Association between copy-number variation on metabolic phenotypes and HDL-C levels in patients with polycystic ovary syndrome.

Polygenic diseases with a broad phenotypic spectrum, such as polycystic ovary syndrome (PCOS), present a particular challenge in terms of identifying the underlying genetic mechanisms, nevertheless genetic variants have impact on the individual phenotype. We aimed to determine if next to genetic variations like SNPs further mechanisms might play a role in the pathogenesis of PCOS. We examined the effect of copy-number variations (CNVs) on metabolic phenotypes in PCOS. The intragenic rs1244979, rs2815752 in NEGR1 gene, and rs780094 in GCKR gene were genotyped and CNVs were determined by droplet digital polymerase chain reaction (ddPCR) in PCOS patients (n = 153) and controls without metabolic syndrome (n = 142). The study indicated that SNPs are not associated with the pathogenesis of PCOS but affect metabolic phenotypes. The CNVs investigated show a lower variability in PCOS than in CON. Furthermore, we provided direct evidence that the copy number, but not the genotype of the CNV in the genomic regions of rs780094(GCKR) is associated with low level of high-density lipoprotein cholesterol in PCOS. This study supports the hypothesis that not only genetic variants, but also CNVs in metabolically relevant genes, have an effect on metabolic phenotypes in our group of PCOS patients.

A key role of GARP in the immune suppressive tumor microenvironment.

In melanoma patients, one of the main reasons for tumor immune escape and therapy failure is the immunosuppressive tumor microenvironment. Herein, suppressive immune cells and inhibitory factors secreted by the tumor itself play a central role.In the present study we show that the Treg activation marker GARP (glycoprotein A repetitions predominant), known to induce peripheral tolerance in a TGF-ß dependent way, is also expressed on human primary melanoma. Interestingly, membrane bound GARP is shed from the surface of both, activated Treg and melanoma cells, and, in its soluble form (sGARP), not only induces peripheral Treg but also a tumor associated (M2) macrophage phenotype. Notably, proliferation of cytotoxic T cells and their effector function is inhibited in the presence of sGARP. GARP expression on Treg and melanoma cells is significantly decreased in the presence of agents such as IFN-α, thus explaining at least in part a novel mechanism of action of this adjuvant therapy.In conclusion, GARP in its soluble and membrane bound form contributes to peripheral tolerance in a multipronged way, potentiates the immunosuppressive tumor microenvironment and thus acts as a negative regulator in melanoma patients. Therefore, it may qualify as a promising target and a new checkpoint for cancer immunotherapy.

How Soluble GARP Enhances TGFß Activation.

GARP (glycoprotein A repetitions predominant) is a cell surface receptor on regulatory T-lymphocytes, platelets, hepatic stellate cells and certain cancer cells. Its described function is the binding and accommodation of latent TGFß (transforming growth factor), before the activation and release of the mature cytokine. For regulatory T cells it was shown that a knockdown of GARP or a treatment with blocking antibodies dramatically decreases their immune suppressive capacity. This confirms a fundamental role of GARP in the basic function of regulatory T cells. Prerequisites postulated for physiological GARP function include membrane anchorage of GARP, disulfide bridges between the propeptide of TGFß and GARP and connection of this propeptide to αvß6 or αvß8 integrins of target cells during mechanical TGFß release. Other studies indicate the existence of soluble GARP complexes and a functionality of soluble GARP alone. In order to clarify the underlying molecular mechanism, we expressed and purified recombinant TGFß and a soluble variant of GARP. Surprisingly, soluble GARP and TGFß formed stable non-covalent complexes in addition to disulfide-coupled complexes, depending on the redox conditions of the microenvironment. We also show that soluble GARP alone and the two variants of complexes mediate different levels of TGFß activity. TGFß activation is enhanced by the non-covalent GARP-TGFß complex already at low (nanomolar) concentrations, at which GARP alone does not show any effect. This supports the idea of soluble GARP acting as immune modulator in vivo.

Kinome Profiling of Regulatory T Cells: A Closer Look into a Complex Intracellular Network.

Regulatory T cells (Treg) are essential for T cell homeostasis and maintenance of peripheral tolerance. They prevent activation of auto-reactive T effector cells (Teff) in the context of autoimmunity and allergy. Otherwise, Treg also inhibit effective immune responses against tumors. Besides a number of Treg-associated molecules such as Foxp3, CTLA-4 or GARP, known to play critical roles in Treg differentiation, activation and function, the involvement of additional regulatory elements is suggested. Herein, kinase activities seem to play an important role in Treg fine tuning. Nevertheless, our knowledge regarding the complex intracellular signaling pathways controlling phenotype and function of Treg is still limited and based on single kinase cascades so far. To gain a more comprehensive insight into the pathways determining Treg function we performed kinome profiling using a phosphorylation-based kinome array in human Treg at different activation stages compared to Teff. Here we have determined intriguing quantitative differences in both populations. Resting and activated Treg showed an altered pattern of CD28-dependent kinases as well as of those involved in cell cycle progression. Additionally, significant up-regulation of distinct kinases such as EGFR or CK2 in activated Treg but not in Teff not only resemble data we obtained in previous studies in the murine system but also suggest that those specific molecular activation patterns can be used for definition of the activation and functional state of human Treg. Taken together, detailed investigation of kinome profiles opens the possibility to identify novel molecular mechanisms for a better understanding of Treg biology but also for development of effective immunotherapies against unwanted T cell responses in allergy, autoimmunity and cancer.

Translating Treg Therapy in Humanized Mice.

Regulatory T cells (Treg) control immune cell function as well as non-immunological processes. Their far-reaching regulatory activities suggest their functional manipulation as a means to sustainably and causally intervene with the course of diseases. Preclinical tools and strategies are however needed to further test and develop interventional strategies outside the human body. "Humanized" mouse models consisting of mice engrafted with human immune cells and tissues provide new tools to analyze human Treg ontogeny, immunobiology, and therapy. Here, we summarize the current state of humanized mouse models as a means to study human Treg function at the molecular level and to design strategies to harness these cells for therapeutic purposes.

Protein kinase CK2 enables regulatory T cells to suppress excessive TH2 responses in vivo.

The quality of the adaptive immune response depends on the differentiation of distinct CD4(+) helper T cell subsets, and the magnitude of an immune response is controlled by CD4(+)Foxp3(+) regulatory T cells (Treg cells). However, how a tissue- and cell type-specific suppressor program of Treg cells is mechanistically orchestrated has remained largely unexplored. Through the use of Treg cell-specific gene targeting, we found that the suppression of allergic immune responses in the lungs mediated by T helper type 2 (TH2) cells was dependent on the activity of the protein kinase CK2. Genetic ablation of the ß-subunit of CK2 specifically in Treg cells resulted in the proliferation of a hitherto-unexplored ILT3(+) Treg cell subpopulation that was unable to control the maturation of IRF4(+)PD-L2(+) dendritic cells required for the development of TH2 responses in vivo.

Soluble GARP has potent antiinflammatory and immunomodulatory impact on human CD4⁺ T cells.

Glycoprotein A repetitions predominant (GARP) is expressed on the surface of activated human regulatory T cells (Treg) and regulates the bioavailability of transforming growth factor-ß (TGF-ß). GARP has been assumed to require membrane anchoring. To investigate the function of GARP in more detail, we generated a soluble GARP protein (sGARP) and analyzed its impact on differentiation and activation of human CD4⁺ T cells. We demonstrate that sGARP efficiently represses proliferation and differentiation of naïve CD4⁺ T cells into T effector cells. Exposure to sGARP induces Foxp3, decreases proliferation and represses interleukin (IL)-2 and interferon-γ production, resulting in differentiation of naïve T cells into induced Treg. This is associated with Smad2/3 phosphorylation and partially inhibited by blockade of TGF-ß signaling. Furthermore, in the presence of the proinflammatory cytokines IL-6 and IL-23, sGARP facilitates the differentiation of naïve T cells into Th17 cells. More important, in a preclinical humanized mouse model of xenogeneic graft-versus-host disease (GVHD), sGARP prevents T cell-mediated destructive inflammation by enhancing Treg and inhibiting T effector cell activity. These results demonstrate a crucial role of sGARP in modulation of peripheral tolerance and T effector cell function, opening the possibility to use sGARP as a potent immunomodulator of inflammatory diseases including transplant rejection, autoimmunity, and allergy.

Genetic variants in central metabolic genes influence some but not all relations of inflammatory markers in a collective with polycystic ovary syndrome.

Patients with polycystic ovary syndrome (PCOS) suffer, in addition to reproductive disturbances, from symptoms of the metabolic syndrome like insulin resistance, elevated coronary risk and visceral obesity. Genes with confirmed associations to the metabolic syndrome are also candidate genes for a relationship to metabolic parameters of the PCOS syndrome. The study presented indicates that genetic variants of the transcription factors LXRα or PPARγ and the PON-1 or the IGF-2 cluster are associated with altered metabolic phenotypes in PCOS patients. Next to this the absolute cytokine levels and the relation of certain cytokines to IL2, IL12 or INFγ are depending on the genotype. These observations support the hypothesis that various genetic variants in metabolic relevant genes might not only alter the metabolic characteristics within a cohort of PCOS patients but might also influence the cytokine level and the overall pattern of secreted cytokines.

Genetic variations in SREBP-1 and LXRα are not directly associated to PCOS but contribute to the physiological specifics of the syndrome.

The polycystic ovary syndrome (PCOS) is a complex endocrine-metabolic disorder consisting of reproductive disturbances associated with all aspects of the metabolic syndrome and genetic components in the pathology of this complex disease is very likely. Accordingly, variations in single genes might affect specific features of PCOS and thereby help to define different subgroups. SREBP-1 or LXRα have been shown to be genetically linked to lipid metabolism or insulin sensitivity. As these are two major aspects of the PCOS phenotype, we evaluated both genes in a cohort of 153 PCOS patients. Analyses of both genes revealed in SREBF-1, i.e. SREBP-1a and SREBP-1c, not any variation and in the LXRα gene no novel sequence variations. Common variants of LXRα (rs2279238:G; all:0.8658; PCOS:0.8627; controls: 0.8686 or A: all:0.13412; PCOS:0.1373; controls:0.1314; (OR (95% CI) 0.9508 (0.4226-2.1385); rs11039155: G: all:0.8767; PCOS:0.8663; controls:0.8857 and A all:0.1233; PCOS:0.1337; controls:0.1143; (OR (95% CI) 0.8383 (0.3618-1.9371)) were also not directly associated to PCOS. Combined analyses of both polymorphism revealed that there was no difference of distribution between the groups. In contrast, analyses of the impact of these polymorphisms on metabolic parameters of the syndrome indicated significant differences related to genotypes. The data indicated that rs11039155 increases metabolic risk, whereas rs2279238 has a protective effect on the overall metabolic risk. The investigation of the PCOS group presented indicates that the combined analyses of variations in putative candidate genes allowed a genotype-phenotype correlation for metabolic features.

A functional GNAQ promoter haplotype is associated with altered Gq expression and with insulin resistance and obesity in women with polycystic ovary syndrome.

OBJECTIVES: The G-protein Gq, encoded by GNAQ, is involved in glucose metabolism. The GNAQ promoter harbours three polymorphisms. The TT(-695/-694)GC polymorphism was already shown to affect Gq transcription. Accordingly, we (i) characterized the GNAQ promoter polymorphisms G(-173)A and G(-168)A, (ii) investigated potential influences upon the TT(-695/-694)GC polymorphism and (iii) studied the associations with metabolic abnormalities in polycystic ovary syndrome (PCOS). METHODS: Characterization of the polymorphisms was performed with electrophoretic mobility shift assays and reporter assays. Inhibition of lipolysis and Gq expression were measured in adipocytes isolated from female mammary tissue. We genotyped 266 healthy Caucasians, 265 women with PCOS, and 293 healthy, age-matched female controls to associate GNAQ promoter polymorphisms and haplotypes with anthropometric and metabolic variables. RESULTS: The A(-168) allele was associated with significantly decreased transcriptional activity and altered transcription factor binding, whereas the G(-173)A polymorphism appeared functionally silent. Linkage and haplotype frequencies analysis resulted in four common haplotypes. In adipose tissue, a 44% higher Gq mRNA concentration was observed in homozygous GC(-695/-694)-G(-168) haplotypes compared with homozygous TT(-695/-694)-G(-168) haplotypes (P=0.046). This was associated with increased insulin inhibition of lipolysis in isolated adipocytes. In PCOS patients, the homozygous GC-G haplotype was associated with decreased insulin resistance and body mass index (BMI) compared with the homozygous TT-G haplotype (homeostatic model assessment of insulin resistance: 3.4+/-0.4 vs. 5.6+/-0.7 mmol/l x mmol/l2, P=0.001; fasting insulin: 86.6+/-11.9 vs. 128.8+/-16.5 pmol/l, P=0.003; BMI: 29.3+/-1.2 vs. 33.9+/-1.3 kg/m2, P=0.002). No association with BMI was found in healthy women. CONCLUSION: G(-168)A is functionally relevant and in linkage with TT(-695/-694)GC. GNAQ promoter diplotypes are associated with insulin resistance and obesity in PCOS.

Regulation of the expression of inducible nitric oxide synthase.

Nitric oxide (NO) generated by the inducible isoform of nitric oxide synthase (iNOS) is involved in complex immunomodulatory and antitumoral mechanisms and has been described to have multiple beneficial microbicidal, antiviral and antiparasital effects. However, dysfunctional induction of iNOS expression seems to be involved in the pathophysiology of several human diseases. Therefore iNOS has to be regulated very tightly. Modulation of expression, on both the transcriptional and post-transcriptional level, is the major regulation mechanism for iNOS. Pathways resulting in the induction of iNOS expression vary in different cells or species. Activation of the transcription factors NF-kappaB and STAT-1alpha and thereby activation of the iNOS promoter seems to be an essential step for the iNOS induction in most human cells. However, at least in the human system, also post-transcriptional mechanisms involving a complex network of RNA-binding proteins build up by AUF1, HuR, KSRP, PTB and TTP is critically involved in the regulation of iNOS expression. Recent data also implicate regulation of iNOS expression by non-coding RNAs (ncRNAs).

Maladaptive coping with illness in women with polycystic ovary syndrome.

OBJECTIVE: To investigate associations between active and passive coping, psychiatric symptoms of depression and anxiety, and quality of life in women with polycystic ovary syndrome (PCOS). To assess the relative contribution of these coping strategies to reduced quality of life in an attempt to clarify the possible relevance of coping for impaired psychosocial well-being in PCOS. DESIGN: Internet-based survey. PARTICIPANTS: 448 German women with PCOS. METHODS: Coping (Freiburg Questionnaire of Coping-with-Illness), anxiety and depression (Hospital Anxiety and Depression Scale [HADS]), and quality of life (Short Form 12 Health Survey [SF-12]) were assessed in an Internet-based survey. Correlation and regression analyses were conducted. RESULTS: In women with PCOS, passive coping was significantly associated with greater anxiety (r= .65; p < .001), depression (r= .61; p < .001), and reduced psychological quality of life (r=-.64, p < .001). In stepwise multiple regression analyses, passive coping, together with depression, anxiety and body mass index (BMI), explained 50.1% of the SF-12 psychological sum score, while active coping did not enter any regression model. CONCLUSION: Data suggested that faced with the diagnosis of PCOS, passive coping may constitute a maladaptive strategy associated with anxiety and depression symptoms and compromised quality of life. Hence, efforts to incorporate psychosocial aspects into counselling and care for women with PCOS should take coping strategies into consideration. Nurses and other health care providers may help to improve coping strategies through education and psychosocial support in women with PCOS.

Large effects on body mass index and insulin resistance of fat mass and obesity associated gene (FTO) variants in patients with polycystic ovary syndrome (PCOS).

BACKGROUND: The polycystic ovary syndrome (PCOS), a common endocrine disorder in women of child-bearing age, mainly characterised by chronic anovulation and hyperandrogenism, is often associated with insulin resistance (IR) and obesity. Its etiology and the role of IR and obesity in PCOS are not fully understood. We examined the influence of validated genetic variants conferring susceptibility to obesity and/or type 2 diabetes mellitus (T2DM) on metabolic and PCOS-specific traits in patients with PCOS. METHODS: We conducted an association study in 386 patients with PCOS (defined by the Rotterdam-criteria) using single nucleotide polymorphisms (SNPs) in or in proximity to the fat mass and obesity associated gene (FTO), insulin-induced gene-2 (INSIG2), transcription factor 7-like 2 gene (TCF7L2) and melanocortin 4 receptor gene (MC4R). To compare the effect of FTO obesity risk alleles on BMI in patients with PCOS to unselected females of the same age range we genotyped 1,971 females from the population-based KORA-S4 study (Kooperative Gesundheitsforschung im Raum Augsburg, Survey 4). RESULTS: The FTO risk allele was associated with IR traits and measures of increased body weight. In addition, the TCF7L2 SNP was associated with body weight traits. For the SNPs in the vicinity of INSIG2 and MC4R and for the other examined phenotypes there was no evidence for an association. In PCOS the observed per risk allele effect of FTO intron 1 SNP rs9939609 on BMI was +1.56 kg/m2, whereas it was +0.46 kg/m2 in females of the same age range from the general population as shown previously. CONCLUSION: The stronger effect on body weight of the FTO SNP in PCOS might well have implications for the etiology of the disease.

Apoptotic markers indicate nonalcoholic steatohepatitis in polycystic ovary syndrome.

BACKGROUND: Polycystic ovary syndrome (PCOS) characterized by chronic anovulation and hyperandrogenism is highly associated with obesity and insulin resistance (IR), two key features of nonalcoholic steatohepatitis (NASH). NASH often leads to cirrhosis, including portal hypertension, liver failure, and hepatocellular carcinoma as long-term complications. The caspase 3-cleaved fragment of cytokeratin 18 (CK18) emerging from ongoing cell death during apoptosis process has been established as a serum marker for NASH. This study was conducted to evaluate the prevalence of NASH in PCOS patients by caspase-cleaved CK18 measurement. METHODS: In 192 PCOS patients [age, 29.0 +/- 6.7 yr; body mass index (BMI), 31.5 +/- 8.2 kg/m(2)] and 73 age-matched controls (age, 28.6 +/- 8.0 yr; BMI, 24.1 +/- 4.6 kg/m(2)), obesity and IR were determined by BMI and area under the curve of insulin response (AUCI), respectively. Apoptotic cell death was measured by M30 ELISA detecting caspase-cleaved CK18 only. RESULTS: M30 levels were significantly elevated in PCOS patients after correction for BMI (304.7 +/- 223.1 vs. 86.3 +/- 165.6 U/liter; P < 0.001). M30 correlated significantly with BMI, AUCI, glucose secretion, low-density lipoprotein, low high-density lipoprotein, and free androgen index. AUCI turned out to be the only independent M30-determining factor in the multiple regression analysis with an effect size of 7.9%. Fifty-one of 186 (27.4%) PCOS patients showed M30 levels of at least 395 U/liter, indicating NASH. CONCLUSION: These data demonstrate elevation of apoptotic cell death, its correlation with IR, and a high prevalence of NASH in PCOS patients. Given this high prevalence, PCOS may be a risk factor for progressive hepatic sequelae. Incidence data are of strong interest.

Medical treatment of hirsutism.

Hirsutism is usually the result of an underlying adrenal, ovarian, or central endocrine abnormality mainly due to polycystic ovary syndrome but may also be idiopathic or drug induced. The aim of medical treatment of hirsutism is to rectify any causal hormonal balance, slow down or stop excessive hair growth, and improve the aesthetic appearance of hirsutism, thereby positively affecting the patient's quality of life. Today, for the majority of women, a monotherapy with oral contraceptives that have antiandrogenic activity is recommended as a first-line treatment for hirsutism. Combining an oral contraceptive pill with an antiandrogen is recommended if clinical improvement of hirsutism is insufficient after 6-9 months' monotherapy. In women who present with hirsutism, hyperandrogenism, and insulin resistance, insulin sensitizers are effective for the hirsutism as well as the hyperinsulinemia, hyperandrogenism, and infertility but there is no convincing evidence that they are effective for hirsutism alone. Topical eflornithine is a medical therapy that can be a useful adjuvant for hirsutism when used in conjunction with systemic medications or with laser/photoepilation.

Mood and sexual function in polycystic ovary syndrome.

Women with polycystic ovary syndrome (PCOS) fail to conform with societal norms for outer appearance. Many PCOS patients thus feel stigmatized in the sense of a loss of "feminine identity." In addition to somatic impairment, mood disturbances such as depression and limitations in emotional well-being, quality of life, and life satisfaction, the diagnosis of PCOS also has a negative impact on sexual self-worth and sexual satisfaction. Both obesity and hirsutism are major determinants of the physical component of quality of life in affected women. However, its psychological aspect appears to be inherent and specific for PCOS. Confirmation of the diagnosis and provision of detailed information to affected women, together with the availability of interdisciplinary treatment aimed at improving PCOS-related symptoms, such as hirsutism, obesity, menstrual irregularity, and infertility, will also reduce psychological distress and improve sexual self-worth. New treatment options, including insulin sensitizers, psychological counseling, and participation in a PCOS support group, are likely to further improve life satisfaction and coping of affected women.

Metformin improves polycystic ovary syndrome symptoms irrespective of pre-treatment insulin resistance.

OBJECTIVE: Insulin resistance (IR) and obesity are common features of the polycystic ovary syndrome (PCOS). Insulin-sensitizing agents have been shown to improve both reproductive and metabolic aspects of PCOS, but it remains unclear whether it is also beneficial in lean patients without pre-treatment IR. The aim of this study was to determine the influence of metformin on the clinical and biochemical parameters of PCOS irrespective of the presence of basal obesity and IR. DESIGN: The effect of 6 months of metformin treatment was prospectively assessed in 188 PCOS patients, divided into three groups according to body mass index (BMI; lean: BMI<25 kg/m2, overweight: BMI 25-29 kg/m2, and obese: BMI30 kg/m2). Outcome parameters, which were also assessed in 102 healthy controls, included body weight, homeostasis model assessment for IR (HOMA-IR), fasting glucose and insulin levels, area under the curve of insulin response (AUCI), hyperandrogenism, and menstrual irregularities. RESULTS: In comparison with the respective BMI-appropriate control groups, only obese but not lean and overweight PCOS patients showed differences in fasting insulin and HOMA-IR. Metformin therapy significantly improved all outcome parameters except fasting glucose levels. Subgroup analyses revealed that in the group of lean PCOS patients without pre-treatment IR, metformin significantly improved HOMA-IR (1.7+/-1.0 vs 1.1+/-0.7 micromol/lxmmol/l2) and fasting insulin levels (7.7+/-4.2 vs 5.4+/-3.9 mU/l), in addition to testosterone levels (2.6+/-0.9 vs 1.8+/-0.7 nmol/l), anovulation rate (2.3 vs 59.5%), and acne (31.8 vs 11.6%; all P<0.017). In the overweight and obese PCOS groups, metformin also showed the expected beneficial effects. CONCLUSION: Metformin improves parameters of IR, hyperandrogenemia, anovulation, and acne in PCOS irrespective of pre-treatment IR or obesity.

Retinol-binding protein 4 levels are elevated in polycystic ovary syndrome women with obesity and impaired glucose metabolism.

OBJECTIVE: Insulin resistance and obesity are common features of the polycystic ovary syndrome (PCOS). Retinol-binding protein 4 (RBP4), a new fat-derived adipokine, has been described to be elevated in obesity and type 2 diabetes. The aim of the present study was to investigate whether serum RBP4 levels are correlated with metabolic parameters, indices of insulin resistance, and endocrine variables in German PCOS women. DESIGN: We assessed the correlation between metabolic and endocrine parameters with RBP4 levels in 200 PCOS patients and 64 healthy controls. METHODS: Serum RBP4 was measured by enzyme-linked immunosorbent assay (Immundiagnostik AG, Bensheim, Germany). In addition, anthropometric variables, clinical signs of hyperandrogenism, and body fat were evaluated, and a glucose tolerance test was performed to assess parameters of insulin resistance and glucose metabolism. RESULTS: Taking the entire PCOS cohort, RBP4 levels were positively correlated with body mass index (BMI), body fat, waist circumference, fasting glucose, and area under the curve for glucose (all P<0.05), but not with indices of insulin resistance. On the other hand, PCOS women with impaired glucose metabolism had higher RBP4 levels than PCOS women with normal glucose metabolism (median 30.6, range 23.3-73.9 versus median 26.3, range 6.4-61.4, P<0.05). Furthermore, no differences were found in RBP4 levels between lean PCOS women and BMI-matched healthy controls. CONCLUSION: In German PCOS women, serum RBP4 levels are associated with obesity and parameters of glucose metabolism but not with PCOS per se.

Diagnostic value of calculated testosterone indices in the assessment of polycystic ovary syndrome.

BACKGROUND: One of the main criteria to establish a diagnosis of polycystic ovary syndrome (PCOS) is hyperandrogenemia. Recent observations suggest that total testosterone may not be a sensitive marker for the detection of androgen excess. The aim of the present study was to compare the value of different androgen determinations for diagnosis of PCOS. METHODS: Untreated PCOS patients (n=133; mean age 28 years) and healthy control women (n=54; mean age 28 years) were included in the study. Measurements of total testosterone and sex hormone-binding globulin (SHBG), luteinizing hormone (LH), follicle-stimulating hormone (FSH), androstendione, dehydroepiandrosterone sulfate (DHEAS) and albumin were performed. In addition, the free androgen index (FAI), free and bioavailable testosterone were calculated. Clinical signs of hyperandrogenism were evaluated by physical examination. The area under the receiver operating characteristic curve (AUC-ROC) was used to compare the sensitivity and specificity of different androgen determinations to detect PCOS, defined as clinical hyperandrogenism and irregular cycles compatible with the National Institutes of Health criteria of chronic anovulation and clinical or biochemical hyperandrogenism. RESULTS: All biochemical parameters of hyperandrogenism were significantly higher in PCOS patients than in controls (all p<0.0001). The highest AUC-ROC was found for bioavailable testosterone (0.852) followed by FAI (0.847) and free testosterone (0.837). Lower AUC-ROC was found for SHBG, total testosterone and androstendione (0.765, 0.799 and 0.706, respectively). When FAI=4.97 was taken as a cutoff value, sensitivity was 71.4% and specificity was 85.2%. A cutoff of 0.78 nmol/L for bioavailable testosterone had even higher sensitivity of 75.9%, but slightly lower specificity of 83.3%. FAI and bioavailable testosterone correlated significantly (all p<0.05) with total testosterone, androstendione, LH/FSH ratio and DHEAS. In addition, free testosterone, bioavailable testosterone and FAI correlated significantly with hirsutism scores, and ovarian volume and follicle count. CONCLUSIONS: ROC analysis provided evidence that calculated testosterone indices (bioavailable testosterone, FAI, free testosterone) are useful parameters for the discrimination of PCOS patients and healthy controls.