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.     

Genetic determinants of insulin action in polycystic ovary syndrome.

INTRODUCTION: Insulin resistance is associated with both type 2 diabetes (T2 D) and polycystic ovary syndrome (PCOS). There is an association of T2 D with several polymorphisms in candidate genes related to insulin resistance. However, there is limited information about the association of these polymorphisms with PCOS. METHODS: 57 non-diabetic women with PCOS and a control group of 567 healthy non-diabetic women underwent an oral glucose tolerance test (OGTT). They were genotyped for the polymorphisms Gly972Arg in IRS-1, Gly1057Asp in IRS-2, SNP 43, 44, and 45 in CAPN10, Pro12Ala in PPAR(gamma)2, C-512 T in FOXC2, and T45 G in adiponectin. RESULTS: Women with PCOS had higher 2-h blood glucose levels (6.5 +/- 0.2 vs. 6.0 +/- 0.06 mmol/l, p = 0.03) compared to control women, higher fasting insulin (79 +/- 7 vs. 53 +/- 2 pmol/l, p = 0.02), and a lower insulin sensitivity estimated from the OGTT (12.4 +/- 1.1 vs. 19.1 +/- 0.5 U, p = 0.0001). More homozygous G allele carriers of the T45 G polymorphism in the adiponectin gene were found in women with PCOS compared to controls (13.2 % vs. 2.6 %, p = 0.008). In women with PCOS, G-allele carriers had lower fasting insulin levels than TT carriers (61 +/- 9 vs. 88 +/- 10, p = 0.02) in contrast to controls (p = 0.03 for interaction genotype x PCOS). The other polymorphisms were distributed equally among women with PCOS and controls (all p > 0.5). SUMMARY: We found a higher prevalence of the T45 G polymorphism in the adiponectin gene in women with PCOS compared to controls. This was not associated with a more insulin resistant phenotype in PCOS, however. Other frequent polymorphisms in genes related to insulin resistance and type 2 diabetes showed no association with PCOS.     

Effect of long-term orlistat treatment on serum levels of advanced glycation end-products in women with polycystic ovary syndrome

BACKGROUND Women with polycystic ovary syndrome (PCOS) exhibit elevated serum advanced glycation end-products (AGE) compared with healthy subjects. Short-term administration of orlistat has been shown to reduce the postmeal increase in serum AGE levels in women with PCOS and in controls. OBJECTIVE: To evaluate the long-term effect of orlistat and a low-calorie diet on serum AGE levels, and on the hormonal and metabolic profile of obese PCOS and normal women. DESIGN: A clinical trial of 6 months of orlistat administration with an energy-restricted diet [basic metabolic rate (BMR) 600 kcal/day] in all subjects. SUBJECTS: Twenty-nine women with PCOS [aged 27.52 +/- 5.77 years; body mass index (BMI) 35.43 +/- 5.31 kg/m(2)] and 18 controls (aged 32.06 +/- 5.64 years; BMI 36.39 +/- 6.47 kg/m(2)). MEASUREMENTS: Serum AGE levels (U/ml), hormonal and metabolic profile. RESULTS: PCOS and controls did not differ in BMI (P = 0.58), waist-to-hip ratio (WHR) (P = 0.44), fasting insulin concentration (P = 0.45) and glucose-to-insulin ratio (GIR) (P = 0.34). PCOS women exhibited statistically higher AGE (P < 0.001) and testosterone levels (P < 0.001) compared with controls. After 6 months of orlistat treatment, AGE levels showed a statistically significant decrease in both groups (PCOS: baseline 9.08 +/- 1.84, post-orlistat 8.56 +/- 1.95, P = 0.001; controls: baseline 5.02 +/- 0.62, post-orlistat 4.91 +/- 0.69, P = 0.03), independently of the BMI reduction in the PCOS group. A significant reduction was observed in BMI (PCOS: P < 0.001; controls: P < 0.001), WHR (PCOS: P = 0.002; controls: P = 0.04), fasting insulin (PCOS: P < 0.001; controls: P = 0.008), and testosterone concentrations in PCOS (P < 0.001). SHBG concentration (PCOS: P = 0.004; controls: P = 0.008) and GIR (PCOS: P < 0.001; controls: P = 0.03) were significantly increased. A significant improvement was also observed in insulin resistance indices post-treatment in both groups. CONCLUSIONS: Our data suggest that orlistat has a beneficial effect in reducing elevated AGE levels and improving the hormonal and metabolic profile in women with PCOS after 6 months of treatment, independently of BMI changes.     

Polycystic ovary syndrome is associated with obstructive sleep apnea and daytime sleepiness: role of insulin resistance

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder of premenopausal women, characterized by chronic hyperandrogenism, oligoanovulation, and insulin resistance. Obstructive sleep apnea (OSA) and excessive daytime sleepiness (EDS) are strongly associated with insulin resistance and hypercytokinemia, independently of obesity. We hypothesized that women with PCOS are at risk for OSA and EDS. Fifty-three women with PCOS (age range, 16-45 yr) and 452 control premenopausal women (age range, 20-42), from a general randomized sample for the assessment of prevalence of OSA, were evaluated in the sleep laboratory for 1 night. In addition, women with PCOS were tested for plasma free and weakly bound testosterone, total testosterone, and fasting blood glucose and insulin concentrations. In this study, PCOS patients were 30 times more likely to suffer from sleep disordered breathing (SDB) than the controls [odds ratio = 30.6, 95% confidence interval (7.2-139.4)]. Nine of the PCOS patients (17.0%) were recommended treatment for SDB, in contrast with only 3 (0.6%) of the control group (P < 0.001). In addition, PCOS patients reported more frequent daytime sleepiness than the controls (80.4% vs. 27.0%, respectively; P < 0.001). PCOS patients who were recommended treatment for SDB, compared with those who were not, had significantly higher fasting plasma insulin levels (306.48 +/- 52.39 vs. 176.71 +/- 18.13 pmol/L, P < 0.01) and a lower glucose-to-insulin ratio (0.02 +/- 0.00 vs. 0.04 +/- 0.00, P < 0.05). Plasma free and total testosterone and fasting blood glucose concentrations were not different between the two groups of PCOS women. Our data indicate that SDB and EDS are markedly and significantly more frequent in PCOS women than in premenopausal controls. Also, insulin resistance is a stronger risk factor than is body mass index or testosterone for SDB in PCOS women. These data support our proposal that, independently of gender, sleep apnea might be a manifestation of an endocrine/metabolic abnormality in which insulin resistance plays a principal role.     

Hyperglycemia alters tumor necrosis factor-alpha release from mononuclear cells in women with polycystic ovary syndrome

CONTEXT: Women with polycystic ovary syndrome (PCOS) are often insulin resistant and have chronic low-level inflammation. OBJECTIVE: The purpose of this study was to determine the effects of hyperglycemia on lipopolysaccharide (LPS)-stimulated TNFalpha release from mononuclear cells (MNC) in PCOS. DESIGN: The study was designed as a prospective controlled study. SETTING: The study was carried out at an academic medical center. PATIENTS: Sixteen reproductive age women with PCOS (eight lean, eight obese) and 14 age-matched controls (eight lean, six obese) participated in the study. MAIN OUTCOME MEASURES: Insulin sensitivity (IS) was derived from a 2-h 75-g oral glucose tolerance test (IS(OGTT)). Percentage of truncal fat was determined by dual-energy absorptiometry. TNFalpha release was measured from MNC cultured in the presence of LPS from blood samples drawn fasting and 2 h after glucose ingestion. RESULTS: IS(OGTT) was lower in women with PCOS compared with controls (3.9 +/- 0.4 vs. 6.3 +/- 1.0; P < 0.03) and was negatively correlated with percentage of truncal fat (r = 0.56; P < 0.002). Truncal fat was greater in lean women with PCOS compared with lean controls (29.8 +/- 2.6 vs. 23.8 +/- 2.5%; P < 0.04). The TNFalpha response was different between obese and lean controls (-96.9 +/- 21.2 vs. 24.4 +/- 21.6 pg/ml; P < 0.03) and obese and lean women with PCOS (-94.1 +/- 34.5 vs. 30.4 +/- 17.6 pg/ml; P < 0.002). Fasting plasma C-reactive protein was elevated (P < 0.003) in obese PCOS and obese controls compared with lean controls. CONCLUSION: An increase in abdominal adiposity and increased TNFalpha release from MNC after hyperglycemia may contribute to insulin resistance in lean PCOS patients. In contrast, obese PCOS patients have more profound chronic inflammation, and thus may have LPS tolerance that protects them from relatively mild excursions in blood glucose.     

The cardiovascular risk of young women with polycystic ovary syndrome: an observational, analytical, prospective case-control study

To evaluate the cardiovascular risk of polycystic ovary syndrome (PCOS), we investigated lipid profile, metabolic pattern, and echocardiography in 30 young women with PCOS and 30 healthy age- and body mass index (BMI)-matched women. PCOS women had higher fasting glucose and insulin levels, homeostasis model assessment score of insulin sensitivity, total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) levels, and TC/high density lipoprotein cholesterol (HDL-C) ratio and lower HDL-C levels than controls. Additionally, PCOS women had higher left atrium size (32.0 +/- 4.9 vs. 27.4 +/- 2.1 mm; P < 0.0001) and left ventricular mass index (80.5 +/- 18.1 vs. 56.1 +/- 5.4 g/m(2); P < 0.0001) and lower left ventricular ejection fraction (64.4 +/- 4.1 vs. 67.1 +/- 2.6%; P = 0.003) and early to late mitral flow velocity ratio (1.6 +/- 0.4 vs. 2.1 +/- 0.2; P < 0.0001) than controls. When patients and controls were grouped according to BMI [normal weight (BMI, >18 and <25 kg/m(2)), overweight (BMI, 25.1-30 kg/m(2)), and obese (BMI, >30 kg/m(2))], the differences between PCOS women and controls were maintained in overweight and obese women. In normal weight PCOS women, a significant increase in left ventricular mass index and a decrease in diastolic filling were observed, notwithstanding no change in TC, LDL-C, HDL-C, TC/HDL-C ratio, and TG compared with controls. In conclusion, our data show the detrimental effect of PCOS on the cardiovascular system even in young women asymptomatic for cardiac disease.     

Overexpression of the phosphoprotein enriched in diabetes gene product (Ped/pea-15) in women with polycystic ovary syndrome

OBJECTIVE: To evaluate Ped/pea-15 (phosphoprotein enriched in diabetes) expression in polycystic ovary syndrome (PCOS) women. DESIGN AND PATIENTS: Thirty PCOS women were studied and compared with other 30 age- and body mass index (BMI)-matched women, considered as the control group. Both patients and controls were divided according to BMI. All subjects underwent endocrine and metabolic investigation and Ped/pea-15 expression was evaluated by western blot analysis. Insulin resistance was assessed by HOMA model and insulin sensitivity index (ISI) composite. RESULTS: Insulin resistance, evaluated by HOMA-R and ISI composite, was significantly higher in PCOS women and in obese controls than in normal weight controls. Ped/pea-15 expression (%) was higher in PCOS women than in controls (440.4 +/- 220.7 vs. 163.0 +/- 45.5; P < 0.001; range 145.5-987% and 97-281%, respectively), and was positively correlated with insulin, BMI, total testosterone, HOMA index, and family history (P < 0.001). In patients with PCOS univariate analysis of variance showed no effect of BMI variation (P = 0.13) on Ped/pea-15 expression levels. On multiple linear regression analysis, the major determinants of Ped/pea-15 overexpression were family history, insulin, and PCOS status independent of BMI. CONCLUSION: These preliminary data (1) highlight the overexpression of Ped/pea-15 in PCOS compared to normal controls, independent of obesity; (2) suggest that Ped/pea-15 overexpression might be an early component of the metabolic syndrome in PCOS; and (3) support the hypothesis that Ped/pea-15 represents a possible useful tool to assess the presence of a genetic condition associated with insulin resistance in PCOS.     

Gender differences in relation to leptin concentration and insulin sensitivity in nondiabetic Chinese subjects.

OBJECTIVE: To investigate the relationship between fasting plasma leptin concentrations and insulin resistance in Chinese men and women. DESIGN: Cross-sectional study design. SUBJECTS: Ninety-six nondiabetic Chinese (51 men and 45 women) with body mass index (BMI) between 18.4-35.8 kg/m2 were studied. MEASUREMENTS: Plasma glucose and insulin concentrations were measured every 30 min for 2 h after a 75 g oral glucose load. The degree of insulin resistance was assessed using a modified insulin suppression test. Plasma leptin values were determined by radioimmunoassay. RESULTS: Fasting plasma glucose, glucose areas, fasting insulin, insulin areas, most of the lipoprotein concentrations and steady state plasma glucose (SSPG) concentrations were relatively similar between men and women. Despite the fact that men had higher BMI values (26.1 +/- 0.5 vs 24.7 +/- 0.5 kg/m2, P < 0.05), fasting plasma leptin concentrations were significantly lower in men than in women (4.9 +/- 0.5 vs 9.0 +/- 0.8 ng/ml, P < 0.001). Fasting leptin values were positively related to SSPG concentrations by simple correlation analysis in both sexes. However, this relationship persisted in men (r = 0.513, P < 0.01) but not in women (r = 0.119, P = NS) after adjustment for BMI. Multiple regression analysis showed that SSPG concentrations, BMI, glucose and insulin responses together accounted for 62.5% and 52.2% of the variation in plasma leptin concentrations in Chinese men and women respectively. CONCLUSION: Fasting plasma leptin concentrations were lower in Chinese men than in Chinese women despite the higher BMI observed in men. After adjustment for BMI, plasma leptin values correlated with the degree of insulin resistance in men but not in women.     

Defining constant versus variable phenotypic features of women with polycystic ovary syndrome using different ethnic groups and populations

CONTEXT: The phenotype of women with polycystic ovary syndrome (PCOS) is variable, depending on the ethnic background. OBJECTIVE: The phenotypes of women with PCOS in Iceland and Boston were compared. DESIGN: The study was observational with a parallel design. SETTING: Subjects were studied in an outpatient setting. PATIENTS: Women, aged 18-45 yr, with PCOS defined by hyperandrogenism and fewer than nine menses per year, were examined in Iceland (n = 105) and Boston (n = 262). INTERVENTION: PCOS subjects underwent a physical exam, fasting blood samples for androgens, gonadotropins, metabolic parameters, and a transvaginal ultrasound. MAIN OUTCOME MEASURES: The phenotype of women with PCOS was compared between Caucasian women in Iceland and Boston and among Caucasian, African-American, Hispanic, and Asian women in Boston. RESULTS: Androstenedione (4.0 +/- 1.3 vs. 3.5 +/- 1.2 ng/ml; P < 0.01) was higher and testosterone (54.0 +/- 25.7 vs. 66.2 +/- 35.6 ng/dl; P < 0.01), LH (23.1 +/- 15.8 vs. 27.6 +/- 16.2 IU/liter; P < 0.05), and Ferriman Gallwey score were lower (7.1 +/- 6.0 vs. 15.4 +/- 8.5; P < 0.001) in Caucasian Icelandic compared with Boston women with PCOS. There were no differences in fasting blood glucose, insulin, or homeostasis model assessment in body mass index-matched Caucasian subjects from Iceland or Boston or in different ethnic groups in Boston. Polycystic ovary morphology was demonstrated in 93-100% of women with PCOS in all ethnic groups. CONCLUSIONS: The data demonstrate differences in the reproductive features of PCOS without differences in glucose and insulin in body mass index-matched populations. These studies also suggest that measuring androstenedione is important for the documentation of hyperandrogenism in Icelandic women. Finally, polycystic ovary morphology by ultrasound is an almost universal finding in women with PCOS as defined by hyperandrogenism and irregular menses.     

Raised plasminogen activator inhibitor-1 (PAI-1) is not an independent risk factor in the polycystic ovary syndrome (PCOS)

BACKGROUND: It has been postulated that an insulin-driven increase in plasminogen activator inhibitor-1 (PAI-1) levels may link insulin resistance to anovulatory infertility in women with PCOS and that it may place them at increased risk of thromboembolic disease. However, previous studies have been conflicting because many have failed to control for body mass index (BMI) which may affect PAI-1. The aim of this study was to investigate PAI-1 activity in women with PCOS and to compare it with unaffected controls of a similar BMI. DESIGN AND PATIENTS: 41 women with PCOS and 25 weight-matched controls participated in this cross-sectional study. Patients were evaluated clinically and by pelvic ultrasound and fasting blood samples were taken for haematological and biochemical tests. MEASUREMENTS: PAI-1 activity, insulin, glucose, triglycerides, total cholesterol, LDL cholesterol, HDL cholesterol, FSH, LH, PRL, testosterone, SHBG, 17-hydroxyprogesterone, plasminogen, fibrinogen (alpha2 antiplasmin, blood pressure and insulin sensitivity with a homeostasis model assessment (HOMA) computer programme. RESULTS: There was no significant difference in BMI or in (log) PAI-1 activity in women with PCOS compared with controls (BMI 29.5 +/- 5.6 vs. 28.4 +/- 6.3 kg/m2, P = 0.25 and PAI-1 2.56 (SD 0.85) vs. 2.14 (SD 0.98) au/ml, P = 0.07). The median fasting insulin level was significantly higher (17 (4.6-134.5) vs. 9.6 (3.7-41.5) mU/l, P < 0.01), and insulin sensitivity significantly lower in the PCOS group, ( 43.17% (5. 48-160) vs. 82.8% (21.8-193), P < 0.01). Women with PCOS also had a significantly higher free androgen index, LH/FSH ratio and a lower HDL/total cholesterol ratio. However blood pressure and all other lipid and haematological measurements were not significantly different between both groups. There were significant positive correlations between (log) PAI-1 activity and BMI (rho = 0.61), triglycerides (rho = 0.49) and fasting insulin (rho = 0.60) and a negative correlation with HDL cholesterol (rho = - 0.46). Triglyceride concentrations showed the most significant relationship with (log) PAI-1 activity on multiple regression. 29% of PCO women (12/41) gave a positive family history of thrombosis compared to 8% (2/25) in the control group. CONCLUSION: Plasminogen activator inhibitor-1 activity is not raised in women with PCOS independent of obesity and these results do not support the hypothesis that it may contribute to their anovulatory infertility, or increase their risk of thrombosis. The only significant metabolic features of the PCOS independent of obesity are insulin resistance, hyperinsulinaemia and lower HDL/total cholesterol ratio. The higher frequency of a positive family history of thrombosis in these women nevertheless requires further explanation.     

Adiponectin is independently associated with insulin sensitivity in women with polycystic ovary syndrome

OBJECTIVE: The polycystic ovary syndrome (PCOS) is associated with obesity and insulin resistance predisposing to diabetes mellitus type 2 and atherosclerosis. Adiponectin is a recently discovered adipocytokine with insulin-sensitizing and putative antiatherosclerotic properties. The aim of the study was to elucidate determinants of circulating adiponectin levels and to investigate the potential role of adiponectin in insulin resistance in PCOS women. PATIENTS AND MEASUREMENTS: Plasma adiponectin and parameters of obesity, insulin resistance and hyperandrogenism were measured In 62 women with PCOS and in 35 healthy female controls. RESULTS: Both in PCOS and controls, adiponectin levels were lower in overweight or obese women than in normal-weight women, without any difference between PCOS and controls after adjustment for body mass index (BMI). In PCOS and in controls there was a significant correlation of adiponectin with BMI (r = -0.516, P < 0.001), fasting insulin (r = -0.404, P < 0.001), homeostasis model sensitivity (HOMA %S) (r = -0.424, P < 0.001) and testosterone (r = -0.279, P < 0.01), but no correlation with androstenedione (r = -0.112, P = 0.325), 17-OH-progesterone (r =-0.031, P = 0.784) or the LH/FSH ratio (r =-0.033, P = 0.753). Multiple linear regression analysis revealed that BMI and HOMA %S but not testosterone were independently associated with adiponectin plasma levels, explaining 16% (BMI) and 13% (HOMA %S) of the variability of adiponectin, respectively. In PCOS patients insulin sensitivity, as indicated by continuous infusion of glucose with model assessment (CIGMA %S) was significantly correlated with adiponectin (r = 0.55; P < 0.001), BMI (r =-0.575; P < 0.001), waist-to-hip ratio (WHR) (r =-0.48; P = 0.001), body fat mass assessed by dual-energy X-ray-absorptiometry (DEXA) [Dexa-fat (total) (r = -0.61; P < 0.001) and Dexa-fat (trunk) (r = -0.59; P < 0.001)] and with testosterone (r = -0.42; P = 0.001). Multiple linear regression analysis demonstrated that markers of obesity such as BMI, total or truncal fat mass, age and adiponectin were independently associated with CIGMA %S, and that circulating adiponectin accounted for about 18% of the degree of insulin resistance in PCOS. By contrast, testosterone was not a significant factor, suggesting that PCOS per se did not affect insulin sensitivity independent from obesity, age and adiponectin. Metformin treatment for 6 months in insulin-resistant PCOS women (n = 9) had no effect on plasma adiponectin (P = 0.59) despite significant loss of weight and fat mass and improvement in hyperandrogenaemia. CONCLUSIONS: PCOS per se is not associated with decreased levels of plasma adiponectin. However, circulating adiponectin is independently associated with the degree of insulin resistance in PCOS women and may contribute to the development and/or maintenance of insulin resistance independent from adiposity.     

Total ghrelin levels during acute insulin infusion in patients with polycystic ovary syndrome

Controversial data were reported concerning fasting ghrelin (decreased, normal or elevated) in polycystic ovary syndrome (PCOS). The aim of our study was to clarify ghrelin levels in non-obese, overweight, and obese PCOS patients; to investigate the effect of acute insulin infusion on ghrelin in PCOS as a chronic insulin-resistant state, with and without the impact of obesity, and to examine ghrelin-androgen interaction. In that order, we evaluated 1) ghrelin levels among 8 nonobese patients with PCOS [body mass index (BMI): 20.52+/-1.31 kg/m2], 8 overweight and obese patients with PCOS (BMI: 34.36+/-6.53 kg/m2) and their respective controls, 2) ghrelin suppression during euglycemic hyperinsulinemic clamp, and 3) ghrelin-androgen interrelationship. After overnight fast, 2-h euglycemic hyperinsulinemic clamp, was performed in all investigated women. Fasting ghrelin was significantly lower in non-obese PCOS than in controls (64.74+/-25.69 vs 108.36+/-52.60; p<0.05) as well as in overweight and obese PCOS in comparison with controls (38.71+/-14.18 vs 98.77+/-40.49; p<0.05). Insulin infusion significantly suppressed ghrelin in all subgroups of investigated women. Analysis of variance for repeatable measures confirmed that there was no significant difference in pattern of response between PCOS and controls. In conclusion, women with PCOS had lower fasting ghrelin and decreased insulin sensitivity independently of their BMI, compared to the controls. In addition, there were no differences between fasting ghrelin levels among non-obese, overweight, and obese women with PCOS. During euglycemic hyperinsulinemic clamp, ghrelin decreased in all studied groups to a similar extent, implying that, compared to chronic hyperinsulinemia, acute hyperinsulinemia reduces ghrelin levels independently of the degree of insulin resistance.     

Effects of rosiglitazone in obese women with polycystic ovary syndrome and severe insulin resistance

Our objective was to evaluate the effectiveness of the insulin-sensitizing agent rosiglitazone in obese women with polycystic ovary syndrome (PCOS) and severe insulin resistance. Twelve obese women with PCOS were recruited. All were hirsute and anovulatory with acanthosis nigricans indicating severe insulin resistance. All women were treated with 4 mg of rosiglitazone daily for 6 months. A standard 75-g oral glucose tolerance test with insulin levels was performed before and after the women were treated with rosiglitazone. Glucose and insulin areas under the curve (AUC) were calculated. Serum levels of total and free testosterone, dehydroepiandrosterone sulfate, LH, and 17-hydroxyprogesterone were also measured before and after treatment. The body mass index was determined before and after treatment. There was a highly significant (r = 0.881, P < 0.0001) positive correlation between insulin response during oral glucose tolerance test and basal total testosterone levels. After treatment with rosiglitazone, there were significant decreases in fasting insulin levels (46.0 +/- 6.5 vs. 16.9 +/- 2.0 microU/ml; P < 0.001), insulin AUC (749.3 +/- 136.3 vs. 225.0 +/- 15.7 microU/ml; P = 0.003), fasting glucose levels (90.8 +/- 3.0 vs. 81.8 +/- 1.9 mg/dl; P = 0.003), and glucose AUC (437.9 +/- 25.0 vs. 322.5 +/- 14.7 mg/dl; P < 0.001). Both total testosterone (96.3 +/- 17.3 vs. 56.1 +/- 5.8 ng/dl; P = 0.01) and free testosterone (5.8 +/- 0.6 vs. 3.4 +/- 0.5 pg/ml; P < 0.001) decreased significantly after treatment, although there was no significant change in LH levels. Levels of SHBG increased significantly (18.3 +/- 3.4 vs. 25.8 +/- 6.6 nmol/liter; P = 0.009) after treatment, and dehydroepiandrosterone sulfate levels decreased significantly (P = 0.04). There was no significant change in body mass index (40.4 +/- 2.4 vs. 41.1 +/- 2.7 kg/m(2)). Eleven of the women reverted to regular ovulatory cycles during the treatment period. We conclude that 1) rosiglitazone therapy improves insulin resistance and glucose tolerance in obese women with PCOS; 2) rosiglitazone decreases ovarian androgen production, which appears to be independent of any changes in LH levels; 3) hyperinsulinemia appears to play a key role in the overproduction of ovarian androgens in these women because attenuation of insulin levels is associated with decreased testosterone levels; and 4) short-term rosiglitazone therapy helps restore spontaneous ovulation.     

Effect of low-dose oral contraceptives on metabolic risk factors in African-American women

CONTEXT: The effect of oral contraceptive pill (OCP) use on cardiovascular risk in African-American women is unknown. OBJECTIVE: Our objective was to examine in African-American women the effect of OCP use on insulin resistance, glucose intolerance, and triglycerides (TGs). DESIGN: This was a cross-sectional study. SETTING: The study was conducted at the National Institutes of Health Clinical Research Center. PARTICIPANTS: A total of 104 healthy nondiabetic African-American women [21 OCP users, 83 controls, age mean +/- sd, 34.7 +/- 7.6 yr, body mass index (BMI) 31 +/- 8.4 kg/m(2)] was included in the study. INTERVENTIONS: Subjects had oral glucose tolerance tests, insulin-modified frequently sampled iv glucose tolerance tests, and fasting lipid profiles. Insulin resistance was determined by the insulin sensitivity index (S(I)). MAIN OUTCOME MEASURES: Insulin resistance, glucose tolerance status, and TG levels were determined. RESULTS: Fasting glucose did not differ between OCP users and controls (P = 0.27). In contrast, compared with controls, 2-h glucose (135 +/- 23 vs.120 +/- 25 mg/dl; P = 0.01) and fasting TGs (73 +/- 31 vs.57 +/- 27 mg/dl; P = 0.02) were higher in OCP users. OCP users tended to be more insulin resistant than controls (S(I): 2.51 +/- 2.01 vs. 3.46 +/- 2.09; P = 0.09). Multiple regression analysis revealed that BMI, age, and OCP use were significant determinants of 2-h glucose (adjusted R(2) = 0.37; P < 0.001) and TG levels (adjusted R(2) = 0.21; P < 0.001). As BMI was a determinant of both 2-h glucose and TGs, participants were divided into nonobese and obese groups, and the analyses repeated. Among the nonobese women, the OCP users were more insulin resistant (S(I): 2.91 +/- 1.58 vs. 4.35 +/- 1.88; P = 0.03) and had a higher prevalence of glucose intolerance than controls (odds ratio 5.7; 95% confidence interval 1.4-24; P = 0.01). CONCLUSION: In African-American women, OCP use is associated with an increase in markers of cardiovascular risk manifested by increased insulin resistance, glucose intolerance, and elevated TGs.     

Plasma homocysteine in polycystic ovary syndrome: does it correlate with insulin resistance and ethnicity?

BACKGROUND: Polycystic ovary syndrome (PCOS) is associated with insulin resistance and premature coronary artery disease (CAD). Hyperhomocysteinaemia is a recognized risk factor for atherosclerosis, particularly among migrant South Asians, and has recently been shown to be correlated positively with the degree of insulin resistance/hyperinsulinaemia. OBJECTIVES: To compare total plasma homocysteine (Hcy) in PCOS with controls from ethnic groups at high and low risk of insulin resistance. METHODS: Case control study of three ethnic groups, Sri Lankans (SL), British Asians (BA) and white Europeans (C), with and without PCOS at specialist centres in Sri Lanka and Yorkshire, UK. Fasting total plasma Hcy concentration was analysed by fluorescence polarization immunoassay and examined for any correlation with age, body mass index (BMI), central obesity, fasting insulin and insulin sensitivity [calculated by the Quantitative Insulin Sensitivity Check Index (QUICKI) method], lipids and testosterone in each ethnic group. RESULTS: Eighty SL with PCOS and 45 controls, 47 BA with PCOS and 11 controls, and 40 C with PCOS and 22 controls were studied. Both Asian groups with PCOS were younger than affected Europeans (P = 0.008). Sri Lankans with PCOS had significantly lower BMI values than other affected groups: mean +/- SEM (SL) 26.3 +/- 0.95; (BA) 30.59 +/- 7.54; (C) 32.1 +/- 5.95 kg/m2 (P = 0.006). However, waist : hip ratios (WHR) of Sri Lankans with PCOS were similar to others: mean +/- SEM (SL) 0.97 +/- 0.01 (BA) 1.04 +/- 0.02 (C) 0.92 +/- 0.01, P = 0.33. Mean plasma Hcy was significantly higher in all PCOS groups than in their ethnically matched controls (Student's t-test): (SL) 10.2 +/- 1.9 vs 9.0 +/- 3.8, P = 0.01; (BA) 7.9 +/- 1.9 vs 6.8 +/- 2.5, P < 0.0001; (C) 8.3 +/- 2.3 vs 6.8 +/- 1.5, P = 0.0007 micromol/l. Sri Lankans with PCOS had significantly greater Hcy concentrations than British Asians and Europeans with PCOS [P = 0.001; single-factor analysis of variance (anova)] and also significantly greater fasting insulin concentrations [(SL) 242.9 +/- 38.9; (BA) 89.4 +/- 8.9; (C) 48.6 +/- 4.8 pmol/l (P = 0.0003)] and significantly lower QUICKI [(SL) 0.308 +/- 0.004; (BA) 0.335 +/- 0.005; (C) 0.375 +/- 0.002 (P = 0.0007)]. Fasting plasma Hcy correlated best with fasting insulin (r = 0.56, P = 0.0001) and QUICKI (r =-0.53, P < 0.0001) in Sri Lankans with PCOS. Hcy in PCOS subjects from all three ethnic groups correlated significantly with fasting insulin following adjustment for age, BMI and WHR (r = 0.45, P = 0.0001), but this was not evident in the controls (r =-0.32, P = 0.1). CONCLUSIONS: Elevation of fasting plasma homocysteine in PCOS varies with ethnicity and correlates significantly with fasting insulin. High homocysteine in young Sri Lankans with PCOS has major implications for their long-term risk for atherosclerosis.     

Decreased soluble leptin receptor levels in women with polycystic ovary syndrome

OBJECTIVE: Polycystic ovary syndrome (PCOS) is associated with insulin resistance and a high incidence of obesity. Leptin, the product of the ob gene, is involved in the regulation of energy balance and obesity and circulates in both free and bound forms. The soluble leptin receptor (sOB-R) is the most important leptin-binding protein, thus influencing the biologically active free leptin level. DESIGN: We assessed the correlation of metabolic and endocrine parameters with leptin and sOB-R levels in 122 PCOS women (aged 27 +/- 5.7 years) and 81 healthy controls (aged 25 +/- 4.0 years). METHODS: Leptin and sOB-R levels were measured using ELISA kits. In addition, anthropometric variables, body fat and endocrine parameters were evaluated and a glucose tolerance test performed to assess indices of insulin resistance and glucose metabolism. RESULTS: In PCOS patients, no correlation was found between leptin or sOB-R and parameters of hyper-androgenism. However, as expected, body mass index (BMI), body fat, waist circumference and indices of insulin resistance were significantly correlated with leptin in PCOS subjects and controls. In a subgroup analysis of lean, overweight and obese PCOS patients, significant differences were found in leptin (29.7 +/- 20.7 vs 45.4 +/- 25.0 vs 67.7 +/- 28.8 ng/ml, P < 0.0001) and sOB-R (8.0 +/- 3.4 vs 6.4 +/- 2.5 vs 5.7 +/- 2.3 ng/ml, P < 0.05). Compared with BMI-matched controls, lean PCOS patients had lower sOB-R levels (8.0 +/- 3.4 vs 12.7 +/- 4.7 ng/ml, P < 0.0001) and higher free leptin indices (4.5 +/- 3.9 vs 2.8 +/- 2.2, P = 0.0285). CONCLUSION: Taking into account that low sOB-R levels supposedly compensate diminished leptin action, PCOS per se might cause leptin resistance.     

Increased circulating levels of matrix metalloproteinase-2 and -9 in women with the polycystic ovary syndrome

INTRODUCTION: Matrix metalloproteinases (MMPs) have been implicated in various pathological processes including inflammatory response, cardiovascular disease, and recently also in ovarian dysfunction. Polycystic ovary syndrome (PCOS) is the most common endocrinopathy in women of reproductive age and is characterized by chronic anovulation, insulin resistance, and increased prevalence of cardiovascular risk factors. Circulating levels of MMPs and their tissue inhibitors (TIMPs) so far have not been assessed in the PCOS. MATERIALS AND METHODS: Serum levels of MMP-2, MMP-9, TIMP-1, and TIMP-2 were measured in 23 women with PCOS [age (mean +/- sd), 30.5 +/- 6.7 yr; body mass index, 35.8 +/- 7.5 kg/m2] and 22 healthy, regularly menstruating women (age, 29.4 +/- 5.6; body mass index, 31.7 +/- 9.2 kg/m2). RESULTS: Women with PCOS had significantly higher concentrations of MMP-2 (999.8 +/- 155 vs. 521.8 +/- 242 ng/ml; P < 0.001), MMP-9 (592.4 +/- 279 vs. 345 +/- 309; P = 0.007), and TIMP-1 levels (823.8 +/- 145 vs. 692 +/- 210 ng/ml; P = 0.02) than control healthy women. There was no difference in TIMP-2 levels (47.3 +/- 30 vs. 44.4 +/- 39.7 ng/ml; P = 0.21) between women with PCOS and controls. CONCLUSIONS: Obese women with PCOS have elevated serum concentrations of MMP-2 and -9. It might be hypothesized that elevated MMP concentrations may be related to increased cardiovascular risk in PCOS and/or menstrual irregularities associated with this syndrome.     

Effect of rosiglitazone on insulin resistance, C-reactive protein and endothelial function in non-obese young women with polycystic ovary syndrome

OBJECTIVE: Women with polycystic ovary syndrome (PCOS) exhibit elevated levels of serum C-reactive protein (CRP) and impaired endothelium dysfunction which are directly correlated with insulin resistance. Because rosiglitazone improves insulin sensitivity, we tested whether rosiglitazone treatment ameliorates high-sensitivity (hs)CRP levels and endothelial dysfunction in these patients. DESIGN: Thirty-one women with PCOS were recruited (mean age, 24.7+/-3.9 (s.e.) years; mean body mass index (BMI), 25.6+/-3.2 kg/m2). All women were treated with 4 mg rosiglitazone daily for 12 months. METHODS: Serum levels of testosterone, LH, FSH, sex hormone-binding globulin (SHBG), insulin and hsCRP were measured. The BMI, hirsutism scores and insulin sensitivity indices were calculated before and after treatment. Arterial endothelium and smooth muscle function was measured by examining brachial artery responses to endothelium-dependent and endothelium-independent stimuli before and after treatment. RESULTS: After treatment with rosigitazone there were significant decreases in serum testosterone (91.2+/-37.5 vs 56.1+/-21.8 ng/dl; P < 0.01) and fasting insulin concentrations (12.5+/-7.6 vs 8.75+/-4.03 microU/ml; P = 0.015). Insulin resistance indices were significantly improved after rosiglitazone treatment (P < 0.05). There were no significant changes in BMI, waist circumference, serum total cholesterol, low-density lipoprotein (LDL)-cholesterol, FSH and LH levels. Hirsutism score was decreased significantly after treatment (10.8+/-1.8 vs 7.6+/-1.7; P < 0.05). Twenty-four of the women reverted to regular menstrual cycles. Levels of SHBG increased significantly after treatment (28.7+/-8.7 vs 48.4+/-11.2 nmol/l; P < 0.01). Serum hsCRP levels were decreased significantly after rosiglitazone treatment (0.25+/-0.1 vs 0.09+/-0.02 mg/dl; P = 0.006). There was also significant improvement in endothelium-dependent vascular responses after rosiglitazone treatment (9.9+/-3.9 vs 16.4+/-5.1%; P < 0.01). CONCLUSIONS: We conclude that rosiglitazone treatment improves insulin sensitivity in women with PCOS. It also decreases androgen production without significant weight gain. More importantly, it has beneficial effects on endothelial dysfunction and low-grade chronic inflammation in normal weight young women with PCOS.     

Microcirculatory damage of common carotid artery wall in obese and non obese subjects

The objective of the present study was to determine whether the intima-media thickness (IMT) is independently related with obesity, and central fat accumulation in healthy subjects. Common carotid artery IMT, parameters of body fat accumulation and distribution (body mass index, waist circumference, waist-to-hip ratio), blood pressure levels, and circulating fasting insulin, glucose, and lipid (cholesterol, HDL-cholesterol, triglycerides, LDL-cholesterol) levels were determined in a population of non-diabetic normal weight and obese subjects. Smoking habits (packs-years) were also taken into account. 239 healthy subjects (143 women and 96 men), with age ranging between 18 and 45 years, were enrolled into the study. They were divided indo two groups according to the body mass index (BMI), obese (132 subjects, 77 woman and 55 men, with BMI greater than 27.0) and controls (107 subjects: 66 women and 41 men, with BMI lower than 27.0). Common carotid artery intima-media thickness was measured by B-mode ultrasound imaging. Fasting plasma metabolic parameters (glucose and lipids) and insulin levels were determined by enzymatic and radioimmunological assays, respectively. Insulin sensitivity was estimated by insulin tolerance test (ITT) and the rate constant for plasma glucose disappearance (KITT) during the 3- to 15-min period following the regular insulin injection was taken as a measure of in vivo insulin action. Obese patients showed higher IMT than controls, and IMT was significantly associated with BMI in the whole population (r = 0.316, p < 0.001). Age (r = 0.327, p < 0.001), KITT (r = -0.201, p < 0.01), fasting blood glucose (r = 0.187, p < 0.01), LDL-chol (r = 0.201, p < 0.01), smoking (r = 0.147, p < 0.05), MBP levels (r = 0.154, p < 0.05), cholesterol (r = 0.152, p < 0.05) and HDL-chol (r = -0.159, p < 0.05) were also significantly associated with IMT. Age (r = 0.330, p < 0.05), BMI (r = 0.299, p < 0.01), waist (r = 0.312, p < 0.001), WHR (r = 0.266, p < 0.001) and KITT (r = -0.259, p < 0.01) were the parameters most strongly correlated with IMT in women, and age (r = 0.324, p < 0.001), BMI (r = 0.338, p < 0.001) waist (r = 0.325, p < 0.001) and LDL-chol (r = 0.283, p < 0.01) where the parameters most strongly correlated with IMT in men. When a stepwise multiple regression analysis was performed for the whole population, only age (p < 0.001) and BMI (p < 0.001) maintained a significant positive relationship with IMT. When a stepwise multiple regression analysis was performed separately for men and women, BMI or waist circumference or WHR were alternatively entered into the model; interestingly, only age, BMI and waist were still significantly correlated with IMT, whereas WHR did not maintain a significant correlation with IMT. In conclusion, BMI and waist circumference, but not WHR, are strongly and independently associated with the IMT of common carotid artery. These results suggests that central fat accumulation may accelerate the development of earlier clinically silent stages of atherosclerosis, thus possibly explaining the higher prevalence of cardiovascular diseases in patients with abdominal obesity.     

Increased levels of serum advanced glycation end-products in women with polycystic ovary syndrome

OBJECTIVE: Women with polycystic ovary syndrome (PCOS) carry a number of cardiovascular risk factors and are considered to be at increased risk for atherosclerosis. Elevated concentrations of advanced glycation end-products (AGE), which exert their effects through interaction with specific receptors (RAGE), have been implicated in the cellular and tissue damage during atherosclerotic processes. DESIGN/PATIENTS: We investigated serum AGE levels in 29 young women with PCOS as well as the expression of their receptor, RAGE, in circulating monocytes and compared them levels with 22 healthy control women. MEASUREMENTS/RESULTS: Women with PCOS had higher levels of serum AGE proteins compared to healthy individuals (9.81 +/- 0.16 vs. 5.11 +/- 0.16, P < 0.0001), and increased RAGE expression was observed in monocytes of PCOS women compared to controls (30.91 +/- 10.11 vs. 7.97 +/- 2.61, P < 0.02). A positive correlation was observed between AGE proteins and testosterone (T) levels (r = 0.73, P < 0.0001). The correlation between AGE proteins and T levels remained high (partial correlation coefficient = 0.61, P = 0.0001) after controlling for body mass index (BMI), insulin levels and the area under the curve for glucose (AUCGLU) during an oral glucose tolerance test (OGTT). A positive correlation was also observed between AGE proteins and the free androgen index (FAI) (r = 0.58, P < 0.0001), waist-to-hip ratio (WHR) (r = 0.31, P < 0.02), insulin (r = 0.46, P < 0.001), homeostasis model assessment (HOMA) (r = 0.47, P < 0.0001), AUCGLU (r = 0.52, P < 0.002) and RAGE (r = 0.59, P < 0.01). A negative correlation was observed between AGE proteins and glucose/insulin ratio (GLU/INS) (r = -0.35, P < 0.01), and the quantitative insulin sensitivity check index (QUICKI) (r =-0.50, P < 0.01). In multiple regression analysis T was the only independent predictor of AGE levels (P < 0.0001, b = 0.044) between BMI, insulin, SHBG and AUCGLU (adjusted R2 = 0.59, F = 44.41, P < 0.0001). CONCLUSION: These data clearly demonstrate, for the first time, that PCOS women without overt hyperglycaemia have increased AGE levels and elevated RAGE expression when compared with controls.