Insulin and polycystic ovary syndrome: a new look at an old subject

Berberine Phospholipid Is an Effective Insulin Sensitizer and Improves Metabolic and Hormonal Disorders in Women with Polycystic Ovary Syndrome: A One-Group Pretest-Post-Test Explanatory Study

Polycystic Ovary Syndrome (PCOS) is the most frequent endocrine disease in females of reproductive age and is characterized by multifactorial unhealthy conditions related to hormonal unbalance and also to dysmetabolism and inflammation. Recently, increasing evidence has shown that natural plant-based products may play a role in PCOS management. The aim of this one-group pretest-post-test explanatory study was to evaluate, in normal-overweight PCOS women with normal menses, the effectiveness of berberine on: Insulin resistance (IR) by Homeostasis Model Assessment (HOMA); Inflammation by C-Reactive Protein (CRP), Tumor Necrosis Factor α (TNF-α); Lipid metabolism; Sex hormone profile and symptoms correlated to hyperandrogenism, such as acne, by Global Acne Grading System (GAGS) and Cardiff Acne Disability Index (CADI); Body composition by DXA. Finally, adverse effects were assessed by liver and kidney functions and creatine phosphokinase (CPK). All these parameters were collected at baseline and 60 days after supplementation with a new bioavailable and safe berberine formulation. Twelve females (aged 26.6 ± 4.9, BMI 25.3 ± 3.6) were supplied for 60 days with two tablets/day (550 mg/table) of the bioavailable berberine. Results showed a statistically significant decrease in HOMA, CRP, TNF-α, Triglycerides, testosterone, Body Mass Index (BMI), Visceral Adipose Tissue (VAT), fat mass, GAGS and CADI scores, and a statistically significant increase in sex hormone-binding globulin (SHBG). Liver and kidney functions and CPK are not statistically significantly different. Therefore, berberine can represent a safe novel dietary supplement, helpful in treatment strategy for PCOS.

Metformin and pioglitazone in polycystic ovarian syndrome: a comparative study

OBJECTIVES

To evaluate the effect of metformin and pioglitazone on insulin resistance, ovulation and hyperandrogenism in women with PCOS.

METHODS

100 patients of age 18-30 years were included in this randomised double blind trial for treatment with either metformin or pioglitazone for a period of 6 months.

RESULTS

Administration of metformin and pioglitazone for 6 months revealed that 50 % of the patients achieved menstrual cyclicity. A decline in F-G grading for hirsutism within the both the groups was observed. The lipid profile also showed a decrease in total cholesterol, an increase in HDL-C, a decrease in VLDL-C levels but more so in the pioglitazone group. HOMA-IR declined more than 50-55 % with pioglitazone and 15 % with metformin. Thus, pioglitazone may be a better treatment option as far as protection from tendency to development of diabetes is conscerned. The rise in serum SHBG levels and decline in free androgen index and L/H ratio are more remarkable with pioglitazone (P < 0.05). Ovulation was restored in 44.2 and 56 % of patients on metformin and pioglitazone, respectively.

CONCLUSION

Pioglitazone may be a new alternative for use in women with PCOS, providing more metabolic and reproductive benefits and possibly protection from developing diabetes and cardiovascular problem.

Is there a dose-response relationship of metformin treatment in patients with polycystic ovary syndrome? Results from a multicentric study

STUDY QUESTION

Do different dosages of metformin account for different clinical and biochemical outcomes in women with polycystic ovary syndrome (PCOS) and do basal anthropometric and metabolic characteristics of the patients provide any indications regarding the dose required to reach the target effect?

SUMMARY ANSWER

Different doses of metformin exerted the same effects on clinical, biochemical and metabolic parameters in patients affected by PCOS.

WHAT IS KNOWN AND WHAT THIS PAPER ADDS

Since the insulin-sensitizing agents came into use in the management of PCOS, metformin has shown a positive benefits-risks ratio. Nonetheless, therapeutic schedules are not well standardized. This is the first study which systematically analyses the effect of different doses of metformin on clinical, hormonal and metabolic features of PCOS. On the basis of our results, higher doses are no more effective than lower doses.

DESIGN

A multicentric cohort prospective study. A total of 250 PCOS women were enrolled, 49 lost to follow-up. Menstrual cyclicity, hormonal assays, oral glucose tolerance test, lipid profile and ultrasonographic pelvic examination were evaluated at the baseline and after 6 months of metformin treatment at different doses (1000, 1500 and 1700 mg).

PARTICIPANTS AND SETTING

A total of 201 PCOS patients completed the study without protocol violations in three university hospitals: seventy-three patients from Centre A (treated with metformin 500 mg twice a day), 60 patients from Centre B (treated with metformin 500 mg three times a day) and 68 patients from Centre C (treated with metformin 850 mg twice a day).

MAIN RESULTS AND THE ROLE OF CHANCE

Metformin exerted an overall positive effect on the clinical and endocrine-metabolic features of PCOS. The degree of these effects was independent of the administered dosage in every range of basal body mass index (BMI). When patients were stratified according to their insulinaemic status, scattered inter-doses differences were found in some of the outcome measures. Patients who exhibited an increase of >2 menstrual cycles/year were considered as responders to treatment. Responders had a higher basal BMI than non-responders and showed a greater reduction in plasma testosterone levels after metformin treatment, but other outcome measures did not differ significantly. Total insulin secretion in the 180 min following the glucose tolerance test before metformin treatment (basal AUC-I) was significantly correlated with the decrease in insulin secretion induced by metformin in both the whole group and in responders, but only correlated with the variation in the number of cycles in responders.

BIAS, CONFOUNDING AND OTHER REASONS FOR CAUTION

The different doses were administered in different centres, and between-centre variation is a potential confounding factor.

GENERALIZABILITY TO OTHER POPULATIONS

The paradigm of using the minimum effective dose of metformin could be pursued in other pathological conditions characterized by insulin resistance.

STUDY FUNDING/COMPETING INTEREST(S)

No funding or competing interests to declare.

Testosterone increases the muscle protein synthesis rate but does not affect very-low-density lipoprotein metabolism in obese premenopausal women

Men and women with hyperandrogenemia have a more proatherogenic plasma lipid profile [e.g., greater triglyceride (TG) and total and low-density lipoprotein-cholesterol and lower high-density lipoprotein-cholesterol concentrations] than healthy premenopausal women. Furthermore, castration of male rats markedly reduces testosterone availability below normal and decreases plasma TG concentration, and testosterone replacement reverses this effect. Testosterone is, therefore, thought to be an important regulator of plasma lipid homeostasis. However, little is known about the effect of testosterone on plasma TG concentration and kinetics. Furthermore, testosterone is a potent skeletal muscle protein anabolic agent in men, but its effect on muscle protein turnover in women is unknown. We measured plasma lipid concentrations, hepatic very low density lipoprotein (VLDL)-TG and VLDL-apolipoprotein B-100 secretion rates, and the muscle protein fractional synthesis rate in 10 obese women before and after trandermal testosterone (1.25 g of 1% AndroGel daily) treatment for 3 wk. Serum total and free testosterone concentrations increased (P < 0.05) by approximately sevenfold in response to testosterone treatment, reaching concentrations that are comparable to those in women with hyperandrogenemia, but lower than the normal range for eugonadal men. Except for a small (∼10%) decrease in plasma high-density lipoprotein particle and cholesterol concentrations (P < 0.04), testosterone therapy had no effect on plasma lipid concentrations, lipoprotein particle sizes, and hepatic VLDL-TG and VLDL-apolipoprotein B-100 secretion rates (all P > 0.05); the muscle protein fractional synthesis rate, however, increased by ∼45% (P < 0.001). We conclude that testosterone is a potent skeletal muscle protein anabolic agent, but not an important regulator of plasma lipid homeostasis in obese women.

Effects of pioglitazone on menstrual frequency, hyperandrogenism and insulin resistance in adoloscents and young adults with polycystic ovary syndrome

STUDY OBJECTIVE

To study the clinical, metabolic and adverse effects of pioglitazone over a period of 6 months in obese adolescent and young adults with polycystic ovary syndrome.

DESIGN

This was an open labeled study. Each patient served as her own control.

SETTING

Outpatient department of a university affiliated teaching hospital.

PARTICIPANTS

Unmarried women (age 15-25 yrs) with chronic anovulatory cycles and obesity, and with clinical evidence of hyperandrogenism.

INTERVENTIONS

Pioglitazone at a dose of 30 mg once daily for a period of 6 months along with dietary advice and exercise.

MAIN OUTCOME MEASURES

Resumption of normal menstrual cycles, clinical improvement in hyperandrogenism and changes in insulin resistance measured by fasting glucose insulin ratios.

RESULTS

Twenty-two women were enrolled. At the end of the study period 91% of the subjects had regularization of menstrual cycles. There was no change in the modified Ferriman-Gallwey hirsutism scores. Decline in fasting insulin levels at the end of the study was 45.6% from baseline along with significant increase in the fasting glucose/insulin ratio from baseline.

CONCLUSION

Administration of pioglitazone for 6 months along with advice about diet and physical activity in obese adolescents and young adult women with polycystic ovary syndrome results in significant improvements in menstrual frequency. There is a significant improvement in insulin resistance using the G/I ratio (<7.5 mg/10(-4) U) as the biochemical marker.

Alteration of ghrelin-neuropeptide Y network in obese patients with polycystic ovary syndrome: role of hyperinsulinism

OBJECTIVE

Insulin, ghrelin, neuropeptide Y (NPY) and leptin interact in the regulation of energy homeostasis. Most of these signals are altered in polycystic ovary syndrome (PCOS), which is characterized by a high prevalence of obesity. The present study was conducted to evaluate ghrelin-NPY and ghrelin-leptin interplays in relation to insulin secretion in obese PCOS subjects.

DESIGN

Pilot prospective study.

PATIENTS

Seven obese PCOS women and seven age-weight matched controls.

MEASUREMENTS

Hormonal measurements, oral glucose tolerance test (OGTT) and a ghrelin test (1 microg/kg i.v. bolus). PCOS patients repeated the clinical work-up after 4 months of metformin treatment (1500 mg/day orally).

RESULTS

At baseline, PCOS women showed a significantly higher insulinaemic response to the OGTT compared to controls (P < 0.05). In basal conditions, PCOS women exhibited lower NPY levels than controls (P < 0.01). Ghrelin injection markedly increased NPY in controls (P < 0.01), whereas PCOS women showed a deeply blunted NPY response to the stimulus (area under the curve--AUC-NPY: P < 0.01 vs. controls.). Metformin treatment induced a significant decrease in insulin levels (P < 0.01) and the concomitant recovery of NPY secretory capacity in response to ghrelin (AUC-NPY: P < 0.05 vs. baseline) in PCOS women. Leptin levels, which were similar in the two groups, were not modified by ghrelin injection; metformin did not affect this pattern.

CONCLUSION

Hyperinsulinaemia seems to play a pivotal role in the alteration of NPY response to ghrelin in obese PCOS women. This derangement could be implicated in the physiopatology of obesity in these patients.

The pathogenetic enigma of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a complex disease with heterogeneous clinical and anatomical features that were first described in 1721 by Antonio Vallisneri. There is still a lack of consensus regarding the criteria to be used for diagnosis of PCOS. Transvaginal ultrasonography with Doppler studies of the ovarian and pelvic vasculature plays an important role in its diagnosis, but findings must be interpreted in light of the patient's symptoms and laboratory findings.

Administration of exogenous ghrelin in obese patients with polycystic ovary syndrome: effects on plasma levels of growth hormone, glucose, and insulin

OBJECTIVE

To assess the effects of the administration of exogenous ghrelin, a peptide with potent GH-releasing activity and glucose-enhancing and insulin-lowering properties, in obese patients with polycystic ovary syndrome (PCOS).

DESIGN

Prospective, controlled study.

SETTING

Academic research environment.

PATIENT(S)

Twenty obese women with PCOS, and 15 obese controls.

INTERVENTION(S)

Oral glucose tolerance test (OGTT) and ghrelin test (1 microg/kg i.v. bolus).

MAIN OUTCOME MEASURE(S)

Basal hormonal assays, including ghrelin, were performed. Glucose, insulin, and C-peptide were assessed in a fasting condition and during the OGTT. Growth hormone, insulin, and glucose were measured basally and every 15 minutes for 90 minutes after the injection of ghrelin.

RESULT(S)

Both groups showed an insulin response to the glucose load above the normal range. Significantly lower levels of ghrelin were detected in patients with PCOS compared to controls (108.96 +/- 27.65 Fmol/mL versus 162.47 +/- 42.23 Fmol/mL). Administration of ghrelin markedly enhanced GH levels in both groups (1,888.59 +/- 1,209.53 ng/mL and 1,639.95 +/- 631.79 ng/mL per 90 minutes as GH area under the curve, respectively), with a peak occurring 30 minutes after injection. Ghrelin also induced a trend toward an increase in plasma glucose levels, and a significant decrease in insulin concentrations in both groups.

CONCLUSION(S)

The injection of ghrelin seems to override the GH secretion defect in obese women with PCOS, and to induce glucoinsulinemic changes in both controls and obese patients with PCOS.

Assessment of insulin sensitivity from measurements in the fasting state and during an oral glucose tolerance test in polycystic ovary syndrome and menopausal patients

BACKGROUND

Polycystic ovary syndrome (PCOS) and menopausal subjects are characterized by an increased cardiovascular and type 2 diabetes mellitus risk, at least partially related to insulin disturbances. The evaluation of insulin resistance in these patients could be useful as primary prevention. The aim of the study was to verify the validity of several indexes of insulin sensitivity in PCOS and menopausal subjects by comparing the data obtained by these indexes to those of euglycemic-hyperinsulinemic clamp studies.

METHODS

One hundred PCOS and 110 menopausal subjects were analyzed; all subjects underwent an oral glucose tolerance test (75 g) and euglycemic-hyperinsulinemic clamp study. Seven PCOS patients and 13 menopausal subjects had impaired glucose tolerance or type 2 diabetes mellitus and were excluded from the study. After analysis of correlation coefficients between the evaluated indexes and the clamp studies, the sensitivity and specificity of different cut-off values for each parameter were analyzed by receiver operating characteristic (ROC) curves.

RESULTS

The best correlation coefficients with clamp studies were obtained with the Avignon insulin sensitivity index (SiM) (R(s) = 0.7812) in PCOS patients and the Matsuda and De Fronzo index (R(s) = 0.6178) in menopausal patients. The best predictive index of insulin resistance in PCOS was a Avignon insulin sensitivity basal index (SibB) value of 62 or less (78% sensitivity, 95% specificity) and an insulin area under the curve (AUC) of 7,000 microIU/ml or more (>/=50,225 pmol/liter) x 120 min (83% sensitivity, 90% specificity). In the menopausal population, the best predictive performance was obtained by an insulin AUC of 10,000 microIU/ml or more (>/=71,750 pmol/liter) x 240 min (70% sensitivity, 88% specificity).

CONCLUSIONS

The presence of high correlation coefficients does not necessarily mean that the indexes of insulin resistance have an optimal predictive performance; this is probably due to the presence of many borderline values. The simple evaluation of insulin AUC seems to effectively replace the euglycemic-hyperinsulinemic clamp in routine clinical practice, allowing results superimposable to those obtained by minimal model analysis.

N-acetyl-cysteine is a novel adjuvant to clomiphene citrate in clomiphene citrate–resistant patients with polycystic ovary syndrome

OBJECTIVE

To evaluate the effect of N-acetyl-cysteine (NAC), a mucolytic drug with insulin sensitizing properties, as an adjuvant therapy in subjects with polycystic ovary syndrome (PCOS) resistant to clomiphene citrate (CC).

DESIGN

Placebo-controlled, double-blind randomized trial.

SETTING

University-based hospital and private infertility practice.

PATIENT(S)

One hundred fifty women diagnosed with CC-resistant PCOS, aged 18-39 years undergoing therapy for infertility were included.

INTERVENTION(S)

The patients were assigned randomly to receive either NAC 1.2 g/d (group I) or placebo (group II) with CC 100 mg/d for 5 days starting at day 3 of the cycle.

MAIN OUTCOME MEASURE(S)

Ovulation rate and pregnancy rate (PR).

RESULT(S)

Combination of CC and NAC significantly increased both ovulation rate and PR in women with CC-resistant PCOS (49.3% vs. 1.3% and 21.3% vs. 0%, respectively). No cases of ovarian hyperstimulation syndrome (OHSS) were reported in the NAC group; two cases of miscarriage (12.5%) were reported.

CONCLUSION(S)

The NAC as an adjuvant to CC was more effective than placebo for CC-resistant patients with PCOS. It is safe and well tolerated.

N-acetyl-cysteine treatment improves insulin sensitivity in women with polycystic ovary syndrome

OBJECTIVE

To evaluate the effect of N-acetyl-cysteine (NAC) on insulin secretion and peripheral insulin resistance in subjects with polycystic ovary syndrome (PCOS).

DESIGN

Prospective data analysis.

SETTING

Volunteer women in an academic research environment.

PATIENT(S)

Six lean and 31 obese subjects, aged 19-33 years.

INTERVENTION(S)

Patients were treated for 5-6 weeks with NAC at a dose of 1.8 g/day orally. A dose of 3 g/day was arbitrarily chosen for massively obese subjects. Six of 31 obese patients with PCOS were treated with placebo and served as controls.

MAIN OUTCOME MEASURE(S)

Before and after the treatment period, the hormonal and lipid blood profile and insulin sensitivity, assessed by an hyperinsulinemic euglycemic clamp, were evaluated and an oral glucose tolerance test (OGTT) was performed.

RESULT(S)

Fasting glucose, fasting insulin, and glucose area under curve (AUC) were unchanged after treatment. Insulin AUC after OGTT was significantly reduced, and the peripheral insulin sensitivity increased after NAC administration, whereas the hepatic insulin extraction was unaffected. The NAC treatment induced a significant fall in T levels and in free androgen index values (P<.05). In analyzing patients according to their insulinemic response to OGTT, normoinsulinemic subjects and placebo-treated patients did not show any modification of the above parameters, whereas a significant improvement was observed in hyperinsulinemic subjects.

CONCLUSION(S)

NAC may be a new treatment for the improvement of insulin circulating levels and insulin sensitivity in hyperinsulinemic patients with polycystic ovary syndrome.

A pilot study of the long-term effects of acipimox in polycystic ovarian syndrome

BACKGROUND

To evaluate the effects of long-term acipimox administration on glucose-induced insulin secretion and peripheral insulin sensitivity in polycystic ovarian syndrome (PCOS), 20 PCOS subjects (eight lean and 12 obese) and 14 body mass index-matched controls (seven lean and seven obese) were investigated.

METHODS

Fasting blood samples were collected for basal hormone and lipoprotein assays, after which patients underwent an oral glucose tolerance test (OGTT). The following day a euglycaemic-hyperinsulinaemic clamp was performed. After 4-6 weeks of treatment with acipimox at a dose of 250 mg given orally three times a day, the patients repeated the study protocol.

RESULTS

No significant differences were found in the glucose, insulin or C-peptide responses to OGTT before and after anti-lipolytic drug administration in any group, nor was there any effect on insulin sensitivity. Concerning the lipid profile, acipimox administration led to a significant decrease of cholesterol and low-density lipoprotein levels in obese PCOS patients as well as in obese and lean controls. Lower triglycerides were found after the drug administration in both obese groups. Post-treatment free fatty acid levels were not significantly different when compared with basal values.

CONCLUSIONS

Acipimox does not appear to be an effective insulin-lowering drug in PCOS, even if it can be used in obese women with PCOS as an additional therapeutic agent to ameliorate the atherogenic lipid profile of the syndrome.

A new ultrasound criterion for the diagnosis of polycystic ovary syndrome: the ovarian stroma/total area ratio

OBJECTIVE

To evaluate whether some ultrasound parameters of ovarian morphology can discriminate between control women and patients with polycystic ovary syndrome (PCOS).

DESIGN

Retrospective data analysis.

SETTING

Volunteers women in an academic research environment.

PATIENT(S)

Eighty amenorrheic or oligomenorrheic women and 30 normal ovulatory control participants.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

We evaluated ovarian volume, area, stroma, and the stroma/total area (S/A) ratio by use of transvaginal pelvic ultrasound; and we assayed serum levels of gonadotropin, androgen, and estradiol during the early follicular phase (days 2 to 5) of the menstrual cycle in regularly cycling controls and on a random day in amenorrheic patients.

RESULT(S)

Patients with PCOS showed significantly higher ovarian volume, area, stroma, and mean S/A ratio when compared to multifollicular and control groups. Cut-off values have been defined for ovarian volume (13.21 mL), area (7.00 cm2), stroma (1.95 cm2), and S/A ratio (0.34). The sensitivity for PCOS diagnosis was 21%, 4%, 62%, and 100%, respectively. The S/A ratio showed the most significant correlation with the androgen levels.

CONCLUSION(S)

The evaluation of the S/A ratio can differentiate between PCOS and control or multifollicular women with both a sensitivity and a specificity of 100%. Furthermore, this ultrasound parameter is strictly related to hormonal milieu and to anthropometric characteristics.

Naltrexone effect on pulsatile GnRH therapy for ovulation induction in polycystic ovary syndrome: a pilot prospective study

The aim of the present study was to analyze the opioid influence on LH pulsatility in polycystic ovary syndrome (PCOS) patients and to evaluate the effectiveness of a long-term opioid antagonist (naltrexone) treatment in improving the pulsatile GnRH therapy which is successful in this syndrome. Ten obese women affected by PCOS participated in the study. Patients were hospitalized during the early follicular phase and underwent an oral glucose tolerance test (OGTT) with 75 g of glucose and a pulse pattern study followed by a GnRH test (100 pg i.v.). All patients were then treated for ovulation induction with pulsatile administration of GnRH (5 microg/bolus every 90 min). Since pregnancies did not occurr in any patient, after spontaneous or progestin-induced menstrual cycles, all patients received naltrexone at a dose of 50 mg/day orally for 8 weeks and during treatment repeated the basal protocol study and the ovulation induction cycle with the same modalities. The naltrexone treatment significantly reduced the insulin response to OGTT and the LH response to GnRH bolus, whereas it did not affect the FSH and LH pulsatility patterns. Concerning the ovulation induction by pulsatile GnRH, naltrexone treatment was able to improve, although not significantly, the ovulation rate (60% pre-treatment vs 90% post-treatment). Furthermore, the maximum diameter of the dominant follicle and the pre-ovulatory estradiol concentration were higher after long-term opioid blockade (follicular diameter 19.5+/-1.76 mm pre-treatment vs 21.6+/-2.19 mm post-treatment, p<0.001; maximum estradiol level 728.7+/-288.5 pmol/l pre-treatment vs 986.4+/-382.1 pmol/l post-treatment, p<0.05). During the naltrexone-pulsatile GnRH co-treatment two pregnancies occurred. In conclusion, our data show that naltrexone-pulsatile GnRH co-treatment is able to improve the ovarian responsiveness to ovulation induction in obese PCOS patients when compared to pulsatile GnRH alone. This action seems to be related to a decrease of insulin secretion. Further randomized studies should be performed in order to obtain significant conclusions on the possible clinical application.