Effects of metformin on gonadotropin-induced ovulation in women with polycystic ovary syndrome

Metformin, a biological and synthetic overview

Metformin is the most widely known anti-hyperglycemic, officially acquired by the USA government in 1995 and in 2001 it became the most prescribed treatment for type II diabetes. But how did it become the must-use drug for this disease in such a short period of time? it all started with traditional medicine, by using a plant known as "goat's rue" for the reduction of blood glucose levels. Its use arose in 1918 and evolved to the metformin synthesis in laboratories a couple of years later, using very rudimentary methods which involved melting and strong heating. Thus, a first synthetic route that allowed the preparation of the initial metformin derivates was established. Some of these resulted toxics, and others outperformed the metformin, reducing the blood glucose levels in such efficient way. Nevertheless, the risk and documented cases of lactic acidosis increased with metformin derivatives like buformin and phenformin. Recently, metformin has been widely studied, and it has been associated and tested in the treatment of type II diabetes, cancer, polycystic ovarian syndrome, cell differentiation to oligodendrocytes, reduction of oxidative stress in cells, weight reduction, as anti-inflammatory and even in the recent COVID-19 disease. Herein we briefly review and analyze the history, synthesis, and biological applications of metformin and its derivates.

Association of HOMA-IR with Ovarian Sensitivity Index in Women Undergoing IVF/ICSI: A Retrospective Cohort Study

BACKGROUND

Insulin resistance (IR) may adversely impact the in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) outcomes. However, the association of IR with ovarian sensitivity during controlled ovarian hyperstimulation (COH) remains controversial.

PURPOSE

We aimed to explore the association between homeostasis model assessment of insulin resistance (HOMA-IR) and ovarian sensitivity index (OSI).

PATIENTS AND METHODS

In this retrospective cohort study, 7836 patients aged between 20 and 39 years with good ovarian reserve were included consecutively between June 2018 and May 2022. HOMA-IR was calculated to evaluate the degree of IR and OSI was used to measure ovarian sensitivity. Owing to skewed distribution, HOMA-IR and OSI were log e transformed to Ln HOMA-IR and Ln OSI. Smoothing splines were generated by generalized additive models to explore the correlation between Ln HOMA-IR and Ln OSI. Then, the relationship between Ln HOMA-IR and Ln OSI was tested with multivariable linear regression model after adjustments for the potential confounders.

RESULTS

We observed negative association between Ln HOMA-IR and Ln OSI after adjustment for potential confounders by using smoothing spline fitting curves in generalized additive model. In the multivariable linear regression model, after full adjustments, each one unit increase in Ln HOMA-IR was related to reduced Ln OSI values (β = -0.12, 95% CI, -0.15, -0.09). As sensitivity analysis, those who had HOMA-IR of quartile 3 (HOMA-IR 2.33-3.43) and quartile 4 (HOMA-IR ≥3.43) had decreases in Ln OSI values (β = -0.07, 95% CI -0.11, -0.03 and β = -0.18, 95% CI -0.22, -0.13, respectively) when compared with patients in the quartile 1 (HOMA-IR <1.63). Furthermore, stratified and interaction analysis showed a strong inverse association of Ln HOMA-IR with Ln OSI in subgroups of PCOS patients and overweight/obese populations (P-value for interaction <0.0001).

CONCLUSION

HOMA-IR value was negatively associated with the ovarian sensitivity assessed by OSI. Among the PCOS and overweight/obese populations, this inverse relationship may be strong. These findings will increase the understanding of the contribution of IR to the development of decreased ovarian sensitivity within the assisted reproductive technology (ART) setting. It may have implications for optimizing gonadotropin dose manipulation in patients with IR undergoing IVF/ICSI.

Prepregnancy Polycystic Ovary Syndrome as a Risk Factor of Subsequent Preterm Labor: A National Population-Based Cohort Study

Background: Preterm labor and the following preterm births, which account for most of the perinatal deaths, are an important issue in public health. The study aims to assess the risk of subsequent preterm labor in pregnant females who have prepregnancy polycystic ovary syndrome (PCOS). Methods: This study has enrolled 1,000,000 randomly sampled females retrieved from the Taiwan National Health Insurance Research Database (NHIRD) during 1998−2012. The study excluded prepregnancy PCOS females who were initially diagnosed at age <15 or >45, and those who had inconsistent diagnoses. Moreover, the medical records of blood hormone tests, gynecologic ultrasonography, pelvic examinations, and tocometers were verified to confirm the accuracy of both diagnoses of PCOS and preterm labor. Among the prepregnancy PCOS females who became pregnant (the case group), each was age-matched to four females without prepregnancy PCOS (the control group). Results: Pregnant females in the case group (n = 1959) had a higher incidence of preterm labor than those in the control group (n = 7836) (42.98% vs. 21.99%, p < 0.0001). Analyzed by using logistic regression, the risk of preterm labor was significantly higher in the case group compared with the control group (crude OR: 2.674; 95% CI: 2.410−2.968, p < 0.0001). After adjustment with covariates, further analysis revealed a similar trend (adjusted OR: 2.405; 95% CI: 2.158−2.680, p < 0.0001). Among 1959 PCOS females in the case group, 196 had undergone metformin treatment. Compared with females without metformin treatment (the non-metformin subgroup), the metformin users (metformin subgroup) presented a reduced risk for preterm labor (adjusted OR: 2.238; 95% CI: 1.657−3.023). The risk of subsequent preterm labor was reduced by about 10% for the metformin subgroup compared with the non-metformin subgroup. Conclusions: Prepregnancy PCOS is an independent and significant risk factor of subsequent preterm labor. Among prepregnancy PCOS females, the risk of preterm labor is lowered by about 10% in metformin users compared with non-metformin females.

Mechanistic and therapeutic insight into the effects of cinnamon in polycystic ovary syndrome: a systematic review

Polycystic ovary syndrome (PCOS) is one of the most common endocrine diseases in the women at their reproductive age. Nowadays, the use of herbal compounds for lesser side effects, as compared to drug treatments, has become popular for the prevention and reduction of the complications of this disease. Evidence suggests that cinnamon, given its antioxidant and anti-inflammatory properties, can be associated with reduced metabolic complications from chronic non-communicable diseases. This systematic review aimed to determine the potential effect of cinnamon on the metabolic status in the PCOS. PICO framework for current systematic review was Population (P): subjects with PCOS; Intervention (I): oral cinnamon supplement; Comparison (C): the group as control or administered placebo; and Outcome (O): changed inflammatory, oxidative stress, lipid profile, glycemic, hormonal and anthropometric parameters and ovarian function. PubMed, Scopus, EMBASE, ProQuest and Google Scholar were searched from their very inception until January, 2020, considering specific keywords to explore the related studies. Out of 266 studies retrieved by the search strategy, only nine were eligible for evaluation. All clinical trials, animal studies, and published English-language journal studies were eligible for this review. The results showed that increased high-density lipoprotein and insulin sensitivity were increased by the cinnamon supplementation while low-density lipoprotein, triglyceride, and blood glucose were decreased in patients with PCOS. However, the results related to the potential effects of cinnamon on body weight and body mass index were inconsistent, thus calling for further studies. Also, despite improved results regarding the effect of cinnamon on oxidative stress and ovarian function, further studies are required to explore the precise mechanisms. Overall, the effects of cinnamon on the improvement of metabolic status in PCOS were promising. However, to observe clinical changes following cinnamon supplementation in PCOS, more clinical trials with higher doses of cinnamon and a longer duration of intervention are needed.

D-chiro-inositol Induces Ovulation in Non-Polycystic Ovary Syndrome (PCOS), Non-Insulin-Resistant Young Women, Likely by Modulating Aromatase Expression: A Report of 2 Cases

Case series

Patients: Female, 19-year-old • Female, 23-year-old

Final Diagnosis: Anovulation

Symptoms: Oligomenorrhea

Medication: —

Clinical Procedure: —

Specialty: Obstetrics and Gynecology

The Risk of Subsequent Miscarriage in Pregnant Women with Prior Polycystic Ovarian Syndrome: A Nationwide Population-Based Study

Objective: To assess the risk of subsequent miscarriage in pregnant women with a prior diagnosis of polycystic ovarian syndrome (PCOS). Methods: Using a nationwide, population-based database (Taiwan National Health Insurance Research Database) during 1998-2012, the study retrieved 1,000,000 randomly-sampled insured citizens as research subjects. The women with a diagnosis of pre-pregnancy PCOS (n = 13,562) who had chromosomal anomalies, artificial abortion, inconsistent diagnoses, and who were initially diagnosed with PCOS at >45 or <15 year-old were excluded, respectively. The records of gynecologic ultrasonography and/or blood tests were checked to verify the accuracy of the diagnoses of both PCOS and miscarriage (ICD-9 CM codes). After pregnancy, every woman with prior PCOS was age-matched to four women without prior PCOS. Results: Pregnant women with prior PCOS (the case group; n = 1926) and those without prior PCOS (the control group; n = 7704) were compared. The incidence of subsequent miscarriage was much higher in the case group compared with the control group (33.80% vs. 4.09%, p < 0.0001). Logistic regression analysis revealed that the risk of subsequent miscarriage was significantly higher in the case group than the control group (odds ratio [OR] 11.98; 95% CI 10.34-13.87, p < 0.0001), and the result remained similar while adjusted with covariates (adjusted OR 11.97; 95% CI 10.27-13.95, p < 0.0001). In the case group, the patient who used metformin had a lower risk of subsequent miscarriage (adjusted OR 9.53; 95% CI 6.69-13.57) when compared with those who did not receive metformin treatment (adjusted OR 12.13; 95% CI 10.38-14.18). Conclusion: For pregnant women, a pre-pregnancy diagnosis of PCOS is an independent and significant risk factor for subsequent miscarriage. The risk of subsequent miscarriage is reduced by about 1/4 for the PCOS patients who undergo metformin treatment compared with those who do not.

Synergic effect of bee pollen and metformin on proliferation and apoptosis of granulosa cells: Rat model of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common cause of infertility associated with metabolic complications. Several classes of pharmacological agents have been used to manage PCOS. These drugs have shown adverse effects. Various studies showed the bee pollen (BP) as a substance rich in phytoestrogens. This study aimed to investigate the effects of BP and metformin alone and in combination with proliferation and apoptosis of granulosa cells in the rat model of PCOS. In this experimental study, 54 Wistar rats (180-210 g), was injected 2 mg of estradiol valerate intramuscularly and six rats were considered as control. After 60 days, the rats were divided into control, sham, and experimental groups. The rats were treated with bee pollen (50, 100, and 200 mg/kg) and metformin (300 mg/kg), either individually or in combination. Ovarian histology assessment was examined by H&E staining. The serum levels of NO and TNF-α were evaluated. The expressions of P53 and Ki67 were measured by IHC. In the BP and metformin-treated PCOS group, the preantral and antral follicles increased, and cystic follicles significantly decreased (p < .01). The levels of TNF-α, NO, as well as the expressions of Ki67 were decreased in the treated groups compared to the PCOS group (p < .01). On the contrary, apoptosis increased in the groups treated with BP compared to the untreated group (p < .01). BP individually or synergistically with metformin improved the symptoms of PCOS.

Protective effects of licorice extract on ovarian morphology, oocyte maturation, and embryo development in PCOS-induced mice: An experimental study

Background

Polycystic ovary syndrome (PCOS) is an oxidative state resulting in ovarian dysfunction. Licorice is one of the natural antioxidants used for the treatment of infertility.

Objective

To evaluate the effect of licorice extract on ovarian morphology, oocyte maturation, and embryo development in PCOS-induced mice.

Materials and Methods

thirty-two female NMIR mice were divided into four groups (n = 8/each): control group receiving no treatment (group I); PCOS group injected with estradiol valerate once daily for 21 days (group II); and experimental groups receiving either 100 mg/kg (group III) or 150 mg/kg (group IV) licorice by gavage along with estradiol valerate once daily for 3 wk. Serum levels of the testosterone and estrogen were measured using ELISA kit. Histological study of ovaries was evaluated, and oocyte maturation, fertilization rate, and embryo development were determined after in vitro maturation.

Results

Experimental groups (III, IV) had significantly higher testosterone and estradiol levels compared to the PCOS group (p ≤ 0.001). A significant increase in the number of healthy follicles (primary, preantral follicles) (p = 0.001), corpus luteum (p = 0.001) with significant decrease in the number of atretic follicles (primary, preantral, cystic follicles) (p ≤ 0.001) was seen in the experimental groups. Increase in the fertilization rate (p ≤ 0.001) and blastocyst stage embryos (p = 0.02, p = 0.004) were observed in the experimental groups.

Conclusion

It appears that the two doses (100 mg and 150 mg) of licorice could decrease ovarian cyst and improve the fertilization rate of oocyte and embryo development in PCOS mice. However, there was no statistically significant difference between the two experimental groups.

New clinical targets of d-chiro-inositol: rationale and potential applications

INTRODUCTION

Inositols have a key role in ovarian physiology and the literature reports a wealth of studies about the major isomer, myo-inositol (MI). However, information about d-chiro-inositol (DCI) is still scarce, despite the ratio MI:DCI is tissue-specific and actively maintained by an insulin-dependent epimerase enzyme.

AREAS COVERED

This expert opinion provides an overview of the physiological contribution of DCI in regulating steroidogenesis. DCI indeed mediates the intracellular signaling of insulin, which induces the biosynthesis of androgens. Studies on second messengers of insulin also revealed that DCI has a specific role in modulating the activity of aromatase enzyme. Specifically, recent findings demonstrated that DCI influences the enzyme gene expression, thus reducing the conversion of androgens into estrogens.

EXPERT OPINION

Available evidence suggests that the effects of DCI administration may be similar to those of aromatase inhibitors, but without causing hypo-estrogenic states. Therefore, DCI treatments should be evaluated for either estrogen-dependent gynecological conditions or low testosterone states in male subjects.

The effect of clomiphene citrate, herbal mixture, and herbal mixture along with clomiphene citrate on clinical and para-clinical parameters in infertile women with polycystic ovary syndrome: a randomized controlled clinical trial

INTRODUCTION

To evaluate the effect of a herbal mixture (i.e., Mentha spicata, Zingiber officinale, Cinnamomum zeylanicum, and Citrus sinensis) alone and in combination with clomiphene citrate (CC) compared to CC on the treatment of polycystic ovary syndrome (PCOS).

MATERIAL AND METHODS

This single-blind randomized clinical trial was conducted on 60 infertile participants with PCOS who were randomly divided into three groups. After spontaneous or progestin-induced withdrawal bleeding, group 1 (n = 20) received routine treatment with CC (50-150 mg) for three menstrual cycles from the 3^rd to 5^th day of menstruation for 5 days while group 2 (n = 20) and group 3 (n = 20) received herbal mixture capsules 700 mg/day and the herbal mixture along with CC for 3 months, respectively. Finally, several related parameters were measured, including the level of sex steroids, homeostatic model assessment for insulin resistance (HOMA-IR), lipid profile (primary outcomes), thyroid hormones, and clinical features. The analysis was based on intention-to-treat analysis.

RESULTS

No statistically significant differences were observed between the groups in terms of socio-demographic characteristics. However, after adjustment for baseline, luteinizing hormone (aMD = 4.9; 95% CI: 3.7-6.2), luteinizing hormone/follicle-stimulating hormone (aMD = 0.9; 95% CI: 0.7-1.2), total testosterone (aMD = -0.12; 95% CI: -0.2 to -0.01) in group 2 and free testosterone (aMD = -6.0; 95% CI: -9.7 to -2.3) in group 3 revealed a significant difference compared to group 1. In addition, HOMA-IR in group 2 (aMD = -1.3; 95% CI: -2.4 to -0.2) decreased significantly compared to group 1. Further, total cholesterol, triglycerides, low-density lipoprotein cholesterol, and very low-density lipoprotein cholesterol decreased significantly in group 2 (aMD = -21.8; 95% CI: -31.5 to -12.1; aMD = -29.9; 95% CI: -47.9 to -12.0; aMD = -21.2; 95% CI: -31.3 to -11.1; aMD = -5.1; 95% CI: -7.5 to -2.7) and group 3 (aMD = -18.3; 95% CI: -27.4 to -9.2; aMD = -26.9; 95% CI: -43.8 to -9.9; aMD = -21.4; 95% CI: -31.1 to -11.7; aMD = -5.9; 95% CI: -8.3 to -3.6) compared to group 1, respectively. However, high-density lipoproteins cholesterol in group 2 (aMD = 6.8; 95% CI: 2.9-10.7) and group 3 (aMD = 10.7; 95% CI: 7.2-14.7) increased remarkably compared to group 1. Overall, clinical outcomes improved significantly in all groups (p < 0.05).

CONCLUSIONS

In general, the herbal mixture along with CC was found to improve free testosterone, HOMA-IR, lipid profile, and clinical features of PCOS women.

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.

Impact of Metformin on IVF Outcomes in Overweight and Obese Women With Polycystic Ovary Syndrome: A Randomized Double-Blind Controlled Trial

OBJECTIVES

To evaluate the impact of metformin on in vitro fertilization (IVF) outcomes in overweight and obese women with polycystic ovary syndrome (PCOS).

METHODS

This was a randomized double-blind placebo-controlled study ( ClinicalTrials.gov : NCT02910817) carried out in a University IVF Center. The study included 102 overweight and obese women (body mass index [BMI] >24 kg/m²) with PCOS who underwent their first fresh autologous IVF-embryo transfer cycle and agreed to participate in the study. The study participants were randomized into 2 groups: metformin group received metformin (1000 mg per day) at the start of controlled ovarian stimulation (COH) until the day of the pregnancy check, and placebo group received placebo tablets in the same duration. The primary outcome measure was the total number of retrieved oocytes.

RESULTS

Both groups were homogenous in baseline demographic characteristics. Metformin group versus the placebo group demonstrated decrease in the mean number of the retrieved oocytes (9.06 ± 4.23 vs 16.86 ± 8.3, P < .01) and similar live birth rate (LBR; 25.5% vs 17.6%, P = .34). The number of fertilized oocytes was lower in the metformin group (5.65 ± 2.66 vs 9 ± 4.55, P < .01). However, the fertilization rate was similar in both groups (62.3% vs 53.4%, P = .10). There was no difference in the implantation rate (15.7% vs 11.8%, P = .32), multiple pregnancy rate (13.4% vs 3.9%, P = .08), or miscarriage rate (23.5% vs 35.7%, P = .46). No cases of ovarian hyperstimulation syndrome (OHSS) were observed in both groups.

CONCLUSION

Short-term administration of metformin to overweight or obese women with PCOS undergoing IVF decreased number of the retrieved oocytes but did not improve the LBR.

SYNOPSIS

Metformin use could decrease the number of retrieved oocytes in overweight and obese women with polycystic ovary syndrome undergoing IVF.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Effect of Casein Phosphopeptide-amorphous Calcium Phosphate and Calcium Sodium Phosphosilicate on Artificial Carious Lesions: An in vitro Study

Aim

To compare new remineralizing agents calcium sodium phosphosilicate paste and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) paste with that of fluoridated toothpaste in remineralization of early carious lesions using scanning electron microscopy and energy-dispersive X-ray (SEM-EDX) analysis.

Materials and methods

Sixty sound extracted premolars were collected and placed in demineralizing solution for 4 days to produce artificial carious lesions. All specimens were evaluated for any loss of mineral content using SEM-EDX analysis. Samples were randomly assigned to three groups: Group I: Fluoridated toothpaste (control), group II: CPP-ACP paste, and group III: Calcium sodium phosphosilicate paste. Specimens were then treated with above-mentioned remineralizing agents and again measured for mineral content using SEM-EDX analysis.

Results

Group III (calcium sodium phosphosilicate paste) showed highest significant difference followed in descending order by group II (CPP-ACP paste) and group I (fluoridated toothpaste).

Conclusion

Calcium sodium phosphosilicate paste showed maximum remineralizing potential compared with CPP-ACP and fluoridated toothpastes.

How to cite this article

Chaudhary I, Tripathi AM, Yadav G, Saha S. Effect of Casein Phosphopeptide-amorphous Calcium Phosphate and Calcium Sodium Phosphosilicate on Artificial Carious Lesions: An in vitro Study. Int J Clin Pediatr Dent 2017;10(3):261-266.

Effect of Resin Infiltration on Artificial Caries: An in vitro Evaluation of Resin Penetration and Microhardness

Aim

To evaluate the effectiveness of resin infiltration on artificial caries lesion by assessing the depth of resin penetration and the change in microhardness of lesion postinfiltration.

Materials and methods

Totally 45 human extracted premolars were used to create an artificial demineralized lesion in enamel using demineralizing solution. A total of 15 samples (group I) were infiltrated with resin. The depth of resin penetration was studied using scanning electron microscope (SEM). Other half (n = 30) of samples was equally divided into three subgroups and Vickers hardness number (VHN) values were obtained to measure the surface microhardness as group 11 a—before demineralization, 11 b—after demineralization, IIc—postresin infiltration.

Results

Mean depth of penetration in group I was 516.8 urn. There was statistically significant increase in VHN values of demineralized lesion postresin infiltration (independent Student’s t-test, p < 0.001).

Conclusion

Penetration depth of the resin infiltrant was deep enough to render beneficial effects, while significant increase in microhardness was observed postresin infiltration.

Clinical significance

Infiltrant used can be considered as a valid treatment option for noncavitated lesions.

How to cite this article

Prajapati D, Nayak R, Pai D, Upadhya N, Bhaskar VK, Kamath P. Effect of Resin Infiltration on Artificial Caries: An in vitro Evaluation of Resin Penetration and Microhardness. Int J Clin Pediatr Dent 2017;10(3):250-256.

Emerging Understanding of Emotional Intelligence of Teenagers

Aim

Emotional intelligence (EI) is the ability to use emotions effectively and productively. It is becoming increasingly clear that these skills are one of the primary foundations for better performance of students in classrooms and in the society as well and EI provides the basis for competencies important "in almost every job." So we accessed the EI of teenagers as a guide of their academic score.

Study design

We analyzed the correlation of academic score to the EI of teenagers in regular schools and part-time unconventional coaching institute using the Bar-On Emotional Quotient questionnaire.

Results and conclusion

The results of our study showed that empathy and self-actualization were highly developed in students of regular conventional school than those attending part-time unconventional coaching institute. The academic score had a significantly positive correlation with empathy, whereas a significantly negative correlation with interpersonal relations. Empathy, interpersonal relation, and impulsive control were significantly higher in females than males. Therefore by inculcating and working toward development of EI in the young generation, we can hope to achieve a more positive environment.

How to cite this article

Sekhri P, Sandhu M, Sachdev V. Emerging Understanding of Emotional Intelligence of Teenagers. Int J Clin Pediatr Dent 2017;10(3):289-292.

Comparison of Dermatoglyphic Pattern among Cleft and Noncleft Children: A Cross-sectional Study

Background

Oral clefts are among the common congenital birth defects with a broad phenotypic gamut. Since the epidermal ridges of the fingers and palms as well as the facial structures like lip, alveolus, and palate are formed from the same embryonic tissues during the same embryonic period, the genetic and environmental factors responsible for causing cleft lip and palate might also affect dermatoglyphic patterns.

Aim

Thus, study was undertaken to compare the dermato-glyphic pattern of children with orofacial clefts and normal children and to determine the correlation of dermatoglyphics with orofacial clefts.

Materials and methods

Total study sample consisted of 120 children in the age group of 3 to 16 years being divided into study and control groups. Dermatoglyphic data obtained from both control and study groups were then subjected to statistical analysis.

Results

Statistically no significant difference was found in the dermatoglyphic pattern and atd angle for both the groups.

Conclusion

It was observed that dermatoglyphics in orofacial clefts may not be distinctive. Further, large-scale studies are recommended to confirm the same.

How to cite this article

Mayall SS, Chaudhary S, Kaur H, Manuja N, Ravishankar T, Sinha AA. Comparison of Derma-toglyphic Pattern among Cleft and Noncleft Children: A Cross-sectional Study. Int J Clin Pediatr Dent 2017;10(3):245-249.

Polycystic ovarian syndrome and the risk of subsequent primary ovarian insufficiency: a nationwide population-based study

OBJECTIVE

To evaluate the risk of subsequent primary ovarian insufficiency (POI) amongst patients with a history of polycystic ovarian syndrome (PCOS).

METHODS

This nationwide, population-based study is an inspection and review of data from the 1998 to 2012 Taiwan National Health Insurance Research Database. In a sample of 1,000,000 randomly sampled individuals, women with PCOS (exposure group; n = 7,049) and women without PCOS (contrast group; n = 70,490) were compared. Women initially diagnosed with PCOS at less than 15 or more than 35 years of age were excluded. Each woman with PCOS was age-matched to 10 women without PCOS. The diagnoses of PCOS and POI (coded using International Classification of Diseases, 9th Revision, Clinical Modification) were further confirmed with blood test results and ultrasonographic findings to ensure the accuracy of the diagnoses.

RESULTS

POI occurred more among women with PCOS compared with women without PCOS (3.73% vs 0.44%; P < 0.001). Using Kaplan-Meier survival analysis, the POI-free survival rates were significantly different between the exposure and contrast groups (P < 0.001). During 10 years of follow-up, Cox proportional-hazard analysis revealed that the risk for POI was significantly higher in the exposure than in the contrast group (hazard ratio [HR] 8.64, 95% confidence interval [CI] 7.33-10.18) and remained similar after adjustment for covariates (adjusted HR 8.31, 95% CI 7.05-9.81). Compared with that of women without PCOS, the risk of POI was even higher for women with PCOS who did not receive metformin treatment (adjusted HR 9.93, 95% CI 8.28-11.90). However, the risk for POI was significantly reduced for women with PCOS who received metformin treatment (adjusted HR 5.66, 95% CI 4.36-7.35).

CONCLUSIONS

As a possible precursor stage, prior PCOS is a significant and independent risk factor for development of POI. The use of metformin reduces the risk of POI.

Effect of Dentin Disinfection with 2% Chlorhexidine Gluconate and 0.3% Iodine on Dentin Bond Strength: An in vitro Study

Objective

Cavity preparation is a surgical procedure that attempts to remove all infected dentin.¹ Bacteria left beneath the filling material is greatest threat to the pulp. To reduce the potential for residual caries development and sensitivity, an antibacterial solution with the ability to disinfect the prepared tooth surface would be of help.² So this study was conducted to evaluate and compare the effect of dentin disinfection with 2% chlorhexidine gluconate (Consepsis) and 0.3% iodine (Ora5) on shear bond strength (SBS) of self-etch adhesives to dentin.

Materials and methods

Buccal surfaces of 36 caries-free permanent third molars were ground to expose dentin. All specimens were mounted on acrylic block, divided randomly into three groups, namely group I (control), group II (Con-sepsis), and group III (Ora5). After the application of cavity disinfectant and bonding procedures as per manufacturer’s instructions, composite cylinders were built. Then SBS was measured using universal testing machine.

Results

Statistical analysis of the measurements were made using one-way analysis of variance (ANOVA), which showed that when cavity disinfectants (Consepsis and Ora5) were used there was significant reduction in SBS of composite to dentin when compared with that of control group.

Interpretation and conclusion

The results indicate that the use of commercially available cavity disinfectants, Consepsis containing 2% chlorhexidine gluconate and Ora5 containing 0.3% iodine and 0.15% potassium iodide with self-etch adhesive (Adper Prompt), would significantly lower SBS of composite to dentin.

How to cite this article

Suma NK, Shashibhushan KK, Reddy VVS. Effect of Dentin Disinfection with 2% Chlorhexidine Gluconate and 0.3% Iodine on Dentin Bond Strength: An in vitro Study. Int J Clin Pediatr Dent 2017;10(3):223-228.

Eruption Chronology in Children: A Cross-sectional Study

Aims and objectives

The purpose of this study is to determine the appropriate reference standard for eruption timing of primary teeth in infants and preschool children of Bhopal city and to determine the role of various factors affecting the eruption of primary dentition.

Materials and methods

A cross-sectional study was conducted among the infants and preschool children (4-36 months) attending the local government or private hospitals, and vaccination centers. Prior to the study, Institutional Ethical Committee clearance and informed written consent from the parents were obtained. The data were collected from full-term infants and preschool children of 4 to 36 months from Bhopal city. Oral examination was done under adequate natural light by a single examiner using mouth mirror and probe. Teeth present in the oral cavity were noted by using Federation Dentaire Internationale system of nomenclature in the preformed pro-forma. The teeth were considered as erupted, when any part of its crown had penetrated the gingiva and was visible in the oral cavity. Height, weight, birth weight, and other close-ended questions in questionnaire were asked from parents.

Results and conclusion

The data collected were statistically analyzed and it was observed that significant relation exists between tooth eruption and birth weight, feeding habits, socioeconomic status, and body mass index (BMI). Based on the findings, it may be concluded that Indian children experienced delayed eruption of primary teeth when compared with children of different countries and standard norms.

How to cite this article

Verma N, Bansal A, Tyagi P, Jain A, Tiwari U, Gupta R. Eruption Chronology in Children: A Cross-sectional Study. Int J Clin Pediatr Dent 2017;10(3):278-282.

Evaluation of Antimicrobial Efficacy of various Intracanal Medicaments in Primary Teeth: An in vivo Study

Introduction

Bacteria and their products play a primary etiological role in the initiation and perpetuation of pulpoperiapical pathosis. Intracanal medication is important for endodontic success as it eliminates microorganisms that persist after chemomechanical preparation.

Aim

To compare antimicrobial efficacy of calcium hydroxide powder, triple antibiotic paste, calcium hydroxide with 2% chlorhexidine solution, and triple antibiotic paste with 2% chlorhexidine solution.

Materials and methods

A total of 48 nonvital primary teeth were included in this study. After access opening first microbiological sample (s1) was collected by using absorbent paper point introducing into canal. Second microbilogical sample (s2) was taken following chemomechanical preparation and the teeth were divided into four groups: Group I: calcium hydroxide (CH) powder with distilled water; group II: CH with 2% chlorhexidine solution; group III: triple antibiotic powder with distilled water; group IV: triple antibiotic paste with 2% chlorhexidine solution. Then the canals were filled with any one group of the medicament and cavity was temporarily sealed with zinc oxide eugenol. After 1 week, a postmedication sample (s3) was collected. Then the canal was filled with Metapex, restored with glass ionomer cement.

Conclusion

From the experiments carried out in this study, with the limitations, an inference can be drawn that a combination of antimicrobial agent used as intracanal medicament is definitely better than single agent like Ca(OH)₂.

How to cite this article

Dutta B, Dhull KS, Das D, Samir PV, Verma RK, Singh N. Evaluation of Antimicrobial Efficacy of various Intracanal Medicaments in Primary Teeth: An in vivo Study. Int J Clin Pediatr Dent 2017;10(3):267-271.

Comparison of Antimicrobial Efficacy of Green Tea, Garlic with Lime, and Sodium Fluoride Mouth Rinses against Streptococcus mutans, Lactobacilli species, and Candida albicans in Children: A Randomized Double-blind Controlled Clinical Trial

Introduction

With greater awareness worldwide, the use of herbs and herbal products has increased to a large extent.

Objective

To evaluate and compare the antimicrobial efficacy of green tea, garlic with lime, and 0.05% sodium fluoride (NaF) mouth rinses against Streptococcus mutans, Lactobacilli species, and Candida albicans.

Materials and methods

A total of 45 children aged 4 to 6 years with severe early childhood caries (S-ECC; based on decayed extracted filled [defs] score) were selected. Children were divided randomly into three equal groups and were asked to rinse with the prescribed mouth rinse once daily for 2 weeks after breakfast under supervision. A base-line and postrinsing nonstimulated whole salivary sample (2 mL) was collected and tested for the number of colony-forming units (CFUs). The data were statistically analyzed using Statistical Package for the Social Sciences (SPSS) version 16.0 software with one-way analysis of variance (ANOVA) and Tukey’s post hoc test.

Results

A statistically significant fall in colony count was found with the three mouth rinses in S. mutans (p < 0.001, p < 0.001) and Lactobacilli spp. (p < 0.001, p < 0.001), but not against C. albicans (p = 0.264, p = 0.264). On comparison, no statistically significant difference was found against S. mutans (p = 1, p = 0.554, p = 0.572), lactobacilli spp. (p = 0.884, p = 0.999, p = 0.819), and C. albicans (p = 0.999, p = 0.958, p = 0.983).

Conclusion

The findings of this study indicate that green tea and garlic with lime mouth rinse can be an economical alternative to NaF mouth rinse both for prevention and therapeutics.

How to cite this article

Thomas A, Thakur S, Habib R. Comparison of Antimicrobial Efficacy of Green Tea, Garlic with Lime, and Sodium Fluoride Mouth Rinses against Streptococcus mutans, Lactobacilli species, and Candida albicans in Children: A Randomized Double-blind Controlled Clinical Trial. Int J Clin Pediatr Dent 2017;10(3):234-239.

Clinical and Radiographic Evaluation of Four Different Pulpotomy Agents in Primary Molars: A Longitudinal Study

Background

The medicament formocresol (FC) used for pulpotomy in primary teeth has great concerns regarding its toxicity due to one of its constituent formaldehyde which acts by tissue fixation. Therefore, new medicaments were introduced which claimed preservation and regeneration of pulp.

Aim

The present study is aimed to compare and evaluate the clinical and radiographic success of FC, pulpotec, mineral trioxide aggregate (MTA), and emdogain (EMD) as pulpotomy medicaments in human primary molars.

Design

A sample of 21 patients with 84 teeth were selected. All the patients have at least four teeth eligible for pulpotomy according to selection criteria. In each mouth, the teeth selected were randomly allocated into four groups with 21 each.

Results

After 24 months of follow-up, the clinical success rates were FC (94%), pulpotec (94%), MTA (100%), and EMD (83%) and radiographically FC (88%), pulpotec (83%), MTA (94%), and EMD (72%), which were statistically not significant (p > 0.05).

Conclusion

The outcome of this study demonstrates MTA has a high success rate compared with FC, pulpotec, and EMD as pulpotomy agent. In addition, MTA, pulpotec, and EMD can be considered as alternatives to FC as pulpotomy agent.

How to cite this article

Sunitha B, Puppala R, Kethineni B, Mallela MK, Peddi R, Tarasingh P. Clinical and Radiographic Evaluation of Four Different Pulpotomy Agents in Primary Molars: A Longitudinal Study. Int J Clin Pediatr Dent 2017;10(3):240-244.

Metformin during ovulation induction with gonadotrophins followed by timed intercourse or intrauterine insemination for subfertility associated with polycystic ovary syndrome

BACKGROUND

Clomiphene citrate (CC) is generally considered first-line treatment in women with anovulation due to polycystic ovary syndrome (PCOS). Ovulation induction with follicle-stimulating hormone (FSH; gonadotrophins) is second-line treatment for women who do not ovulate or conceive while taking CC. Metformin may increase the effectiveness of ovulation induction with gonadotrophins and may promote safety by preventing multiple pregnancy.

OBJECTIVES

To determine the effectiveness and safety of metformin co-treatment during ovulation induction with gonadotrophins with respect to rates of live birth and multiple pregnancy in women with PCOS.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility (CGF) Group specialised register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, PsycINFO and the Cumulative Index to Nursing and Allied Health Literature (CINAH) on 8 June 2016, and the reference lists of included and other relevant studies. We searched ongoing trials registries in the World Health Organization (WHO) portal and on clinicaltrials.gov on 4 September 2016.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) reporting data on comparison of clinical outcomes in women with PCOS undergoing ovulation induction with gonadotrophins plus metformin versus gonadotrophins alone or gonadotrophins plus placebo.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane. Primary review outcomes were live birth rate and multiple pregnancy rate. Secondary outcomes were ovulation rate, clinical pregnancy rate, ovarian hyperstimulation syndrome (OHSS) rate, miscarriage rate, cycle cancellation rate and adverse effects.

MAIN RESULTS

We included five RCTs (with 264 women) comparing gonadotrophins plus metformin versus gonadotrophins. The gonadotrophin used was recombinant FSH in four studies and highly purified FSH in one study. Evidence was of low quality: The main limitations were serious risk of bias due to poor reporting of study methods and blinding of participants and outcome assessors. Live birth Metformin plus FSH was associated with a higher cumulative live birth rate when compared with FSH (odds ratio (OR) 2.31, 95% confidence interval (CI) 1.23 to 4.34; two RCTs, n = 180; I² = 0%; low-quality evidence). This suggests that if the chance of live birth after FSH is assumed to be 27%, then the chance after addition of metformin would be between 32% and 60%. Other pregnancy outcomes Metformin use was associated with a higher ongoing pregnancy rate (OR 2.46, 95% CI 1.36 to 4.46; four RCTs, n = 232; I² = 0%; low-quality evidence) and a higher clinical pregnancy rate (OR 2.51, 95% CI 1.46 to 4.31; five RCTs, n = 264; I² = 0%; low-quality evidence). Multiple pregnancy Results showed no evidence of a difference in multiple pregnancy rates between metformin plus FSH and FSH (OR 0.55, 95% CI 0.15 to 1.95; four RCTs, n = 232; I² = 0%; low-quality evidence) and no evidence of a difference in rates of miscarriage or OHSS. Other adverse effects Evidence was inadequate as the result of limited available data on adverse events after metformin compared with after no metformin (OR 1.78, 95% CI 0.39 to 8.09; two RCTs, n = 91; I² = 0%; very low-quality evidence).

AUTHORS' CONCLUSIONS

Preliminary evidence suggests that metformin may increase the live birth rate among women undergoing ovulation induction with gonadotrophins. At this moment, evidence is insufficient to show an effect of metformin on multiple pregnancy rates and adverse events. Additional trials are necessary before we can provide further conclusions that may affect clinical practice.

The neuroendocrine genesis of polycystic ovary syndrome: A role for arcuate nucleus GABA neurons

Polycystic ovary syndrome (PCOS) is a prevalent and distressing endocrine disorder lacking a clearly identified aetiology. Despite its name, PCOS may result from impaired neuronal circuits in the brain that regulate steroid hormone feedback to the hypothalamo-pituitary-gonadal axis. Ovarian function in all mammals is controlled by the gonadotropin-releasing hormone (GnRH) neurons, a small group of neurons that reside in the pre-optic area of the hypothalamus. GnRH neurons drive the secretion of the gonadotropins from the pituitary gland that subsequently control ovarian function, including the production of gonadal steroid hormones. These hormones, in turn, provide important feedback signals to GnRH neurons via a hormone sensitive neuronal network in the brain. In many women with PCOS this feedback pathway is impaired, resulting in the downstream consequences of the syndrome. This review will explore what is currently known from clinical and animal studies about the identity, relative contribution and significance of the individual neuronal components within the GnRH neuronal network that contribute to the pathophysiology of PCOS. We review evidence for the specific neuronal pathways hypothesised to mediate progesterone negative feedback to GnRH neurons, and discuss the potential mechanisms by which androgens may evoke disruptions in these circuits at different developmental time points. Finally, this review discusses data providing compelling support for disordered progesterone-sensitive GABAergic input to GnRH neurons, originating specifically within the arcuate nucleus in prenatal androgen induced forms of PCOS.

ROLE OF INSULIN SENSITIZERS ON CARDIOVASCULAR RISK FACTORS IN POLYCYSTIC OVARIAN SYNDROME: A META-ANALYSIS

OBJECTIVE

Polycystic ovarian syndrome (PCOS) is associated with an increase in cardiovascular (CV) risk factors such as insulin resistance, with accompanying hyperinsulinemia and hyperlipidemia, which are predisposing factors for type 2 diabetes mellitus and CV disease. The aim of this meta-analysis is to examine the effect of insulin sensitizers on clinical and biochemical features of PCOS and risk factors for CV disease.

METHODS

A systematic literature review was conducted, and randomized controlled clinical trials were identified by a search of bibliographic databases: Medline database (from 1966 forward), EMBASE (January 1985 forward), and Cochrane Central Register of Controlled Trials. Reviews of reference lists further identified candidate trials. Data was independently abstracted in duplicate by 2 investigators using a standardized data-collection form. Articles without a comparison group and randomization allocation were excluded. Reviewers worked independently and in duplicate to determine the methodological quality of trials, then collected data on patient characteristics, interventions, and outcomes.

RESULTS

Of 455 studies, 44 trials were eligible. A random effects model was used. Significant unadjusted results favoring treatment with insulin sensitizers were obtained for body mass index (BMI) (effect size [ES] of 0.58), waist to hip ratio (WHR) (ES of 0.02), low-density-lipoprotein cholesterol (LDL-C) (ES of 0.11), fasting insulin (ES of 2.82), fasting glucose (ES of 0.10), free testosterone (ES of 1.88), and androstenedione level (ES of 0.76).

CONCLUSION

Treatment with insulin sensitizers in women with PCOS results in improvement in CV factors such as BMI, WHR, LDL-C, fasting insulin, glucose, free testosterone, and androstenedione.

Impact of metformin on reproductive tissues: an overview from gametogenesis to gestation

Metformin is an oral anti-hyperglycemic drug that acts as an insulin sensitizer in the treatment of diabetes mellitus type 2. It has also been widely used in the treatment of polycystic ovary syndrome (PCOS) and gestational diabetes. This drug has been shown to activate a protein kinase called 5' AMP-activated protein kinase or AMPK. AMPK is present in many tissues making metformin's effect multi factorial. However as metformin crosses the placenta, its use during pregnancy raises concerns regarding potential adverse effects on the mother and fetus. The majority of reports suggest no significant adverse effects or teratogenicity. However, disconcerting reports of male mouse offspring that were exposed to metformin in utero that present with a reduction in testis size, seminiferous tubule size and in Sertoli cell number suggest that we do not understand the full suite of effects of metformin. In addition, recent molecular evidence is suggesting an epigenetic effect of metformin which could explain some of the long-term effects reported. Nevertheless, the data are still insufficient to completely confirm or disprove negative effects of metformin. The aims of this review are to provide a summary of the safety of metformin in various aspects of sexual reproduction, the use of metformin by gestating mothers, and its possible side-effects on offspring from women who are administered metformin during pregnancy.

Metformin and gonadotropins for ovulation induction in patients with polycystic ovary syndrome: a systematic review with meta-analysis of randomized controlled trials

The current systematic review with meta-analysis of randomized controlled trials (RCTs) was aimed to evaluate the effects of metformin on reproductive outcomes in patients with polycystic ovary syndrome (PCOS) who receive gonadotropins for ovulation induction. After systematic review of electronic databases and websites for registration of RCTs, a total of 7 RCTs reporting data on 1023 cycles were included in the final analysis. Descriptive data showed an overall low studies' quality due to unclear sequence generation and allocation concealment, lack of blinding procedure, incomplete outcome data and several biases and/or confounders. Data synthesis showed that metformin improved live-birth (odds ratio [OR] = 1.94, 95% confidence interval [CI] 1.10 to 3.44; P = 0.020) and pregnancy (OR = 2.25, 95% CI 1.50 to 3.38; P < 0.0001) rates, without significant heterogeneity across the studies (P = 0.230, estimation of inconsistency = 30%; and P = 0.710, estimation of inconsistency = 0%, respectively, for live-birth and pregnancy rates). A significant reduction of cancellation rate was observed after metformin administration (OR = 0.41, 95% CI 0.24 to 0.72, P = 0.002) without significant heterogeneity across the studies (P = 0.500, estimation of inconsistency = 0%). Metformin administration influenced or did not influence other secondary endpoints assessed with a significant heterogeneity. In conclusion, metformin administration increases the live-birth and pregnancy rate in PCOS patients who receive gonadotropins for ovulation induction. Further well designed, blinded, placebo-controlled, and adequately powered RCTs are need to confirm that metanalytic results.

Metformin decreases the incidence of ovarian hyperstimulation syndrome: an experimental study

Background

In assisted reproduction cycles, gonadotropins are administered to obtain a greater number of oocytes. A majority of patients do not have an adverse response; however, approximately 3-6% develop ovarian hyperstimulation syndrome (OHSS). Metformin reduces the risk of OHSS but little is known about the possible effects and mechanisms of action involved.

Objective

To evaluate whether metformin attenuates some of the ovarian adverse effects caused by OHSS and to study the mechanisms involved.

Material and methods

A rat OHSS model was used to investigate the effects of metformin administration. Ovarian histology and follicle counting were performed in ovarian sections stained with Masson trichrome. Vascular permeability was measured by the release of intravenously injected Evans Blue dye (EB). VEGF levels were measured by commercially immunosorbent assay kit. COX-2 protein expression was evaluated by western blot and NOS levels were analyses by immunohistochemistry.

Results

Animals of the OHSS group showed similar physiopathology characteristics to the human syndrome: increased body weight, elevated progesterone and estradiol levels (P<0.001), increased number of corpora lutea (P<0.001), higher ovarian VEGF levels and vascular permeability (P<0.001 and P<0.01); and treatment with metformin prevented this effect (OHSS+M group; P<0.05). The vasoactive factors: COX-2 and NOS were increased in the ovaries of the OHSS group (P<0.05 and P<0.01) and metformin normalized their expression (P<0.05); suggesting that metformin has a role preventing the increased in vascular permeability caused by the syndrome.

Conclusion

Metformin has a beneficial effect preventing OHSS by reducing the increase in: body weight, circulating progesterone and estradiol and vascular permeability. These effects of metformin are mediated by inhibiting the increased of the vasoactive molecules: VEGF, COX-2 and partially NOS. Molecules that are increased in OHSS and are responsible for a variety of the symptoms related to OHSS.

Metformin inhibits follicle-stimulating hormone (FSH) action in human granulosa cells: relevance to polycystic ovary syndrome

BACKGROUND

Women with anovulatory polycystic ovary syndrome (PCOS) are generally insulin-resistant and as a consequence are often treated with the biguanide metformin. Results with metformin have, however, been variable with some studies demonstrating induction of regular cycles and an increase in ovulation, whereas others do not. Hence more understanding is needed regarding the mechanism of metformin's actions in ovarian granulosa cells especially in light of previous demonstrations of direct actions.

OBJECTIVE

The aim of this study was to investigate metformin's interaction with the FSH/cAMP/protein kinase A pathway, which is the primary signaling pathway controlling CYP19A1 (aromatase) expression in the ovary.

METHODS

The effect of metformin on FSH and forskolin-stimulated aromatase expression in human granulosa cells was measured by quantitative real-time PCR. Activity was assessed after transfection with a promoter II-luciferase construct, and by an RIA measuring conversion of androgen to estrogens. The effect on FSH receptor (FSHR) mRNA was assessed by quantitative PCR. Levels of phosphorylated cAMP response element binding protein (CREB) and CREB-regulated transcription coactivator 2 (CRTC2) were measured by Western blotting and cAMP by a bioluminescent assay.

RESULTS

Metformin markedly reduced FSH but not forskolin-stimulated aromatase expression and activity. This effect was exerted by inhibition of basal and ligand-induced up-regulation of FSHR expression. Metformin also reduced FSH-induced phosphorylation of CREB and hence CRE activity, which could potentially disrupt the CREB-CREB-binding protein-CRTC2 coactivator complex that binds to CRE in promoter II of the aromatase gene. This is mediated in an AMP-activated protein kinase-independent manner, and does not involve alteration of cAMP levels.

CONCLUSION

These finding have implications for the use of metformin in the treatment of anovulation in women with PCOS.

Genetic variants associated with insulin signaling and glucose homeostasis in the pathogenesis of insulin resistance in polycystic ovary syndrome: a systematic review

BACKGROUND

Polycystic ovary syndrome must be recognized as a serious issue due to its implication on long term health regardless of an individual's age. PCOS and insulin resistance are interlinked, as approximately 40 % of women with PCOS are insulin resistant. However, the detailed molecular basis for insulin resistance that is coupled with PCOS remains poorly understood.

OBJECTIVE

To review the published evidence that polymorphisms in genes that are involved in insulin secretion and action are associated with an increased risk of PCOS.

METHODS

We reviewed articles published through November 2012 which concerned polymorphisms of genes related to insulin signaling and glucose homeostasis as well as their associations with PCOS. The articles were identified via Medline searches.

CONCLUSIONS

No consistent evidence emerged of a strong association between the risk of PCOS and any known gene that is related to insulin signaling and glucose homeostasis. Moreover, recent genome-wide association studies are inconsistent in identifying the associations between PCOS and insulin metabolism genes. Many of the studies reviewed were limited by heterogeneity in the PCOS diagnosis and by not have having a sufficient number of study participants. Further studies are warranted to determine predisposing risk factors which could modify environmental factors and thus reduce the risk of PCOS. Large genome-wide association studies devoted solely to PCOS will be necessary to identify new candidate genes and proteins that are involved in PCOS risk.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Achieving a successful pregnancy in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a disease of complex and still poorly understood cause and of variable phenotypes. It is characterized by anovulation, hyperandrogenism, and polycystic ovaries. Infertility is commonly present. A variety of methods has been used successfully to achieve pregnancy in women with PCOS. Maintenance of pregnancy is complicated by a higher rate of premature spontaneous abortions and high risk of gestational diabetes, hypertension, and preeclampsia. However, with careful monitoring and treatment, the outcome of pregnancy in most women with PCOS is excellent.

Clinical outcomes of ovulation induction with metformin, clomiphene citrate and human menopausal gonadotrophin in polycystic ovary syndrome

This pilot study evaluated the effects of coadministration of metformin with clomiphene citrate (CC) and human menopausal gonadotrophin (HMG) in women with CC-resistant polycystic ovary syndrome (PCOS). Sixty women with PCOS were randomly assigned to receive 3 months' treatment with metformin or placebo together with CC and HMG. Transvaginal ultrasound was used to monitor follicular development and ovulation was induced by human chorionic gonadotrophin (HCG). The number of dominant follicles, the oestradiol level on the day HCG was given and the amount of HMG required were significantly lower in the metformin group than in the placebo group, whereas the mono-ovulatory rate and pregnancy rate in the third cycle were significantly higher. The cumulative pregnancy rate in the metformin group (43.3%) was higher than in the placebo group (20.0%), but this difference did not reach statistical significance. In conclusion, coadministration of metformin with CC and HMG reduced the amount of HMG required and increased the mono-ovulatory rate and pregnancy rate.

Metformin administration restores allopregnanolone response to adrenocorticotropic hormone (ACTH) stimulation in overweight hyperinsulinemic patients with PCOS

OBJECTIVE

To investigate the adrenal response in terms of allopregnanolone secretion in a group of hyperinsulinemic patients with polycystic ovary syndrome (PCOS).

DESIGN

Controlled clinical study.

SETTING

Patients with PCOS in a clinical research environment.

PATIENTS

Twenty-two overweight patients with PCOS with hyperinsulinism were enrolled after informed consent.

INTERVENTIONS

All patients underwent hormonal evaluations, oral glucose tolerance test (OGTT) and adrenocorticotropic hormone (ACTH) test before and after 4 months of metformin administration (500 mg p.o. bi-daily). Ultrasound examinations and Ferriman-Gallway score were also performed. Main outcome measures. plasma luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin (PRL), estradiol, 17-hydroxy-progesterone (17OHP), androstenedione (A), testosterone (T), allopregnanolone, glucose, insulin, C peptide concentrations, body mass index (BMI).

RESULTS

Metformin administration reduced significantly LH, A, T, insulin and BMI, while allopregnanolone was significantly increased with no change in progesterone plasma levels. Insulin response to OGTT decreased and allopregnanolone response to ACTH stimulation before while this was restored after the treatment interval. The Ferriman-Gallway score as well as the ovarian volume was significantly decreased after 4 months of metformin therapy.

CONCLUSIONS

In overweight patients with PCOS with hyperinsulinism, allopregnanolone secretion is impaired and metformin administration restored normal allopregnanolone concentrations modulating both steroid syntheses from the ovaries and from adrenal gland.

Effect of chronic treatment with Rosiglitazone on Leydig cell steroidogenesis in rats: in vivo and ex vivo studies

BACKGROUND

The present study was designed to examine the effect of chronic treatment with rosiglitazone - thiazolidinedione used in the treatment of type 2 diabetes mellitus for its insulin sensitizing effects - on the Leydig cell steroidogenic capacity and expression of the steroidogenic acute regulatory protein (StAR) and cholesterol side-chain cleavage enzyme (P450scc) in normal adult rats.

METHODS

Twelve adult male Wistar rats were treated with rosiglitazone (5 mg/kg) administered by gavage for 15 days. Twelve control animals were treated with the vehicle. The ability of rosiglitazone to directly affect the production of testosterone by Leydig cells ex vivo was evaluated using isolated Leydig cells from rosiglitazone-treated rats. Testosterone production was induced either by activators of the cAMP/PKA pathway (hCG and dbcAMP) or substrates of steroidogenesis [22(R)-hydroxy-cholesterol (22(R)-OH-C), which is a substrate for the P450scc enzyme, and pregnenolone, which is the product of the P450scc-catalyzed step]. Testosterone in plasma and in incubation medium was measured by radioimmunoassay. The StAR and P450scc expression was detected by immunocytochemistry.

RESULTS

The levels of total circulating testosterone were not altered by rosiglitazone treatment. A decrease in basal or induced testosterone production occurred in the Leydig cells of rosiglitazone-treated rats. The ultrastructural and immunocytochemical analysis of Leydig cells from rosiglitazone-treated rats revealed cells with characteristics of increased activity as well as increased StAR and P450scc expression, which are key proteins in androgen biosynthesis. However, a number of rosiglitazone-treated cells exhibited significant mitochondrial damage.

CONCLUSION

The results revealed that the Leydig cells from rosiglitazone-treated rats showed significant reduction in testosterone production under basal, hCG/dbcAMP- or 22 (R)-OH-C/pregnenolone-induced conditions, although increased labeling of StAR and P450scc was detected in these cells by immunocytochemistry. The ultrastructural study suggested that the lower levels of testosterone produced by these cells could be due to mitochondrial damage induced by rosiglitazone.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH STRATEGY

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

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.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH STRATEGY

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Metformin inhibits aromatase via an extracellular signal-regulated kinase-mediated pathway

Metformin treatment, now widely prescribed in polycystic ovary syndrome, is aimed at correcting the associated insulin resistance, but it has also been shown to directly inhibit ovarian steroidogenesis. The mechanisms, however, by which metformin inhibits estradiol production in human granulosa cells remains unknown. Granulosa luteal cells were incubated with metformin, insulin, or combined metformin and insulin treatment, and aromatase mRNA expression was quantified using real-time RT-PCR. Enzyme activity was assessed by the conversion of (3)H-androstenedione to estrone and estradiol. Metformin's effect on the expression of specific untranslated first exon aromatase promoters was analyzed using semiquantitative PCR. The involvement of MAPK kinase (MEK)/ERK pathway was investigated by immunoblotting for aromatase, phosphorylated, and total ERK-1,2 from cells cultured as above with/without the MEK inhibitor PD98059. Metformin significantly inhibited basal and insulin-stimulated aromatase mRNA expression, with parallel results from the aromatase activity assay and protein assessment. This suppression was via down-regulation of aromatase promoter II, I.3, and 1.4 expression and was reversed by the addition of PD98059. Involvement of the ERK signaling pathway was demonstrated by the significant increase in phosphorylated ERK-1,2 with the combined metformin and insulin treatment. We have shown for the first time in human granulosa cells that metformin signficantly attenuated basal and insulin-stimulated P450 aromatase mRNA expression and activity, via silencing of key promoters. This occurred by activation of MEK/ERK pathway, which negatively regulated aromatase production. This is an important consideration given metformin's widespread use in polycystic ovary syndrome and may further support a possible therapeutic indication in estrogen-dependent breast tumors.