Endocrine and metabolic effects of octreotide, a somatostatin analogue, in lean PCOS patients with either hyperinsulinaemia or lean normoinsulinaemia

The effects on insulin secretion and on the glycaemic and androgen status before and after short-term treatment with octreotide were evaluated in 16 normal weight patients with polycystic ovarian syndrome (PCOS). Hyperinsulinaemia was determined by measuring the insulin response after oral glucose tolerance test (OGTT). Seven patients (group A) were classified as normoinsulinaemic, while nine patients (group B) were considered hyperinsulinaemic according to insulin response after OGTT. Octreotide treatment did not modify either glycaemic or insulinaemic response after OGTT, or androgen profile, in normoinsulinaemic patients. On the contrary, a significant decrease in the basal concentrations of luteinizing hormone (LH), testosterone and androstenedione, and a significant increase in serum concentrations of sex hormone-binding globulin (SHBG) were observed in the hyperinsulinaemic group of patients, in which we observed also a significant decrease of insulinaemic response and a decompensation of the glycaemic profile after OGTT. Our study is the first report showing that: (i) octreotide does not appear to significantly influence pituitary release of gonadotrophins in this group of PCOS patients; (ii) octreotide is able to reduce insulin release, LH and androgen concentrations in lean PCOS patients with hyperinsulinaemia. Due to the presence of a decompensation of glucose homeostasis during treatment, octreotide does not seem advisable for long-term therapy of hyperandrogenism in lean PCOS patients with hyperinsulinaemia.     

Insulin secretion in polycystic ovarian disease: effect of ovarian suppression by GnRH agonist

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.     

Insulin sensitivity, insulin secretion, and metabolic and hormonal parameters in healthy women and women with polycystic ovarian syndrome

To study the contributions of body mass, body fat distribution and family history of type 2 diabetes mellitus to hyperinsulinaemia, insulin secretion and resistance in polycystic ovarian syndrome (PCOS), 17 lean (LC) and 17 obese (OC) healthy control subjects, and 15 lean (LPCOS) and 28 obese (OPCOS) women with PCOS were investigated. Waist:hip ratio (WHR), serum concentrations of sex steroids, glucose and insulin during a 75 g oral glucose tolerance test (OGTT), and insulin and C-peptide early phase secretion, and insulin sensitivity index using a euglycaemic hyperinsulinaemic clamp were assessed. The PCOS subjects had a higher mean WHR than the controls. A trend towards hyperinsulinaemia and impairment of insulin sensitivity (including the rates of both glucose oxidation and non-oxidation) was observed in LPCOS subjects, but only in OPCOS subjects were these changes significant. Early phase insulin secretion but not the early phase C-peptide secretion was increased in PCOS subjects compared to controls, suggesting that peripheral hyperinsulinaemia in PCOS women was mainly due to the observed lowered hepatic insulin extraction and insulin resistance in skeletal muscle. Moreover, the presence of a family history of type 2 diabetes did not affect early phase insulin or C-peptide secretion in the PCOS group. These results confirm and strengthen earlier contentions, that insulin resistance is a characteristic defect in PCOS and is worsened particularly by abdominal obesity.     

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.     

Effect of feeding on growth hormone response to growth hormone-releasing hormone in polycystic ovarian syndrome: relation with body weight and hyperinsulinism

The plasma growth hormone (GH) response to direct stimulation with growth hormone-releasing hormone (GHRH) before and after a standard meal was investigated in 14 polycystic ovarian syndrome (PCOS) subjects. Data were compared with those obtained from 14 healthy normovulatory matched patients. All women underwent an oral glucose tolerance test (OGTT) (75 g) and basal plasma hormone concentrations were evaluated. On a different day all subjects had a GHRH test (50 microg GHRH) both before and after lunch randomly. In obese PCOS subjects the GH response to GHRH was blunted after a meal, while in obese control patients there was an enhanced response of GH to GHRH after a meal. Normal control subjects showed an inhibition of the GH response after feeding and lean PCOS subjects showed a trend toward an augmented GHRH related secretion after a meal significantly higher than normal controls (P < 0.05) but not significantly higher than the pre-prandial response. In conclusion, the data indicate in PCOS a derangement of GH secretion related to food ingestion; in particular obese PCOS patients did not exhibit any change of GH response after a meal compared with the paradoxical response observed in obese controls. Several other factors beyond body mass index and hyperinsulinism could be involved in these pathophysiological events.     

Adipocyte resistin mRNA levels are down-regulated by laparoscopic ovarian electrocautery in both obese and lean women with polycystic ovary syndrome

BACKGROUND: The aim of this study was to investigate serum and adipocyte mRNA expression of resistin in lean and obese women with polycystic ovary syndrome (PCOS) before and 3 months after laparoscopic ovarian electrocauterization (LOE). METHODS: Adipose tissue obtained from 12 women with PCOS (six obese and six lean, body mass index > 27 kg m(-1) as threshold point) before and after LOE was analysed. Gene expression of resistin was measured by semi-quantitative RT-PCR. Ten lean, age-matched healthy women served as controls. RESULTS: Both lean and obese women with PCOS had significantly higher fasting and 2 h insulin and homeostasis model insulin resistance index (HOMA(IR)) values and lower fasting glucose-to-insulin ratios (G(0)/I(0)) than did the controls. The serum levels of glucose and insulin and HOMA(IR) were significantly decreased, and the G(0)/I(0) ratio was significantly increased 3 months after LOE. No difference was found in serum resistin levels between controls and either obese or lean women with PCOS before LOE, nor between PCOS patients before and after LOE. However, resistin mRNA expression levels in both lean and obese women with PCOS before LOE were significantly higher than that in controls and were decreased significantly after LOE back to control levels. CONCLUSION: Local resistin activity may be actively involved in the pathogenesis of PCOS. LOE reduces insulin resistance and down-regulates resistin mRNA expression in lean and obese women with PCOS.     

白细胞介素18和白细胞介素10参与多囊卵巢综合征发病的初步研究

目的探讨血清炎症因子白细胞介素18（IL-18）、白细胞介素10（IL-10）与多囊卵巢综合征（PCOS）发病的关系。方法选取48例PCOS患者和32例对照,分为肥胖组与非肥胖组。测定血清空腹血糖（FBG）、空腹胰岛素（FINS）、卵泡刺激素（FSH）、黄体生成素（LH）和睾酮（T）;酶联免疫吸附试验（ELISA）方法检测血清IL-18、IL-10。结果 PCOS组血清IL-18水平高于对照组,IL-10水平低于对照组,差异有显著性;PCOS肥胖组与非肥胖组相比,IL-18水平升高,IL-10水平下降,差异有显著性;两PCOS组与各自对照组相比,IL-18水平升高,IL-10水平下降,差异有显著性。PCOS组患者血清IL-18与BMI、WHR、FINS及HOMA-IR呈显著正相关,血清IL-10与WHR、FINS及HOMA-IR呈显著负相关。结论 PCOS患者血清中IL-18水平明显升高,IL-10水平明显下降,并且在肥胖的PCOS患者中升高和下降的更明显。慢性炎症可能参与PCOS的发病,并且与胰岛素抵抗和肥胖有关。     

Serum visfatin in relation to insulin resistance and markers of hyperandrogenism in lean and obese women with polycystic ovary syndrome

BACKGROUND: Visfatin, a protein secreted by adipose tissue, is suggested to play a role in pathogenesis of insulin resistance. In polycystic ovary syndrome (PCOS), insulin resistance might be involved in the development of endocrine and metabolic abnormalities. The aim of the study was to asses the relation between serum visfatin concentration and insulin sensitivity and markers of hyperandrogenism in lean and obese PCOS patients. METHODS: The study group consisted of 70 women with PCOS (23 lean and 47 obese) and 45 healthy women (25 lean and 20 obese). Euglycemic hyperinsulinemic clamp and the measurements of serum visfatin, sex hormones were performed. RESULTS: The PCOS group had lower insulin sensitivity (P=0.00049) and higher serum visfatin (P=0.047) in comparison to the control group. The decrease in insulin sensitivity was present in both the lean (P=0.019) and obese (P=0.0077) PCOS subjects, whereas increase in serum visfatin was observed only in lean PCOS subjects (P=0.012). In the whole group, serum visfatin was negatively correlated with insulin sensitivity (r=-0.27, P=0.004). This relationship was also observed in the subgroup of lean (r=-0.30, P=0.038), but not obese women. Additionally, in lean women, visfatin was associated with serum testosterone (r=0.47, P=0.002) and free androgen index (r=0.48, P=0.002), independently of other potential confounding factors. CONCLUSIONS: Visfatin is associated with insulin resistance and markers of hyperandrogenism in lean PCOS patients.     

Impact of overnight dexamethasone suppression on the adrenal androgen response to an oral glucose tolerance test in women with and without polycystic ovary syndrome

In order to test the hypothesis that adrenocortical overactivity, possibly related to the stress of testing, may impact on the measurement of circulating androgen concentrations during glucose- induced hyperinsulinaemia, we prospectively screened 10 patients with the polycystic ovary syndrome (PCOS) and nine healthy control women with an oral glucose tolerance test (OGTT), before and after the administration of dexamethasone. Blood sampling was performed at 0, 30, 60, 90, and 120 min following the oral ingestion of 75 g of glucose, before and after the administration of 1.0 mg dexamethasone on the evening prior to testing. Total and free testosterone, androstenedione, dehydroepiandrosterone (DHEA), DHEA sulphate (DHEAS), cortisol, glucose and insulin were assessed during the 2 h OGTT. Women with PCOS had increased basal concentrations of free testosterone, total testosterone, androstenedione, and insulin compared to control women. In women with PCOS an acute decline in circulating concentrations of DHEAS occurred during the OGTT. In PCOS women there were no changes in other ovarian or adrenal androgens during OGTT before or following dexamethasone administration. In control women DHEA concentrations declined during the OGTT. Following overnight dexamethasone suppression in control women, circulating concentrations of DHEAS and testosterone also declined. It is concluded that: (i) in PCOS women only the concentration of circulating DHEAS decreased during glucose-induced hyperinsulinaemia and dexamethasone administration did not further alter androgen responses to an OGTT; (ii) it is possible that, in these hyperandrogenic patients, the insulin-related suppression of adrenocortical testosterone and DHEA is negated by their much greater ovarian secretion of these androgens; (iii) in control women DHEA concentrations acutely declined during the OGTT and the administration of dexamethasone resulted in the acute decline of DHEA, DHEAS, and testosterone; (iv) it appears that the stress related to testing impacts on the androgen response to OGTT, at least in healthy women.      

Rosiglitazone and ethinyl estradiol/cyproterone acetate as single and combined treatment of overweight women with polycystic ovary syndrome and insulin resistance

BACKGROUND: Few studies have evaluated insulin sensitizers in comparison/association with oral contraceptives (OC) in women with polycystic ovary syndrome (PCOS) with insulin resistance (IR). This study assessed the effects of a thiazolidinedione versus an anti-androgenic estrogen-progestin followed by their sequential combinations in overweight PCOS women. METHODS AND RESULTS: Twenty-eight candidates in whom elevated insulin was not normalized after 4 months of diet were randomly assigned to 6 months of rosiglitazone 4 mg/day or to ethinyl estradiol 35 mg/cyproterone acetate 2 mg (EE/CPA: 21/28 days cycle). Each group then received both medications for another 6 months. Rosiglitazone reduced insulin, IR indices [homeostasis model assessment (HOMA) and quantitative sensitivity check index (QUICKI)] and the insulin area under the curve in response to an oral glucose tolerance test (OGTT), but had limited effect on lipids, androgens and hirsutism. EE/CPA did not modify insulin and OGTT response but increased high-density lipoprotein cholesterol and triglycerides and decreased androgens and hirsutism. Similar changes occurred during combined treatments. End results were highly significant in combined groups without noticeable side-effects or changes in safety parameters. CONCLUSIONS: In obese PCOS women with high insulin not corrected by diet, the combination of rosiglitazone and EE/CPA may be used to achieve complementary beneficial effects on endocrine-metabolic anomalies and clinical symptoms.     

Proinsulin serum concentrations in women with polycystic ovary syndrome: a marker of beta-cell dysfunction?

BACKGROUND: The aim of this study was to establish the effect of polycystic ovary syndrome (PCOS) adjusted for adiposity on proinsulin concentrations. METHODS: Ninety-one women with PCOS and 72 normal cycling (NC) women were recruited. A 2 h, 75 g oral glucose tolerance test was performed. Glucose and insulin were measured in each sample. Proinsulin and C-peptide were determined at 0 and 30 min and the fasting proinsulin/insulin ratio (PI/I) was calculated. Insulin sensitivity was estimated by insulin sensitivity index (ISI) composite, and beta-cell function was estimated by insulinogenic index. RESULTS: Insulin, proinsulin and C-peptide concentrations were higher in women with PCOS than in NC women (P < 0.05). PI/I and insulinogenic index were similar in both groups. Proinsulin concentrations increased with body mass index (P < 0.05) only in women with PCOS; therefore, proinsulin concentrations were higher in obese PCOS patients compared with obese control women (P < 0.05). Moreover, a positive association between proinsulin concentrations and waist diameter adjusted for C-peptide (P < 0.05) and a negative association between proinsulin concentrations and ISI composite values were observed in PCOS patients (P < 0.05). CONCLUSIONS: Data suggest that in PCOS patients an elevated proinsulin concentration could reflect insulin resistance more than beta-cell dysfunction. However, the elevated concentration of proinsulin in these patients could also result from impaired beta-cell function resulting from intra-abdominal obesity independently of insulin resistance.     

Leptin concentrations in hirsute women with polycystic ovary syndrome or idiopathic hirsutism: influence on LH and relationship with hormonal, metabolic, and anthropometric measurements.

BACKGROUND: The known association between leptin, obesity and insulin action suggests that leptin may have a role in polycystic ovarian syndrome (PCOS) but this has only been addressed peripherally. METHODS: We assessed the influence of leptin on LH and investigated the relationship between leptin and body mass index (BMI), waist:hip ratio (WHR), androgen concentrations, fasting insulin and insulin:glucose ratio (IGR) in 27 women with PCOS and in 20 age- and weight-matched women with regular, ovulatory menstrual cycles and idiopathic hirsutism (IH). RESULTS: Leptin concentrations were significantly higher in obese PCOS women than in normal weight women with either PCOS or IH (P = 0.0028), but did not differ between obese women with PCOS and IH. WHR, insulin concentrations and IGR were significantly higher in obese PCOS patients in comparison with the three other groups. In IH patients, the association between leptin concentrations and WHR was lost after adjustment for BMI. In PCOS patients, a significant correlation was observed between leptin and fasting insulin concentrations, IGR, WHR and LH. After adjustment for BMI, only the correlation with LH remained significant. A stepwise regression model was set up with LH as the dependent variable to test the hypothesis that the concentrations of leptin might be modulating the concentrations of LH in PCOS patients. The relationship of LH concentrations with IGR was found to be BMI dependent. In contrast, leptin concentrations contributed negatively and significantly to LH concentrations, independently of either BMI or IGR. CONCLUSIONS: We speculate that the known attenuation in basal or stimulated response of LH in obese PCOS patients might be related to leptin resistance, which could influence LH hypersecretion. In IH ovulatory patients, normal LH concentrations suggest the presence of preserved regulatory mechanisms of GnRH pulsatility. Further studies are needed to specifically investigate the proposed correlation between leptin and GnRH modulation in PCOS.     

Adiponectin and resistin in PCOS: a clinical, biochemical and molecular genetic study

BACKGROUND: We conducted a cross-sectional case-control study to evaluate the possible involvement of adiponectin and resistin in the pathogenesis of polycystic ovary syndrome (PCOS). METHODS: Seventy-six PCOS patients and 40 non-hyperandrogenic women matched for BMI and degree of obesity were included. Serum adiponectin and resistin levels, anthropometrical and hormonal variables, the 45 T-->G and 276 G-->T polymorphisms in the adiponectin gene, and the -420 C-->G variant in the resistin gene, were analysed. RESULTS: Serum adiponectin concentrations were reduced in PCOS patients compared with controls (P = 0.038) irrespective of the degree of obesity, whereas serum resistin levels were increased in overweight and obese women compared with lean subjects (P = 0.016), irrespective of their PCOS or controls status. The adiponectin and resistin polymorphisms were not associated with PCOS and did not influence serum levels of adiponectin, resistin and other clinical and hormonal variables. In a multiple regression model, the waist-to-hip ratio, free testosterone levels and age, but not insulin resistance, were the major determinants of hypoadiponectinaemia. CONCLUSIONS: PCOS patients present with hypoadiponectinaemia, in relation with abdominal adiposity and hyperandrogenism. Our present results suggest that hyperandrogenism and abdominal obesity, by reducing the serum levels of the insulin sensitizer adipokine adiponectin, might contribute to the insulin resistance of PCOS.     

Insulin resistance in women with hirsutism

Introduction

There are still not enough data showing whether patients with idiopathic hirsutism (IH) also have insulin resistance. The association between polycystic ovary syndrome (PCOS) and insulin resistance is well documented in the literature, but the Rotterdam Consensus has concluded that principally obese women with PCOS should be screened for the metabolic syndrome. We intended to investigate the presence/absence of insulin resistance in non-obese women with hirsutism.

Material and methods

Twenty-eight women with PCOS (14 non-obese and 14 obese), 12 non-obese with IH, and 16 non-obese healthy women were included in the study. The presence of insulin resistance was investigated by using basal insulin levels and the homeostasis model assessment (HOMA) score in the study group.

Results

Patients with obese and nonobese PCOS had significantly (p < 0.05) higher basal insulin levels and HOMA scores than IH and control subjects. Insulin levels and HOMA scores did not differ between obese and non-obese PCOS patients. Patients with IH did not show any difference from the control group.

Conclusions

Insulin resistance exists in non-obese women with PCOS as well as obese women with PCOS. The PCOS is associated with insulin resistance independent of obesity. Insulin resistance should be assessed in all hirsute women with PCOS regardless of their body mass index. More studies in larger numbers of patients should be performed to investigate the role of insulin resistance in women with IH.     

Controlled oral glucose tolerance test: evaluation of insulin resistance with an insulin infusion algorithm that forces the OGTT glycaemic curve within the normal range. A feasibility study.

This is a technical study to show the feasibility of a computer-controlled oral glucose tolerance test (OGTT) using a specific algorithm, consisting of an OGTT carried out while insulin is infused as required to keep glycaemia within the normal range (National Diabetes Data Group 1979 criteria). This technique allows (a) the amount of insulin (insulin area) required to maintain a normal glycaemic curve to be assessed, a parameter indicating the degree of insulin resistance; and (b) the unique parameter consisting of the insulin secretory response (C-peptide) to a normal glycaemic curve under the inhibitory feedback exerted by the insulin levels required to maintain normal glycaemia to be obtained. Preliminary results confirmed the feasibility of this approach by showing that during the test while the glycaemic area was kept normal the insulinaemic area (endogenous + infused insulin) increased markedly in obese (n = 8) and obese diabetic (n = 5) subjects compared with normal subjects (n = 6), with values of 145.10 +/- 26.71, 204.75 +/- 20.77 and 68.25 +/- 5.93 nmol l-1 min-1 respectively (P < 0.01 in both instances). In contrast, endogenous insulin secretion (C-peptide levels) remained almost unchanged. Compared with data in normal subjects, free fatty acid (FFA) values were basally elevated in the obese and obese diabetic patients, and underwent a smaller decrease during the test. The FFA areas were greater than normal in both groups of patients, suggesting that FFAs were not fully suppressible despite the highest possible insulin levels (higher insulin levels would produce hypoglycaemia). The computer-controlled OGTT might be useful for the metabolic study of patients in the clinical setting.     

Effect of ovarian suppression on glucose metabolism of young lean women with and without ovarian hyperandrogenism

Gonadal steroids are believed to influence glucose metabolism, oestrogens inducing an improvement and androgens or progestins a deterioration. At baseline and after 3 months of ovarian suppression with a gonadotrophin-releasing hormone analogue (GnRHa: goserelin depot 3.75 mg/28 days), glucose metabolism was evaluated in eight lean women affected by ovarian hyperandrogenism (PCOS) and six age-weight-matched non-hyperandrogenic women (controls) by using both an oral glucose tolerance test (75 g; OGTT) and the minimal model method. The latter method allows calculation of peripheral insulin sensitivity (Si) and glucose dependent glucose utilization (Sg). In PCOS, higher fasting concentrations (P < 0.05) of insulin and C-peptide, and lower Sg (P < 0.05) and Si (P < 0.01) were found. GnRHa did not significantly modify glucose metabolism of controls, while in women with PCOS it decreased fasting glucose (P < 0.05) and significantly increased Si (P < 0.03) up to control values. The present data indicate that strong suppression of ovarian activity improves Si in lean women with PCOS, while it is without relevant effects on glucose metabolism of non-hyperandrogenic women.     

Serum and follicular resistin levels in women with polycystic ovarian syndrome during IVF-stimulated cycles

BACKGROUND: Resistin is a hormone linking obesity and insulin resistance. The aim of this study was to compare resistin levels in serum or follicular fluid from women with polycystic ovarian syndrome (PCOS) and controls, both of whom were undergoing IVF. METHODS: We compared serum and follicular resistin levels in 21 PCOS women and in 18 healthy, normal ovulation, age- and body mass index (BMI)-matched non-PCOS women undergoing IVF. Correlations between serum or follicular fluid resistin levels and reproductive outcome were evaluated. RESULTS: There was no significant difference in either serum or follicular resistin levels between the control group and the PCOS group as a whole or those with insulin resistance [homeostasis model assessment of insulin resistance index applied to oral glucose tolerance test (HOMA(OGTT)) <4.7]. However, resistin levels in follicular fluid were unexpectedly significantly lower than serum levels (P<0.0001) in both the PCOS and control groups. No significant correlation was found between resistin levels and BMI, estradiol, LH, or fasting or 2 h glucose or insulin levels or between follicular resistin levels and fertilization rate, implantation rate, clinical pregnancy rate, or early miscarriage rate in PCOS. CONCLUSION: Resistin is unlikely to be a major determining factor in the growth and maturation of oocytes during IVF-stimulated cycles in PCOS.     

Endocrino-metabolic features in women with polycystic ovary syndrome during pregnancy

To elucidate the mechanism of metabolic adaptation of women with polycystic ovary syndrome (PCOS) during pregnancy, the endocrino- metabolic features of a group of PCOS patients with or without gestational diabetes were studied longitudinally during the three trimesters of gestation. Oral glucose tolerance test (OGTT, 100 g) and hyperinsulinaemic-euglycaemic clamp were performed throughout the study. Plasma concentrations of insulin and glucose were determined by radioimmunoassay and glucose oxidase technique, respectively. Five of 13 PCOS patients developed gestational diabetes (GD) at the third trimester (PCOS-GD), while the other eight patients did not develop any alteration of glucose metabolism (PCOS-nGD). Both fasting glucose and insulin plasma concentrations did not change significantly during pregnancy and no difference was seen between the two groups. On the contrary PCOS-GD group early exhibited higher values of area under the curve (AUC) for glucose and insulin response to OGTT with respect to those found in PCOS-nGD group. This difference was already significant in the first gestational trimester. Moreover insulin sensitivity value (M) was significantly lower in the first trimester of gestation in PCOS- GD as compared with that found in PCOS-nGD group. However, as gestation proceeded, M value decreased in PCOS-nDG group and the difference from PCOS patients developing gestational diabetes was not sustained into the second and third trimesters. Both groups had similar body mass index values and AUC insulin increase from first to third trimester of gestation. It is concluded that early alteration of insulin sensitivity and secretion constitute specific risk factors in PCOS patients for the development of abnormalities of glucose tolerance.      

Effect of pioglitazone treatment on the adrenal androgen response to corticotrophin in obese patients with polycystic ovary syndrome

BACKGROUND: To investigate the effect of pioglitazone on adrenal steroidogenesis in polycystic ovary syndrome (PCOS), we studied 11 obese (two with BMI >25 kg/m(2); nine with BMI >27 kg/m(2)) PCOS women before and after 6 months of treatment at a dose of 45 mg/day. METHODS: During the early follicular phase, ultrasonography and hormonal assays were performed. On separate days, all women underwent an oral glucose tolerance test (OGTT), a euglycaemic hyperinsulinaemic clamp and an adrenocorticotrophin hormone (ACTH) test. The same protocol was repeated after therapy. RESULTS: Pioglitazone treatment significantly reduced the insulin response to OGTT and improved the insulin sensitivity indices (P < 0.01 and P = 0.03 respectively). A significant decrease was found in LH (P < 0.05) and androstenedione (P < 0.01) levels after therapy, whereas the other hormonal parameters improved but not significantly. Pioglitazone administration reduced the response of 17alpha-hydroxyprogesterone (17OHP) and androstenedione to ACTH (P < 0.01 and P < 0.02 respectively), most likely through an inhibition of cytochrome P450. The same treatment was able to rebalance the relative activity of 17,20-lyase, as documented by an increase in the androstenedione:17OHP ratio (P < 0.05) after ACTH stimulation. CONCLUSIONS: Our data support the contention that insulin enhances ACTH-stimulated steroidogenesis, while inducing a relative impairment of 17,20-lyase activity. Whether the beneficial effects of pioglitazone on this imbalance could be related to the ameliorated glyco-insulinaemic metabolism or to a direct effect on the adrenal glands remains to be determined.     

Early impaired ��-cell function in chinese women with polycystic ovary syndrome

Background: The pathogenic factors that account for the development of diabetes condition in Chinese women with polycystic ovary syndrome (PCOS) remain elusive. Aim: To clarify the pathogenic features by evaluating the levels of insulin sensitivity and β cell function in these women with PCOS, either separately or by using of a disposition indexes (DIs). Methods: Cross-sectional study involving 137 Chinese women with PCOS and 123 normal women were examined by anthropometry, lipid profile, sex hormone, high-sensitivity C reactive protein, oral glucose tolerance tests and insulin tolerance tests. Results: After controlling for BMI status, the Matsuda Index was significantly lower in women with PCOS in comparison to those of normal women (p<0.000). The early phase of insulin secretion (insulinogenic index) remained significantly lower in lean women with PCOS(LP) than those of both lean and obese women of control group (p=0.007, and p = 0.01, respectively). The mean HOMA-F values were significantly lower (p =0.045) in obese women with PCOS (OP) than those of BMI-matched women. Further, all DIs derived from non-fasting state indexes in women with PCOS were significantly lower than those of BMI-matched control women (p<0.001 for all). Lastly, DIs derived from fasting states indexes in OP were significantly lower than those of LP. Conclusion: Early impaired β cell function was detected in both LP and OP. However, more serious primary defect in insulin action was detected in LP compared to OP. These findings imply that early screening and intervention for PCOS would be therapeutic for Chinese women.