Insulin-lowering drugs in polycystic ovary syndrome

Non-alcoholic fatty liver disease in premenopausal women with polycystic ovary syndrome: A systematic review and meta-analysis

Background and Aim

Non‐alcoholic fatty liver disease (NAFLD) and polycystic ovary syndrome (PCOS) are prevalent conditions sharing common pathogenic factors. We performed a systematic literature review and meta‐analysis aiming to investigate the association between NAFLD and PCOS among premenopausal PCOS patients.

Methods

Relevant studies were systematically identified from scientific databases until 2019. We calculated pooled odds ratio (OR) using a random‐effect model, and heterogeneity was addressed through I². Subgroup analyses and meta‐regression for various covariates were performed.

Results

Of the 1833 studies retrieved, 23 studies with 7148 participants qualified for quantitative synthesis. The pooled result showed that women with PCOS had a 2.5‐fold increase in the risk of NAFLD compared to controls (pooled OR 2.49, 95% confidence interval [CI] 2.20–2.82). In subgroup analyses comparing PCOS to controls, South American/Middle East PCOS patients had a greater risk of NAFLD (OR 3.55, 95% CI 2.27–5.55) compared to their counterpart from Europe (OR 2.22, 95% CI 1.85–2.67) and Asia (OR 2.63, 95% CI 2.20–3.15). Insulin resistance and metabolic syndrome were more frequent in the PCOS group (OR 1.97, 95% CI 1.44–2.71 and OR 3.39, 95% CI 2.42–4.76, respectively). Study quality and body mass index (BMI) were the only covariates that showed a relationship with the outcome in the meta‐regression, with a regression coefficient of −2.219 (95% CI −3.927 to −0.511) and −1.929 (95% CI −3.776 to −0.0826), respectively.

Conclusions

This meta‐analysis indicates that premenopausal PCOS patients are associated with 2.5‐fold increase in the risk of NAFLD, and BMI seems to be the main cofactor.

Inositols in PCOS

(1) Background: Myoinositol (MI) and D-chiro-inositol (DCI) are involved in a number of biochemical pathways within oocytes having a role in oocyte maturation, fertilization, implantation, and post-implantation development. Both inositols have a role in insulin signaling and hormonal synthesis in the ovaries. (2) Methods: Literature search (with key words: inositols, myo-inositol, d-chiro-inositol, PCOS) was done in PubMed until Sept. 2020 and 197 articles were identified, of which 47 were of clinical trials (35 randomized controlled trials). (3) Results: Many studies have demonstrated that in patients with polycystic ovarian syndrome (PCOS) MI treatment improved ovarian function and fertility, decreased the severity of hyperandrogenism including acne and hirsutism, positively affected metabolic aspects, and modulated various hormonal parameters deeply involved in the reproductive axis function and ovulation. Thus treating with MI has become a novel method to ameliorate PCOS symptoms, improve spontaneous ovulation, or induce ovulation. The current review is focused on the effects of MI and DCI alone or in combination with other agents on the pathological features of PCOS with focus on insulin resistance and adverse metabolic outcomes. (4) Conclusions: The available clinical data suggest that MI, DCI, and their combination in physiological ratio 40:1 with or without other compound could be beneficial for improving metabolic, hormonal, and reproductive aspects of PCOS.

Pioglitazone suppresses excessive follicular development in murine preantral follicles

Polycystic ovary syndrome (PCOS) is an endocrine disease that is common in women in their reproductive period. Patients with this disease suffer from anovulation and hyperandrogenism. Ovulation induction with exogenous gonadotropin often causes ovarian hyperstimulation syndrome because many small antral follicles pause in their growth. Treatment with insulin sensitizers is reportedly effective for both anovulation associated with PCOS, and suppression of excessive follicular growth; however, the underlying mechanism of action remains unknown. Although pioglitazone is known as an insulin sensitizer, it also has a potent modulator of cell growth and apoptosis irrespective of insulin resistance. To clarify the effect of pioglitazone on follicular growth, we performed in vitro culture of murine preantral follicles. Secondary follicles (100-160 μm in diameter) isolated from 6-week-old ICR mice were individually cultured for 13 days. Culture conditions were as follows: 1) follicle-stimulating hormone (FSH; 33 mIU/mL; control), 2) FSH plus dihydrotestosterone (DHT; 500 ng/mL), 3) FSH plus pioglitazone (5 ng/mL), and 4) FSH plus DHT/pioglitazone. Survival rate and follicle diameter were evaluated, and concentrations of estradiol (E2) and vascular endothelial growth factor (VEGF) in culture media were measured. mRNA expression of various growth-promoting factors and Vegf within follicles were also assessed. Although no significant differences were observed with regard to survival rate, follicle diameters on day 13 were significantly different.

Compared with the control group, the DHT group showed enhanced growth, while groups administered pioglitazone showed stagnation of the accelerated growth induced by DHT. Although DHT treatment enhanced the expression of bone morphogenetic protein 2 (Bmp2) mRNA, pioglitazone exposure suppressed induction of Bmp2 mRNA by DHT. Vegf mRNA and protein expression were also significantly reduced when pioglitazone was added to culture media containing DHT.

Administration of pioglitazone negatively affected follicular growth and VEGF levels, which may suppress excessive follicular growth and prevent ovarian hyperstimulation syndrome.

Elevated fasting insulin is associated with cardiovascular and metabolic risk in women with polycystic ovary syndrome

AIMS

PCOS is associated with various immediate and long term health complications. The aim of this study was to investigate the association of serum fasting insulin concentration with cardiovascular and metabolic risk factors in women with polycystic ovary syndrome.

METHODS

A total of 349 women, 249 women with polycystic ovary syndrome and 100 age-matched healthy controls, were recruited in this case-control study. Fasting insulin and various other biochemical, hormonal and clinical parameters were measured in all participants. The correlation of insulin with cardiometabolic risk factors was evaluated in PCOS women with normal and high serum insulin concentration.

RESULTS

Fasting Insulin, BMI, WHR, FAI, LH: FSH, HOMA, QUICKI were significantly higher in PCOS women compared with healthy controls (p < 0.01). Fasting insulin showed a positive correlation with more cardiovascular and metabolic risk factors in PCOS compared to controls. The BMI, BAI, LAP, HOMA IR, QUICKI and FAI were significantly higher (all p < 0.05) in PCOS patients with higher insulin levels than with PCOS women with normal levels.

CONCLUSION

Fasting insulin is an important determinant in the pathogenesis of obesity and hyperandrogenism in PCOS. It is associated with an increased risk of cardiovascular and metabolic disorders in women with PCOS.

The use of inositol(s) isomers in the management of polycystic ovary syndrome: a comprehensive review

The aim of this review is to present the current data about the role of inositols in the management of polycystic ovary syndrome (PCOS) women and in the prevention and treatment of gestational diabetes mellitus (GDM). We analyzed the available literature with key words PCOS, Myo-inositol, D-chiro-inositol, assisted reproductive technologies and GDM. The most recent literature would suggest that Myo-inositol, D-chiro-inositol and their combination in physiological ratio 40:1 could represent an important therapeutic strategy for the improvement of metabolic, hormonal and reproductive aspects of PCOS. In assisted reproductive technologies, however, myo-inositol and the combined treatment, despite D-chiro-inositol monotherapy, are able to improve clinical outcomes. Myo-inositol monotherapy results more effective in preventing and treating GDM even if a larger cohort of studies is needed to better clarify these results.

High Value-Added Biomolecules from Beach Waste of Marine Origin-Screening for Potential Candidates among Seagrass of the Cymodoceaceae Family

Background:

Detrital leaves from seagrass of the Cymodoceaceae family were assayed for biologically active molecules that have commercial as well as societal benefits.

Objective:

We focused on L-chiro-inositol, a very rare natural occurring cyclitol, and chicoric acid, a polyphenolic compound, in which both applications were found in the nutraceutical segment.

Method:

Six species of seagrass belonging to the genera Syringodium, Cymodocea and Halodule were collected from their native habitat. The L-chiro-inositol content of the crude aqueous extracts prepared from different batches of Cymodocea nodosa flotsam was measured by quantitative 1H-NMR spectroscopy. High concentrations were found with values ranging from 22.2 to 35.0 mg.g-1 plant dw. The presence of L-chiro-inositol in the tropical species C. rotundata, C. serrulata, Syringodium isoetifolium, and Halodule pinifolia was also characterized by qualitative NMR. The chicoric acid content of crude aqueous methanolic extracts prepared from C. rotundata, C. serrulata, S. isoetifolium, and Halodule pinifolia was determined by quantitative HPLC-DAD. The values found ranged from 0.39 to 6.15 mg.g-1 dry weight. Chicoric acid was unambiguously identified as the major phenolic in S. isoetifolium, and Halodule pinifolia, while it was found in mixture with flavonol derivatives in C. rotundata and C. serrulata. Flavonol derivatives are also of interest for their bioactivity.

Result:

Considering the demonstrated therapeutic applications of L-chiro-inositol and chicoric acid, their high value on the nutraceutical market, and their rare occurrence in the plant kingdom, their presence in Syringodium, Cymodocea and Halodule detrital leaves makes this abundant biomass of interest for dietary and pharmaceutical applications.

Conclusion:

These results show that there is a real potential for harvesting beachcast Cymodoceacea.

Inositol Treatment and ART Outcomes in Women with PCOS

Polycystic ovary syndrome (PCOS) affects 5-10% of women in reproductive age and is characterized by oligo/amenorrhea, androgen excess, insulin resistance, and typical polycystic ovarian morphology. It is the most common cause of infertility secondary to ovulatory dysfunction. The underlying etiology is still unknown but is believed to be multifactorial. Insulin-sensitizing compounds such as inositol, a B-complex vitamin, and its stereoisomers (myo-inositol and D-chiro-inositol) have been studied as an effective treatment of PCOS. Administration of inositol in PCOS has been shown to improve not only the metabolic and hormonal parameters but also ovarian function and the response to assisted-reproductive technology (ART). Accumulating evidence suggests that it is also capable of improving folliculogenesis and embryo quality and increasing the mature oocyte yield following ovarian stimulation for ART in women with PCOS. In the current review, we collate the evidence and summarize our current knowledge on ovarian stimulation and ART outcomes following inositol treatment in women with PCOS undergoing in vitro fertilization (IVF) and/or intracytoplasmic sperm injection (ICSI).

Ovulation induction with myo-inositol alone and in combination with clomiphene citrate in polycystic ovarian syndrome patients with insulin resistance

BACKGROUND

Insulin resistance plays a key role in the pathogenesis of polycystic ovarian syndrome (PCOS). One of the methods for correcting insulin resistance is using myo-inositol.

AIM

The aim of the present study is to evaluate the effectiveness of myo-inositol alone or in combination with clomiphene citrate for (1) induction of ovulation and (2) pregnancy rate in anovulatory women with PCOS and proven insulin resistance.

PATIENTS AND METHODS

This study included 50 anovulatory PCOS patients with insulin resistance. All of them received myo-inositolduring three spontaneous cycles. If patients remained anovulatory and/or no pregnancy was achieved, combination of myo-inositol and clomiphene citrate was used in the next three cycles. Ovulation and pregnancy rate, changes in body mass index (BMI) and homeostatic model assessment (HOMA) index and the rate of adverse events were assessed.

RESULTS

After myo-inositol treatment, ovulation was present in 29 women (61.7%) and 18 (38.3%) were resistant. Of the ovulatory women, 11 became pregnant (37.9%). Of the 18 myo-inositol resistant patients after clomiphene treatment, 13 (72.2%) ovulated. Of the 13 ovulatory women, 6 (42.6%) became pregnant. During follow-up, a reduction of body mass index and HOMA index was also observed.

CONCLUSION

Myo-inositol treatment ameliorates insulin resistance and body weight, and improves ovarian activity in PCOS patients.

Insulin-like growth factor-II: its role in metabolic and endocrine disease

Insulin-like growth factor-II (IGF-II) is a widely expressed 7·5 kDa mitogenic peptide hormone. Although it is abundant in serum, understanding of its physiological role is limited compared with that of IGF-I. IGF-II regulates foetal development and differentiation, but its role in adults is less well understood. Evidence suggests roles in a number of tissues including skeletal muscle, adipose tissue, bone and ovary. Altered IGF-II expression has been observed in metabolic conditions, notably obesity, diabetes and the polycystic ovary syndrome. This article summarizes what is known about the actions of IGF-II and its dysregulation in metabolic and endocrine diseases. The possible causes and consequences of dysregulation are discussed along with the implications for diagnostic tests and future research.

Beneficial effects of pioglitazone and metformin in murine model of polycystic ovaries via improvement of chemerin gene up-regulation

Background

Polycystic ovary syndrome (PCO) is recognized as the most common endocrinopathy in female. Chemerin is a novel adipocytokine that is expressed in ovary and upregulated in adipose tissue of obese, PCO patients. To date there is no report about the regulation of ovarian chemerin gene expression after PCO induction and treatment by insulin sensitizing drugs including pioglitazone and metformin.

Thirty female rats were divided into six experimental groups with five rats in each group including control group, PCO group (i.m injection of 4 mg estradiol benzoate for 40 days), metformin treated (200 mg/kg/day for 21 days), pioglitazone treated (20 mg/kg/day, for 21 days), PCO + metformin and PCO + pioglitazone. PCO was detected by microscopic observation of vaginal smear and treatment by metformin and pioglitazone was initiated one week after that. Ovarian chemerin expression was analyzed by real time PCR and western blotting.

Results

Our results demonstrated that PCO induction resulted in elevation of chemerin mRNA and protein levels in ovary in concomitant with incidence of insulin resistance and increasing androgen and progesterone production. We observed that metformin and pioglitazone attenuated ovarian chemerin expression and improved insulin resistance and abnormal steroid production in PCO rats.

Conclusion

Based on data presented here we concluded that alteration of ovarian chemerin expression may has important role in PCO development and manipulation of chemerin expression or signaling by pioglitazone or metformin can be a novel therapeutic mechanism in the treatment of PCO patients by these drugs.

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.

Metformin-clomiphene citrate vs. clomiphene citrate alone: Polycystic ovarian syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is the commonest endocrinopathy in women that is associated with reproductive and metabolic disorders.

OBJECTIVES

We compared the ovulation and conception rates after the treatment with clomiphene citrate (CC) alone and in combination with metformin in infertile patients presented with polycystic ovarian syndrome (PCOS).

MATERIALS AND METHODS

This randomized controlled trial of independent cases and controls was conducted at the Department of Obstetrics and Gynecology, Hera General Hospital, Makkah, Saudi Arabia from February 01 to December 31, 2008. The 42 subjects diagnosed as PCOS were divided into group A and B (21 subjects in each) for management with CC + metformin and CC alone, respectively. Group A received 500 mg three times a day of metformin continuously from the first cycle for 6 months or till pregnancy was confirmed. In both groups CC was started at a dose of 50 mg from day-2 till day-6 of the menstrual cycle. The dose of CC was increased to 100 mg in second and 150 mg in third cycle, and then remained 150 mg for the remaining three cycles. With ovulation the dose of CC was unaltered in both groups. Data were analyzed using Statistical Package for the Social Sciences (SPSS) version 16.

RESULTS

More than 50% females in both groups were had body mass index > 25. Group A achieved high rate of regular cycles, ovulation success, and conception than group B (71.4% vs. 38.1%; P = 0.03), (76.2% vs. 38.1%; P = 0.021), and (66.6% vs. 28.6%; P = 0.01), respectively.

CONCLUSION

Management with metformin + CC increased the ovulation and conception rates.

Cardiometabolic aspects of the polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder amongst women of reproductive age and is associated with various metabolic perturbations, in addition to chronic anovulation and factors related to androgen excess. In general, women live longer than men and develop cardiovascular disease at an older age. However, women with PCOS, as compared with age- and body mass index-matched women without the syndrome, appear to have a higher risk of insulin resistance, hyperinsulinemia, glucose intolerance, dyslipidemia, and an increased prothrombotic state, possibly resulting in a higher rate of type 2 diabetes mellitus, fatty liver disease, subclinical atherosclerosis, vascular dysfunction, and finally cardiovascular disease and mortality. Further alterations in PCOS include an increased prevalence of sleep apnea, as well as various changes in the secretion and/or function of adipokines, adipose tissue-derived proinflammatory factors and gut hormones, all of them with direct or indirect influences on the complex signaling network that regulates metabolism, insulin sensitivity, and energy homeostasis. Reviews on the cardiometabolic aspects of PCOS are rare, and our knowledge from recent studies is expanding rapidly. Therefore, it is the aim of the present review to discuss and to summarize the current knowledge, focusing on the alterations of cardiometabolic factors in women with PCOS. Further insight into this network of factors may facilitate finding therapeutic targets that should ameliorate not only ovarian dysfunction but also the various cardiometabolic alterations related to the syndrome.

Role of the peroxisome proliferator-activated receptors, adenosine monophosphate-activated kinase, and adiponectin in the ovary

The mechanisms controlling the interaction between energy balance and reproduction are the subject of intensive investigations. The integrated control of these systems is probably a multifaceted phenomenon involving an array of signals governing energy homeostasis, metabolism, and fertility. Two fuel sensors, PPARs, a superfamily of nuclear receptors and the kinase AMPK, integrate energy control and lipid and glucose homeostasis. Adiponectin, one of the adipocyte-derived factors mediate its actions through the AMPK or PPARs pathway. These three molecules are expressed in the ovary, raising questions about the biological actions of fuel sensors in fertility and the use of these molecules to treat fertility problems. This review will highlight the expression and putative role of PPARs, AMPK, and adiponectin in the ovary, particularly during folliculogenesis, steroidogenesis, and oocyte maturation.

Thiazolidinediones and Fertility in Polycystic Ovary Syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is the most frequent cause of female infertility. The treatment of PCOS patients with insulin sensitizers, such as metformin or thiazolidinediones, increases the ovulation rate and the number of successful pregnancies. The positive action of the insulin-sensitizing treatments could be explained by a decrease in the peripheral insulin resistance but also by a direct action at the ovarian level. We report in this review different hypotheses of thiazolidinediones actions to improve PCOS (steroid secretion by ovarian cells ; insulin sensitivity in muscle and adipocyte and fat redistribution).

Clinical features, investigations and management of adolescents with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is defined as chronic anovulation with evidence of hyperandrogenism, after the exclusion of secondary causes. It is commonly linked to obesity and the presence of the metabolic syndrome.

OBJECTIVES

To review the clinical features and medical assessment of adolescents referred for PCOS to gynecology or endocrinology services at The Hospital for Sick Children (Toronto, Ontario).

METHODS

A chart review was conducted of all adolescents with PCOS referred during a one-year period. Measures included clinical findings, investigations and management.

RESULTS

Forty-one adolescent girls, with a mean age +/- SD of 14.7+/-1.5 years, were reviewed. Common presenting complaints were menstrual irregularities in 35 of 41 girls (85%) and hirsutism in 28 of 41 girls (68%), with 32 of 41 adolescents (78%) having more than one complaint. The majority (31 of 38 [82%]) were overweight or obese. Features associated with the metabolic syndrome (hypertension, dyslipidemia, insulin resistance and obesity) were identified in some adolescents, but were not consistently assessed. Blood pressure was assessed in 38 adolescents, fasting plasma glucose in 27, triglycerides in 22 and cholesterol in 21. Only four of 28 adolescents (15%) who underwent pelvic ultrasound demonstrated ovarian cysts. Investigations and management differed somewhat between endocrinologists and gynecologists. Most adolescents (34 of 41 [83%]) received pharmacological treatment: oral contraceptive pill (21 of 34 [62%]); intermittent medroxyprogesterone acetate to induce withdrawal bleeding (nine of 34 [26%]); metformin (two of 34 [6%]); or oral contraceptive pill and antiandrogen (two of 34 [6%]).

CONCLUSIONS

Adolescents with PCOS are at risk of developing metabolic abnormalities. Polycystic ovaries were not a consistent finding. The most commonly prescribed treatment was the oral contraceptive pill. Greater attention should be placed on screening adolescents with PCOS for diabetes, hypertension and dyslipidemia, allowing for earlier identification and management of potentially modifiable cardiovascular risk factors.

Peroxisome proliferator-activated receptor gamma and early folliculogenesis during an acute hyperandrogenism condition

Acute hyperandrogenism decreases serum P levels and induces early apoptosis of antral follicles by a mechanism mediated by the peroxisome proliferator-activated receptor gamma system and independent of the steroidogenic acute regulator protein.

The role of insulin-sensitizing agents in the treatment of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) represents a heterogeneous spectrum of disorders, mainly characterized by chronic oligoanovulation and hyperandrogenism. Although not included in the diagnostic criteria, insulin resistance is recognized as a fundamental pathogenetic factor of the syndrome. Thus, the use of insulin-sensitizing drugs, such as metformin and thiazolidinediones, has been proposed for PCOS treatment. These agents are unique because they exert both metabolic and endocrine/ovarian beneficial effects. In this review the results of up-to-date clinical studies and meta-analyses on the possible gynaecological actions of insulin sensitizers are discussed. It has been shown that, as well as favourable metabolic influences, such as improvement in glucose, lipid and proinflammatory profiles, these agents also exert beneficial endocrine and ovarian effects, including amelioration of reproductive abnormalities, restoration of ovulation and menstrual cycles, increase in pregnancy rates and reduction of androgen production. Therefore, current data support the use of insulin sensitizers, along with lifestyle measures and/or other agents, in women with PCOS, especially in the presence of insulin- or clomifene-resistance.

Retinol-binding protein 4 in polycystic ovary syndrome--association with steroid hormones and response to pioglitazone treatment

CONTEXT

Polycystic ovary syndrome (PCOS) is frequently associated with insulin resistance.

OBJECTIVE

The aim of the study was to investigate a putative role of the adipokines retinol-binding protein 4 (RBP4), adiponectin, and visfatin in a cohort of patients with PCOS and their response to treatment with pioglitazone.

DESIGN AND SETTING

We conducted a randomized, controlled, double-blind study at a tertiary referral center.

PATIENTS AND INTERVENTIONS

Forty premenopausal women with PCOS were allocated to receive treatment with either pioglitazone (30 mg/d) or a placebo for a period of 3 months.

MAIN OUTCOME MEASURES

Serum concentrations of RBP4, adiponectin, and visfatin were determined along with metabolic and hormonal parameters before and after treatment.

RESULTS

Serum adiponectin concentrations were higher after treatment with pioglitazone (P = 0.003), whereas RBP4 levels tended to decrease (P = 0.06), and visfatin concentrations remained unchanged. We found RBP4 serum concentrations at baseline to be positively correlated with serum levels of testosterone (R = 0.446; P = 0.005), 17-OH progesterone (R = 0.345, P = 0.037), and dehydroepiandrosterone sulfate (R = 0.347; P = 0.041). However, these correlations were abolished after treatment with pioglitazone. Patients with high RBP4 levels had significantly higher hirsutism scores (P = 0.038 before and P = 0.034 after treatment). In contrast, serum adiponectin concentrations were related to parameters of impaired glucose metabolism, and no significant associations were detected for visfatin.

CONCLUSIONS

Our results suggest that RBP4 may contribute to endocrine changes and to the phenotypic manifestation of patients with PCOS because higher RBP4 concentrations are associated with higher androgen levels and higher clinical hirsutism scores independently of pioglitazone treatment. The molecular involvement of RBP4 in human steroid metabolism requires further clarification.

Clinical spectrum of premature pubarche: links to metabolic syndrome and ovarian hyperandrogenism

Premature pubarche-defined as the appearance of pubic hair before age 8 years in girls and 9 years in boys-has been traditionally considered a benign entity. However, recent evidence supports the notion that premature pubarche in girls may be a forerunner of the metabolic syndrome, and may precede the development of clinical ovarian androgen excess in adolescence. This sequence seems to occur more frequently when premature pubarche was preceded by reduced fetal growth and followed by excessive postnatal catch-up in height and particularly in weight; hyperinsulinemia appears to be a key factor in the development of this sequence of events. In girls with premature pubarche and a history of a low birth weight, puberty tends to start earlier and to have a faster course, so that final height may be moderately reduced. In these girls, metformin therapy may reverse the progression to clinical ovarian hyperandrogenism, normalize body composition and excess visceral fat, and delay pubertal progression without attenuating linear growth and bone mineralization, suggesting that adult height may be improved. Long-term follow-up of these patients is needed to fully determine the ultimate effects of insulin sensitization as well as the maintenance of these benefits after discontinuation of therapy.

Polycystic ovary syndrome: treatment strategies and management

BACKGROUND

The polycystic ovary syndrome (PCOS) is possibly the most common endocrine disorder in premenopausal women, with prevalences in the 6-7% range reported worldwide. Although PCOS is primarily a disorder of androgen excess, affected women frequently present with abdominal adiposity and insulin resistance, explaining the association of PCOS with metabolic comorbidities and an increased cardiovascular risk. Abdominal adiposity, and very especially the compensatory hyperinsulinism resulting from insulin resistance, further contribute to hyperandrogenism. These pathophysiological mechanisms must be considered when deciding the optimal therapy for PCOS patients.

OBJECTIVE

To review the impact of the current approaches to the treatment of PCOS on the metabolic associations and the cardiovascular risk of these women.

METHODS

Review of published studies addressing the effects of different treatment strategies of PCOS.

RESULTS

The resolution of PCOS after the marked and sustained weight loss attained after bariatric surgery makes this therapeutic option a first-line strategy in women presenting with severe obesity. In patients with lesser grades of obesity who desire fertility, a short trial of metformin, followed by classic ovulation induction and/or assisted reproductive techniques in case pregnancy is not achieved in a few months, is a reasonable approach. If fertility is not an immediate concern, third generation oral contraceptive pills containing a neutral or antiandrogenic progestin remains the drug of choice, considering their efficacy, their excellent tolerability, and their overall metabolic safety.

CONCLUSION

Strategies targeting obesity and abdominal adiposity, insulin resistance and hyperandrogenism, alone or in combination, are effective in ameliorating the signs and symptoms of hyperandrogenism while improving the metabolic comorbidities and the cardiovascular risk of these patients in most cases.

Thiazolidinediones: effects on insulin resistance and the cardiovascular system

Thiazolidinediones (TZDs) have been used for the treatment of hyperglycaemia in type 2 diabetes for the past 10 years. They may delay the development of type 2 diabetes in individuals at high risk of developing the condition, and have been shown to have potentially beneficial effects on cardiovascular risk factors. TZDs act as agonists of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) primarily in adipose tissue. PPAR-gamma receptor activation by TZDs improves insulin sensitivity by promoting fatty acid uptake into adipose tissue, increasing production of adiponectin and reducing levels of inflammatory mediators such as tumour necrosis factor-alpha (TNF-alpha), plasminogen activator inhibitor-1(PAI-1) and interleukin-6 (IL-6). Clinically, TZDs have been shown to reduce measures of atherosclerosis such as carotid intima-media thickness (CIMT). However, in spite of beneficial effects on markers of cardiovascular risk, TZDs have not been definitively shown to reduce cardiovascular events in patients, and the safety of rosiglitazone in this respect has recently been called into question. Dual PPAR-alpha/gamma agonists may offer superior treatment of insulin resistance and cardioprotection, but their safety has not yet been assured.

Comparative safety of newer oral antidiabetic drugs

Oral antidiabetic agents were introduced into clinical practice during the 1950s. Biguanides and sulfonylureas are still used extensively today and their safety and tolerability profiles are well defined. Developments and refinements within these classes have included the introduction of second- and third-generation sulfonylureas, the introduction of modified-release preparations, and the emergence of fixed-dose preparations with metformin and with novel drugs. The latter include the thiazolidinediones, agents with a putative genomic mechanism of action that have been under intense scrutiny since the emergence of severe hepatotoxicity with troglitazone. Recent concerns about thiazolidinediones have centred on the issue of oedema and the risk of precipitating heart failure in vulnerable patients. Only prolonged exposure will determine the long-term safety of thiazolidinediones. Rapid-acting non-sulfonylurea secretagogues appear to be effective and perhaps safer than sulfonylureas in some groups of patients with certain comorbidities (e.g., those with renal impairment). alpha-Glucosidase inhibitors have an excellent safety record and acarbose has been shown to retard the progression from impaired glucose tolerance to Type 2 diabetes. However, their use is limited by tolerability issues.

The metabolic syndrome in polycystic ovary syndrome

Much overlap is present between the polycystic ovary syndrome (PCOS) and the metabolic syndrome. This article reviews the existing data regarding the prevalence, characteristics, and treatment of the metabolic syndrome in women with PCOS. The prevalence of the metabolic syndrome in PCOS is approximately 43-47%, a rate 2-fold higher than that for women in the general population. High body mass index and low serum HDL cholesterol are the most frequently occurring components of the metabolic syndrome in PCOS. The pathogenic link between the metabolic syndrome and PCOS is most likely insulin resistance. Therefore, the presence of the metabolic syndrome in PCOS suggests a greater degree of insulin resistance compared to PCOS without the metabolic syndrome. Obesity, atherogenic dyslipidemia, hypertension, impaired fasting glucose/impaired glucose tolerance, and vascular abnormalities are all common metabolic abnormalities present in PCOS. Lifestyle modification has proven benefit and pharmacological therapy with insulin-sensitizing agents has potential benefit in the treatment of the metabolic syndrome in women with PCOS.

Recent findings concerning thiazolidinediones in the treatment of diabetes

Thiazolidinediones (TZDs) are peroxisomal proliferator-activated receptor (PPAR)-gamma agonists. They increase insulin action through several mechanisms including: stimulation of the expression of genes that increase fat oxidation and lower plasma free fatty acid levels; increased expression, synthesis and release of adiponectin; and stimulation of adipocyte differentiation resulting in more and smaller fat cells. TZDs lower blood sugar comparably to sulfonylureas and metformin. The clinical use of TZDs is limited due to the long duration of time required before they reach their full blood sugar-lowering action (3-4 months) and adverse effects such as fluid retention, resulting in excessive weight gain and occasionally in peripheral and/or pulmonary oedema and congestive heart failure. Troglitazone, a TZD that has since been removed from the market because of hepatoxicity, has been demonstrated to decrease the progression from normal or impaired glucose tolerance to overt Type 2 diabetes mellitus. Pioglitazone, another TZD, marginally decreased the incidence of cardiovascular complications in patients with Type 2 diabetes mellitus (PROactive trial). Other, as yet, unapproved uses of TZDs include: non-alcoholic fatty liver disease, in which TZDs reduced hepatic fat accumulation and improved liver function tests; polycystic ovary syndrome, where TZDs improved ovulation, hirsutism and endothelial dysfunction; and lipodystrophies, where TZDs increased body fat (marginally) and decrease liver size. Lastly, because PPAR-alpha and -gamma agonists improve atherosclerotic vascular disease and insulin sensitivity, respectively, dual PPAR-alpha/gamma agonists, which are currently undergoing clinical trials, may be useful in treating patients with the metabolic syndrome.

Endocrine-metabolic effects of the treatment with pioglitazone in obese patients with polycystic ovary syndrome

The hyperandrogenism found in polycystic ovary syndrome (PCOS) can be a consequence of hyperinsulinemia as a result of peripheral insulin resistance. Metformin and insulin sensitizers have become a potential therapeutic tool for treating these patients; however, there are few studies with pioglitazone in PCOS. Elevated luteinizing hormone/follicle-stimulating hormone (LH/FSH) ratios and LH hyper-responsivity to stimulation with gonadotropin-releasing hormone (GnRH) are common findings in PCOS. The reason why hyperinsulinemia produces hyperandrogenism and whether insulin action on the pituitary alters gonadotropin liberation remain unknown. In the present study, we evaluated the effect of pioglitazone (30 mg/day for 2 months) on insulin response to an oral glucose tolerance test (OGTT), serum levels of androgens and sex hormone-binding globulin (SHBG), and pituitary gonadotropin response to GnRH stimulation in 15 obese PCOS women. We found a significant decrease in insulin response to the OGTT and also in total and free testosterone levels, an increase in SHBG and a reduction in the LH response to GnRH stimulation after pioglitazone treatment. In conclusion, this short-term treatment with pioglitazone decreased hyperinsulinemia and hyperandrogenemia in obese PCOS patients, and there was a significant reduction in LH response to GnRH stimulation. Further research should be carried out to establish the risks and benefits of pioglitazone, which would assist in the physiopathologic comprehension of PCOS.

Un rôle pour PPARγ dans la reproduction ?

Synthetic molecules of the glitazone family are currently used in the treatment of type II diabetes. Glitazones also improve secondary pathologies that are frequently associated with insulin resistance such as the polycystic ovary syndrome (PCOS). Glitazones bind to the peroxysome proliferator-activated receptor gamma (PPARgamma), a nuclear receptor which is highly expressed in adipose tissue. PPARgamma also binds natural ligands such as long-chain fatty acids. Recently, several groups have shown that PPARgamma is also highly expressed in ovarian granulosa cells, and that glitazones are able to modulate in vitro granulosa cell proliferation and steroidogenesis in several species. These recent data raise new questions concerning the underlying mechanism of the effect of glitazones on PCOS. One might hypothesize, as for other << glucophage >> molecules such as metformin, that it is the general improvement of glucose metabolism and insulin sensitivity by glitazones which indirectly, and via an unknown mechanism, ameliorates ovarian functionality. The data discussed here suggest now an alternative possibility, that glitazones act directly at the ovarian level. Moreover, PPARgamma also seems to play a key role in the maturation of the placenta. In particular, inactivation of PPARgamma in mice is lethal, since the foetus is unable to develop because of alterations of placental maturation. In women, the activation of PPARgamma in placenta leads to an increase of placental hormone secretion. Overall, these results raise some questions about the role of natural ligands of PPARgamma such as long chain fatty acids on female fertility and the interactions between energy metabolism and reproduction in general.

Metformin monotherapy in lean women with polycystic ovary syndrome

This study was carried out to compare ovulation and pregnancy rates in response to metformin therapy in lean and obese women with polycystic ovary syndrome (PCOS). A total of 34 (17 lean and 17 obese) women with PCOS were treated with 500 mg metformin 3 times daily for 12 weeks. In the lean and obese groups, the mean body mass index was 24 and 36, and the mean fasting insulin concentrations were 12 and 21 mIU/l respectively. There was no difference between the two groups as regarding age, DHEA-S, androstenedione, 17-OH progesterone and LH concentrations. In the lean and obese groups 15/17 women (88%) and 5/17 women (29%) ovulated while 11/17 women (65%) and 3/17 women (18%) conceived respectively. Comparison between the groups was found to be statistically significant. Metformin monotherapy is very effective in improving ovulation and pregnancy rates in lean women with PCOS as compared with obese women.

Expression and functional role of peroxisome proliferator-activated receptor-gamma in ovarian folliculogenesis in the sheep

Peroxisome proliferator-activated receptor (PPARgamma) is a nuclear receptor that is activated by fatty acids and derivatives and the antidiabetic glitazones, which plays a role in the control of lipid and glucose homeostasis. In the present work, we tested the hypothesis that PPARgamma plays a role in reproductive tissues by studying its expression and function in the hypothalamo-pituitary-ovary axis in the sheep. PPARgamma 1 and PPARgamma 2 proteins and mRNAs were detected in whole ovine pituitary and ovary but not in hypothalamic extracts. In situ hybridization on ovarian section localized PPARgamma mRNA in the granulosa layer of follicles. Interestingly, PPARgamma expression was higher in small antral (1-3 mm diameter) than in preovulatory follicles (>5 mm diameter) (P < 0.001) and was not correlated with healthy status. To assess the biological activity of ovarian PPARgamma, ovine granulosa cells were transfected with a reporter construct driven by PPARgamma-responsive elements. Addition of rosiglitazone, a PPARgamma ligand, stimulated reporter gene expression, showing that endogenous PPARgamma is functional in ovine granulosa cells in vitro. Moreover, rosiglitazone inhibited granulosa cell proliferation (P < 0.05) and increased the secretion of progesterone in vitro (P < 0.05). This stimulation effect was stronger in granulosa cells from small than from large follicles. In contrast, rosiglitazone had no effect on LH, FSH, prolactin and growth hormone secretion by ovine pituitary cells in vitro. Overall, these data suggest that PPARgamma ligands might stimulate follicular differentiation in vivo likely through a direct action on granulosa cells rather than by modulating pituitary hormone secretion.

Characteristics predictive of response to ovarian diathermy in women with polycystic ovarian syndrome

OBJECTIVE AND STUDY DESIGN

Ovarian needle diathermy was used in the treatment of clomiphene-resistant polycystic ovarian syndrome (PCOS). Factors predictive of pregnancy in our study group included younger age, lower body weight, and surgery before 1998.

RESULTS AND CONCLUSION

Insulin resistance and adhesions at surgery were negatively associated with pregnancy. Sixty-six percent of the study group cycled spontaneously after surgery and 50% became pregnant.

Treatment of polycystic ovary syndrome with insulin-lowering agents

Early diagnosis and therapy of the underlying insulin resistance of heritable polycystic ovary syndrome (PCOS), often manifested at menarche, facilitate the reduction and/or reversal of the reproductive and metabolic morbidity of PCOS, as well as reduce the risk factors for cardiovascular disease. PCOS is characterised by oligoamenorrhoea, clinical and biochemical hyperandrogenism, infertility, recurrent miscarriage, insulin resistance, hyperinsulinaemia, gestational diabetes, impaired glucose tolerance, Type 2 diabetes, morbid obesity, hypertension, hypofibrinolysis, hypertriglyceridaemia, low levels of high density lipoprotein-cholesterol and a sevenfold risk increase in cardiovascular disease. Insulin sensitising-lowering agents reduce insulin resistance and hyperinsulinaemia, reverse PCOS endocrinopathy and ameliorate the reproductive, metabolic and cardiovascular morbidity of the disorder. The largest literature on the subject discusses metformin. Improved pregnancy outcomes in women with PCOS receiving metformin may be attributed to its ability to reduce insulin resistance, hyperinsulinaemia and hypofibrinolytic plasminogen activator inhibitor activity by the enhancement of folliculogenesis and improvement of oocyte quality.

The role of lifestyle modification in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common endocrine condition with reproductive and metabolic consequences, including anovulation, infertility and an increased prevalence of diabetes mellitus. Obesity, central obesity and insulin resistance are strongly implicated in its etiology and reduction of these risk factors should be a central treatment focus. Short-term weight loss has been consistently successful in reducing insulin resistance and restoring ovulation and fertility. However, problems arise with maintaining weight loss and precisely quantifying the associated long-term benefits of risk factor change. Although recent research indicates modest long-term lifestyle changes might reduce the extent of impaired glucose tolerance and delay the conversion to diabetes mellitus in the general population, this has not yet been examined in women with PCOS. Current conservative treatment should emphasize sustainable weight loss through dietary modification and exercise. Modifying additional lifestyle factors, including alcohol consumption, psychosocial stressors and smoking, are also crucial in long-term treatment of PCOS.

Weight Loss and Medication in Polycystic Ovary Syndrome Therapy

Polycystic ovary syndrome, which is a complex syndrome, affects approximately 6% of reproductive-age women. Many abnormalities are associated with polycystic ovary syndrome, but confusion still exists about their causation. Diagnosis of polycystic ovary syndrome is by exclusion. Management of the metabolic aspects of polycystic ovary syndrome focuses on minimizing insulin resistance and hyperinsulinemia with diet therapy or insulin-lowering drugs.

Potential Utility of Insulin Sensitizers in the Treatment of Patients with Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a form of functional ovarian hyperandrogenism. It is one of the most common endocrinologic disorders in women of reproductive age. Women with PCOS may present with menstrual irregularities, chronic anovulation, infertility, obesity and hyperandrogenism. PCOS is associated with insulin resistance and hyperinsulinemia in most, if not all, patients. Besides its gynecological manifestations, PCOS is also associated with increased metabolic and cardiovascular risks. These risks are strongly linked to insulin resistance, and during recent years a novel therapeutic approach using insulin-sensitizing agents has been extensively investigated. In most studies conducted to date, metformin and the thiazolidinedione agent troglitazone have resulted in improved insulin sensitivity, resumption of regular menses and decreased serum androgen levels. Insulin-sensitizing agents may be a useful adjuvant therapy for women with PCOS.