Endocrine and metabolic effects of metformin versus ethinyl estradiol-cyproterone acetate in obese women with polycystic ovary syndrome: a randomized study

Metformin, a biguanide antihyperglycemic drug, has been shown to improve ovarian function and glucose metabolism in women with polycystic ovary syndrome (PCOS), but results concerning its effects on insulin sensitivity are controversial. Oral contraceptive pills are commonly used in the treatment of PCOS; but, like metformin, their influence on insulin sensitivity is not well known. We randomized 32 obese (body mass index > 27 kg/m2) women with PCOS, either to metformin (500 mg x 2 daily for 3 months, then 1,000 mg x 2 daily for 3 months) or to ethinyl estradiol (35 microg)-cyproterone acetate (2 mg) oral contraceptive pills (Diane Nova) for 6 months. Metformin significantly decreased the waist-to-hip ratio, serum testosterone, fasting free fatty acid, and insulin concentrations and improved oxidative glucose utilization and menstrual cyclicity, with slight (but nonsignificant) improvements in insulin hepatic extraction and insulin sensitivity. Diane Nova significantly decreased serum testosterone and increased serum sex hormone-binding globulin concentrations and glucose area under the curve during oral glucose tolerance test. It is concluded that metformin, probably by way of its effect on adipose tissue, leads to reduction of hyperinsulinemia and concomitant improvement in the menstrual pattern; and therefore, it offers a useful alternative treatment for obese, anovulatory women with PCOS. Despite slight worsening of glucose tolerance, Diane Nova is an efficient treatment for women with hyperandrogenism and hirsutism.     

Effects of metformin and ethinyl estradiol-cyproterone acetate on lipid levels in obese and non-obese women with polycystic ovary syndrome

OBJECTIVE: Women with polycystic ovary syndrome (PCOS) exhibit risk factors for cardiovascular diseases such as abdominal obesity, insulin resistance and dyslipidemia. Insulin sensitizers, especially metformin, have been shown to improve these metabolic disturbances, but there are only a few studies on their effects on serum lipids in polycystic ovary syndrome. METHODS: Thirty-five women with PCOS (18 obese and 17 non-obese) were randomized to 6-month treatments with metformin or ethinyl estradiol-cyproterone acetate oral contraceptive pills. RESULTS: In the whole-study population (non-obese and obese women) serum levels of high-density lipoprotein cholesterol increased from 1.4+/-0.2 to 1.6+/-0.1 mmol/l (means +/-S.E. throughout) at 3 and 6 months (P < 0.001), the total cholesterol:high-density lipoprotein cholesterol ratio decreased significantly from 3.8+/-0.3 to 3.3+/-0.2 at 6 months (P < 0.001) and a similar trend was observed in serum triglyceride levels during metformin treatment. In the oral contraceptive group, serum levels of total cholesterol increased from 4.9+/-0.3 to 5.4+/-0.3 mmol/l (P < 0.05), high-density lipoprotein cholesterol increased from 1.2+/-0.1 to 1.5+/-0.1 mmol/l (P < 0.001), the total cholesterol:high-density lipoprotein cholesterol ratio decreased from 4.6+/-0.4 to 3.7+/-0.2 (P < 0.001) and triglycerides increased from 1.3+/-0.1 to 1.9+/-0.2 mmol/l at 6 months of treatment (P < 0.001). Serum low-density lipoprotein cholesterol levels remained unchanged during both treatments. Milder but similar changes in the subgroups of obese and non-obese women were observed during both treatments. Moreover, in the whole-study population both systolic (P = 0.02) and diastolic (P = 0.05) blood pressures decreased over the 6 months of metformin treatment. CONCLUSION: In women with PCOS, metformin treatment had beneficial effects on lipid profile and blood pressure, and therefore it could be useful in the prevention of cardiovascular complications in these women.     

Retinol-binding protein in nonobese women with polycystic ovary syndrome

Objective Although polycystic ovary syndrome (PCOS) is frequently associated with insulin resistance, cardiovascular disease and various metabolic diseases, the mechanisms linking PCOS to metabolic changes are not fully understood. Retinol‐binding protein (RBP) was recently reported as an adipocytokine that may link insulin resistance and lipid metabolism. The aim of this study was to investigate the potential role of RBP in women with PCOS. Research design and methods Fifty women with PCOS and 40 healthy women, all of whom were age‐ and weight‐matched, were studied. Blood was obtained to determine RBP levels as well as metabolic and hormonal parameters, and the homeostasis model assessment of insulin resistance (HOMA‐IR) was calculated for each subject. Results The RBP levels were higher (P < 0·01) in women with PCOS after adjusting for age, body mass index (BMI), mean blood pressure, triglyceride (TG), high density lipoprotein (HDL)‐cholesterol, low density lipoprotein (LDL)‐cholesterol, fasting glucose, fasting insulin, estimated glomerular filtration rate (GFR), LH/FSH, total testosterone and SHBG levels. PCOS status was the strongest predictor of elevated RBP levels. In both the PCOS and control groups, RBP levels were significantly correlated with HOMA‐IR (P = 0·03 in the PCOS group; P = 0·01 in controls). In addition, RBP levels were significantly correlated with total cholesterol, LDL‐cholesterol and TG levels in PCOS (P < 0·01, P < 0·01 and P = 0·01, respectively). Conclusions Higher RBP levels in the PCOS group, when compared to the non‐PCOS group, were observed, and this difference may play a role in the pathophysiology found in women with PCOS. Further studies are needed to clarify the role of RBP in these women.     

Prediction of insulin sensitivity in nonobese women with polycystic ovary syndrome

Insulin resistance is a frequent (although not constant) abnormality in both obese and nonobese women with polycystic ovary syndrome (PCOS). It plays a key role in the predisposition to type 2 diabetes, which is the most important health consequence of the syndrome. Identification of patients with insulin resistance is significant both for follow-up and for therapeutic reasons. The aim of the study was to evaluate the relationships between insulin sensitivity, measured by euglycemic clamp, and both endocrine and metabolic indices and to identify the best model for predicting insulin sensitivity. A total of 41 nonobese women fulfilling the diagnostic criteria for PCOS were enrolled in the study. None of the androgens correlated with the insulin sensitivity index. All clamp parameters correlated with SHBG, triglycerides, and body mass index, although no correlation was found with waist to hip ratio or waist circumference. The close relationship between insulin sensitivity and SHBG was documented by factor analysis and by its presence in all prediction models as the most significant (or even the single) predictor of the insulin sensitivity index. In conclusion: 1) a decreased level of SHBG can be used as a single reliable parameter in the prediction of insulin sensitivity in nonobese women with PCOS; and 2) waist to hip ratio, waist circumference, and androgen concentrations have no predictive value.     

Metformin administration versus laparoscopic ovarian diathermy in clomiphene citrate-resistant women with polycystic ovary syndrome: a prospective parallel randomized double-blind placebo-controlled trial

At present, it is unclear what the role is of laparoscopic ovarian diathermy (LOD) and of metformin administration as second-line treatments for ovulation induction in women with polycystic ovary syndrome (PCOS) after failure of clomiphene citrate (CC) treatment. The aim of the present study was to compare in a randomized double-blind placebo-controlled fashion the effectiveness of LOD with metformin administration in the treatment of CC-resistant women with PCOS. A total of 120 overweight primary infertile anovulatory CC-resistant women with PCOS were enrolled and randomized into two groups of treatment. Group A underwent diagnostic laparoscopy, whereas group B underwent LOD. At hospital discharge, the patients were treated for 6 months with metformin cloridrate (group A; 850 mg twice daily) or with multivitamins (group B). The ovulation, pregnancy, abortion, and live-birth rates were evaluated. At the end of the study, the total ovulation rate was not statistically different between both treatment groups (54.8 vs. 53.2% [correction] in groups A and B, respectively), whereas the pregnancy (21.8 [correction] vs. 13.4%), the abortion (9.3 [correction] vs. 29.0%), and the live-birth (86.0 [correction] vs. 64.5%) rates were significantly (P < 0.05) different between the two groups. Our data show that metformin administration is more effective than LOD in overall reproductive outcomes in overweight infertile CC-resistant women with PCOS.     

Metformin administration improves leukocyte count in women with polycystic ovary syndrome: a 6-month prospective study

INTRODUCTION: Polycystic ovary syndrome (PCOS) is a common disorder associated with a wide range of endocrine and metabolic abnormalities. Low-grade chronic inflammation is a related complication recently observed in PCOS. Increased white blood cell (WBC) count was previously reported in PCOS women. OBJECTIVE: To evaluate the effects of six months metformin administration on WBC count in PCOS women. PATIENTS AND METHODS: Fifty normal-weight PCOS women without additional metabolic or cardiovascular diseases were enrolled and treated with metformin (850 mg twice daily) for 6 months in a prospective baseline-controlled clinical study. At baseline and after treatment, WBC count and C-reactive protein (CRP) were evaluated in each patient. The whole hormonal profile, serum insulin and glucose levels (at fasting and during a 75 g 2-h oral glucose tolerance test), serum lipid profile were also assessed. RESULTS: A significant difference was observed in WBC count (7050 +/- 552 vs 6080 +/- 577 cell/mm(3) +/- s.d., P<0.001) and CRP levels (1.8 +/- 0.9 vs 1.1 +/- 0.6 mg/l +/- s.d., P<0.001) after metformin treatment in comparison with baseline values. SHBG levels and the free androgen index also changed significantly (P<0.001). Finally, high-density lipoproteins and the area under curve for glucose/area under curve for insulin ratio also significantly increased (P<0.001), whereas low-density lipoproteins and area under curve for insulin were significantly reduced (P<0.001). No other change was found in any of the biochemical parameters evaluated. CONCLUSION: A six-month course of metformin reduces WBC count in PCOS women.     

Metformin reduces serum C-reactive protein levels in women with polycystic ovary syndrome

Low-grade chronic inflammation, reflected in elevated levels of serum C-reactive protein (CRP), has recently been linked to obesity, insulin resistance syndromes such as polycystic ovary syndrome (PCOS), and an increased risk of cardiovascular disease. Because the insulin sensitizer metformin has been shown to improve metabolic disturbances in PCOS, it was of particular interest to examine serum CRP levels during metformin therapy. Twenty nonobese women [body mass index (BMI) /==" BORDER="0"> 27 kg/m(2)) with PCOS were randomized to receive either metformin (500 mg twice daily for 3 months, then 1000 mg twice daily for 3 months) or ethinyl estradiol (35 micro g)-cyproterone acetate (2 mg) oral contraceptive pills. The serum concentrations of CRP were significantly higher in obese than in nonobese subjects at baseline [4.08 +/- 0.53 (SE) vs. 1.31 +/- 0.28 mg/liter; P < 0.001] and correlated to BMI and to a lesser extent waist-hip ratio, suggesting that the elevated CRP levels may be related to obesity and not only to PCOS itself. During metformin treatment, serum CRP levels decreased significantly from 3.08 +/- 0.7 mg/liter to 1.52 +/- 0.26 mg/liter at 6 months in the whole study population (P = 0.006) and especially in obese subjects. In contrast, the treatment with ethinyl estradiol-cyproterone acetate increased serum CRP levels from 2.91 +/- 0.68 mg/liter to 4.58 +/- 0.84 mg/liter (P < 0.001). Whether this effect is related to estrogen action in the liver or whether it reflects increased inflammation process and possible risks for cardiovascular disease remains unclear. The decrease of serum CRP levels during metformin therapy is in accordance with the known beneficial metabolic effects of this drug and suggests that CRP or other inflammation parameters could be used as markers of treatment efficiency in women with PCOS.     

Metformin and weight loss in obese women with polycystic ovary syndrome: comparison of doses

CONTEXT: Metformin treatment of women with polycystic ovary syndrome (PCOS) is widespread, as determined by studies with diverse patient populations. No comparative examination of weight changes or metabolite responses to different doses has been reported. OBJECTIVE: The aim of this study was to determine whether different doses of metformin (1500 or 2550 mg/d) would have different effects on body weight, circulating hormones, markers of inflammation, and lipid profiles. DESIGN: The study included prospective cohorts randomized to two doses of metformin. SETTING: The study was performed at a university teaching hospital with patients from gynecology/endocrinology clinics. PATIENTS: The patients studied were obese (body mass index, 30 to <37 kg/m2; n = 42) and morbidly obese (body mass index, > or =37 kg/m2; n = 41) women with PCOS. INTERVENTION: Patients were randomized to two doses of metformin, and parameters were assessed after 4 and 8 months. MAIN OUTCOME MEASURES: The main outcome measures were changes in body mass, circulating hormones, markers of inflammation, and lipid profiles. Results: Intention to treat analyses showed significant weight loss in both dose groups. Only the obese subgroup showed a dose relationship (1.5 and 3.6 kg in 1500- and 2550-mg groups, respectively; P = 0.04). The morbidly obese group showed similar reductions (3.9 and 3.8 kg) in both groups. Suppression of androstenedione was significant with both metformin doses, but there was no clear dose relationship. Generally, beneficial changes in lipid profiles were not related to dose. CONCLUSION: Weight loss is a feature of protracted metformin therapy in obese women with PCOS, with greater weight reduction potentially achievable with higher doses. Additional studies are required to determine whether other aspects of the disorder may benefit from the higher dose of metformin.     

Metformin or antiandrogen in the treatment of hirsutism in polycystic ovary syndrome

Hirsutism is a common and distressing symptom frequently encountered in women with polycystic ovary syndrome (PCOS), who also show relative insulin resistance. The aim of this trial, in which hirsutism was the primary end point, was to compare the efficacy of the oral antihyperglycemic medication metformin with that of an established treatment, combined ethinyl estradiol and cyproterone acetate. Patients (n = 52) were randomized to receive either metformin (500 mg, three times daily) or Dianette (ethinyl estradiol, 35 micro g; cyproterone acetate, 2 mg) treatment for 12 months, with assessments before treatment, at 6 months, and at 12 months. Both objective and subjective methods of evaluating hirsutism were used, and in addition, patient perceptions were examined. The results show that metformin is potentially an effective treatment for moderate to severe hirsutism in women with PCOS. They also suggest that in some respects (Ferriman-Gallwey score and patient self-assessment), it is more efficacious than the standard treatment (Dianette). The objective evaluation of hair diameter reduction showed that both treatments were moderately effective at multiple anatomical sites. Dianette treatment was responsible for profound suppression of androgen activity, in contrast to metformin, which induced negligible change. However, metformin did reduce markers of insulin resistance. The data suggest that hirsutism may be effectively treated by reducing hyperinsulinemia.     

Licogliflozin versus placebo in women with polycystic ovary syndrome: A randomized,double-blind,phase 2 trial

Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism and insulin resistance. The dual sodium-glucose co-transporter 1/2 inhibitor (SGLT1/2i) licogliflozin (LIK066) ameliorates hyperinsulinism in patients with diabetes and obesity. This study examines the effect of licogliflozin on androgens in women with PCOS. In a multicentre, randomized, placebo-controlled, double-blind, 2-week trial, patients with PCOS received licogliflozin 50 mg or placebo three times a day (TID). Changes in free testosterone (FT), other androgens and variables of insulin resistance were analysed. Concentration of FT did not change (TR_LIK066:TR_PCB [FT]: 0.88; 90% CI: 0.70-1.11; P = .353). Licogliflozin reduced androstendione (A4) by 19% (TR_LIK066:TR_PCB [A4]: 0.81; 90% CI: 0.68-0.99; P = .089) and dehydroepiandrosteron sulphate (DHEAS) by 24% (TR_LIK066:TR_PCB [DHEAS]: 0.76; 90% CI: 0.65-0.89; P = .008). Hyperinsulinaemia was reduced by 70% by licogliflozin (highest insulin concentration [MAXI]; TR_LIK066:TR_PCB [MAXI]: 0·26; 90% CI:0.20-0.34; P < .001 and area under the curve insulin [AUCI]; TR_LIK066:TR_PCB [AUCI]: 0.32; 90% CI: 0.25-0.41; P < .001). Diarrhoea and nausea occurred as common adverse events. Dual inhibition of SGLT1/2 ameliorates hyperinsulinaemia and hyperandrogenaemia in women with PCOS. Licogliflozin may represent a promising novel treatment option for PCOS.     

Metformin, pre-eclampsia, and pregnancy outcomes in women with polycystic ovary syndrome.

Aims Was metformin during pregnancy in women with polycystic ovary syndrome (PCOS) associated with pre‐eclampsia, and was it safe for mother and neonate? Methods In the current study, pre‐eclampsia and other pregnancy outcomes were prospectively studied in 90 women with PCOS who conceived on metformin 1.5–2.55 g/day, and had ≥ 1 live birth (97 pregnancies, 100 live births) compared with 252 healthy women (not known to have PCOS) with ≥ 1 live birth, consecutively delivered in a community obstetrics practice. Results Women with PCOS were older than controls (33 ± 5 vs. 29 ± 6 years, P < 0.0001), more likely to be > 35 years old at conception (23 vs. 13%, P = 0.028), much heavier (93 ± 23 vs. 72 ± 18 kg, P < 0.0001, BMI 33.8 ± 7.8 kg/m² vs. 25.6 ± 5.9, P < 0.0001), and more likely to be Caucasian (97 vs. 90%, P = 0.05), but there were similar numbers with preconception Type 2 diabetes mellitus [2/90 (2.2%) vs. 1/252 (0.4%), P = 0.17]. Pre‐eclampsia in PCOS (5/97 pregnancies, 5.2%), did not differ (P = 0.5) from controls (9/252, 3.6%), nor did it differ (P = 1.0) in PCOS vs. control primigravidas [2/45 (4.4%) vs. 4/91 (4.4%)]. Development of gestational diabetes in PCOS did not differ from controls [9/95 pregnancies (9.5%) vs. 40/251 (15.9%), P = 0.12]. Of the 100 live births to 90 women with PCOS, there were no major birth defects. Mean ± sd birth weight of the 80 live births ≥ 37 weeks gestation in women with PCOS (3414 ± 486 g) did not differ from controls’ 206 live births ≥ 37 weeks (3481 ± 555 g), P = 0.34, nor did the percentage of ≥ 37 week gestation neonates ≥ 4000 g (12.5 vs. 17.5%, P = 0.3) or ≥ 4500 g (1.3 vs. 2.9%, P = 0.7). Conclusions Metformin is not associated with pre‐eclampsia in pregnancy in women with PCOS, and appears to be safe for mother and fetus.     

Metformin therapy increases insulin-stimulated release of D-chiro-inositol-containing inositolphosphoglycan mediator in women with polycystic ovary syndrome

Some actions of insulin are mediated by putative inositolphosphoglycan mediators, and a deficiency in D-chiro-inositol-containing inositolphosphoglycan (DCI-IPG) may contribute to insulin resistance in women with polycystic ovary syndrome (PCOS). Furthermore, similar effects of DCI and metformin, an insulin-sensitizing drug, have been demonstrated in PCOS women. To determine whether metformin improves insulin actions by increasing biologically active DCI-IPG in women with PCOS, we analyzed DCI-IPG during an oral glucose tolerance test in 19 obese women with PCOS before and after 4-8 wk of metformin or placebo. After treatment, the mean (+/-SE) area under the curve (AUC) during the oral glucose tolerance test of insulin (AUC(insulin)) decreased significantly more in the metformin group, compared with the placebo group [-3574 +/- 962 vs. +1367 +/- 1021 micro IU/min.ml (-26 +/- 7 vs. +10 +/- 7 nmol/min.liter), P = 0.003], but the AUC of DCI-IPG (AUC(DCI-IPG)) decreased similarly in both groups (-1452 +/- 968 vs. -2207 +/- 1021%/min, P = 0.60). However, the ratio of AUC(DCI-IPG)/AUC(insulin) increased by 160% after metformin and decreased by 29% after placebo (P = 0.002 between groups). Moreover, metformin seemed to improve the positive correlation between AUC(DCI-IPG) and AUC(insulin) but not placebo (r = 0.32, P = 0.68 at baseline; r = 0.52, P = 0.12 after metformin; and r = -0.39, P = 0.30 after placebo). We conclude that in obese women with PCOS, metformin may improve the action of insulin in part by improving insulin-mediated release of DCI-IPG mediators, as evidenced by increased bioactive DCI-IPG released per unit of insulin.     

The effects of metformin on metabolic and cardiovascular risk factors in nonobese women with polycystic ovary syndrome

Objective There are conflicting data regarding the effects of metformin in lean women with polycystic ovary syndrome (PCOS). Thus, our aim was to evaluate the effects of 6 months of metformin therapy on various metabolic and cardiovascular risk factors in lean women with PCOS. Design This was a prospective clinical study performed in a University hospital. Patients Twenty nonobese PCOS women and 20 age‐ and BMI‐matched healthy women were included in the study. Metformin (2550 mg/day) was administered for 6 months in women with PCOS. The hormonal and metabolic parameters were evaluated before and after metformin treatment. Measurements The main outcome measures were serum androgens, FSH, LH, oestradiol, 17‐hydroxyprogesterone, glucose, insulin, lipid profile, lipoprotein(a) [Lp(a)] and homocysteine levels. In addition 24‐h ambulatory blood pressure monitoring (ABPM) and carotid intima‐media thickness (IMT) were taken. Results After 6 months of metformin therapy, women with PCOS had decreased LH, total testosterone, free androgen index and slightly increased SHBG levels. Metformin treatment resulted in resumption of regular menses in 12 (60%) patients, and in 8 (40%) of them serum progesterone level was compatible with ovulation. Glucose and insulin responses to oral glucose tolerance test (OGTT) and homeostasis model assessment of insulin resistance (HOMA‐IR) did not improve after the metformin therapy. There were no significant changes in terms of cardiovascular risk factors such as lipids and homocysteine, IMT and ABPM. Conclusion Metformin may have beneficial effects in lean PCOS women in terms of resumption of menses without any remarkable effect on metabolic and cardiovascular risk factors.     

Dissociation of endothelial function and arterial stiffness in nonobese women with polycystic ovary syndrome (PCOS)

Objective Polycystic ovary syndrome (PCOS) is associated with cardiovascular risk but it is not clear if this is independent of obesity and insulin resistance. This study therefore investigates endothelial function and arterial stiffness in nonobese, noninsulin resistant women with PCOS. Design This is cross‐sectional case–control study. Patients A total of 19 young women with PCOS, with body mass index (BMI) <30 kg/m², and 19 healthy controls matched for age and BMI were included in the study. Measurements Endothelial function was assessed with flow mediated dilatation (FMD) of the brachial artery, while arterial stiffness was assessed with pulse wave velocity (PWV) and augmentation index (AI). Results There were no significant differences between PCOS and control subjects when assessing the following clinical and biochemical variables: blood pressure, homeostasis model assessment insulin‐resistance index, lipids and oestradiol. Women with PCOS had higher free androgen index scores (5·14 ± 3·47 vs. 3·25 ± 1·42, P = 0·036). The PCOS subjects had significantly lower FMD of the brachial artery compared with the controls (6·5 ± 2·9%vs. 10·5 ± 4·0%, P < 0·01). There were no significant differences in markers of arterial stiffness (PWV 5·8 ± 1·1 vs. 6·0 ± 1·0, P = 0·58, AI 16·5 ± 10·2 vs. 20·3 ± 10·2, P = 0·25). Conclusions Women with polycystic ovary syndrome who are young, nonobese, and have no biochemical evidence of insulin resistance, have abnormal vascular function, but normal arterial stiffness, when compared with age and weight matched control subjects. Whether this leads to a greater risk of cardiovascular disease requires further investigation.