To evaluate the effect of N-acetyl-cysteine (NAC) on insulin secretion and peripheral insulin resistance in subjects with polycystic ovary syndrome (PCOS). Prospective data analysis. 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.
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.
To evaluate whether some ultrasound parameters of ovarian morphology can discriminate between control women and patients with polycystic ovary syndrome (PCOS). Retrospective data analysis. 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.
To investigate the involvement of opioid tone, obesity, and hyperinsulinemia in GH secretion in women with polycystic ovary syndrome (PCOS). Controlled clinical study. Catholic University of Sacred Heart School of Medicine in Rome, Italy. PATIENT(S): Twenty-two patients with PCOS and 14 healthy, normally ovulating volunteers, matched for age and body mass index. INTERVENTION(S): Patients underwent a GH-releasing hormone (GHRH) test and an oral glucose tolerance test before and after 4-5 weeks of treatment with 50 mg/d of naltrexone. MAIN OUTCOME MEASURE(S): Serum concentrations of GH, insulin, glucose, steroids, and gonadotropins, as well as the GH area under the curve (AUC-GH) and the insulin area under the curve (AUC-I), were measured before and after naltrexone treatment. RESULT(S): In patients with PCOS, the administration of naltrexone increased the GH response to the GHRH test without interfering with the insulin response to the oral glucose tolerance test. However, the GH response to the GHRH test was improved significantly only in lean patients with PCOS, whereas obese patients with PCOS did not show any improvement in GH secretion. In obese control subjects, the treatment reduced plasma basal insulin concentrations and increased the AUC-GH, whereas in lean control subjects, the treatment reduced the GHRH-induced response. In normoinsulinemic patients with PCOS, the GH response to the GHRH test increased significantly after treatment, whereas the AUC-I was not affected. In hyperinsulinemic patients with PCOS, treatment with naltrexone significantly reduced the AUC-I, whereas the AUC-GH increased only in lean hyperinsulinemic patients with PCOS. CONCLUSION(S): Naltrexone treatment improves GHRH-induced GH secretion in patients with PCOS. However, this GH response is heterogeneously represented in relation to both obesity and hyperinsulinism.
Hyperinsulinemia secondary to a poorly characterized disorder of insulin action is a feature of polycystic ovarian disease (PCOD). On the other hand, being generally admitted that opioids may play a role in glycoregulation and that opioid tone is altered in PCOD, an involvement of the opioids in determining the hyperinsulinemia of PCOD patients could be suggested. The aim of this study was to evaluate the effect of a chronic opioid blockade on insulin metabolism and peripheral insulin sensitivity in PCOD hyperinsulinemic patients. Twenty-three women with PCOD were studied. An oral glucose tolerance test (OGTT) and a clamp study were performed at baseline (during the follicular phase) and after 6 weeks of naltrexone administration (50 mg/d orally). Based on the insulinemic response to the OGTT, 16 women were classified as hyperinsulinemic and seven as normoinsulinemic. Naltrexone treatment significantly reduced fasting (P < .05) and area under the curve (AUC) (P < .02) plasma insulin levels only in the hyperinsulinemic group. Moreover, hyperinsulinemic patients showed similar C-peptide incremental areas after naltrexone treatment, whereas in the same patients the fractional hepatic insulin extraction calculated from the incremental areas of insulin and C-peptide was found to be increased after chronic opioid blockade by naltrexone. For peripheral insulin sensitivity, the hyperinsulinemic group showed significantly lower (P < .01) total-body glucose utilization (M) compared with the normoinsulinemic group. No change in the M value was found after treatment in both groups. These data suggest that the insulin sensitivity and hyperinsulinemia after an OGTT are two distinct deranged features of the insulin disorder of PCOD patients.
Recent data indicate that an altered opioid tone could be involved in the LH hypersecretion and metabolic alterations seen in polycystic ovary syndrome (PCOS). The aim of the present study was to investigate the presence of a common mechanism of action of opioids on altered insulin and gonadotropin release in patients suffering from PCOS. Twenty-eight women affected by PCOS and 8 normal ovulatory women were studied; an oral glucose tolerance test (OGTT) and GnRH tests were performed during the follicular phase before and after 6 weeks of naltrexone treatment (50 mg/day, orally). Plasma levels of sex hormone-binding globulin and steroids were assayed in the basal samples, whereas FSH and LH were analyzed during the GnRH stimulus. Insulin and glucose were assayed by the OGTT. Based on the insulinemic response to OGTT, 17 women were classified as hyperinsulinemic and 11 as normoinsulinemic. No difference in glucose and hormone plasma concentrations was observed before and after naltrexone treatment in both groups. Only basal sex hormone-binding globulin values were higher in normoinsulinemic compared to hyperinsulinemic subjects. Administration of the opioid antagonist significantly reduced the insulin response to OGTT only in the hyperinsulinemic group. No difference were found in the LH increment after the GnRH stimulus in both group of patients before treatment; on the contrary, naltrexone administration reduced the LH response to GnRH in hyperinsulinemic women but failed to be effective in normoinsulinemic subjects. Only 5 patients showed no concordance of drug-induced changes in insulin and LH secretion. In control subjects, naltrexone failed to have any effect on insulin or LH secretion. These data support the involvement of endogenous opioids in the regulation of insulin and LH secretion in a specific group of PCOS patients exhibiting an exaggerated insulin response to OGTT.
Metabolic and Endocrine Agents · Insulin Sensitizing Agents
A total of 17 women affected by polycystic ovarian disease (PCOD) were studied to evaluate the involvement of endogenous opioids in the pathophysiology of the hyperinsulinism in PCOD by administering naltrexone, an oral opioid antagonist. An oral glucose tolerance test (OGTT) was performed at baseline (on day 5 of the cycle) and repeated after 6 weeks of naltrexone administration. Plasma glucose, insulin and connecting peptide (c-peptide) concentrations were evaluated in all samples. Based on their insulinaemic response to OGTT, patients were classified as hyperinsulinaemic or normoinsulinaemic. Naltrexone treatment significantly (P < 0.007) reduced the insulin response to OGTT in the hyperinsulinaemic group without affecting the c-peptide incremental area; in the normoinsulinaemic group there was a slight, but not significant, increase in both c-peptide and insulin incremental areas. The two groups showed similar c-peptide incremental areas after naltrexone treatment. There was no significant difference in the c-peptide:insulin incremental areas molar ratio between the two groups; after treatment, a significant increase in this ratio was observed in both groups. When we considered the data as an expression of the fractional hepatic extraction of insulin, we found a lower value for hyperinsulinaemic in comparison with normoinsulinaemic patients (not significant), and a significant (P < 0.01) improvement of this parameter in the hyperinsulinaemic group after naltrexone administration. In conclusion, we suggest that the contribution to hyperinsulinaemia in PCOD patients may be at least in part due to both increased pancreatic secretion and reduced hepatic removal of insulin. Chronic pharmacological inhibition of opioid tone could improve the insulin plasma concentration by acting chiefly on the liver metabolism of insulin in hyperinsulinaemic patients.
We investigated the impact of pregestationally elevated insulin plasma levels on glycemic control in pregnant women with polycystic ovary disease (PCOD). Twelve patients with PCOD who became pregnant within six months following evaluation of their metabolic status were the study subjects. Four were obese and six (two obese) had a hyperinsulinemic response to the oral glucose tolerance test (OGTT). They were tested with the OGTT at 28-30 weeks of gestation. We also tested 12 normal patients and 10 consecutive patients with gestational diabetes; all were at the same gestational age. Plasma levels of insulin and glucose were determined in the samples collected for a period of four hours after glucose load (100 g). All PCOD patients significantly increased their insulin secretion in pregnancy. The hyperinsulinemic PCOD patients developed gestational diabetes (two patients) and impaired gestational glucose tolerance (three patients). The area under the insulin curve was greater in PCOD patients than in control and gestational diabetes patients (P < .01). In spite of their large increase in insulin secretion observed during pregnancy, patients with PCOD may develop a derangement of glycemic control, probably related to their pregestational insulinemic status.
Lanzone A et al., 1995·The Journal of reproductive medicine
We investigated the impact of pregestationally elevated insulin plasma levels on glycemic control in pregnant women with polycystic ovary disease (PCOD). Twelve patients with PCOD who became pregnant within six months following evaluation of their metabolic status were the study subjects. Four were obese and six (two obese) had a hyperinsulinemic response to the oral glucose tolerance test (OGTT). They were tested with the OGTT at 28-30 weeks of gestation. We also tested 12 normal patients and 10 consecutive patients with gestational diabetes; all were at the same gestational age. Plasma levels of insulin and glucose were determined in the samples collected for a period of four hours after glucose load (100 g). All PCOD patients significantly increased their insulin secretion in pregnancy. The hyperinsulinemic PCOD patients developed gestational diabetes (two patients) and impaired gestational glucose tolerance (three patients). The area under the insulin curve was greater in PCOD patients than in control and gestational diabetes patients (P < .01). In spite of their large increase in insulin secretion observed during pregnancy, patients with PCOD may develop a derangement of glycemic control, probably related to their pregestational insulinemic status.
Metabolic and Endocrine Agents · Insulin Sensitizing Agents
Fulghesu AM et al., 1993·Obstetrics and gynecology
To evaluate the involvement of endogenous opiates in the pathophysiology of the hyperinsulinism in patients affected by polycystic ovary disease by administering naloxone and naltrexone. We also studied the hormonal status following long-term opioid antagonist administration. Twenty-one women affected by polycystic ovary disease participated in the study. An oral glucose tolerance test (GTT) was performed at baseline and repeated after short-term naloxone infusion and after 6 weeks of naltrexone administration. Plasma glucose and insulin levels were evaluated in all samples. Gonadotropins, sex hormone-binding globulin, and androgen levels were determined initially and after the naltrexone treatment. None of the patients showed any alteration of glucose tolerance. Based on the insulin response to the GTT, the patients were classified as normo- or hyperinsulinemic. Opioid antagonist administration significantly reduced the insulin response to the GTT in hyperinsulinemic patients, without affecting their glycemic levels. In normoinsulinemic patients, glucose plasma levels were increased whereas insulin levels were not modified by the treatments. Gonadotropin and androgen plasma concentrations were not modified after naltrexone administration. This work supports a role for the endogenous opiates in the regulation of exaggerated insulin secretion in patients with polycystic ovary disease. The reduction of insulin secretion failed to demonstrate any hormonal modification in such hyperandrogenized patients.
Metabolic and Endocrine Agents · Insulin Sensitizing Agents
To evaluate the involvement of endogenous opiates in the pathophysiology of the hyperinsulinism in patients affected by polycystic ovary disease by administering naloxone and naltrexone. We also studied the hormonal status following long-term opioid antagonist administration. Twenty-one women affected by polycystic ovary disease participated in the study. An oral glucose tolerance test (GTT) was performed at baseline and repeated after short-term naloxone infusion and after 6 weeks of naltrexone administration. Plasma glucose and insulin levels were evaluated in all samples. Gonadotropins, sex hormone-binding globulin, and androgen levels were determined initially and after the naltrexone treatment. None of the patients showed any alteration of glucose tolerance. Based on the insulin response to the GTT, the patients were classified as normo- or hyperinsulinemic. Opioid antagonist administration significantly reduced the insulin response to the GTT in hyperinsulinemic patients, without affecting their glycemic levels. In normoinsulinemic patients, glucose plasma levels were increased whereas insulin levels were not modified by the treatments. Gonadotropin and androgen plasma concentrations were not modified after naltrexone administration. This work supports a role for the endogenous opiates in the regulation of exaggerated insulin secretion in patients with polycystic ovary disease. The reduction of insulin secretion failed to demonstrate any hormonal modification in such hyperandrogenized patients.
In order to test the hypothesis that endogenous opiates are at least partially responsible for hyperinsulinaemia in patients with polycystic ovarian disease (PCOD), the effect of naloxone (an opiate receptor blocker) on the insulin response to oral glucose load (OGTT) was studied in 20 women with PCOD and 17 control subjects at days 5-8 of their follicular phase. After fasting overnight for 10-12 h, each woman received an i.v. bolus injection (2 mg) of naloxone or an equal volume of saline infusion followed by a constant infusion of naloxone or saline solution at a rate of 8 ml/h (1 mg/h of naloxone) for 5 h. OGTT (75 g) was performed 1 h after the bolus injection. The naloxone study was performed 48 h after the saline study. Naloxone did not modify the insulin response to OGTT in either group. When the data were related to the insulin response, in PCOD hyperinsulinaemic patients, naloxone significantly reduced (P less than 0.02) the insulin response to OGTT without any change in glycaemic response curves. In control and PCOD normoinsulinaemic patients, naloxone did not change significantly either the glycaemia or the insulin levels after OGTT. No change of gonadotrophin and steroid secretion was found in any patient receiving naloxone. In conclusion, endogenous opiates may play a significant role in hyperinsulinaemia in PCOD.
Nine obese and ten non-obese women with polycystic ovarian disease (PCO), and seven obese and eight non-obese normal women, had an oral glucose tolerance test (OGTT) before and after treatment with GnRH agonist (buserelin 400 micrograms/day s.c. for 8 weeks) in order to investigate the effect of ovarian suppression on their insulinaemic secretion. Luteinizing hormone (LH), follicle-stimulating hormone (FSH), oestradiol (E2), androstenedione (A), testosterone (T), DHEAS, cortisol and insulin (I) were measured at time 0 of OGTT; in all samples of OGTT, E2, T, A and I were also assayed. PCO patients showed higher basal androgen levels than control patients. All subjects showed a normal glycaemic response to OGTT. The mean fasting and areas under the curve (ISA) of plasma I were significantly greater in the obese PCO women than in non-obese PCO, the normal obese and non-obese women. All PCO patients showed significantly higher fasting I and ISA values in respect to all control patients. Hyperinsulinaemic responses were 89% in PCO obese, 30% in non-obese PCO and 29% in obese control patients. After buserelin treatment, these values did not change significantly in respect to pretreatment in all groups, in spite of a significant decrease of androgen secretion. During OGTT, no variations of steroid plasma concentrations were seen in both normal or hyperinsulinaemic PCO patients. The data of this study show that hyperandrogenism, hyperinsulinism and obesity were associated with different modalities in PCO patients and that a marked decrease of androgen secretion did not restore a normal insulinaemic response to OGTT, suggesting that hyperandrogenism does not produce hyperinsulinism.