Correction of hyperinsulinemia in oligoovulatory women with clomiphene-resistant polycystic ovary syndrome: a review of therapeutic rationale and reproductive outcomes

Expanding therapeutic horizons: glucagon-like peptide-1 receptor agonists and sodium glucose transporter-2 inhibitors in poly cystic ovarian syndrome: a comprehensive review including systematic review and network meta-analysis of randomized clinical trials

BACKGROUND

Polycystic ovary syndrome (PCOS) is a complex endocrine characterized by hyperandrogenism, hormonal imbalances, and metabolic disruptions, leading to reproductive complications and increased risk of cardiometabolic diseases. While lifestyle modifications are the cornerstone of PCOS management, pharmacological interventions, including metformin, oral contraceptives, and anti-androgens, are commonly utilized. Recently, glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and sodium-glucose cotransporter-2 inhibitors (SGLT2is) have shown promising results in PCOS management.

METHODS

This study conducted a comprehensive review of randomized clinical trials evaluating the effects of GLP-1 RAs and SGLT2is in women with PCOS. A systematic literature search was performed, and network meta-analysis using random-effects model that generated mixed treatment comparison estimates was employed to assess the comparative efficacy of these drug classes on clinical (menstrual frequency, pregnancy rate and proportion of patients with regular menstrual cycles), anthropometric, hormonal, and metabolic parameters. Additionally, a systematic review of preclinical studies investigating GLP-1 RAs and SGLT2is in animal models of PCOS was undertaken.

RESULTS

This comprehensive meta-analysis included 27 RCTs (1642 participants). GLP-1 RAs (alone and in combination with metformin) were observed to improve menstrual frequencies. GLP-1 RAs showed significant reductions in all anthropometric parameters, while SGLT2is was observed to improve wait hip ratio (WHR) and android gynoid fat (AGF) ratio (in addition to reduced body weight observed with SGLT2is/metformin combination). Reductions in WHR and AGF ratio were better with SGLT2is compared to GLP-1 RAs. The combination of GLP-1 RAs and SGLT2is was observed to have superior efficacy in reducing body weight, percent fat mass, and AGF ratio compared to GLP-1 RAs alone. Regarding hormonal parameters, GLP-1 RAs were observed with significant improvement in free androgen index (FAI), free testosterone, androstenedione, and sex hormone binding globulin levels. SGLT2is was observed with significant improvements in FAI and total testosterone, outperforming GLP-1 RAs in reducing these parameters. Regarding metabolic parameters, GLP-1 RAs significantly improved triglycerides, markers of insulin resistance and fasting and postprandial plasma glucose. SGLT2is was associated with significant improvements in homeostatic model assessment for insulin resistance (HOMA-IR) and fasting plasma glucose, and in combination with metformin, SGLT2is significantly improved triglycerides. SGLT2is outperformed GLP-1 RAs in reducing LDL cholesterol and HOMA-IR. The combination of SGLT2is and GLP-1 RAs was better than GLP-1 RAs in reducing triglycerides and fasting plasma glucose. However, the strength of evidence for these findings was very low. Systematic assessment of animal studies revealed a potential association of several molecular pathways, including AMPK-α, SIRT1, FDX, PI3K/AKT, endothelial adhesion molecules (VCAM, ICAM, and E-selectin), STAR, and CYP17A1, with the therapeutic effects of GLP-1 RAs and SGLT2is in PCOS. Both drug classes were associated with significant improvements in ovarian morphology in animal studies.

CONCLUSION

This systematic review and meta-analysis advance our understanding of GLP-1 RAs and SGLT2is in PCOS management. While both drug classes demonstrate efficacy in metabolic parameters, their distinct mechanisms offer unique therapeutic advantages. SGLT2is excel in improving hormonal profiles and insulin resistance, whereas GLP-1 RAs show consistent benefits in weight management. The enhanced efficacy of combination therapy suggests a potential paradigm shift in PCOS treatment strategies, moving beyond traditional monotherapy approaches. These findings support the therapeutic potential of both drug classes, individually or combined, in PCOS management, providing a foundation for more personalized treatment approaches.

Review of current guidelines for recurrent pregnancy loss: new strategies for optimal evaluation of women who may be superfertile

The current evidence-based guidelines for the evaluation of recurrent pregnancy loss recommended by the American Society for Reproductive Medicine and by the European Society of Human Reproduction and Embryology are compared and contrasted in this review. The clinical use of either of these guidelines will result in a probable diagnosis for only half of the affected patients. New strategies for a full evaluation of recurrent pregnancy loss incorporating 24- chromosome microarary on the products of conception offer more explanations for patients and caregivers. This new algorithm should decrease the use of empiric, unproven treatments. Combining the results of genetic testing on the miscarriage tissue with the conventional diagnostic tests has made it possible to explain the etiology of pregnancy loss in more than 90% of the cases. This cost-saving strategy can decrease the emotional distress and frustration for both couples and physicians when it comes to management of recurrent pregnancy loss.

Loss of function of endothelin-2 leads to reduced ovulation and CL formation

Endothelin-2 (EDN2), a potent vasoconstrictive peptide, is transiently produced by periovulatory follicles at the time of ovulation when corpus luteum (CL) formation begins. EDN2 induces contraction of ovarian smooth muscles ex vivo via an endothelin receptor A-mediated pathway. In this study, we aimed to determine if EDN2 is required for normal ovulation and subsequent CL formation in?vivo. In the ovaries of a mouse model that globally lacks the Edn2 gene (Edn2 knockout mouse; Edn2KO), histology showed that post-pubertal Edn2KO mice possess follicles of all developmental stages, but no corpora lutea. When exogenous gonadotropins were injected to induce super-ovulation, Edn2KO mice exhibited significantly impaired ovulation and CL formation compared to control littermates. Edn2KO ovaries that did ovulate in response to gonadotropins did not contain histologically and functionally identifiable CL. Intra-ovarian injection of EDN2 peptide results suggest partial induction of ovulation in Edn2KO mice. Endothelin receptor antagonism in wild type mice similarly disrupted ovulation, CL formation, and progesterone secretion. Overall, this study suggests that EDN2 is necessary for normal ovulation and CL formation.

Classic and cutting-edge strategies for the management of early pregnancy loss

There are few conditions in medicine associated with more heartache to patients than recurrent pregnancy loss (RPL). The management of early RPL is a formidable clinical challenge for physicians. Great strides have been made in characterizing the incidence and diversity of this heterogeneous disorder, and a definite cause of pregnancy loss can be established in more than half of couples after a thorough evaluation. In this review, current data are evaluated and a clear roadmap is provided for the evaluation and treatment of RPL.

Evaluation and management of recurrent early pregnancy loss

Recurrent pregnancy loss affects up to 5% of couples trying to establish a family. Evaluation classically begins after 3 consecutive miscarriages of less than 10 weeks of gestation but may be warranted earlier if a prior miscarriage was found to be euploid, or if there is concomitant infertility and/or advancing maternal age. The evaluation begins with an extensive history and physical, followed by a diagnostic screening protocol. Management must be evidence-based; unproven treatments should be avoided. If no factor is identified, many couples will still eventually have a successful pregnancy outcome with supportive therapy alone.

Use of Metformin for Ovulation Induction in Women Who Have Polycystic Ovary Syndrome With or Without Evidence of Insulin Resistance

OBJECTIVE

To determine whether women with polycystic ovary syndrome (PCOS) and abnormal insulin levels treated with metformin had different rates of ovulation and pregnancy from women with PCOS and normal insulin levels.

METHODS

The outcomes of treatment with metformin in 146 infertile women with PCOS were analyzed using a retrospective cohort study design. Baseline characteristics and initial blood work results were recorded. The follow-up period was three months, and the primary outcome was ovulation.

RESULTS

Of the 146 women with PCOS, one third had elevated fasting insulin levels. After treatment with metformin, cumulative rates of ovulation were similar in women with elevated fasting serum insulin levels (48.8%) and those with normal levels (44.7%). Rates of ovulation were also similar in women with normal and abnormal glucose to insulin ratios. There was no difference in cumulative pregnancy rates based on fasting insulin levels. A fasting insulin level above 20 mU/L correlated with an abnormal glucose to insulin ratio (98%).

CONCLUSION

In anovulatory women with PCOS, fasting insulin levels and glucose to insulin ratios do not predict the ovulatory response to metformin.

Predictive value of glucose-insulin ratio in PCOS and profile of women who will benefit from metformin therapy: obese, lean, hyper or normoinsulinemic?

OBJECTIVE

The aim of the present study is to evaluate sub-groups of PCOS patients who will benefit from metformin therapy and to find out any predictors of ovulation in PCOS sub-groups.

METHOD

In the current prospective-randomized, placebo-controlled, double-blind study, PCOS patients (n = 116) were divided into six main groups according to glucose to insulin ratio (G-I ratio mg/10(-4) U) and body mass index (BMI kg/m2) as: Group 1: normoinsulinemic (G-I ratio > or = 4.5 mg/10(-4) U), lean (BMI < 25) (n = 37); Group 2: normoinsulinemic, overweight (BMI: 25-29.9) (n = 19); Group 3: normoinsulinemic, obese (BMI > or = 30) (n = 18); Group 4: hyperinsulinemic (G-I ratio < 4.5 mg/10(-4) U), lean (n = 28); Group 5: hyperinsulinemic, overweight (n = 17); Group 6: hyperinsulinemic, obese (n = 20). Patients in each group were randomized onto placebo or metformin treatments (850 mg two to three times per day according to BMI). The rate of ovulation, biochemical profile, hormonal profile and clinical symptoms of hyperandrogenism were evaluated before and after 6 months of metformin and placebo treatments.

RESULT(S)

We observed a significant decrease in WHR following metformin therapy in the normoinsulinemic overweight sub-group (P < 0.05). The duration of the menstrual cycle significantly decreased in the normoinsulinemic obese sub-group on metformin therapy (P < 0.05). Metformin had a significant effect on hirsutism scores in hyperinsulinemic lean women (P < 0.05) and decreased DHEAS levels significantly in the lean hyperinsulinemic and normoinsulinemic groups (P < 0.05). Metformin had significant effects on ovulation in only lean hyperinsulinemic women (P < 0.05).

CONCLUSIONS

Clinical outcomes of metformin therapy may be categorized on the basis of basal BMI and insulin levels in PCOS patients.

Metformin treatment of PCOS during adolescence and the reproductive period

Insulin resistance is a common feature of PCOS. Hyperinsulinemia has been causally linked with all features of the syndrome, such as hyperandrogenism, reproductive disorders, and metabolic disturbances. Several insulin-sensitizing agents have been tested in the management of PCOS. Metformin is the only drug currently in widespread clinical use for PCOS. In a high percentage of patients, treatment with metformin is followed by regularization of the menstrual cycle, less pronounced hyperandrogenism and cardiovascular risk factors, and some improvement in the response to therapies aimed at induction of ovulation. In adolescent girls who are anovulatory and moderately obese, metformin administration can have a normalizing effect on multiple aberrations within the endocrine-metabolic status. During the reproductive period, metformin administration can improve reproductive function and the establishment of pregnancy. A role of metformin in prevention of gestational diabetes and hypertensive complications of pregnancy has yet to be shown. Finally, any real benefit of insulin-lowering treatment in terms of lesser cardiovascular risk in women with PCOS women remains to be demonstrated.

Determination of Maternal Body Composition in Pregnancy and Its Relevance to Perinatal Outcomes

Three models and 10 specific methods for determining maternal body composition are discussed and their perinatal relevance reviewed. English language publications (1950 to January 2004) were searched electronically and by hand. Search terms included "body composition," "human," " pregnancy," "obesity," "adiposity," "regional," "2-, 3-, 4-component," "truncal," "peripheral," "central," "visceral" along with specific techniques and outcomes listed subsequently. Three models of body composition are described: 2-component being fat and fat-free mass; 3-component being fat, water, and protein; and 4-component being fat, water, protein, and osseous mineral. Ten techniques of body composition assessment are described: 1) anthropometric techniques including skinfold thicknesses and waist-hip ratio; 2) total body water (isotopically labeled); 3) hydrodensitometry (underwater weighing); 4) air-displacement plethysmography; 5) bio-impedance analysis (BIA); 6) total body potassium (TBK); 7) dual-energy x-ray absorptiometry (DEXA); 8) computed tomography (CT); 9) magnetic resonance imaging (MRI); and 10) ultrasound (USS). Most methods estimate total adiposity. Regional fat distribution-central (truncal) compared with peripheral (limb) or visceral compared with subcutaneous-is important because of regional variation in adipocyte metabolism. Skinfolds, DEXA, CT, MRI, or USS can distinguish central from peripheral fat. CT, MRI, or USS can further subdivide central fat into visceral and subcutaneous. Perinatal outcomes examined in relation to body composition include pregnancy duration, birth weight, congenital anomalies, gestational diabetes, gestational hypertension, and the fetal origins of adult disease. A few studies suggest that central compared with peripheral fat correlates better with birth weight, gestational carbohydrate intolerance, and hypertension. Means of accurately assessing maternal body composition remain cumbersome and impractical, but may more accurately predict perinatal outcomes than traditional assessments such as maternal weight.

Metformin in obstetric and gynecologic practice: a review

Metformin is a common treatment for women who have insulin resistance manifesting as type 2 diabetes or polycystic ovarian syndrome (PCOS). With an increasing number of these patients conceiving, it is expected that the use of metformin in and around the time of pregnancy will increase. This article reassesses the mechanisms, safety, and clinical experience of metformin use in obstetrics and gynecology. Metformin is an attractive therapeutic option because administration is simple, hypoglycemia rare, and weight loss promoted. There is a large volume of research supporting the use of metformin treatment in diabetes mellitus, androgenization, anovulation, infertility, and recurrent miscarriage. Although metformin is known to cross the placenta, there is, as yet, no evidence of teratogenicity. Metformin has an array of complex actions, accounting for the varied clinical roles, many of which are still to be fully evaluated. Much research is still needed.

Effects of metformin on body mass index, menstrual cyclicity, and ovulation induction in women with polycystic ovary syndrome

OBJECTIVE

Metformin has been used as a treatment in many studies of the infertility associated with polycystic ovary syndrome (PCOS). We will review the literature on this topic as it specifically relates to changes in body mass index (BMI), improvement in menstrual cyclicity, and effects on ovulation and pregnancy rates.

DESIGN

Review of studies addressing biochemical and clinical changes in women with PCOS on metformin.

MAIN OUTCOME MEASURE(S)

Changes in BMI, menstrual cyclicity, ovulation rate, and pregnancy rate.

RESULT(S)

Metformin has been shown to produce small but significant reductions in BMI. Multiple observational studies have confirmed an improvement in menstrual cyclicity with metformin therapy. The studies addressing the concomitant use of metformin with clomiphene citrate initially predicted great success, but these have been followed by more modest results. There is little data in the literature concerning the use of metformin and hMGs.

CONCLUSION(S)

Some (but not all) women with PCOS have improvements in their menstrual cycles while on metformin. The data supporting the use of metformin in ovulation induction with clomiphene citrate and hMG remain to be confirmed by large, randomized, prospective studies.

Polycystic ovary syndrome [PCOS]: comprehensive management in primary care

Polycystic ovary syndrome is a common premenopausal endocrino-metabolic disorder. In addition to hyperandrogenism, menstrual abnormalities, ovulatory disturbances and infertility, insulin resistance, dyslipidemia, and obesity may eventuate in long-term cardiovascular consequences.

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.

Pregnancies following use of metformin for ovulation induction in patients with polycystic ovary syndrome

OBJECTIVE

To assess pregnancy outcome in anovulatory infertility patients diagnosed with polycystic ovary syndrome (PCOS) who were treated with metformin.

DESIGN

Case series.

SETTING

Outpatient.

PATIENT(S)

Anovulatory patients (n = 48) with a diagnosis of PCOS based on clinical, diagnostic, and laboratory evaluations were enrolled in the study over a 15-month period.

INTERVENTION(S)

Metformin was started at 500 mg b.i.d. for 6 weeks and then increased to 500 mg t.i.d. if no ovulation occurred. Clomiphene citrate (CC; 50 mg) was added if no ovulatory response occurred after 6 weeks.

MAIN OUTCOME MEASURE(S)

Resumption of menses, presumptive ovulation, and pregnancy.

RESULT(S)

Nineteen of 48 (40%) patients resumed spontaneous menses following treatment and showed presumptive evidence of ovulation with metformin alone; 15/48 (31%) required CC (50 mg) in conjunction with metformin therapy, and 10 of these 15 (67%) had evidence of ovulation; 20/48 (42%) conceived with a median time to conception of 3 months, and 7 of these 20 (35%) had spontaneous abortions (SAB); 19/48 (40%) had gastrointestinal-related side effects, and 5 of 48 patients (10%) had to decrease the dosage of metformin. Only 1 patient discontinued therapy.

CONCLUSION(S)

Metformin alone in patients with PCOS results in a substantial number of pregnancies, with 69% (20/29) of those who ovulated conceiving in less than 6 months.

Diagnostic and treatment characteristics of polycystic ovary syndrome: descriptive measurements of patient perception and awareness from 657 confidential self-reports

BACKGROUND: This investigation was undertaken to describe patient perception and awareness of the polycystic ovary syndrome (PCOS), the most common cause of anovulation/oligoovulation among women of reproductive age. METHODS: Fifteen parameters were evaluated by a computer-based research instrument accessed by a large, unscreened population. Incomplete questionnaires were not entered, and responses were electronically tabulated to block duplicate submissions. RESULTS: From 657 participants, the majority (63%) were between 26-34 years old; mean BMI was 30.4 kg/m2. 343 of 657 had at least one pregnancy and 61% of the study group had taken fertility medicine (any type) at least once. Physicians were the most common provider of PCOS information for all study participants, irrespective of age. Patient emotions associated with the diagnosis of PCOS included "frustration" (67%), "anxiety" (16%), "sadness" (10%), and "indifference" (2%). Self-reported patient aptitude regarding PCOS was scored as high or "very aware" in >60% of women. Respondents were also asked: "If your PCOS could be safely and effectively helped by something else besides fertility drugs or birth control pills, would that interest you?" Interest in alternative PCOS treatments was expressed by 99% of the sample (n = 648). CONCLUSIONS: In our study population, most women associated negative emotions with PCOS although the self-reported knowledge level for the disorder was high. While these women regarded their obstetrician-gynecologist as integral to their PCOS education, traditional PCOS therapies based on oral contraceptives or ovulation induction agents were regarded as unsatisfactory by most women.

Plasma homocysteine, fasting insulin, and androgen patterns among women with polycystic ovaries and infertility

OBJECTIVE

To measure plasma homocysteine, androgen, and insulin concentrations in women with normal and polycystic-appearing ovaries in an infertility setting.

METHODS

Among women referred for infertility evaluation (n = 54), homocysteine, androstenedione, DHEAS, total testosterone, fasting insulin/glucose and methyltetrahydrofolate reductase (MTHFR) polymorphism status (C677T mutation) were studied. Ovaries were examined via transvaginal sonogram by one observer and scored as either normal (n = 18) or polycystic (n = 36).

RESULTS

When polycystic ovaries were identified, mean total testosterone was significantly higher than when non-polycystic ovaries were present (p = 0.01), although no measured androgen was outside the normal reference range in either group. Average BMI was higher in the polycystic group, but the difference was not significant (p = 0.10). We observed a trend toward higher mean fasting insulin levels in women with polycystic ovaries, but this increase did not reach statistical significance (p = 0.07). Median plasma homocysteine was identical (7.0 mmol/l) in both populations, and no study subject exceeded the current recommended maximum reference value.

CONCLUSIONS

In this population, the presence of polycystic ovaries was associated with higher serum androgens (especially total testosterone) although none of the measured androgens were above the normal range. While fasting insulin levels were also higher in this group, median plasma homocysteine levels were similar irrespective of ovarian morphology. Concomitant plasma homocysteine derangements in this population of young, lean patients with polycystic-appearing ovaries seem unlikely. Further studies are needed to clarify the role(s) of homocysteine in human reproductive physiology.