a 3-month treatment period of single-agent therapy (rosiglitazone or metformin), and then a 3-month period of combined therapy.

RESULTS

Abnormal endometrial histology was found in 3 subjects at baseline, including 1 case of adenocarcinoma of the endometrium in an asymptomatic subject, who was excluded from further study. The 2 other abnormal cases (simple hyperplasia) resolved with treatment. Three months of single-agent therapy showed a benefit of rosiglitazone (n = 9) over metformin (n = 6) in terms of reducing circulating unbound testosterone levels (-11.8; 95% CI: -21.7 to -2.0 ng/dL) and 2-hour glucose (-42.0; 95% CI: -76.2 to -7.8 mg/dL), 2-hour insulin (-150.4; 95% CI: -272.7 to -28.1 microU/mL) as well as a significant decrease in integrated levels of glucose and insulin by area under the curve analysis, all obtained from oral glucose tolerance testing. Daily urinary progestin-to-estrogen ratios improved on rosiglitazone compared to metformin therapy (0.08; 95% CI: 0.02 to 0.14). Ovulatory rates tended to improve on both single-agent and combined treatments (30/90 cycles, 33%), compared to baseline ovulatory rate (2/15, 13%). Despite 6 months of therapy alone or in combination, 5 women displayed no evidence of biochemical ovulation by urinary or serum progestin measurements.

CONCLUSION

This study provides preliminary evidence that insulin-sensitizing drugs may have beneficial effects on the endometrium, although the exact mechanism beyond improving ovulatory function is still unknown. In addition, we suggest that rosiglitazone may be more beneficial than metformin therapy on raised insulin and androgen levels in an obese PCOS population. Combined therapy did not demonstrate significant benefit above and beyond single-agent therapy.

Metformin and polycystic ovary syndrome

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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