Asymmetrical dimethylarginine, inflammatory and metabolic parameters in women with polycystic ovary syndrome before and after metformin treatment

CONTEXT: Insulin resistance plays a significant role in the pathogenesis of the polycystic ovary syndrome (PCOS) and represents a link to the unfavorable cardiovascular risk profile frequently found in affected patients. The endogenous nitric oxide synthase inhibitor asymmetrical dimethyl-L-arginine (ADMA) is associated with atherosclerosis and represents an independent marker for cardiovascular morbidity and mortality. OBJECTIVE: We investigated ADMA levels among other cardiovascular, metabolic, and hormonal parameters in women with PCOS and the effects of metformin treatment on these parameters. DESIGN: A cross-sectional study and clinical trial were performed. PATIENTS AND PARTICIPANTS: Women with PCOS (n = 83) compared with a control group of healthy women (n = 39) were studied. INTERVENTIONS: In a subgroup of patients with PCOS (n = 21), the effect of metformin was assessed after 6 months of treatment. MAIN OUTCOME MEASURES: ADMA, intima media thickness (IMT), metabolic and hormonal parameters, and markers of inflammation were investigated. RESULTS: ADMA levels were significantly higher in the PCOS group compared with controls (0.57 +/- 0.15 vs. 0.50 +/- 0.11; P = 0.024). Androgens, C-reactive protein, fasting C-peptide, area under the curve (AUC) insulin, AUC glucose, homeostatic assessment of insulin resistance, fasting insulin, glycosylated hemoglobin, cholesterol, low-density lipoprotein cholesterol, triglycerides, and IMT were significantly higher in women with PCOS compared with controls. In PCOS patients ADMA was found to be positively correlated with body mass index (BMI), waist to hip ratio, parameters of insulin sensitivity, hyperandrogenemia (free testosterone, free androgen index), and IMT. Treatment with metformin ameliorated hyperandrogenemia and decreased ADMA levels (0.53 +/- 0.06 vs. 0.46 +/- 0.09, P = 0.013). Decrease in ADMA levels subsequent to metformin treatment did not correlate with change in BMI or metabolic parameters. CONCLUSIONS: ADMA amd parameters of insulin sensitivity are elevated in women with PCOS and the degree of insulin resistance confers the greatest influence on ADMA level. Metformin treatment led to improvement of hormonal and metabolic parameters and decreased ADMA levels possibly independent of BMI and metabolic changes.     

Lower insulin sensitivity differentiates hirsute from non-hirsute Sicilian women with polycystic ovary syndrome

OBJECTIVE: It is well known that hyperandrogenism and insulin-resistance with or without compensatory hyperinsulinism are closely associated, but the Rotterdam Consensus has concluded that principally obese women with polycystic ovary syndrome (PCOS) should be evaluated for the metabolic syndrome. Our aim was to study insulin sensitivity in PCOS women with hirsutism regardless of obesity. METHODS: Clinical characteristics, sex hormones and fasting- and after OGTT-glycemia and insulinemia, homeostatic model of insulin resistance (HOMA IR), and Matsuda index of insulin sensitivity were analyzed in 130 women with PCOS. Hirsutism has been evaluated through the Ferriman-Gallwey (FG) map scoring system. RESULTS: PCOS women with hirsutism (57.7% of participants) showed significant higher values of total testosterone levels (P = 0.016), free testosterone (P = 0.027), DHEA sulfate (P = 0.017), and Delta4androstenedione (P = 0.018). They had similar body mass index (BMI) (P = 0.073) and were significantly less insulin sensitive (P = 0.002) than those without hirsutism (42.3% of participants). In women with PCOS and hirsutism, there was a significant correlation between FG score and insulin-sensitivity indexes (HOMA IR, rho = 0.33, P = 0.005; Matsuda index, rho = -0.34, P = 0.003) but not with the androgen levels. Moreover, women with hirsutism showed a significantly greater insulin (P = 0.019), C-peptide (P = 0.002), and glucose (P = 0.024) areas under the curve (auc2h). CONCLUSIONS: Our study suggests that the increased responsiveness of the pilo-sebaceous unit to androgens seems to be influenced by insulin sensitivity and that insulin resistance should be assessed in all hirsute women with PCOS regardless of their BMI, as insulin resistance was found in hirsute women irrespective of whether they were overweight or obese.     

Prevalence of adrenal androgen excess in patients with the polycystic ovary syndrome (PCOS)

OBJECTIVE: To determine the prevalence of adrenal androgen (AA) excess in the polycystic ovary syndrome (PCOS) using age- and race-specific normative values. DESIGN: Cross-sectional observational study. PATIENTS: One hundred and eight-two (88 Black and 94 White) age-matched healthy eumenorrhoeic nonhirsute women (controls) and 213 (27 Black and 186 White) women with PCOS were recruited. MEASUREMENTS: Total testosterone (T), free T, androstenedione (A4), dehydroepiandrosterone sulfate (DHEAS) and SHBG, as well as fasting insulin and glucose, were measured in plasma. RESULTS: The mean total T, free T, A4, DHEAS and body mass index (BMI) were higher in women with PCOS than in control women. DHEAS levels were significantly lower in Black controls than White controls, whereas fasting insulin and BMI were higher in Black controls. In control and Black PCOS women, DHEAS levels did not correlate with BMI, waist-to-hip ratio (WHR) or fasting insulin. Among White women with PCOS, DHEAS levels correlated negatively with BMI and fasting insulin. DHEAS levels decreased similarly with age in control and PCOS women of either race. For each race and age group the upper 95% normative values for log DHEAS was calculated, and the number of PCOS subjects with log DHEAS values above this level were assessed. The prevalence of supranormal DHEAS levels was 33.3% and 19.9%, respectively, among Black and White women with PCOS. CONCLUSIONS: The prevalence of DHEAS excess is approximately 20% among White and 30% among Black PCOS patients, when using age- and race-adjusted normative values. This study also indicates that the age-associated decline in DHEAS levels is observable and similar in both control and PCOS women, regardless of race. While BMI and fasting insulin had little impact on circulating DHEAS levels in healthy women, among White PCOS patients these parameters were negatively associated with circulating DHEAS levels.     

Differential effects of insulin sensitivity on androgens in obese women with polycystic ovary syndrome or normal ovulation

The differential effects of insulin sensitivity and adiposity on androgen concentrations in women with polycystic ovary syndrome (PCOS) are unclear. To address this issue, we divided 43 overweight women into 4 groups based on both their clinical classification (PCOS or normal) and whether they were insulin resistant (IR) or insulin sensitive (IS) by their steady-state plasma glucose concentrations. Total testosterone concentrations were significantly increased as a function of both clinical classification (PCOS vs normal, P < .0001) and steady-state plasma glucose concentration (IR vs IS, P = .002). Mean testosterone concentrations were higher in PCOS-IR compared with PCOS-IS, normal-IR, or normal-IS women (P < .005). In addition, there was a statistically significant interaction (P = .03) between clinical classification (PCOS vs normal) and insulin sensitivity (IR vs IS) for testosterone concentrations. In contrast, androstenedione concentrations were higher in women with PCOS (P = .001), irrespective of whether they were IR or IS (P = .31); and no interaction between clinical classification and insulin sensitivity was discerned (P = .34). These results indicate that both PCOS and insulin resistance independently contributed to increased total testosterone concentrations within a group of overweight/obese women. These findings are consistent with the hypothesis that the ovaries of women with PCOS are hypersensitive to the ability of insulin to increase testosterone production and that the more insulin resistant the patient, the higher the testosterone concentration. In contrast, androstenedione concentrations seem to be independent of differences in insulin resistance. Our findings emphasize the need to increase understanding of the factors that modulate ovarian androgen secretion.     

Metabolic risk factors and markers of cardiovascular and renal damage in overweight subjects

BACKGROUND: The prevalence of overweight and obesity in the United States has dramatically increased. Obesity clusters with a variety of hemodynamic and metabolic disturbances that increase the risk of cardiovascular disease. In this study we evaluated whether overweight subjects with hypertension also manifest hemodynamic and metabolic abnormalities compared with individuals of normal weight. METHODS: In a cohort of 129 patients with essential hypertension we measured the relationship between body mass index (BMI), blood pressure (BP), insulin sensitivity, lipid profile, and markers of organ damage including thickness of the carotid artery (IMT) and urine albumin excretion (UAE). A total of 41 normotensive, age-matched, healthy individuals served as control subjects. RESULTS: Hypertensive individuals showed higher levels of serum triglycerides, insulin area-under-the-curve (AUC), UAE, and greater IMT than normotensive subjects. Overweight hypertensive subjects showed higher levels of serum triglycerides, LDL cholesterol, glucose AUC, insulin AUC, UAE, and IMT than hypertensive subjects with normal body weight (BMI <25). Night-time systolic BP was higher and night-time fall in BP was lower among overweight than among normal-weight hypertensive patients. Simple regression analysis showed that BMI was correlated with age, UAE, BP, insulin and glucose AUC, serum triglycerides, cholesterol, and IMT in hypertensive subjects. However multiple regression analyses showed that BMI significantly correlated only with UAE. CONCLUSIONS: The study results show that increased body weight clusters with a variety of hemodynamic and metabolic abnormalities in hypertensive subjects. However multiple regression analyses showed a significant correlation only between BMI and UAE, a marker and predictor of cardiovascular and renal disease.     

Glucose intolerance,insulin resistance,and hyperandrogenemia in first degree relatives of women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is associated with hyperinsulinemia, insulin resistance (IR), increased risk of glucose intolerance, and type 2 diabetes. Family studies have indicated a genetic susceptibility to PCOS. The aims of this study were 1) to assess glucose tolerance status, gonadotropins, and androgens in first degree relatives of patients with PCOS; and 2) to assess IR in normal glucose tolerant (NGT) family members. One hundred two family members of 52 patients with PCOS [Mothers(PCOS) (n = 34; mean age, 46.5 yr; mean body mass index (BMI), 28.8 kg/m(2)), Fathers(PCOS) (n = 24; mean age, 50.4 yr; mean BMI, 27.5 kg/m(2)), Sisters(PCOS) (n = 19; mean age, 25.1 yr; mean BMI, 22.9 kg/m(2)), and Brothers(PCOS) (n = 25; mean age, 23.7 yr; mean BMI, 22.5 kg/m(2))] and 82 unrelated healthy control subjects without a family history of diabetes or PCOS (4 age- and weight-matched subgroups, i.e. Control(MothersPCOS), Control(FathersPCOS), Control(SistersPCOS), and Control(BrothersPCOS)) were studied. Glucose and insulin (at baseline and during a 75-g, 2-h oral glucose tolerance test) were measured. IR was assessed by fasting insulin (FI), fasting glucose to insulin ratio (FGI), homeostatic model assessment (HOMA IR), and area under the curve for insulin during the oral glucose tolerance test (AUC(insulin)) in NGT Mothers(PCOS), Fathers(PCOS), Sisters(PCOS), Brothers(PCOS), and matched control subgroups. Including the prestudy-diagnosed 3 mothers and 2 fathers with diabetes, diabetes and impaired glucose tolerance (IGT) were noted in 16% and 30% of Mothers(PCOS) and 27% and 31% of Fathers(PCOS), respectively. There was no diabetes in Sisters(PCOS) and Brothers(PCOS). IGT was found in 5% of Sisters(PCOS). Impaired fasting glucose was found in 3% of Mothers(PCOS) and 4% of Brothers(PCOS). The analysis of NGT family members showed that Mothers(PCOS) had higher FI (P < 0.05), HOMA IR (P < 0.05), and AUC(insulin) (P < 0.01) and lower FGI (P < 0.05) than Control(MothersPCOS), whereas all IR parameters were comparable between Fathers(PCOS) and their matched control subgroup. Sisters(PCOS) had higher FI (P < 0.05), HOMA IR (P < 0.01), and AUC(insulin) (P < 0.05) and lower FGI (P < 0.01), and Brothers(PCOS) had higher AUC(insulin) (P < 0.01) than their matched control subgroups, respectively. Mothers(PCOS) had higher testosterone levels than Control(MothersPCOS) (P < 0.01 and P < 0.05 for pre- and postmenopausal women, respectively). Sisters(PCOS) had higher LH (P < 0.01), testosterone (P < 0.001), androstenedione (P < 0.01), and dehydroepiandrosterone sulfate (P < 0.05) levels than Control(SistersPCOS). There was no difference in gonadotropin and androgen levels in Fathers(PCOS) compared with Control(FathersPCOS) or in Brothers(PCOS) compared with Control(BrothersPCOS). Our results suggest that 1) first degree relatives of patients with PCOS may be at high risk for diabetes and glucose intolerance; 2) NGT female family members have insulin resistance; and 3) mothers and sisters of PCOS patients have higher androgen levels than control subjects. We propose that the high risks of these impairments warrant screening in first degree relatives of patients with PCOS.     

Early endocrine, metabolic, and sonographic characteristics of polycystic ovary syndrome (PCOS): comparison between nonobese and obese adolescents

Approximately half of all women with polycystic ovary syndrome (PCOS) are overweight or obese, and studies have reported endocrine and metabolic differences between lean and obese women with PCOS. PCOS has not been as extensively investigated in the adolescent population. The objectives of our study were to further characterize early endocrine and metabolic alterations in adolescents with PCOS and to determine whether differences between nonobese and obese women with PCOS are present early in its course. We studied an ethnically heterogeneous group of 48 adolescents: 11 nonobese with PCOS [age, 16.1 +/- 1.9 yr; body mass index (BMI), 22.5 +/- 1.5 kg/m(2)], 22 obese with PCOS (age, 15.5 +/- 1.4 yr; BMI, 35.9 +/- 6.2 kg/m(2)), and 15 obese controls (age, 14.4 +/- 1.5 yr; BMI, 35.8 +/- 7.1 kg/m(2)). Fasting levels of glucose, insulin, proinsulin, hemoglobin A1c, testosterone, SHBG, Delta4-androstenedione (Delta4-A), dehydroepiandrosterone sulfate (DHEAS), LH, FSH, IGF-I, IGF binding protein-1, free IGF-I, and lipids were measured. Six of the 11 nonobese PCOS subjects, 11 of the 22 obese PCOS subjects, and six of the 15 controls underwent standard oral glucose tolerance testing. The insulin response to the oral glucose tolerance test was measured by the insulin area under the curve (I(AUC120)). Measures of insulin sensitivity were calculated as the fasting glucose to insulin ratio, quantitative insulin sensitivity check index, and composite insulin sensitivity index. The nonobese adolescents with PCOS demonstrated higher levels of LH, SHBG, Delta4-A, DHEAS, dihydrotestosterone, free IGF-I, and high-density lipoprotein, and lower low-density lipoprotein, compared with the obese PCOS group. Fasting levels of insulin and proinsulin, I(AUC120), and log I(AUC120) were higher, and the fasting glucose to insulin ratio, quantitative insulin sensitivity check index, and composite insulin sensitivity index were lower in the obese compared with the nonobese PCOS subjects. Greater levels of LH and androgens, including total and free testosterone, Delta4-A, and DHEAS, and lower SHBG levels were found in the obese PCOS group compared with the obese controls. Adolescents with PCOS manifest clinical, metabolic, and endocrine features similar to those of adult women, and differences between nonobese and obese women with PCOS may be detected in adolescence. Our findings indicate a more pronounced alteration in the hypothalamo-pituitary-adrenal axis in nonobese adolescents with PCOS and a more marked dysregulation of insulin levels and impairment of insulin sensitivity in their obese counterparts. Our data also suggest differences in the IGF system between nonobese and obese adolescents with PCOS.     

Low serum 25-hydroxyvitamin D concentrations are associated with insulin resistance and obesity in women with polycystic ovary syndrome.

Insulin resistance (IR) and central obesity are common features of the polycystic ovary syndrome (PCOS). Vitamin D is thought to play a role in the pathogenesis of type 2 diabetes by affecting insulin metabolism. The aim of our study was to investigate the effect of 25-hydroxyvitamin D (25-OH-VD) on metabolic parameters and IR in PCOS. In 120 untreated PCOS patients (median age 28 years) levels of 25-OH-VD (radioimmunoassay method provided by DiaSorin), calcium and anorganic phosphate were measured. In addition, endocrine and metabolic variables were evaluated and a glucose tolerance test was performed to assess indices of IR. In the entire PCOS cohort, 25-OH-VD concentrations were negatively correlated with body mass index (r=-0.2765), body fat (r=-0.2490), HOMA-IR (r=-0.1947), hyperinsulinemia (r=-0.1892) and leptin levels (r=-0.2834), and positively correlated with HDL cholesterol (r=0.2630) (all p<0.05). Subgroup analysis of lean, overweight and obese women revealed significant higher 25-OH-VD levels in lean women. Differences remained significant when women were divided according to their 25-OH-VD levels. Women with hypovitaminosis D (<9 ng/ml) had higher mean BMI, indices of IR and leptin levels compared to women with normal serum levels (all p<0.05). Analysis of vitamin D and biochemical endocrine PCOS features revealed a significant correlation only between 25-OH-VD and sex hormone-binding globulin as well as the free androgen index. In conclusion, in PCOS women, low 25-OH-VD levels are associated with obesity and insulin resistance but not with PCOS per se.     

Overweight women with polycystic ovary syndrome have evidence of subclinical cardiovascular disease

CONTEXT: Polycystic ovary syndrome (PCOS) is associated with insulin resistance (IR) and the metabolic syndrome. There are no adequate data demonstrating significantly increased cardiovascular disease (CVD) mortality. In the absence of clinical outcome studies, surrogate markers of early CVD can provide insight into early CVD. OBJECTIVE: The aim of this study was to clarify whether overweight women with PCOS have an increased prevalence of cardiovascular risk factors and early CVD, compared with age- and body mass index-matched controls, to determine the contribution of PCOS per se to CVD status. DESIGN AND PATIENTS: This was a case control study of 100 overweight women with PCOS and 20 subjects of similar body mass index and age. MAIN OUTCOME MEASURES: Noninvasive markers of early CVD [carotid intimal media thickness, pulse wave velocity (PWV), and brachial arterial flow-mediated vasodilation] were measured. Metabolic parameters studied included insulin, glucose, C-reactive protein, lipids, and androgens. RESULTS: Subjects with PCOS had elevated testosterone (2.5 +/- 0.2 vs. 1.3 +/- 0.1 nmol/liter), dehydroepiandrosterone sulfate (4.9 +/- 0.3 vs. 3.6 +/- 0.4 mmol/liter), fasting insulin (19.6 +/- 1.4 vs. 6.8 +/- 0.8 microU/ml), and homeostasis model assessment of IR (4.1 +/- 0.3 vs. 1.3 +/- 0.2), compared with controls. In addition, those with PCOS had elevated cholesterol (5.1 +/- 0.1 vs. 4.6 +/- 0.2 mmol/liter) and triglycerides (1.4 +/- 0.1 vs. 0.9 +/- 0.1 mmol/liter), whereas there were no differences in either C-reactive protein or 24-h ambulatory blood pressure parameters. Subjects with PCOS also had increased arterial stiffness (PWV, 7.4 +/- 0.1 vs. 6.6 +/- 0.2 m/sec) and endothelial dysfunction (flow-mediated vasodilation, 9.8 +/- 0.4 vs. 13.3 +/- 0.9), compared with controls. There was no difference in mean intimal media thickness between the groups. Stepwise regression in PCOS subjects showed that IR and lipids were independent predictors of PWV. CONCLUSION: Overweight women with PCOS have increased cardiovascular risk factors and evidence of early CVD, compared with weight-matched controls, potentially related to IR.     

Phenotypic characteristics according to insulin sensitivity in non-obese Korean women with polycystic ovary syndrome

Over 50% of women with polycystic ovary syndrome (PCOS) have been reported to have varying degree of insulin resistance and it may contribute to hyperandrogenism. The aim of the study is to identify whether the insulin resistance is present in non-obese Korean women with PCOS and whether the phenotype is different according to insulin sensitivity. Seventy-three non-obese (BMI<23 kg/m(2)) women with PCOS and 34 age and BMI comparable control women with regular menstrual cycles were examined. Standard 75 g OGTT was performed to determine the status of glucose tolerance. Insulin sensitivity was measured by euglycemic hyperinsulinemic clamp technique. The fasting plasma glucose (p<0.01) and post-glucose load plasma insulin (p<0.01) of women with PCOS were higher than those of controls. Glucose disposal rate (M-value) was lower in women with PCOS compared to controls (p<0.05). Insulin resistant (IR) and insulin sensitive (IS) PCOS were divided by the M-value of 25-percentile (5.5mg/kg min) in controls. Between IR and IS groups, DHEAS (p<0.01), post-glucose load plasma insulin (p<0.05) showed differences after the adjustment for BMI. Our non-obese women with PCOS showed significant insulin resistance compared to their age and BMI comparable control subjects and their insulin resistance may contribute to hyperandrogenism especially via adrenal androgen overproduction.     

Correlation of plasma insulin and insulin-like growth factor-I with indices of androgen transport and metabolism in women with polycystic ovary syndrome

OBJECTIVE: Polycystic ovary syndrome (PCOS) is said to be associated with hyperinsulinaemia. Insulin stimulates androgen production by ovarian tissue in vitro and previous studies have identified a positive correlation of insulin with androstenedione. The aim of the present study was to discover whether insulin levels correlate with clinical presentation and with markers of androgen transport and metabolism in women with PCOS. DESIGN: Within-group analysis of clinical and biochemical characteristics of a consecutive series of women with PCOS, focusing on correlations of plasma insulin with clinical presentation and androgens. Insulin levels were also compared with a control group of normal women. PATIENTS: Forty-seven women who presented with hirsutism, cycle abnormalities or both, with ultrasound proven PCOS, were recruited. Mean age was 26.6 +/- 0.7 years (mean +/- SEM), BMI 27.3 +/- 1.2 kg/m2. MEASUREMENTS: Plasma insulin levels were measured at 30-minute intervals for 3 hours following a 75 g glucose load. Blood was also taken for measurement of testosterone (T), androstenedione (A), free testosterone (fT), sex hormone binding globulin (SHBG) and insulin-like growth factor-I (IGF-I). Androsterone glucoronide (AG), a marker of peripheral androgen metabolism, was also measured. RESULTS: Neither basal insulin nor the sum of insulin measurements during the glucose tolerance test (sumINS) in women with PCOS were significantly different from a control group with normal ovaries. Within the PCOS group, basal insulin was greater in women with irregular cycles or amenorrhoea than in those with regular ovulatory menses (8.0 +/- 1.1 vs 3.1 +/- 1.5 mU/l, P less than 0.01) despite similarly raised androgen levels. Both basal insulin and sumINS correlated with BMI in women with PCO (r = 0.37, P less than 0.05 and r = 0.64, P less than 0.01 respectively) but not in controls. There was no significant correlation between insulin or IGF-I levels and T, A or AG despite a positive correlation of AG (but no other androgen) with BMI. SHBG showed an inverse correlation and fT correlated positively with sumINS (r = -0.51, P less than 0.01; r = 0.39, P less than 0.05). Regression analysis of each of the androgens on the other variables demonstrated no significant relationship between insulin and androgens. CONCLUSIONS: These data suggest that, in vivo, the major effect of insulin on androgen secretion is mediated by changes in SHBG rather than by direct stimulation of ovarian androgen production. Higher insulin concentrations in anovulatory compared with ovulatory women with hyperandrogenaemia may indicate that insulin resistance in the ovary contributes to the mechanism of anovulation in PCOS.     

Serum adiponectin in women with polycystic ovarian syndrome and its relation to clinical, metabolic and endocrine parameters

Several studies have demonstrated that low levels of serum adiponectin are present in obesity, insulin resistance, hypertension and hyperlipidemias. The aim of our study was to determine whether serum adiponectin level is different between patients with polycystic ovarian syndrome (PCOS) and control subjects. We also investigated relationships between various cardiovascular risk factors, levels of serum adiponectin and other hormones, such as androstendione, testosterone, estradiol, DHEAS, sex hormone binding globulin (SHBG), and leptin. We also analysed the correlation between serum adiponectin and free androgen index. Ninety-one women with clinical diagnosed PCOS and 53 healthy control subjects, carefully matched by body mass index (BMI) and age, were enrolled in the study. The fasting blood samples were obtained and all participants underwent an oral 75 g glucose tolerance test. The prevalences of impaired glucose tolerance (IGT), hypertension and hypertriglyceridemia were higher in the PCOS group. PCOS women had increased androgen concentrations and higher free androgen index and decreased level of serum SHBG. Lower serum adiponectin concentrations were observed among cases than in controls (median 13.7 microg/ml vs 17.8 microg/ml, p<0.001) despite being matched by BMI. In the PCOS group adiponectin levels correlated significantly with: BMI (r=-0.32, p=0.002), waist circumference (r=-0.32, p=0.003), waist-to-hip ratio (WHR, r=-0.38, p=0.001), triglycerides (r=-0.31, p=0.007), SHBG (r=0.30, p=0.003) and free androgen index (r=-0.29, p=0.02). In contrast, the adiponectin level does not appear to be related to total testosterone, DHEAS and leptin levels. The adiponectin and SHBG levels were found to be decreased in PCOS women with IGT compared to PCOS women with normal glucose tolerance, but after adjustment by BMI or WHR, the differences were no longer statistically significant. To exclude a possible confounding effect due to a higher prevalence of IGT in the PCOS group, this comparison was repeated for the subgroup of 58 PCOS women and 48 control women after excluding those with IGT. Neither adiponectin nor SHBG were significantly different between those subgroups. Multiple regression analysis revealed that serum adiponectin concentrations were best predicted by WHR, free androgen index and presence of IGT when all patients were considered. In PCOS subjects, the only independent predictor of adiponectin concentrations was glucose tolerance status. CONCLUSIONS: Lower adiponectin levels were observed in PCOS group than in control women, and these differences were probably due to higher prevalence of IGT in these cases.     

Age-related differences in features associated with polycystic ovary syndrome in normogonadotrophic oligo-amenorrhoeic infertile women of reproductive years.

OBJECTIVE: To assess the effect of age on clinical, endocrine and sonographic features associated with polycystic ovary syndrome (PCOS) in normogonadotrophic anovulatory infertile women of reproductive years. DESIGN: Cross-sectional study. METHODS: Four hundred and seventy-two oligo-amenorrhoeic infertile patients, presenting with normal FSH and oestradiol concentrations, aged 17-42 years underwent a standardised initial evaluation including: cycle history, body mass index, waist-to-hip ratio and transvaginal ultrasound scanning of ovaries. Fasting blood samples were obtained for extensive endocrine evaluation. Cycle duration, serum levels of gonadotrophins, androgens, oestradiol, insulin, glucose, inhibin B as well as mean number of follicles, ovarian volume and ovarian stroma echogenicity were assessed. RESULTS: Older women had significantly lower LH and androgen and inhibin B serum levels. Similarly, older women presented with a reduced number of ovarian follicles. Age was inversely correlated with cycle duration (r=-0.112, P=0.02), LH (r=-0.154, P=0.001), testosterone (r=-0.194, P=0.001), androstenedione (r=-0.170, P=0.001), dehydroepiandrosterone (r=-0.157, P=0.001), insulin (r=-0.126, P=0.02), inhibin B (r=-0.118, P=0.03) serum levels and mean follicle number (r=-0.100, P=0.03). A positive correlation was observed between age and glucose to insulin ratio (r=0.138, P=0.009). CONCLUSIONS: Advanced age in normogonadotrophic anovulatory infertile women is associated with lower LH and androgen levels and with a decreased number of ovarian follicles. Although during reproductive years observed differences are relatively small, these age-related changes may affect the observed incidence of PCOS.     

Glucose-to-insulin ratio rather than sex hormone-binding globulin and adiponectin levels is the best predictor of insulin resistance in nonobese women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS), the main androgen disorder in women, has been suggested to be associated with a high risk of developing cardiovascular disease and type 2 diabetes. In many PCOS patients, overweight or central obesity is generally associated with increases in fasting insulin levels, insulin resistance, and glucose intolerance, and has been identified as a target for new therapeutic strategy, including early change in lifestyle. Early biochemical marker(s) for identifying at-risk patients will be useful for prevention studies. The main goal of the present study was to search for such tool(s). We investigated 16 nonobese PCOS women by performing euglycemic hyperinsulinemic clamp and measuring insulin levels during fasting and oral glucose tolerance test, as well as the serum concentrations of SHBG, leptin, and adiponectin, the newly identified adipose factors. Eight of the 16 patients had a steady-state glucose disposal rate less than 8.5 mg/kg.min, the lowest normal value for nonobese control women. These insulin-resistant patients had significant higher body mass index (BMI) and waist-to-hip ratio (WHR), and lower high-density lipoprotein cholesterol and SHBG levels. As expected, glucose disposal correlated negatively with BMI (P = 0.01), WHR (P = 0.01), and fasting insulin level (P = 0.003). On stepwise regression analysis, however, the glucose-to-insulin ratio (GIR) emerged as the strongest independent parameter to appraise insulin resistance (R(2) = 0.61). SHBG level correlated positively with GIR (P < 0.001) and negatively with BMI (P = 0.003) but did not correlate with either insulin response during the glucose tolerance test or plasma leptin and/or adiponectin levels. In contrast, BMI was the only independent predictive parameter of SHBG (P = 0.003, R(2) = 0.73). Interestingly, plasma adiponectin levels were positively associated with glucose disposal rate (P = 0.043) and negatively with WHR (P = 0.024), waist circumference being the best predictor of adiponectin level (P < 0.01). Leptin level correlated only with BMI (r = 0.62, P = 0.01). This study confirmed that insulin resistance, despite the lack of obesity as such, is clearly present in many PCOS women, and demonstrated that GIR is the best predictor for insulin resistance. It was also shown that adiponectin level is a good indicator of abdominal fat mass and is associated to insulin resistance. Finally, low SHBG levels in PCOS are intimately associated with BMI, suggesting that some signal(s) from the adipose tissue, independent of adiponectin and leptin, may regulate liver production of SHBG.     

A comparison between the effects of low dose (1 microg) and standard dose (250 microg) ACTH stimulation tests on adrenal P450c17alpha enzyme activity in women with polycystic ovary syndrome

OBJECTIVE: Numerous studies have found elevated androgen production by the adrenal glands in patients with polycystic ovary syndrome (PCOS). However, the role and the mechanisms responsible for the adrenal androgen excess in women with PCOS are not well understood. DESIGN: Our aim was to compare 17-hydroxyprogesterone (17-OHP), androstenedione, dehydroepiandrosterone sulfate (DHEAS) and cortisol responses to a low dose (1 microg) ACTH stimulation test (LDT) with the responses to a standard dose (250 microg) ACTH stimulation test (SDT) in patients with PCOS. METHODS: Fifty women with PCOS (mean age 25.4+/-0.7 years) and 20 healthy women (mean age 27.3+/-2.2 years) were included in the study. The patients and controls underwent ACTH stimulation tests with 1 microg and 250 microg synthetic ACTH in the follicular phase of their cycles. Venous blood was drawn at 0, 30 and 60 min for determination of serum cortisol, 17-OHP, androstenedione and DHEAS levels. RESULTS: In PCOS subjects, peak and area under the curve (AUC) 17-OHP (9.3+/-0.3 nmol/l, 378.4+/-61 nmol/lx60 min), androstenedione (15.6+/-0.6 nmol/l, 806.4+/-52 nmol/lx60 min) and DHEAS (7.5+/-0.4 micromol/l, 385.6+/-25.5 micromol/lx60 min) responses to SDT were significantly higher than the levels in healthy women (respectively 5.7+/-0.3 nmol/l and 249.4+/-52.2 nmol/lx60 min for 17-OHP; 9.1+/-0.3 nmol/l and 413.7+/-31.6 nmol/lx60 min for androstenedione; 4.3+/-0.4 micromol/l and 224.9+/-24.5 micromol/lx60 min for DHEAS) (P<0.05). Peak and AUC cortisol responses to SDT were similar in PCOS and control subjects. Peak and AUC cortisol and 17-OHP responses to LDT in women with PCOS were similar to the values obtained in healthy women. Peak androstenedione (12.5+/-0.6 nmol/l) and peak (6.5+/-0.5 nmol/l) and AUC (336.3+/-22.4 micromol/lx60 min) DHEAS responses to LDT were significantly higher in women with PCOS. CONCLUSIONS: These results show that LDT is capable of revealing the adrenal hyperactivity in women with PCOS. Adrenal P450c17alpha enzyme dysregulation in PCOS is revealed by ACTH stimulation at a pharmacological dose (250 microg) but not by a physiological dose (1 microg). LDT is able to demonstrate adrenal hyperactivity characterized by an increase in DHEAS levels.     

Androgen response to endogenous insulin secretion during the frequently sampled intravenous glucose tolerance test in normal and hyperandrogenic women

Women with ovarian hyperandrogenism frequently have insulin resistance, whose underlying mechanism remains to be determined. In the present study we have investigated the relationship between insulin sensitivity and the acute effect of endogenous insulin secretion on circulating androgen levels. Insulin sensitivity, glucose-mediated insulin release, and glucose/insulin-stimulated androgen responses were determined during a frequently sampled iv glucose tolerance test in a group of 19 women with clinical evidence of polycystic ovary syndrome (PCOS) and 9 age- and weight-matched controls. Insulin (I), glucose, androstenedione, testosterone (T), free T, and dehydroepiandrosterone (DHEA) levels were measured before and during the 3 h following iv administration of glucose (300 mg/kg). Intravenous tolbutamide (300-500 mg) was injected 20 min after the glucose injection. Insulin sensitivity (SI) was calculated by application of the minimal model of glucose kinetics. Fasting androstenedione, T, free T, and I concentrations were significantly higher in the women with PCOS than in controls (P less than 0.02). In PCOS subjects, fasting I was correlated with both T (r = 0.51; P less than 0.05) and DHEA (r = 0.706; P less than 0.01). SI was significantly lower in PCOS subjects [SI, 68.35 +/- 8.34 min-1/(nmol/mL] than in control subjects (SI, 133.36 +/- 21.7 min-1/(nmol/mL)]. A significant decline in DHEA levels was observed in control subjects 3 h after glucose administration (from 28.4 +/- 3.0; final, 16.2 +/- 2.4; P less than 0.02). PCOS women with normal insulin sensitivity [SI, greater than 75.0 min-1/(nmol/mL)] showed a similar fall in DHEA (from 20.3 +/- 2.5 to 12.8 +/- 1.8 nmol/L; P less than 0.02). No significant change occurred in insulin-resistant PCOS subjects [SI, less than 75.0 min-1/(nmol/mL)]. Other androgen levels showed a modest nonsignificant decline during the study in PCOS and control groups. These findings confirm the weight-independent insulin resistance of some hyperandrogenic women. The failure of glucose-stimulated endogenous insulin secretion to significantly depress DHEA levels in insulin-resistant women with PCOS may account in part for their androgen excess.     

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.     

Ovarian age-related responsiveness to human chorionic gonadotropin in women with polycystic ovary syndrome

Ovarian steroid secretion capacity starts to decline as early as around the age of 30 yr. Whether an age-related decrease in androgen secretion, as in normal women, also occurs in women with polycystic ovary syndrome (PCOS) and whether the enhanced androgen production in PCOS remains throughout the fertile period of life are not known. The aim of this study was to determine the age-related serum basal and gonadotropin-stimulated androgen levels in women with PCOS and to compare the results with those obtained from our previous study in healthy women with normal ovaries. Human chorionic gonadotropin (hCG) stimulation tests were carried out among 42 women with PCOS (age, 16-44 yr; body mass index, 31.02 +/- 1.1 kg/m(2)). An im injection of 5000 IU hCG was given 2-4 d after spontaneous or progestin-induced menstrual bleeding, and blood samples for LH, FSH, inhibin B, 17-hydroxyprogesterone, androstenedione (A), testosterone (T), and estradiol assays were collected at 0, 24, 48, and 96 h. In women with PCOS, basal serum T and A levels were about 50% higher than in healthy women. The responses of A and T to hCG [area under the curve (AUC), 96 h)] were significantly higher in women with PCOS than in normal women [A, 1183.6 +/- 60 (+/-se) vs. 814.4 +/- 39 (P 相似文献   

The administration of estrogens, combined with anti-androgens, has beneficial effects on the hormonal features and asymmetric dimethyl-arginine levels, in women with the polycystic ovary syndrome

The present study was designed in order to: (a) compare ET-1 and ADMA levels, between women with PCOS (n=106) and healthy controls (n=30); (b) determine the effects of treatment with estrogens and anti-androgens on the hormonal features of PCOS, insulin resistance, ET-1 and ADMA levels. Women with PCOS were randomized in five therapeutic protocols: (I) 17beta-estradiol+cyproterone acetate 50mg; (II) conjugated estrogen+CA 50 mg; (III) ethinyl estradiole+CA 2mg; (IV) EE+CA 52 mg; (V) EE+desogestrel. In all women, gonadotropin, PRL, androgen, SHBG, insulin, glucose, ET-1 and ADMA levels were determined; in women with PCOS, testosterone, SHBG, ET-1 and ADMA levels were measured again after 3, 6, 12 months of treatment and insulin and glucose levels after 12 months. ET-1 and ADMA concentrations were higher in women with PCOS, and they were positively correlated with each other. ADMA levels were decreased and IR was increased with treatment. Treatment with synthetic estrogens (EE) resulted in a more pronounced increase in SHBG and a more pronounced decrease in FAI, compared to natural estrogens. Conclusively, PCOS is associated with endothelial dysfunction, which is ameliorated by the administration of estrogens and anti-androgens, independent of IR.     

Overweight in children is associated with arterial endothelial dysfunction and intima-media thickening

OBJECTIVE: We sought to study arterial endothelial function and carotid intima-media thickness (IMT), both early markers of atherosclerosis, in overweight compared to normal children. DESIGN: Case-control comparison. SUBJECTS: A total of 36 asymptomatic overweight children (body mass index (BMI)>23; mean 25+/-3) aged 9-12 y and 36 age- and gender-matched nonobese healthy children (BMI<21) from a school community. MEASUREMENTS: The key parameters were: BMI, arterial endothelial function (ultrasound-derived endothelium-dependent dilation) and carotid artery IMT. The secondary parameters measured included body fat content, waist-hip ratio (WHR), blood pressures, blood lipids, insulin and glucose. RESULTS: The two groups were well matched for blood pressures, cholesterol and glucose levels, but BMI (P<0.0001), body fat (P=0.001), WHR (P<0.05), fasting blood insulin (P=0.001) and triglyceride levels (P<0.05) were higher in obese children. Overweight was associated with impaired arterial endothelial function (6.6+/-2.3 vs 9.7+/-3.0%, P<0.0001) and increased carotid IMT (0.49+/-0.04 mm vs 0.45+/-0.04 mm, P=0.006). The degree of endothelial dysfunction correlated with BMI (P<0.003) on multivariate analysis. CONCLUSION: Obesity, even of mild-to-moderate degree, is independently associated with abnormal arterial function and structure in otherwise healthy young children.