Increased growth hormone response to clonidine in nonobese normoinsulinemic patients with polycystic ovary syndrome

High sensitive serum C-reactive protein and its relationship with other cardiovascular risk factors in normoinsulinemic polycystic ovary patients without metabolic syndrome

PURPOSE

The aims of the study were to investigate high sensitive serum C-reactive protein (HS-CRP) levels in normoinsulinemic polycystic ovary syndrome (PCOS) patients without metabolic syndrome and whether there was any relationship between HS-CRP and other cardiovascular risk factors such as obesity and serum lipids.

METHODS

A total of 52 normoinsulinemic PCOS women without metabolic syndrome and 48 normoandrogenic ovulatory women were enrolled in the study. Standard clinical examinations, and ultrasonographic and endocrine screening including FSH, LH, total testosterone, free testosterone, sex hormone-binding globulin, dehydroepiandrosterone sulfate, low-density lipoprotein (LDL), high-density lipoprotein (HDL), total cholesterol (TC) and triglyceride (TG) were measured. Normal insulin sensitivity was defined on the basis of fasting serum glucose and insulin levels, serum insulin response to an oral glucose tolerance test and homeostatic model of insulin resistance. HS-CRP was assessed spectrophotometrically.

RESULTS

PCOS patients had increased HS-CRP compared to the control group (P < 0.0001). HS-CRP was positively correlated with body mass index (BMI) (r = 0.44, P < 0.0001), waist-to-hip ratio (WHR) (r = 0.66, P < 0.0001), LDL (r = 0.62, P < 0.0001), TC (r = 0.56, P < 0.0001) and TG (r = 0.38, P < 0.0001), and negatively correlated with HDL (r = -0.45, P < 0.0001). There was also a strong association between HS-CRP and PCOS status (r = 0.69, P < 0.0001) in the study. Multivariate regression analysis demonstrated that BMI, WHR, LDL, HDL and PCOS status were also the independent variables that influenced HS-CRP in the overall group.

CONCLUSION

Elevated HS-CRP was associated with cardiovascular risk factors in normoinsulinemic PCOS without metabolic syndrome. These patients need more intensive screening or treatment for this disease.

Modulation of the acoustic startle response by the level of arousal: comparison of clonidine and modafinil in healthy volunteers

A sudden loud sound evokes an electromyographic (EMG) response from the orbicularis oculi muscle in humans together with an auditory evoked potential (AEP) and an increase in skin conductance (SC). Startle responses are inhibited by weak prepulses (prepulse inhibition, (PPI)) and may also be modified by the level of alertness. We compared the sedative drug clonidine and the alerting drug modafinil on sound-evoked EMG, AEP, and SC responses, on the PPI of these responses and on level of arousal and autonomic functions. Sixteen healthy male volunteers participated in four weekly sessions (clonidine 0.2 mg, modafinil 400 mg, their combination, placebo) in a double-blind, cross-over, balanced design. Responses were evoked by sound pulses of 115 and 85 dB (PPI) for 40 ms and recorded conventionally. Level of alertness, autonomic functions (pupil diameter, blood pressure, heart rate, salivation, temperature) and the plasma levels of the hormones prolactin, thyroid-stimulating hormone and growth hormone were also measured. Data were analyzed with analysis of variance with multiple comparisons. Both prepulses and clonidine attenuated all three startle responses and modafinil antagonized clonidine's effects on the EMG and AEP responses. None of the drugs affected PPI. Clonidine showed sedative and sympatholytic effects, and modafinil showed alerting and sympathomimetic effects. In conclusion, startle responses were susceptible not only to PPI but also to the level of arousal.

Estimation of truncal adiposity using waist circumference or the sum of trunk skinfolds: a pilot study for insulin resistance screening in hirsute patients with or without polycystic ovary syndrome

Insulin resistance (IR) is an independent risk factor for cardiovascular disease and is a prevalent metabolic disturbance among women with polycystic ovary syndrome (PCOS). Central adiposity, a marker of IR and an accurate anthropometric method to estimate truncal adiposity, may represent a key clinical tool for IR screening in subpopulations at higher metabolic and cardiovascular risk, such as women with PCOS. The aims of the present study were (1) to investigate the influence of androgens on IR and central obesity in overweight or obese hirsute women with or without PCOS and (2) to test the reliability of the sum of trunk skinfolds (subscapular, suprailiac, and abdominal) to estimate truncal adiposity. This observational, cross-sectional study included 37 hirsute patients with body mass index of 25 kg/m(2) or greater and aged between 14 and 41 years. Twenty-four had PCOS, and 13 had ovulatory cycles, normal androgen levels, and isolated hirsutism, named idiopathic hirsutism (IH). Nutritional, anthropometric, clinical, and laboratory evaluations were performed. Body composition was assessed by measurement of waist circumference and skinfold thickness and by dual-energy x-ray absorptiometry (DXA). Both groups presented similar ages, body mass index, and hirsutism score. The PCOS group had higher androgen levels, homeostasis model assessment (HOMA) index, and fasting insulin levels. Free androgen index was positively associated with HOMA, independent of truncal adiposity (r = 0.441, P = .009). Strong correlations were also observed between truncal adiposity measured by DXA and both the sum of trunk skinfolds (r = 0.863, P = .0001) and waist circumference in hirsute patients (r = 0.947, P = .0001). In our study, IR (HOMA index >/=3.8) was associated with truncal obesity, with a more androgenic profile, and with an unfavorable lipid profile. In conclusion, hirsutism per se appears not to be a risk for IR and related cardiovascular disease unless there is presence of central adiposity and/or abnormal androgen profile as observed in patients with PCOS. Waist circumference and the sum of trunk skinfolds represent accurate methods to estimate truncal adiposity, but waist circumference measurement seems to be the simplest method of clinical screening for IR in hirsute women.

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

OBJECTIVE

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

DESIGN

Prospective, controlled study.

SETTING

Academic research environment.

PATIENT(S)

Twenty obese women with PCOS, and 15 obese controls.

INTERVENTION(S)

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

MAIN OUTCOME MEASURE(S)

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

RESULT(S)

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

CONCLUSION(S)

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

CAPN10 UCSNP-43, UCSNP-19 and UCSNP-63 polymorphisms and metabolic syndrome in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a heterogeneous endocrine disorder with individual susceptibility determined by genetic and environmental risk factors. Recently, studies have evaluated the CAPN10 gene in PCOS patients, suggesting that different alleles may play a role in PCOS susceptibility. We performed a cross-sectional study with 88 southern Brazilian hirsute patients with PCOS or idiopathic hirsutism (IH) to assess the influence of CAPN10 genetic variants on clinical and biochemical features of metabolic syndrome. PCOS patients were defined by oligo/amenorrheic cycles (<9 cycles/year), increased levels of serum testosterone and/or free androgen index, and exclusion of other disorders associated with hyperandrogenism. IH was diagnosed in hirsute patients with regular ovulatory cycles (luteal-phase progesterone levels >3.8 ng/ml), normal androgen levels, and without any known underlying disease (n = 29). Metabolic syndrome was defined according to the 2001 criteria of the National Cholesterol Education Program, Adult Treatment Panel III. UCSNP-43 polymorphism of CAPN10 was related to metabolic syndrome (p = 0.047) in PCOS; UCSNP-19 and UCSNP-63 were not associated with phenotypic traits in PCOS. These results provide evidence that CAPN10 gene UCSNP-43 polymorphisms may influence the PCOS metabolic phenotype. This should be further confirmed in large population-based studies.

Association between ovarian volume and serum insulin levels in ovulatory patients with idiopathic hirsutism

We assessed the influence of insulin on ovarian volume in 45 women with regular, ovulatory menstrual cycles, normal androgen levels, and isolated hirsutism (idiopathic hirsutism). Insulin levels, insulin-to-glucose ratio, and homeostasis model assessment (HOMA) were significantly higher in patients with ovarian volume >9 cm3 than in women with smaller ovaries (P<.05), and insulin levels presented a significant positive correlation with ovarian volume (r = 0.37, P=.02), which was independent of body mass index (BMI) or the luteinizing hormone/follicle-stimulating hormone (LH/FSH) ratio.

Association between androgen receptor gene CAG repeat polymorphism and plasma testosterone levels in postmenopausal women

OBJECTIVES

The biologic action of androgens in target cells depends on plasma androgen levels and receptor transcriptional activity. We investigated the relationship between androgen receptor (AR) CAG repeat polymorphism, serum androgen levels, and anthropometric, metabolic, and hormonal variables in 39 postmenopausal women, taking into consideration the patterns of X-chromosome inactivation.

METHODS

Genomic DNA was extracted from peripheral leukocytes. Polymerase chain reactions (PCRs) were performed to amplify the polymorphic (CAG)n repeat of the human AR gene, which were analyzed with GeneScan software (Applied Biosystems, Foster City, CA). The X-chromosome inactivation analysis was based on the AR gene methylation patterns.

RESULTS

The mean age of participants was 54.7 years; mean age at menopause was 48 years. The number of CAG repeats ranged from 15 to 30, with a median length of 23. Analysis of X-chromosome inactivation patterns showed 19 cases with a degree of skewing (DS) > or =70% and seven with a DS > or =90%. The X-weighted CAG repeat biallelic mean was significantly lower in individuals with total testosterone (TT) greater than 0.56 ng/mL (group mean) than in the group with TT < or =0.56 (P=.018). No difference was observed between the groups regarding dehydroepiandrosterone sulfate (DHEA-S). Plasma TT was significantly higher in the group with the smaller X-weighted CAG repeat biallelic mean (P=.01). Free androgen index (FAI) was also significantly higher in this group (P=.033). Testosterone levels and FAI were inversely correlated to X-weighted CAG repeat biallelic mean.

CONCLUSION

Our data indicate an association between testosterone plasma levels and AR CAG repeats in postmenopausal women, and suggest that plasma levels of androgens in postmenopausal women may be related to variants of the AR gene.

PCOS: an ovarian disorder that leads to dysregulation in the hypothalamic–pituitary–adrenal axis?

This review focuses on the role of the ovaries in the pathogenesis of the polycystic ovarian syndrome. In particular, the failure of follicular development, hypothalamo-pituitary dysregulation, alterations in adrenal steroid output and derangement of intermediary metabolism are discussed in the context of the ovaries. It is concluded that the central and adrenal alterations associated with PCOS are unlikely to be primary but rather are secondary to the events within the ovary.