Effects of the insulin sensitizing drug metformin on ovarian function, follicular growth and ovulation rate in obese women with oligomenorrhoea

A novel action of insulin sensitizing drug as a potential promotor of preovulatory follicles, ovulation rate and prolificacy in sheep

The effect of the insulin-sensitizing drug metformin on preovulatory follicle (POF) number, ovulation rate, fetal rate and prolificacy was studied in forty-six cyclic Malpura ewes. After estrus synchronization, the ewes were equally divided into two groups (n = 23). The treatment group (MET) received a daily oral dose of metformin at a rate of 500 mg/animal for approximately 12 weeks, spanning five estrous cycles, as against untreated control (CON). All the ewes were bred to proven rams at the end of treatment. Ovarian ultrasound scans were performed at each estrus and day 9 of each cycle to assess the number and diameter of POFs and corpora lutea (CL), respectively. A comprehensive assessment of circulating hormones including, estradiol, progesterone, androstenedione, and insulin as well as metabolic indicators such as glucose, and lipid profile parameters was performed. At the end of treatment on the day of estrus (E5D0), the treatment showed a stimulatory effect on follicular development with a 53.2% (P < 0.001) increase in the number of POFs. It also increased the ovulation rate by 67.4% (P < 0.01), with a higher proportion (χ2df1 = 10.7, P < 0.001) of ewes in the MET group having multiple ovulations compared to the CON group (82.6 vs. 30.4%). With 1.48 ± 0.12 prolificacy rate in MET ewes, the proportion of ewes giving birth to multiple lambs was 2.9-fold higher than in the CON group. Plasma estradiol, insulin, glucose, total cholesterol, and LDL-cholesterol concentrations were lower (P < 0.05) in the MET ewes than in the CON. The results of the present study indicate that metformin can increase the number of POF, ovulation rate, fetal rate and prolificacy in ewes, while reducing the plasma estradiol, insulin, glucose and cholesterol in MET ewes.

The effects of metformin on stereological and ultrastructural features of the ovary in streptozotocin -induced diabetes adult rats: An experimental study

Background

Diabetes is a chronic disease that can affect almost all of the body organs, including male and female reproductive systems.

Objective

This study was designed to investigate the preventive effects of metformin on stereological and ultrastructure characteristics of the ovary in the streptozotocin-induced diabetes adult female rats.

Materials and Methods

Seventy adult (8-10 wk) female Sprague-Dawley rats (180-200 gr) were equally divided, as follows: (n = 10/each) control; STZ-induced diabetes (single dose of 65 mg/kg STZ, IP); metformin-treated (50 mg/100 gr of body weight, orally); diabetic-metformin-treated; sham 1, (single dose of sodium citrate); sham 2, (0.5 ml of daily oral distilled water); and sham 3, (sodium citrate + distilled water treated). The body mass index, ovarian weight, blood sugar level, cholesterol, and triglyceride were measured. The stereological and ultrastructural features of ovary were assessed.

Results

The blood sugar of induced-diabetic rats was increased (p < 0.01). The BMI (p < 0.01), number of granulosa cells (p = 0.04), primordial, primary and secondary follicles (p = 0.03), total volume of ovary (p < 0.01) and cortex, nucleus diameter ratio to the ooplasm were decreased. The number of atretic follicles in the diabetic and diabetic + metformin-treated rats were increased (p < 0.01). The ultrastructural characteristics of ovary were more damaged in diabetic rats.

Conclusion

Diabetes has destructive effects on ovarian follicles and causes follicular atresia. Also, the size of oocytes, numbers of granulosa cells and ooplasmic organelles, which are involved in the folliculogenesis are affected by diabetes and metformin has no preventive effects.

Can Antidiabetic Drugs Improve Male Reproductive (Dys)Function Associated with Diabetes?

The alarming increase in the number of diabetic patients worldwide raises concerns regarding the impact of the disease on global health, not to mention on social and economic aspects. Furthermore, the association of this complex metabolic disorder with male reproductive impairment is worrying, mainly due to the increasing chances that young individuals, at the apex of their reproductive window, could be affected by the disease, further contributing to the disturbing decline in male fertility worldwide. The cornerstone of diabetes management is glycemic control, proven to be effective in avoiding, minimizing or preventing the appearance or development of disease-related complications. Nonetheless, the possible impact of these therapeutic interventions on male reproductive function is essentially unexplored. To address this issue, we have made a critical assessment of the literature on the effects of several antidiabetic drugs on male reproductive function. While the crucial role of insulin is clear, as shown by the recovery of reproductive impairments in insulin-deficient individuals after treatment, the same clearly does not apply to other antidiabetic strategies. In fact, there is an abundance of controversial reports, possibly related to the various study designs, experimental models and compounds used, which include biguanides, sulfonylureas, meglitinides, thiazolidinediones/glitazones, bile acid sequestrants, amylin mimetics, as well as sodiumglucose co-transporter 2 (SGLT2) inhibitors, glucagon-like peptide 1 (GLP1), α-glucosidase inhibitors and dipeptidyl peptidase 4 (DPP4) inhibitors. These aspects constitute the focus of the current review.

Association between duration of obesity and severity of ovarian dysfunction in rat-cafeteria diet approach

Consumption of unhealthy, energy-dense palatable food during early age leads to obesity in children and the onset of obesity during childhood has a profound effect on the reproductive health of women. In this study, the mechanism underlying diet-induced obesity on ovarian dysfunction was studied by exposing rats to cafeteria diet (CAFD) for two different durations. For that purpose, 21-day-old female Sprague Dawley rats were fed ad libitum with a standard diet (control group) and a cafeteria diet (CAFD group) for a period of 20 weeks (20 W) and 32 weeks (32 W). We observed obesity, hyperglycemia, hyperlipidemia, hyperleptinemia and hypoadiponectinemia in CAFD fed groups. Hyperinsulinemia, hypergonadotrophism, hypertestosteronemia and hyperprogesteronemia were observed in the 20 W-CAFD group. Conversely, in the 32 W-CAFD group hypersecretion declined to hyposecretion. The levels of estradiol remained low during both time periods. The duration of estrous cycle was extended in the CAFD fed rats. The ovary weight was higher in the 20 W-CAFD fed rats but it was drastically reduced over a longer duration cafeteria diet feeding. In the 20 W-CAFD fed rats, the protein levels of LHR, StAR, CYP11A1, 3β-HSD and 17β-HSD were increased but FSHR and CYP19A1 levels were decreased in the ovary. On the other hand, gonadotropin receptor and the protein levels of steroidogenic enzymes were decreased in the ovary of 32 W-CAFD fed rats. We conclude that the duration of energy-dense diet consumption has differential regulatory mechanism in altering the ovarian steroid production. In 20 W-CAFD fed rats, hypergonadotropic condition was observed whereas, 32 W-CAFD consumption induced hypogonadotropic hypogonadism.

Antidiabetic therapies and male reproductive function: where do we stand?

Diabetes mellitus has been increasing at alarming rates in recent years, thus jeopardizing human health worldwide. Several antidiabetic drugs have been introduced in the market to manage glycemic levels, and proven effective in avoiding, minimizing or preventing the appearance or development of diabetes mellitus-related complications. However, and despite the established association between such pathology and male reproductive dysfunction, the influence of these therapeutic interventions on such topics have been scarcely explored. Importantly, this pathology may contribute toward the global decline in male fertility, giving the increasing preponderance of diabetes mellitus in young men at their reproductive age. Therefore, it is mandatory that the reproductive health of diabetic individuals is maintained during the antidiabetic treatment. With this in mind, we have gathered the available information and made a critical analysis regarding the effects of several antidiabetic drugs on male reproductive function. Unlike insulin, which has a clear and fundamental role on male reproductive function, the other antidiabetic therapies' effects at this level seem incoherent. In fact, studies are highly controversial possibly due to the different experimental study approaches, which, in our opinion, suggests caution when it comes to prescribing such drugs to young diabetic patients. Overall, much is still to be determined and further studies are needed to clarify the safety of these antidiabetic strategies on male reproductive system. Aspects such as the effects of insulin levels variations, consequent of insulin therapy, as well as what will be the impact of the side effect hypoglycemia, common to several therapeutic strategies discussed, on the male reproductive system are still to be addressed.

Metformin therapy for the reproductive and metabolic consequences of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS), the most common hormonal disorder among women of reproductive age, has various metabolic and reproductive consequences. Metformin was originally shown to lower testosterone levels in women with PCOS in the 1990s, an effect presumably related to its insulin sensitising actions. However, the precise mechanisms of metformin action in PCOS remain unclear and there is considerable heterogeneity in the clinical response to this therapy in women with PCOS. Recent evidence indicates that genetic factors may play a significant role in predicting response to metformin therapy in PCOS and future studies are needed to further identify women who are most likely to benefit from this therapy. At present, there is no clear evidence to support broad metformin use in PCOS. Well-designed prospective trials are needed to establish clear benefit for metformin use in the treatment of the reproductive and metabolic consequences associated with PCOS.

Therapeutic effects of metformin and laparoscopic ovarian drilling in treatment of clomiphene and insulin-resistant polycystic ovary syndrome

OBJECTIVE

To compare the therapeutic effects of metformin (Met) and laparoscopic ovarian drilling (LOD) in clomiphene and insulin-resistant patients with polycystic ovary syndrome (CIRPCOS).

METHODS

A total of 110 patients were randomly divided into two groups. One group was administered Met (n = 55), while the other group underwent LOD (n = 55). Rates of ovulation, pregnancy, and abortion were compared between both groups.

RESULTS

Rates of normal menstruation, ovulation, and pregnancy in the LOD group were higher than in the Met group: 76.4% (42/55) vs. 58.2% (32/55), P < 0.04; 50.8% (11/258) vs. 33.5% (94/281), P < 0.001; 38.2% (21/55) vs. 20.0% (11/55), P < 0.03. The difference in the early abortion rate between both groups was not statistically significant.

CONCLUSIONS

Although Met can significantly improve a patient's insulin resistance, we found that in patients diagnosed with CIRCPOS, LOD can be much more effective in improving rates of normal menstruation, ovulation, and pregnancy.

Metformin induces a prompt decrease in LH-stimulated testosterone response in women with PCOS independent of its insulin-sensitizing effects

BACKGROUND

The use of insulin-sensitizing drugs has been shown to improve both the reproductive and the metabolic aspects of PCOS. However, the mechanisms by which metformin exerts its effects in PCOS are still not completely understood. There is growing evidence of a direct effect of metformin on ovarian steroidogenesis, independent of its effects on insulin sensitivity.

METHODS

We evaluated the short-term effects of metformin compared to placebo on basal and LH- stimulated androgen secretion as well as on hormonal and metabolic parameters in 19 women with PCOS during a four-day randomized, double-blinded placebo-controlled clinical trial. In a three month follow-up evaluation, we investigated the longer-term therapeutic effects of metformin on ovulation, metabolic and endocrine parameters.

RESULTS

Compared to placebo, 2 days of metformin was associated with a borderline significant reduction in the free androgen index (FAI) (p = 0.05) and with a reduction in the serum concentration of LH-stimulated testosterone (T) (p = 0.03). Following three months of use, a decline in serum T was observed, independent of changes in weight, metabolic parameters, or insulin sensitivity.

CONCLUSIONS

In women with PCOS, Metformin induces a prompt decrease in LH-stimulated T secretion after only several days of use. This action precedes the medication's effects on insulin sensitivity or weight loss.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Long versus short course treatment with metformin and clomiphene citrate for ovulation induction in women with PCOS

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy among reproductive-aged women. Apart from infertility, women with PCOS often have other endocrine disorders, including insulin resistance, hyperinsulinaemia and hyperandrogenism. Metformin,combined with clomiphene citrate (CC), has been shown to be more effective in ovulation induction when compared with clomiphene citrate alone. The optimal duration for metformin pretreatment before initiation of clomiphene citrate, however, is unknown.

OBJECTIVES

To determine the effectiveness of short-course (less than four weeks) metformin plus CC versus long-course (four weeks or more) metformin plus CC with regard to ovulation and achievement of pregnancy in infertile women with PCOS.

SEARCH METHODS

We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register, the Cochrane Central Register of Controlled Trials, MEDLINE, CINAHL, EMBASE and PsycINFO (all from inception to 1 February 2012).

SELECTION CRITERIA

Randomised controlled trials comparing short-course (less than four weeks) metformin plus CC versus long-course (four weeks or more) metformin plus CC for ovulation or achievement of pregnancy in infertile women with PCOS.

DATA COLLECTION AND ANALYSIS

No trials were found that met the selection criteria.

MAIN RESULTS

No randomised controlled trials were identified.

AUTHORS' CONCLUSIONS

There are insufficient data to determine whether short-course metformin pretreatment is as effective as the conventional long-course metformin pretreatment before initiation of clomiphene citrate for ovulation induction in infertile women with PCOS. A well-designed randomised controlled trial is needed to answer this important clinical question.

Efficacy of 2-hour post glucose insulin levels in predicting insulin resistance in polycystic ovarian syndrome with infertility

BACKGROUND:

Insulin resistance (IR) is central to the pathogenesis of polycystic ovarian syndrome (PCOS), but tests for determining IR are elaborate, tedious and expensive.

AIMS:

To evaluate if “2-hour post-glucose insulin level” is an effective indicator of IR and can aid in diagnosing IR in infertile PCOS women.

SETTINGS AND DESIGN:

Observational study at infertility clinic of a tertiary care center.

MATERIALS AND METHODS:

50 infertile women with PCOS and 20 females with tubal/male factor infertility were evaluated for the presence of IR, as defined by the fasting/2-hour post-glucose insulin levels cutoffs of >25/>41 μU/mL, respectively. The clinical, metabolic and endocrinologic profile was determined in both the groups.

STATISTICAL ANALYSIS:

Statistical analysis was performed using SPSS (Chicago, IL, USA).

RESULTS:

Body mass index, post load glucose, insulin, glucose/insulin ratio, area under curve (AUC) of glucose and insulin and insulinogenic index were significantly lower in the controls as compared to the PCOS group. “2-hour post-glucose insulin levels” were elevated in 88% of PCOS individuals but were normal in all females not suffering from PCOS. These levels significantly correlated with AUC of glucose and insulin, and insulinogenic index and inversely correlated with 2-hour glucose to insulin ratio (r=0.827, 0.749 and –0.732, respectively).

CONCLUSIONS:

“2-hour post-glucose insulin levels” appears to be a good indicator of IR. It can be a useful tool, especially in low resource setting where a single sample can confirm the diagnosis, thus reducing cost and repeat visits.

Phosphorylation and activation of AMP-activated protein kinase (AMPK) by metformin in the human ovary requires insulin

Metformin is commonly used to treat women with polycystic ovary syndrome, but its precise mechanism of action is unclear, and it even appears to have direct ovarian effects. At the cellular level, it may act either via an insulin-dependent pathway or an independent pathway by activating AMP-activated protein kinase (AMPK). In the ovary, metformin directly decreased estradiol and progesterone production by human granulosa cells, and inhibition of progesterone production by metformin in rat granulosa cells caused an increase in phosphorylated AMPK (pAMPK). We investigated whether metformin activates AMPK in the human ovary by looking for changes in phosphorylation of AMPK and its downstream target acetyl CoA carboxylase (ACC). mRNA and protein for α1 and α2 AMPK subunits were present in all human ovarian tissue. Neither 100 nm nor 2 mm of metformin affected subunit expression. After 1 or 4 h, neither dose of metformin increased pAMPK or pACC, although after 1 h, the addition of insulin significantly enhanced pAMPK, whereas insulin alone had no effect on phosphorylation of either AMPK or ACC. The addition of compound C, an inhibitor of AMPK, negated the effect of metformin in the presence of insulin on pAMPK. This effect on AMPK was not due to a change in the ADP/ATP ratio measured by HPLC. In summary, the presence of insulin was required to cause a metformin-induced increase in pAMPK in these human ovarian cells. Although previous data suggest that metformin may act via an insulin-independent pathway, our results therefore imply that insulin may be required to initiate an effect.

Short-term metformin treatment for clomiphene citrate-resistant women with polycystic ovary syndrome

OBJECTIVE

To evaluate the effect of a short-course pretreatment with metformin on hyperandrogenism, insulin resistance, cervical scores, and pregnancy rates in women with clomiphene citrate (CC)-resistant polycystic ovary syndrome (PCOS).

METHODS

Thirty-seven women with CC-resistant PCOS were randomly assigned to be pretreated with 500 mg of metformin or placebo 3 times per day for 2 cycles, and 100 mg of CC was given on days 5 through 9 of the second cycle in both groups. Luteinizing hormone (LH), follicle stimulating hormone (FSH), dehydroepiandrostendione sulfate (DHEAS), total testosterone (T), glucose, and insulin levels were measured at baseline and after the first cycle, as well as body mass index (BMI), cervical score, and pregnancy rate.

RESULTS

After 1 cycle, BMI, total T level, and percentage of participants with insulin resistance were significantly decreased in the metformin group, without any significant decrease in LH, FSH, and DHEAS levels; and in the second cycle, CC treatment resulted in a higher ovulation rate and a thicker endometrium in the metformin group. The pregnancy rate and cervical scores were also higher in that group.

CONCLUSION

The short-course pretreatment with metformin decreased hyperandrogenism and insulin resistance and improved cervical sores, ovulation rate, and pregnancy rate among women with CC-resistant PCOS.

Assessment of genomic instability in normal and diabetic rats treated with metformin

To examine if a single or multiple oral administration of metformin, a member of the biguanide class of anti-diabetic agents, has any genotoxic and cytotoxic potential in normal and diabetic rats, a mammalian model, cytogenetic assays through several endpoints such as induction of micronuclei, chromosome aberrations, mitotic activity of bone marrow cells, sperm-head anomaly and assays of some oxidative stress markers have been conducted by the use of standard techniques. Diabetes was induced by streptozotocin injection. Metformin was administrated to both diabetic and non-diabetic rats in single doses of 100, 500 or 2500 mg/kg along with vehicle control groups for diabetic and non-diabetic rats. The animals were killed by cervical dislocation at 24h after treatment, and then bone marrow cells were sampled. Also, a multiple dose study has done in which diabetic and non-diabetic animals were treated with 100 or 500 mg/kg of metformin daily for 4 or 8 weeks after which the animals were killed by cervical dislocation, and then bone marrow and sperm cells were collected. Concurrent control groups were also included in each experiment. The obtained results revealed that metformin was neither genotoxic nor cytotoxic for the rats in all groups at all tested doses. Moreover, metformin significantly reduced the diabetes-induced genomic instability and cell proliferation changes in somatic and germinal cells in a dose-dependent manner (2500, 500, >100mg/kg). In addition, diabetes induced marked biochemical alterations characteristic of oxidative stress including, enhanced lipid peroxidation and reduction in the reduced glutathione level. Treatment with metformin ameliorated these biochemical markers. In conclusion, metformin is a non-genotoxic or cytotoxic compound and may protect from genomic instability induced by hyperglycemia. Apart from its well-known anti-diabetic effect, the antigenotoxic effect of metformin could be possibly ascribed to its radical scavenger effect that modulated the genomic instability responses and cell proliferation changes induced by hyperglycemia.

Abdominal fat accumulation, and not insulin resistance, is associated to oligomenorrhea in non-hyperandrogenic overweight/obese women

BACKGROUND

There is a very high prevalence of obese women in the infertile population and many studies have highlighted the link between obesity and infertility. The aim of this study was to evaluate the prevalence of oligomenorrhea in uncomplicated obesity, and to examine whether this menstrual alteration is associated with anthropometric, hormonal, and metabolic parameters.

PATIENTS AND METHODS

This is a cross-sectional study of 266 overweight and obese body mass index (BMI) > or =25.0 kg x m(-2)] women, all having apparent normal fertility. Measurements included BMI, central fat accumulation (evaluated by waist circumference), blood pressure levels, and fasting insulin, glucose, and lipid (triglycerides, total and HDL-cholesterol) serum concentrations, and insulin resistance [estimated by (homeostasis model assessment) HOMAIR] during the early follicular phase (days 2-5 of the menstrual cycle).

RESULTS

One hundred and seventy-one (64.3%) of 266 women had normal menstrual cycles, 57 (21.4%) had oligomenorrhea, and 38 (14.3%) had hypermenorrhea and/or polimenorrhea. Women with oligomenorrhea had higher waist circumference, BMI, HOMAIR, and insulin levels than women with normal menstrual cycles. When association among oligomenorrhea and other variables (waist circumference, BMI, insulin and HOMAIR) was evaluated by logistic regression, and odds ratio was calculated per unit of SD increase, only waist circumference maintained a significant relationship with oligomenorrhea.

CONCLUSIONS

This study shows that more than 20% of women with simple obesity have oligomenorrhea, and suggests that central fat accumulation seems to have a possible direct role in this menstrual alteration, independently of hyperinsulinemia and/or insulin resistance.

An RCT of metformin versus orlistat for the management of obese anovulatory women

BACKGROUND

Treatment of obesity-related anovulation poses a significant clinical challenge. Occasionally, the use of antiobesity medications such as orlistat or insulin sensitizing agents such as metformin is sometimes indicated in these patients. This study aimed to compare the effects of metformin and orlistat for improving ovulation in obese anovulatory women.

METHODS

This was an open-label RCT. A total of 40 women were randomized to receive either metformin (n = 20) or orlistat (n = 20). BMI as well as the androgen profile and the ovulatory status were assessed at baseline and at four weekly intervals for 3 months. Different anthropometric and endocrine parameters were also assessed as possible predictors of ovulation.

RESULTS

There was no significant difference between the two study arms regarding the ovulation rate for metformin and orlistat [40% (n = 8/20) and 25% (n = 5/20), respectively, P = 0.31]. Both arms showed a significant drop in the BMI, testosterone and androstendione concentrations (P < 0.05), but there was no difference between the two arms. Patients who ovulated had significantly lower concentrations of baseline LH, androstendione, dehydroepiandrosterone and free androgen index (P < 0.05). Among these factors, a low baseline LH was found to be the only independent predictor of ovulation (area under curve, 0.85).

CONCLUSIONS

Both metformin and orlistat show a similar effect on weight loss, ovulation rates and androgen concentrations. However, the effects on ovulation rates need to be confirmed in larger studies. The presence of a low baseline serum LH was found to be the most important predictor of ovulation. The study was registered at clinicaltrials.gov. NCT00292799.

Extended-release metformin does not reduce the clomiphene citrate dose required to induce ovulation in polycystic ovary syndrome

CONTEXT

When used for ovulation induction, higher doses of clomiphene may lead to antiestrogenic side effects that reduce fecundity. It has been suggested that metformin in combination with clomiphene can restore ovulation to some clomiphene-resistant anovulators with polycystic ovary syndrome (PCOS).

OBJECTIVE

Our objective was to determine if cotreatment with extended-release metformin (metformin XR) can lower the threshold dose of clomiphene needed to induce ovulation in women with PCOS.

DESIGN

A secondary analysis of data from the National Institute of Child Health and Human Development Cooperative Multicenter Reproductive Medicine Network prospective, double-blind, placebo-controlled multicenter clinical trial, Pregnancy in Polycystic Ovary Syndrome, was performed.

SETTING

Study volunteers at multiple academic medical centers were included.

PARTICIPANTS

Women with PCOS and elevated serum testosterone who were randomized to clomiphene alone or with metformin (n = 209 in each group) were included in the study.

INTERVENTIONS

Clomiphene citrate, 50 mg daily for 5 d, was increased to 100 and 150 mg in subsequent cycles if ovulation was not achieved; half also received metformin XR, 1000 mg twice daily. Treatment was for up to 30 wk or six cycles, or until first pregnancy.

MAIN OUTCOME MEASURES

Ovulation was confirmed by a serum progesterone more than or equal to 5 ng/ml, drawn prospectively every 1-2 wk.

RESULTS

The overall prevalence of at least one ovulation after clomiphene was 75 and 83% (P = 0.04) for the clomiphene-only and clomiphene plus metformin groups, respectively. Using available data from 314 ovulators, the frequency distribution of the lowest clomiphene dose (50, 100, or 150 mg daily) resulting in ovulation was indistinguishable between the two treatment groups.

CONCLUSION

Metformin XR does not reduce the lowest dose of clomiphene that induces ovulation in women with PCOS.

Long versus short course treatment with Metformin and Clomiphene Citrate for ovulation induction in women with PCOS

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common endocrinopathy among reproductive-aged women. Apart from infertility, women with PCOS often have other endocrine disorders, including insulin resistance,hyperinsulinaemia and hyperandrogenism. Metformin,combined with clomiphene citrate (CC), has been shown to be more effective in ovulation induction when compared with clomiphene citrate alone. The optimal duration for metformin pretreatment before initiation of clomiphene citrate, however, is unknown.

OBJECTIVES

To determine the effectiveness of short-course (less than four weeks) metformin plus CC versus long-course (four weeks or more) metformin plus CC with regard to ovulation and achievement of pregnancy in infertile PCOS women.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group Trials Register (December 2006), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2006, 2006 issue 4), MEDLINE (1950 to 7 January 2007), CINAHL (1982 to December 2006) and EMBASE (1980 to 7 January 2007).

SELECTION CRITERIA

Randomised controlled trials comparing short-course (less than four weeks) metformin plus CC versus long-course (four weeks or more) metformin plus CC for ovulation or achievement of pregnancy in infertile PCOS women.

DATA COLLECTION AND ANALYSIS

No trials were found that met the selection criteria.

MAIN RESULTS

No randomised controlled trials were identified.

AUTHORS' CONCLUSIONS

There are insufficient data to determine whether short-chouse metformin pretreatment is as effective as the conventional long-course metformin pretreatment before initiation of clomiphene citrate for ovulation induction in infertile PCOS patients. A well-designed randomised controlled trial is needed to answer this important clinical question.

Comparison of clomiphene citrate, metformin, or the combination of both for first-line ovulation induction and achievement of pregnancy in 154 women with polycystic ovary syndrome

OBJECTIVE

To determine which first-line medication is more effective in polycystic ovary syndrome (PCOS) patients for ovulation induction and pregnancy achievement and to verify whether any patient characteristic is associated with a better response to therapy.

DESIGN

Observational comparative study.

SETTING

Fertility clinic.

PATIENT(S)

One hundred fifty-four infertile women with oligomenorrhea and hyperandrogenism.

INTERVENTION(S)

Group 1 (56 patients) received clomiphene citrate (CC) 50 mg from days 5-9 of the cycle. Group 2 (57 patients) received 500 mg of metformin 3 times a day. Group 3 (41 patients) received both medications.

MAIN OUTCOME MEASURE(S)

Ovulation and pregnancy.

RESULT(S)

Patients receiving metformin alone had an increased ovulation rate compared with those receiving CC alone (75.4% vs. 50%). Patients on metformin had similar ovulation rates compared with those in the combination group (75.4% vs. 63.4%). Pregnancy rates were equivalent in the 3 groups. Response to metformin was independent of body weight and dose. Finally, nonsmoking predicted better ovulatory response overall as well as lower fasting glucose for CC and lower androgens for metformin.

CONCLUSION(S)

Metformin is better for ovulation induction than CC alone and equivalent for pregnancy achievement. We suggest that metformin can be used first for ovulation induction in patients with PCOS regardless of their weight and insulin levels because of its efficacy and known safety profile.

Effects of metformin on inappropriate LH release in women with polycystic ovarian syndrome and insulin resistance

The role of hyperinsulinaemia in neuroendocrine abnormalities in polycystic ovarian syndrome (PCOS) is controversial. The present study applied frequent blood sampling to assess the response of LH to metformin treatment in insulin-resistant women with PCOS. Thirteen predominantly overweight women with PCOS were studied before and after treatment with 1.5 g/day metformin for 3 months. Serum LH and testosterone were measured every 10 min for 10 h; LH was measured for an additional 2 h after gonadotrophin-releasing hormone (GnRH) administration. LH pulses were characterized by cluster analysis, secretory LH episodes by a deconvolution procedure, and synchronicity of paired LH-testosterone concentrations by lag-specific cross-correlation. After treatment, basal LH concentrations, amplitude of LH pulses, LH secretory amplitude, response to exogenous GnRH, and basal testosterone concentrations significantly decreased in seven patients, whereas in the remaining women these parameters remained unaltered. Before treatment, decreased coordinate LH and testosterone release was manifested by all patients; metformin treatment led to re-establishment of the feed-back control of testosterone on LH secretory rates by -20 to 0 min. Treatment did not modify the glucose:insulin ratio or serum insulin concentrations. In conclusion, administration of metformin allowed the identification of two subsets of PCOS women in whom neuroendocrine abnormalities may improve independently of the presence of insulin resistance or hyperinsulinaemia.

Two weeks of metformin improves clomiphene citrate-induced ovulation and metabolic profiles in women with polycystic ovary syndrome

OBJECTIVE

To determine if short courses of metformin (MET) administration in patients with polycystic ovary syndrome (PCOS) would reduce fasting insulin and improve the efficacy of clomiphene citrate (CC) to induce ovulation.

DESIGN

A randomized prospective trial involving 31 subjects with PCOS and infertility.

SETTING

University-based medical center.

PATIENT(S)

Obese patients (body mass index > 29 kg/m2) with PCOS.

INTERVENTION(S)

Patients with PCOS were treated either with CC or CC+MET for 2 weeks.

MAIN OUTCOME MEASURE(S)

Ovulation as determined by serum P, serum insulin, and total and free T.

RESULT(S)

In the CC/MET group, a significant increase in sex hormone-binding globulin (SHBG) levels, a decrease in fasting insulin, and an increase in fasting glucose/fasting insulin was detected on day 21 of the cycle. Of these parameters, only SHBG levels increased significantly in the CC group. In the CC/MET group, a significant increase in day 21 progesterone occurred, with 44% of subjects ovulating in the CC+MET group as compared with 6.7% in the CC group. Five subjects in the CC+MET group and none in the CC group conceived. Total and free testosterone levels did not change significantly for either group.

CONCLUSION(S)

In obese PCOS patients, 2 weeks of MET significantly reduces serum insulin and insulin resistance and increases SHBG levels, resulting in an improved response to CC. This regimen may be beneficial in noncompliant patients or those with intolerance to the side effects of MET.

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.

Ultra-short metformin pretreatment for clomiphene citrate-resistant polycystic ovary syndrome

OBJECTIVE

To evaluate the effect of ultra-short (12 days) metformin pretreatment in clomiphene-citrate (CC) resistant polycystic ovary syndrome (PCOS).

METHOD

Eighty women with CC-resistant PCOS were randomly allocated to metformin pretreatment or usual treatment. Forty women received 1500 mg metformin daily for 12 days, followed by clomiphene 150 mg daily for 5 days along with metformin. Forty women (control group) received the same dose of clomiphene but no metformin pretreatment.

RESULTS

In the metformin group, 17 (42.5%) women ovulated, and 6 (15%) conceived. In the control group, 5 (12.5%) women ovulated but none conceived. Compared with the control group, the metformin group had significantly higher ovulation (P = 0.03) and pregnancy rates (P = 0.026).

CONCLUSION

Twelve days of metformin pretreatment improves ovulation and pregnancy rates in women with CC-resistant PCOS.

Combined lifestyle modification and metformin in obese patients with polycystic ovary syndrome. A randomized, placebo-controlled, double-blind multicentre study

BACKGROUND

It has been reported that women with polycystic ovary syndrome (PCOS) benefit from metformin therapy.

METHODS

A randomized, placebo-controlled, double-blind study of obese (body mass index >30 kg/m2), oligo-/amenorrhoeic women with PCOS. Metformin (850 mg) twice daily was compared with placebo over 6 months. All received the same advice from a dietitian. The primary outcome measures were: (i) change in menstrual cycle; (ii) change in arthropometric measurements; and (iii) changes in the endocrine parameters, insulin sensitivity and lipid profile.

RESULTS

A total of 143 subjects was randomized [metformin (MET) = 69; placebo (PL) = 74]. Both groups showed significant improvements in menstrual frequency [median increase (MET = 1, P < 0.001; PL = 1, P < 0.001)] and weight loss [mean (kg) (MET = 2.84; P < 0.001 and PL = 1.46; P = 0.011)]. However, there were no significant differences between the groups. Logistic regression analysis was used to analyse the independent variables (metformin, percentage of weight loss, initial BMI and age) in order to predict the improvement of menses. Only the percentage weight loss correlated with an improvement in menses (regression coefficient = 0.199, P = 0.047, odds ratio = 1.126, 95% CI 1.001, 1.266). There were no significant changes in insulin sensitivity or lipid profiles in either of the groups. Those who received metformin achieved a significant reduction in waist circumference and free androgen index.

CONCLUSIONS

Metformin does not improve weight loss or menstrual frequency in obese patients with PCOS. Weight loss alone through lifestyle changes improves menstrual frequency.

Metabolic and ovarian effects of rosiglitazone treatment for 12 weeks in insulin-resistant women with polycystic ovary syndrome

BACKGROUND

Insulin sensitizers have favourable metabolic and ovarian effects in polycystic ovary syndrome (PCOS). This study examined rosiglitazone, a thiazolidinedione, in PCOS.

METHODS

In a prospective, open-label study, the effects of rosiglitazone on metabolism and ovarian function were examined in 42 non-diabetic women with PCOS classified according to the National Institute of Child Health and Human Development criteria and insulin resistance (IR) by steady-state plasma glucose (SSPG) > or =10 mmol/l on octreotide-modified insulin suppression testing. Participants were randomized to rosiglitazone 2, 4 or 8 mg daily for 12 weeks. Endpoints included ovulation and menstrual pattern; serum testosterone, sex hormone-binding globulin (SHBG), and LH; and changes in IR and glucose-insulin responses on 8 h mixed-meal profile.

RESULTS

After rosiglitazone 8 mg daily for 12 weeks, SSPG declined and insulinaemia fell by 46%; lower doses gave lesser effects. Serum LH, total and free testosterone were unchanged; SHBG increased. With rosiglitazone, ovulation occurred in 23/42 women (55%), without significant dose dependence. Both before and during treatment, ovulators on rosiglitazone had lower circulating insulin and free testosterone and higher SHBG than non-ovulators. Testosterone declined only in a subgroup of ovulators with early vaginal bleeding after starting rosiglitazone.

CONCLUSIONS

Rosiglitazone in insulin-resistant PCOS promoted ovulation and dose-dependently decreased IR and insulinaemia; ovulators had lower circulating insulin and testosterone.

Does metformin induce ovulation in normoandrogenic anovulatory women?

OBJECTIVE

This study was undertaken to evaluate the efficacy of metformin in women with anovulation who do not have evidence for hyperandrogenism and classic polycystic ovary syndrome.

STUDY DESIGN

A randomized trial of metformin (1500 mg daily) and placebo in 24 anovulatory women was undertaken for 3 months. Assessments of changes in hormone levels and insulin sensitivity were carried out. Abnormal hormonal values were defined by levels exceeding the range in normal ovulatory controls.

RESULTS

Anovulatory women had normal androgen levels and luteinizing hormone but had higher serum insulin and lower insulin sensitivity compared with controls. Over 3 months, there were 16 ovulatory cycles with metformin and only 4 with placebo ( P < .05). Success of ovulation did not correlate with changes in androgen, insulin, or insulin sensitivity parameters.

CONCLUSION

Metformin may be useful for inducing ovulation in anovulatory women who do not have hyperandrogenism. This effect may be independent of a lowering of androgen or insulin levels.

Efficacy of metformin on ovulation induction in Asian women with polycystic ovary syndrome

The aim of this study was to assess the efficacy of metformin on induction of ovulation in Asian women with clomiphene citrate (CC)-resistant polycystic ovary syndrome (PCOS). Twenty PCOS women who did not respond to CC were enrolled in the study. All received 500-1500 mg/day of metformin for 4 weeks. If no dominant follicle was observed with monitoring by transvaginal ultrasound, 50-150 mg of CC per day for 5 days were added. Timing of sexual intercourse was determined or intrauterine insemination was carried out 36 h after administration of human chorionic gonadotropin. A total of six cycles, pregnancy or anovulation despite taking 150 mg of CC were considered as completion of the study. Blood samples were obtained before and at the end of the 4th week of treatment for hormonal assay. Ovulation was observed in 68 (89.5%) of 76 cycles, of which 34 (44.7%) occurred with metformin alone. Twelve women conceived; therefore, the pregnancy rate was 17.6% per ovulated cycle and 60% per woman. One (8.3%) had an abortion. Four women had minimal adverse effect, but one experienced a severe gastrointestinal effect during the fourth cycle. Insulin and androstenedione levels were significantly decreased after 4 weeks of treatment. In conclusion, these series demonstrated the excellent efficacy of metformin on induction of ovulation and pregnancy in Asian women with CC-resistant PCOS.

Is ovulation induction still a therapeutic problem in patients with polycystic ovary syndrome?

Polycystic ovary syndrome (PCOS) is one of the most common endocrine diseases affecting women of fertile age, and is characterized by hyperandrogenism, chronic anovulatory cycles and oligomenorrhea or amenorrhea. Given the repercussions of chronic anovulation on sterility, PCOS is a heavy social burden. Here we describe the procedures used to induce ovulation in PCOS patients, the surgical approach and medical treatments that are still being experimented.

Polycystic ovarian syndrome: diagnosis and management

Polycystic ovarian syndrome (PCOS) affects 4% to 12% of women of reproductive age. The lack of well-defined diagnostic criteria makes identification of this common disease confusing to many clinicians. Also, with the varied manifestations of the disorder a patient may present to any one of several providers: an internist, family practitioner, nurse practitioner, pediatrician, gynecologist, dermatologist, or endocrinologist. Furthermore, the most distressing aspect of PCOS for any given patient may change over time, from hirsutism as a teenager to infertility as a young adult--potentially requiring several different providers along the way. It is important, therefore, that those caring for these patients understand not only the management issues pertinent to their specialty, but also appreciate the other potential health risks in these women. Recent insights into the pathophysiology of PCOS have shown insulin resistance to play a substantial role and as such have brought the long-term issues of type 2 diabetes mellitus and its resultant increased risk of coronary artery disease to the forefront. No longer can irregular menses and/or hirsutism be thought of as benign nuisances. This review will focus on the two most confusing aspects of PCOS for the practicing provider--diagnosis/differential diagnosis and treatment options. Special attention is given to the role of insulin resistance and the potential utility of insulin sensitizers in management. The benefit and utmost importance of lifestyle modification for the long-term health of these women is stressed as well. It is hoped that some clarity in this regard will allow more women to not only be diagnosed and managed properly for their presenting symptoms (hirsutism, irregular menses, etc.), but also to be educated and managed for the continuing health risk of insulin resistance throughout their lives.

Treatment of PCOS with metformin and other insulin-sensitizing agents

A significant proportion of women with polycystic ovary syndrome (PCOS) suffer from insulin resistance and compensatory hyperinsulinemia. Growing evidence indicates that elevated serum insulin induces hyperandrogenism, which in turn leads to anovulation and infertility. Hyperinsulinemia also contributes to the increased risk for cardiovascular disorders and type 2 diabetes mellitus. These concepts provide a rationale for therapies focused on treatments of insulin resistance. Metformin is the most extensively studied insulin-sensitizing agent for the treatment of women with PCOS. Use of metformin leads to a decrease in serum insulin and androgen levels, as well as an improvement in ovulatory function. Other insulin-sensitizing agents studied in women with PCOS include troglitazone, rosiglitazone, pioglitazone, and D-chiro-inositol.

The role of metformin in the management of polycystic ovary syndrome

PURPOSE OF REVIEW

The purpose of this review is to provide a critical summary of recent studies on the clinical effects of metformin in polycystic ovary syndrome.

RECENT FINDINGS

After the recognition that hyperinsulinaemia is a fundamental disturbance in polycystic ovary syndrome, a novel and promising form of therapy in the form of insulin-sensitizing drugs has been introduced. Among these, metformin is the most widely used. This therapeutic intervention has been shown to exert beneficial effects on the endocrine and metabolic disturbances that characterize the syndrome and, more recently, to improve the reproductive outcome in women with polycystic ovary syndrome. With rapid progress in this area, metformin use has also been extended to the management of lean polycystic ovary syndrome patients.

SUMMARY

Although most studies are nonrandomized trials, current data provide a rationale for metformin as first-line management for women with polycystic ovary syndrome, alone or in combination with conventional treatments. Controversy still exists, however, regarding the mechanisms by which metformin exerts its beneficial effects in polycystic ovary syndrome.

Enhanced granulosa cell responsiveness to follicle-stimulating hormone during insulin infusion in women with polycystic ovary syndrome treated with pioglitazone

Women with polycystic ovary syndrome (PCOS) are known to exhibit insulin resistance with compensatory hyperinsulinemia. To determine the role of hyperinsulinemia on follicle function in PCOS, we examined 24-h estradiol (E(2)) responses to recombinant human FSH (r-hFSH), 75 IU, before and during insulin infusion both before and after administration of pioglitazone (30 mg/d) in seven PCOS women. Each subject underwent two 10-h hyperinsulinemic-euglycemic clamps at rates of 30 (low dose) and 200 (high dose) mU/m(2).min, respectively. During both low- and high-dose insulin infusions, E(2) responses to r-hFSH were unaltered compared with that observed in the absence of insulin. Pioglitazone administration for 5 months improved insulin sensitivity as indicated by significantly (P < 0.05) increased glucose infusion rates during the clamp studies. At 3 months of treatment, r-hFSH-stimulated E(2) responses were not different from those observed before treatment. With pioglitazone treatment, E(2) responses to r-hFSH remained unchanged during low-dose insulin infusion, whereas a highly significant (P < 0.02) increased response was noted with the high-dose hyperinsulinemic-euglycemic clamp. In addition to a greater magnitude of response, peak levels of E(2) were sustained longer compared with that seen before treatment. The data indicate that granulosa cell responsiveness to FSH was enhanced by insulin after improved insulin sensitivity induced by pioglitazone. These findings are consistent with the possibility that PCOS granulosa cells are insulin resistant.

Obese patients with polycystic ovary syndrome: evidence that metformin does not restore sensitivity of the gonadotropin-releasing hormone pulse generator to inhibition by ovarian steroids

Women with polycystic ovary syndrome (PCOS) have reduced GnRH sensitivity to suppression by ovarian steroids, which can be ameliorated by androgen blockade. We studied nine PCOS women and nine controls to determine whether metformin could change feedback inhibition by estradiol (E(2)) and progesterone (P). LH was measured every 10 min, and FSH, E(2), P, and testosterone (T) were measured every 2 h. Frequently sampled iv glucose tolerance test was performed at the end of each admission. After the first admission, metformin (500 mg, three times a day) was started. The second admission occurred on d 8-11 of the next menstrual cycle in controls and on d 28 in PCOS patients. Patients subsequently took E(2) and P for 1 wk until the third admission. At baseline, PCOS women had higher T, free T, androstenedione, and estrone. After 4 wk of metformin, controls had a slight reduction in total T, but free T was unchanged. However, PCOS patients had reduced insulin, T, and E(2), and increased LH mean/amplitude and FSH. After ovarian steroids, controls had a greater reduction in LH pulse frequency than PCOS (61 vs. 25%). These results suggest that the beneficial effects of metformin on ovulatory function in obese PCOS women are probably not mediated by enhanced hypothalamic sensitivity.

Increased luteinizing hormone secretion in women with polycystic ovary syndrome is unaltered by prolonged insulin infusion

In PCOS women with insulin resistance, hyperinsulinemia may contribute to inappropriate gonadotropin secretion. To determine whether insulin influences gonadotropin release in PCOS, pulsatile LH secretion and gonadotropin responses to GnRH were evaluated before (phase 1) and during (phase 2) insulin infusion. In phase 1, 11 PCOS and 9 normal women on separate days underwent 1) frequent blood sampling (q 10 min) for 12 h and 2) gonadotropin stimulation by successive doses of GnRH, 2 microg, 10 microg, and 20 microg, administered i.v. at 4 h intervals over a continuous 12 h. In phase 2, studies were repeated 2 h after initiation of a 12-h hyperinsulinemic-euglycemic clamp (80 mU/m(2).min). Administration of insulin to both groups failed to alter mean serum gonadotropin concentrations, LH pulse frequency, or LH pulse amplitude. Moreover, gonadotropin responses to GnRH were unchanged by insulin infusion. In PCOS and normal women, a significant reduction of serum androstenedione was associated with insulin administration, whereas no differences were noted for the remaining androgens and estrogens measured. These findings demonstrated that in PCOS women, LH secretion and gonadotropin responses to GnRH were not influenced by insulin administration. Insulin infusion had little effect on steroid hormone production with the possible exception of androstenedione. These results suggest that inappropriate LH secretion in PCOS is not a direct consequence of insulin resistance and compensatory hyperinsulinemia.

Insulin-lowering agents in the management of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a medical condition that has brought multiple specialists together. Gynecologists, endocrinologists, cardiologists, pediatricians, and dermatologists are all concerned with PCOS patients and share research data and design clinical trials to learn more about the syndrome. Insulin resistance is a common feature of PCOS and is more marked in obese women, suggesting that PCOS and obesity have a synergistic effect on the magnitude of the insulin disorder. Hyperinsulinemia associated with insulin resistance has been causally linked to all features of the syndrome, such as hyperandrogenism, reproductive disorders, acne, hirsutism, and metabolic disturbances. Women with PCOS should be evaluated for cardiovascular risk factors, such as lipid profile and blood pressure. Modification of diet and lifestyle should be suggested to those who are obese. Several insulin-lowering agents have been tested in the management of PCOS. In particular, metformin is the only drug currently in widespread clinical use for treatment of PCOS. In a high percentage of patients, treatment with metformin is followed by regularization of menstrual cycle, reduction in hyperandrogenism and in cardiovascular risk factors, and improvement in response to therapies for induction of ovulation.

Laparoscopic treatment of polycystic ovaries: is it time to relinquish the procedure?

OBJECTIVE

To evaluate the role of laparoscopic ovarian drilling and treatment with metformin in the management of the polycystic ovary syndrome (PCOS).

DESIGN

A literature search was conducted using the keywords laparoscopy, laparoscopic ovarian drilling, laparoscopic ovarian diathermy, PCOS, metformin, and ovulation. The MEDLINE and EMBASE databases and the Cochrane Database of Systematic Reviews were searched.

RESULTS

No randomized comparisons have been done between laparoscopic ovarian drilling and metformin therapy. However, the ovulation and pregnancy rates appear to be similar for both techniques. Both treatments decrease the incidence of ovarian hyperstimulation and the cancellation rate of IVF cycles. However, unlike laparoscopic ovarian drilling, metformin may decrease the incidence of type 2 diabetes and coronary heart disease.

CONCLUSION(S)

Given the similar magnitude of the results without the potential risks and complication of surgery, we propose that laparoscopic ovarian drilling should be used sparingly in favor of less invasive treatment with metformin.

Descriptive review of the evidence for the use of metformin in polycystic ovary syndrome

Use of metformin in polycystic ovary syndrome (PCOS) is becoming increasingly accepted and widespread, but clinical practice is ahead of the evidence. Although a wide range of benefits in metabolic, reproductive, and clinical measures have been reported from non-randomised trials with metformin, close inspection of results from the adequately controlled studies shows that the benefits are modest. Our aim in this descriptive review is not to define practice guidelines but to improve clinicians' knowledge of the available published clinical evidence, concentrating on the few randomised controlled trials. We also highlight other issues, including hirsutism, acne, pregnancy, and neonatal outcome, that require more attention before clinical recommendations for the use of metformin in PCOS can be formalised. The potentially greater benefits achievable by lifestyle changes alone are also emphasised. We hope that the review will lead to more judicious use of metformin in PCOS and a more structured approach to research.

Ovulation induction--optimizing results and minimizing risks

The aim of ovulation induction therapy should be, wherever possible, to correct the underlying disturbance and achieve safe, repeated unifollicular ovulation to achieve the live birth of singleton babies. This article outlines the main causes of anovulatory infertility but deals mostly with the management of anovulatory polycystic ovary syndrome (PCOS), which is the most common problem to confront specialists in reproductive medicine. PCOS is associated with insulin resistance, particularly in those who are overweight. Thus, strategies to achieve weight loss and improve insulin sensitivity, including the use of drugs such as metformin, enhance reproductive function. Therapies to induce ovulation involve first the use of the anti-oestrogen clomiphene citrate. For those who fail to ovulate in response to clomiphene citrate, the principal options include parenteral gonadotrophin therapy or laparoscopic ovarian diathermy.

Metformin has direct effects on human ovarian steroidogenesis

OBJECTIVE

To investigate the possibility of direct effects of metformin on ovarian steroidogenesis.

DESIGN

Cultured ovarian cells.

SETTING

Academic research environment.

PATIENT(S)

Women undergoing bilateral salpingoophorectomy for benign gynecological disease.

MAIN OUTCOME MEASURE(S)

Estradiol and P were measured in granulosa cell (GC) conditioned medium and androstenedione (A) and P in theca conditioned medium.

RESULT(S)

The effect of addition of metformin alone to GCs was variable, but significant inhibition of both P and E2 was seen (range 0%-30%). Metformin dose-dependently inhibited gonadotrophin and insulin-stimulated P and E2 production (range 25%-50%). In theca, metformin inhibited A production (0%-40%) with no effect on P. In the presence of insulin, A was inhibited dose-dependently and P increased by a similar magnitude.

CONCLUSION(S)

These results demonstrate a direct effect of metformin on ovarian steroidogenesis. The inhibitory effects on androgen production in particular would be beneficial in polycystic ovary syndrome (PCOS).

[Should infertile women with polycystic ovarian syndrome be treated with metformine?]

Polycystic ovary syndrome is a frequent endocrine disorder often associated with insulin resistance and hyperinsulinaemia which may play a role in hyperandrogenism and anovulation. The use of "insulin sensitizing" agents has been suggested to reduce insulin resistance and hyperandrogenism. In that respect, the use of metformin in polycystic ovary syndrome is reviewed. Although its mechanism of action is still unclear, metformin proved to be effective to restore cyclicity and spontaneous ovulation. The synergistic effect of clomiphene citrate and metformin was demonstrated in some studies, suggesting that metformin could be helpful for women with clomiphene citrate resistance. However, the potential effect of metformin administration for reducing hyperstimulation in women treated with exogenous FSH, or for preventing early miscarriages has to be confirmed. Here, we propose a guideline for the use of metformin, as an adjuvant therapy, to restore cyclicity and ovulation in women with polycystic ovary syndrome.

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.