Evidence for a genetic basis for hyperandrogenemia in polycystic ovary syndrome

Polycystic ovary syndrome is associated with genetic polymorphism in the insulin signaling gene IRS-1 but not ENPP1 in a Japanese population

Recent studies indicate that insulin resistance resulting from altered post-receptor signaling is associated with polycystic ovary syndrome (PCOS). We hypothesized that insulin receptor substrate-1 (IRS-1) Gly972Arg polymorphism and/or ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) Lys121Gln polymorphism predisposes women to PCOS and that these polymorphisms also affect anthropometric variables, glucose metabolism and androgen synthesis. To test those ideas, we studied the genotypes, indexes of insulin resistance, and hormone profiles in 123 Japanese women with PCOS and 380 healthy Japanese controls. We found that there were significantly more IRS-1 972Arg carriers among the PCOS patients than among the healthy controls (10.6% vs. 4.8%, p=0.029), which is consistent with our finding that women carrying the IRS-1 972Arg allele had a significantly increased risk of developing PCOS (odds ratio: 3.31, 95% confidence interval: 1.49-7.35). By contrast, the ENPP1 Lys121Arg polymorphism was distributed equally among PCOS patients and controls. In addition, neither of these polymorphisms studied affected the anthropometric variables, metabolic parameters or androgen levels of women with PCOS. We conclude that the IRS-1 Gly972Arg polymorphism is associated with PCOS in the Japanese population.

Genes for enzymes regulating dehydroepiandrosterone sulfonation are associated with levels of dehydroepiandrosterone sulfate in polycystic ovary syndrome

CONTEXT

The adrenal androgen (AA) metabolite dehydroepiandrosterone sulfate (DHEAS) is often elevated in women with polycystic ovary syndrome (PCOS); AA excess in PCOS appears to be, in part, a heritable trait. Dehydroepiandrosterone (DHEA) sulfonation is controlled by the enzymes DHEA sulfotransferase (SULT2A1) and steroid sulfatase (STS). Polymorphisms in these genes have not been evaluated as modulators of DHEAS level in PCOS.

OBJECTIVE

The aim was to test the hypothesis that variants in the SULT2A1 and STS genes are associated with DHEAS levels in women with PCOS.

DESIGN

Women with and without PCOS were genotyped for seven single nucleotide polymorphisms (SNPs) in SULT2A1 and seven SNPs in STS. SNPs and haplotypes were determined and tested for association with DHEAS.

SETTING

Subjects were recruited from the reproductive endocrinology clinic at the University of Alabama at Birmingham; controls were recruited from the surrounding community. Genotyping took place at Cedars-Sinai Medical Center in Los Angeles.

PARTICIPANTS

A total of 287 white women with PCOS and 187 controls participated in the study.

MAIN MEASUREMENTS

SULT2A1 and STS genotype and DHEAS levels were measured.

RESULTS

In women with PCOS, SNP rs182420 in SULT2A1 was associated with DHEAS (P = 0.0035). Two haplotypes carrying the minor allele of rs182420 were also associated with DHEAS (P = 0.04 each). Variants within STS were not associated with DHEAS level. No associations were observed in control women.

CONCLUSION

This study presents genetic evidence suggesting a potential role of SULT2A1, but not STS, in the inherited AA excess of PCOS.

The adipose cell lineage is not intrinsically insulin resistant in polycystic ovary syndrome

Selective resistance to the effects of insulin on glucose metabolism in skeletal muscle and adipose tissue is a key feature of polycystic ovary syndrome (PCOS). The pathogenesis of insulin resistance in skeletal muscle in PCOS involves interaction of in vivo environmental factors with intrinsic defects in insulin signaling. We aimed to determine whether (1) intrinsic defects in insulin action/signaling and cytokine secretion were present in adipose cells in PCOS and (2) insulin resistance can be induced in control adipose cells by culture in medium conditioned by insulin-resistant PCOS fibroblasts. Subcutaneous abdominal preadipocytes from obese women with PCOS (n = 7) and age- and body mass index-matched controls (n = 5) were cultured for several generations in vitro. Basal and insulin-stimulated glycogen synthesis and basal glucose transport did not differ in the preadipocytes from women with PCOS and controls. Abundance of insulin receptor (IR) beta subunit, insulin receptor substrate (IRS) 1 and 2, p85 subunit of phosphatidylinositol 3-kinase, and extracellular signal-regulated kinase (ERK)1/2 activation did not differ. Secretion of tumor necrosis factor alpha and interleukin 6 did not differ. Insulin action on glycogen synthesis in control preadipocytes was not altered by coculture with or growth in media conditioned by PCOS skin fibroblasts with constitutive serine phosphorylation of IRbeta subunit (IR ser+), indicating that IR ser+ cells do not secrete an insulin resistance-inducing factor. We conclude that in contrast to skeletal muscle and skin fibroblasts, there is no evidence for intrinsic defects in insulin signaling in the PCOS adipose cell lineage, indicating that insulin resistance in these cells is likely due to factors in the in vivo environment.

Genetics of polycystic ovarian syndrome

Polycystic ovarian syndrome is a complex disorder with multiple factors affecting its etiology. Elucidation of specific genes and mode of inheritance remains a significant challenge. Linkage and association studies have resulted in over 50 candidate genes as a source of heritable predisposition; however, small sample sizes and failure to reproduce results have hindered efforts. In addition, low fecundity, lack of a male phenotype, and variation of diagnostic criteria represent unique challenges to discovery of polycystic ovarian syndrome genes. A concerted effort will be necessary to conclusively rule in or rule out candidate genes.

The effects of metformin and rosiglitazone, alone and in combination, on the ovary and endometrium in polycystic ovary syndrome

OBJECTIVE

To examine the effects of metformin and rosiglitazone, alone and in combination, on endometrial histology and ovarian steroid production.

STUDY DESIGN

Randomized open-label study of metformin and rosiglitazone in 16 women with polycystic ovary syndrome (PCOS) performed at a single academic health center. The study consisted of a 6-week baseline observation period, a 3-month treatment period of single-agent therapy (rosiglitazone or metformin), and then a 3-month period of combined therapy.

RESULTS

Abnormal endometrial histology was found in 3 subjects at baseline, including 1 case of adenocarcinoma of the endometrium in an asymptomatic subject, who was excluded from further study. The 2 other abnormal cases (simple hyperplasia) resolved with treatment. Three months of single-agent therapy showed a benefit of rosiglitazone (n = 9) over metformin (n = 6) in terms of reducing circulating unbound testosterone levels (-11.8; 95% CI: -21.7 to -2.0 ng/dL) and 2-hour glucose (-42.0; 95% CI: -76.2 to -7.8 mg/dL), 2-hour insulin (-150.4; 95% CI: -272.7 to -28.1 microU/mL) as well as a significant decrease in integrated levels of glucose and insulin by area under the curve analysis, all obtained from oral glucose tolerance testing. Daily urinary progestin-to-estrogen ratios improved on rosiglitazone compared to metformin therapy (0.08; 95% CI: 0.02 to 0.14). Ovulatory rates tended to improve on both single-agent and combined treatments (30/90 cycles, 33%), compared to baseline ovulatory rate (2/15, 13%). Despite 6 months of therapy alone or in combination, 5 women displayed no evidence of biochemical ovulation by urinary or serum progestin measurements.

CONCLUSION

This study provides preliminary evidence that insulin-sensitizing drugs may have beneficial effects on the endometrium, although the exact mechanism beyond improving ovulatory function is still unknown. In addition, we suggest that rosiglitazone may be more beneficial than metformin therapy on raised insulin and androgen levels in an obese PCOS population. Combined therapy did not demonstrate significant benefit above and beyond single-agent therapy.

Investigation of hypothalamo-pituitary-gonadal axis and glucose intolerance among the first-degree female relatives of women with polycystic ovary syndrome

OBJECTIVE

To assess the glucose intolerance and the hypothalamo-pituitary-gonadal (HPG) axis in the first-degree relatives (FDRs) of patients with polycystic ovary syndrome (PCOS).

DESIGN

Clinical study of the female FDRs of patients with PCOS.

SETTING

Outpatients at endocrinology department of a university hospital.

PATIENT(S)

Seventy FDRs of PCOS patients and 20 healthy women were evaluated.

INTERVENTION(S)

Basal hormonal investigations, buserelin test, and 75-g oral glucose tolerance test (OGTT) were performed.

MAIN OUTCOME MEASURE(S)

Basal hormone levels were measured. Additionally, insulinogenic index, glucose and insulin responses to OGTT, and FSH, LH, E(2), and 17-OHP responses to buserelin test were obtained.

RESULT(S)

Four (5.7%) of the FDRs showed impaired glucose tolerance, and the FDRs had significantly higher fasting plasma glucose (P<.05) and basal insulin (P<.01) than control subjects. Peak and area-under-the-curve (AUC) insulin (P<.001) and AUC glucose (P<.05) responses to OGTT were also significantly higher in the FDRs than in control subjects. The FDRs showed higher insulinogenic index than the control subjects (P<.001). The FDRs had significantly (P<.05) higher LH and DHEAS levels and lower (P<.005) 17-OHP levels than the control subjects. Peak (P<.05) and AUC (P<.01) LH responses to buserelin testing were lower in the FDRs than in the control subjects while peak (P<.05) and AUC (P<.01) E(2) responses to buserelin were higher in the FDRs than in the control subjects.

CONCLUSION(S)

These data support the hypothesis that FDRs of PCOS patients may have insulin resistance and the HPG axis is more susceptible than in control subjects. The FDRs also have an increased prevalence of hyperandrogenism and high DHEAS levels compared with the background population.

Relation of nutrients and hormones in polycystic ovary syndrome

BACKGROUND

Insulin resistance, infertility, and hirsutism, common characteristics of polycystic ovary syndrome (PCOS), improve with even modest weight loss. Optimal dietary treatment for PCOS is not known.

OBJECTIVE

We compared the effects of acute protein administration with those of glucose challenges on hormones related to obesity and insulin resistance (ie, cortisol and insulin), hirsutism [ie, dehydroepiandosterone (DHEA) and androstenedione], and hunger (ie, ghrelin).

DESIGN

Patients with PCOS (n = 28; aged 26 +/- 2 y) were tested with a 5-h oral-glucose-tolerance test (OGTT) and a euvolemic, euenergetic protein challenge.

RESULTS

Glucose ingestion caused larger fluctuations in blood glucose and more hyperinsulinemia than did protein (P < 0.01, overall treatment-by-time interaction). During the protein challenge, cortisol and DHEA declined over 5 h. During OGTT, cortisol and DHEA increased after the third hour and began to show significant divergence from protein from the fourth hour (P <or= 0.01). During OGTT, 18 patients who had a blood glucose nadir of <69 mg/dL had elevated cortisol (baseline: 10.4 +/- 0.4; nadir: 5.9 +/- 0.1; peak: 12.7 +/- 0.9 microg/dL) and DHEA (baseline: 15.6 +/- 1.3; nadir: 11.2 +/- 1.0; peak: 24.6 +/- 1.6 ng/mL) (P < 0.01), whereas the remaining 10 patients with a glucose nadir of 76 +/- 2 mg/dL had no increase in adrenal steroids. Both glucose and protein suppressed ghrelin (from 935 +/- 57 to 777 +/- 51 pg/mL and from 948 +/- 60 to 816 +/- 61 pg/mL, respectively). After glucose ingestion, ghrelin returned to baseline by 4 h and increased to 1094 +/- 135 pg/mL at 5 h. After the protein challenge, ghrelin remained below the baseline (872 +/- 60 pg/mL) even at 5 h. The overall treatment effect was highly significant (P < 0.0001).

CONCLUSIONS

Glucose ingestion caused significantly more hyperinsulinemia than did protein, and it stimulated cortisol and DHEA. Protein intake suppressed ghrelin significantly longer than did glucose, which suggested a prolonged satietogenic effect. These findings provide mechanistic support for increasing protein intake and restricting the simple sugar intake in a PCOS diet.

The genetics of the polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a very common endocrine disorder that has a strong genetic component and is characterized by polycystic ovaries, hyperandrogenemia, and menstrual irregularity. During the past decade, the roles of more than 70 candidate genes have been evaluated for a causal role in PCOS; however, because of genetic and phenotypic heterogeneity and underpowered studies, the results of many of these studies remain inconclusive. Here, the results of the genetic analysis of several candidate genes and gene regions-CYP11A (encoding cytochrome P450, family 11, subfamily A polypeptides), CAPN10 (encoding calpain 10), the insulin gene VNTR (variable number of tandem repeats), and D19S884 (a dinucleotide repeat marker mapping to chromosome 19p13.2)-are discussed in detail. Although past genetic studies of PCOS have yielded only modest results, resources and techniques have been assembled to remedy the major deficits of these early studies, promising that the next few years will be a very exciting and rewarding era for the genetic analysis of PCOS.

The (TAAAA)n microsatellite polymorphism in the SHBG gene influences serum SHBG levels in women with polycystic ovary syndrome

BACKGROUND

Hyperandrogenaemia is a common feature of polycystic ovary syndrome (PCOS). The sex hormone-binding globulin (SHBG) gene was proposed as being a PCOS candidate gene. A possible influence of the microsatellite polymorphism (TAAAA)(n) in the SHBG gene on serum SHBG levels in PCOS patients was investigated.

METHODS

One hundred and twenty-three PCOS patients and 110 age-matched controls were included in the study. Peripheral blood samples were obtained. Genotyping of the (TAAAA)(n) polymorphism in the SHBG gene was performed. Serum LH, FSH, SHBG and total testosterone concentrations were determined.

RESULTS

SHBG alleles with 6-11 TAAAA repeats were found. None of the SHBG alleles or genotypes were present at a significantly more frequent rate in PCOS patients compared with controls. Serum SHBG levels were significantly lower (P < 0.001) in PCOS patients compared with controls and were found to be strongly influenced by the (TAAAA)(n) SHBG polymorphism, in both the PCOS (55.3%) and control (33.1%) groups of patients.

CONCLUSIONS

The (TAAAA)(n) SHBG gene polymorphism might be an important predictor for serum SHBG levels and, consequently, for hyperandrogenaemic clinical presentation of PCOS.

Genetic variants in peroxisome proliferator-activated receptor gamma influence insulin resistance and testosterone levels in normal women, but not those with polycystic ovary syndrome

OBJECTIVE

To investigate the relationship of the peroxisome proliferator-activated receptor gamma (PPARG) Pro12Ala and silent exon 6 (His447His) polymorphisms with the clinical features of polycystic ovary syndrome (PCOS).

DESIGN

Patients with PCOS and control subjects were genotyped for Pro12Ala and His447His. Associations between genotype, diagnosis, and hormonal/metabolic parameters were assessed.

SETTING

Subjects were recruited from the reproductive endocrinology clinic at the University of Alabama at Birmingham, Birmingham, Alabama. Control subjects were recruited from the surrounding community. Genotyping was performed at the Cedars-Sinai Medical Center in Los Angeles, California.

PATIENT(S)

Participants included 285 white women with PCOS and 187 controls.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The Pro12Ala and His447His genotypes, and hormonal and metabolic phenotypes.

RESULT(S)

The Pro12Ala and His447His genotypes did not influence risk of PCOS or its component phenotypes in patients with PCOS. In controls, Pro12Ala did not influence measures of insulin resistance or androgen production. However, carriers of the His447His T-allele had significantly decreased free and total T levels, and a significantly decreased homeostasis model assessment index of insulin resistance. Furthermore, haplotypes in controls bearing the His447His T-allele were also associated with decreased T.

CONCLUSION(S)

Peroxisome proliferator-activated receptor gamma does not appear to be an important modifier gene in PCOS. In controls, however, the His447His T-allele may be in linkage disequilibrium with a functional variant that influences insulin resistance and T production.

Insulin sensitivity and resistin expression in nitric oxide-deficient rats

AIMS/HYPOTHESIS

The aim of this study was to investigate changes in insulin sensitivity and expression of the gene encoding resistin (Retn) in adipocytes from long-term nitric oxide (NO)-deficient rats.

METHODS

Male Sprague-Dawley rats received [Formula: see text]-nitro-L: -arginine methyl ester (L-NAME 0.5 mg/ml) in their drinking water for 4 weeks, while control rats received plain drinking water. During the experimental period, changes in plasma glucose, insulin and C-peptide levels were measured. After administration of L-NAME for 4 weeks, insulin sensitivity was evaluated in vivo and in vitro. An insulin binding assay was also performed to determine the number and binding affinity of insulin receptors in adipocytes. Adipocyte Retn mRNA levels were examined using northern blotting.

RESULTS

Successful induction of NO deficiency was demonstrated by an increase in systemic blood pressure. No difference in plasma glucose levels was found between the two groups. Compared with the control rats, plasma insulin and C-peptide levels were significantly decreased in the NO-deficient rats, and insulin sensitivity was significantly increased. Insulin-stimulated glucose uptake and insulin binding capacity, but not binding affinity, were significantly increased in adipocytes isolated from NO-deficient rats. In addition, adipocyte Retn mRNA levels, but not plasma resistin levels, were significantly decreased in NO-deficient rats, and the Retn mRNA levels were negatively correlated with insulin sensitivity.

CONCLUSIONS/INTERPRETATION

Insulin sensitivity was increased in NO-deficient rats and this was associated with insulin binding capacity and downregulated Retn expression. These findings suggest that NO plays a regulatory role in metabolism. Dysregulation of NO production may result in the development of metabolic disorders.

Heritability of dehydroepiandrosterone sulfate in women with polycystic ovary syndrome and their sisters

OBJECTIVE

To test the hypothesis that adrenal androgen (AA) secretion is an inherited trait in PCOS and that serum DHEAS concentrations, as a marker of AA secretion, will be correlated between women with PCOS and their sisters.

DESIGN

Prospective case-control.

SETTING

Tertiary care center.

PATIENT(S)

Sixty-two PCOS probands and 69 sisters.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The DHEAS concentrations and clinical phenotypes were obtained. Familial correlation between sisters was estimated. A variance components model was used to estimate the heritability (h(2)) of the DHEAS levels. Body mass index (BMI)-adjusted DHEAS levels were used in all of the analyses.

RESULT(S)

There was no difference in age between the proband and sister groups (28.7 +/- 8.1 years vs. 28.0 +/- 8.8 years, P=.65), and probands had higher BMI values (33.4 +/- 7.6 kg/m(2) vs. 27.9 +/- 7.0 kg/m(2), P<.001). Sixteen of the 69 (23.2%) sisters were affected by PCOS. The sister-sister correlation of DHEAS level was 0.28 +/- 0.12 for the whole group (P<.05), and this correlation was higher, at 0.38 +/- 0.14 (P< or =.05), after excluding 31% of the affected sisters and 34% of the unaffected sisters who received hormonal therapy at or within 3 months of the time of the study. The h(2) estimates of DHEAS were 0.43 (P=.037) and 0.44 (P=.062) when all sisters and only untreated sisters, respectively, were included in the analysis.

CONCLUSION(S)

The correlation of serum DHEAS levels between PCOS probands and their sisters suggests a familial component in the regulation of DHEAS levels and possibly AA production in PCOS. The h(2) estimates of 0.43-0.44 for BMI-adjusted DHEAS suggest that genetic factors account for between 40% and 50% of the overall variation in DHEAS levels in these women. Our results support the hypothesis that circulating AA levels represent an inherited trait in PCOS.

Polymorphism in HSD17B6 is associated with key features of polycystic ovary syndrome

OBJECTIVE

To investigate polymorphisms in androgen metabolism regulators that are implicated in the etiology of polycystic ovary syndrome (PCOS) in vitro; to investigate HSD17B6 and GATA6 to determine whether these genes are associated with susceptibility to PCOS or key phenotypic features of patients with PCOS.

DESIGN

Case-control association study.

SETTING

Participants with PCOS were recruited from a clinical-practice database, and controls, from the general community.

PATIENT(S)

One hundred seventy-three patients with PCOS and who were of Caucasian descent and conformed to the National Institutes of Health (NIH) diagnostic criteria; 107 normally ovulating women of Caucasian descent from the general community.

INTERVENTION(S)

Drawing of blood for DNA extraction.

MAIN OUTCOME MEASURE(S)

Frequency of HSD17B6 and GATA6 polymorphisms in cases and controls. Association of single-nucleotide polymorphisms from HSD17B6 in subjects with PCOS with key phenotypes of PCOS: androgen status, insulin resistance, and body mass index.

RESULT(S)

Allele distribution for the single-nucleotide polymorphism rs898611 in HSD17B6 was significantly different between PCOS and control subjects (P=.03). Presence of the polymorphic allele was associated with reduced fasting glucose-insulin ratio (P=.02) and increased homeostasis model assessment (P<.01) and body mass index (P<.001) as well as with reduced T (P=.03) in the PCOS group. No association was seen between GATA6 and any of the variables studied.

CONCLUSION(S)

These data suggest that polymorphisms in the HSD17B6 gene are associated with PCOS and key clinical phenotypes of the disorder.

Early origins of polycystic ovary syndrome

The prenatally androgenised female rhesus monkey has become a model for polycystic ovary syndrome (PCOS) in women, with early prenatal androgenisation entraining a permanent PCOS-like phenotype characterised by luteinising hormone (LH) hypersecretion due to reduced hypothalamic sensitivity to steroid negative feedback and relative insulin excess associated with increased abdominal adiposity. These combined reproductive and metabolic abnormalities occur in combination with ovarian hyperandrogenism and follicular arrest in adulthood, and with premature follicle differentiation and impaired embryo development during gonadotrophin therapy for in vitro fertilization (IVF). The ability of prenatal androgen excess in fetal rhesus monkeys to entrain multiple organ systems in utero provides evidence that the hormonal environment of intrauterine life programmes target tissue differentiation, raising the possibility that hyperandrogenism in human fetal development promotes PCOS in adulthood. This hypothesis developed in prenatally androgenised female rhesus monkeys, however, also must include data from clinical studies of PCOS to clarify the homology between human and non-human primates in intrafollicular steroidogenesis and its impact on oocyte developmental competency. By doing so, future studies promise to develop new clinical strategies that will lead to improved pregnancy outcome and reduced pregnancy loss in women with disorders of insulin action, including PCOS, obesity and diabetes mellitus.

Fine mapping of genetic susceptibility to polycystic ovary syndrome on chromosome 19p13.2 and tests for regulatory activity

CONTEXT

Little is known about genes that contribute to polycystic ovary syndrome (PCOS). We previously found linkage and association of PCOS with the dinucleotide marker D19S884 in two independent sets of families; allele 8 of D19S884 confers increased risk.

OBJECTIVE/DESIGN

The objectives of the study were: 1) use the transmission/disequilibrium test (TDT) to assess linkage and association between PCOS and D19S884 (and nearby markers) in a third set of families; and 2) test D19S884 and surrounding DNA sequence for in vitro regulatory activity in lymphoblastoid cell lines (LCLs) and granulosa cells.

SETTING/SUBJECTS

We studied 98 new families with a PCOS proband, father, mother, and other available offspring. We analyzed data from these families separately and in combination with data obtained previously.

INTERVENTIONS

Interventions were venipuncture.

MAIN OUTCOME MEASURES

Measures were transmission frequencies and in vitro functional studies.

RESULTS

The first result we found was that in the 98 new families, the TDT was significant for allele 8 of D19S884 (P = 0.043). In the total collection of 465 families, the TDT evidence is very strong (nominal P < 7 x 10(-5)). Results for all other genetic markers near D19S884 were nonsignificant after correction for multiple testing. The second result was that an approximately 800-bp fragment containing various alleles of D19S884 showed modest but reproducible promoter activity in LCLs. However, no allelic differences were detected. No activity of this fragment was detected in granulosa cells.

CONCLUSIONS

This is the second independent confirmation of linkage and association of D19S884 with PCOS. We found in addition that some sequence in the region of D19S884 confers in vitro promoter activity in LCLs.

Steroidogenic alterations and adrenal androgen excess in PCOS

BACKGROUND

This cross-sectional study was undertaken to improve our understanding of the steroidogenic alterations leading to adrenal hyperandrogenism in polycystic ovarian syndrome (PCOS).

METHODS

Two-hundred and thirty-four women with clinical and biochemical features suggestive of PCOS underwent metabolic and hormonal evaluation. We used the androstenedione/DHEAS ratio as a surrogate for the level of ovarian 3betaHSD activity. We then selected the 90th percentile for the ratio in those with elevated DHEAS (>9 micromol/l) as the cut-off level beyond which excess DHEAS production will be minimized by excess ovarian 3betaHSD activity. This cut-off level was at a ratio of 1.5 and all PCOS women were then divided into two groups, the higher (>1.5) being the group with excess ovarian 3betaHSD activity. We hypothesized that women with a high ratio would be unlikely to have DHEAS excess due to the rapid conversion of DHEA to androstenedione. Those with a low ratio (concordant ovarian and adrenal steroidogenesis) could then either have high DHEAS or normal DHEAS, depending on whether CYP17 activity was higher or lower respectively.

RESULTS

Insulin resistance was found to be associated with decreased CYP17 activity while irregular cycles and neuroendocrine dysfunction were determined to be associated with higher ovarian 3betaHSD activity.

CONCLUSION

Adrenal androgen excess in PCOS seems to be related to insulin sensitivity as well as decreased activity of 3betaHSD, the latter being preferentially present in those women with regular cycles or without neuroendocrine dysfunction.

Diagnostic criteria for polycystic ovarian syndrome

Until recently no universally accepted clinical definition existed for the polycystic ovary syndrome (PCOS). What has emerged from research over the last 30 yr is a profound heterogeneity and ongoing speculation regarding etiology. The various symptoms and signs related to PCOS have now been extensively evaluated as to their possible contribution to the diagnosis. Consensus has been reached for the use of oligomenorrhea or amenorrhea, clinical or biochemical hyperandrogenism, and polycystic ovaries at ultrasound as key diagnostic criteria. Obesity, insulin resistance, and the so-called metabolic syndrome should be recognized as associated conditions that present long-term health risks for diagnosed PCOS cases. The way all these features need to be applied in the work up of the individual index patient is reviewed here.

The role of genes and environment in the etiology of PCOS

Both genes and the environment contribute to PCOS. Obesity, exacerbated by poor dietary choices and physical inactivity, worsens PCOS in susceptible individuals. The role of other environmental modifiers such as infectious agents or toxins are speculative. Phenotype confusion has characterized genetic studies of PCOS. Although several loci have been proposed as PCOS genes including CYP11A, the insulin gene, the follistatin gene, and a region near the insulin receptor, the evidence supporting linkage is not overwhelming. The strongest case can be made for the region near the insulin receptor gene (but not involving this gene), as it has been identified in two separate studies, and perhaps most importantly has not yet been refuted by larger studies. However, the responsible gene at chromosome 19p13.3 remains to be identified. To date, no gene has been identified that causes or contributes substantially to the development of a PCOS phenotype.

Insulin resistance in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is associated with insulin resistance. There are also defects in pancreatic beta-cell function in affected women. These abnormalities are heritable. There are post-binding defects in insulin receptor signaling, with selective resistance to insulin's metabolic actions and constitutively activated mitogenic signaling in skeletal muscle. Intrinsic and environmental abnormalities interact to produce peripheral insulin resistance in PCOS. A susceptibility gene region for PCOS is located on chromosome 19p13.2. The susceptibility allele is also associated with a metabolic phenotype.

Genetic and environmental origins of obesity relevant to reproduction

Obesity has a negative impact on reproductive health, particularly in women with polycystic ovarian syndrome (PCOS). Obesity itself is the product of both genetic and environmental influences, although the current 'epidemic' of obesity is largely related to changes in diet and lifestyle. Single gene defects leading to obesity and disordered reproductive function are rare but can are informative about metabolic pathways involved in appetite regulation. There is good evidence that PCOS has an important genetic background, which probably involves the interaction of several genes. The phenotype of PCOS and its impact on reproductive function is profoundly affected by obesity, which, in turn has both genetic and environmental influences. Understanding the genetic basis of PCOS is important but improvements in diet and lifestyle are the best means of improving reproductive function.

Molecular mechanisms of insulin resistance and associated diseases

Insulin resistance is a state in which higher than normal concentrations of insulin are required for normal response. The most common underlying cause is central obesity, although primary insulin resistance in normal-weight individuals is also possible. Excess abdominal adipose tissue has been shown to release increased amounts of free fatty acids which directly affect insulin signalling, diminish glucose uptake in muscle, drive exaggerated triglyceride synthesis and induce gluconeogenesis in the liver. Other factors presumed to play the role in insulin resistance are tumour necrosis factor alpha, adiponectin, leptin, IL-6 and some other adipokines. Hyperinsulinaemia which accompanies insulin resistance may be implicated in the development of many pathological states, such as hypertension and hyperandrogenaemia. Insulin resistance underlies metabolic syndrome and is further associated with polycystic ovary syndrome and lipodystrophies. When beta-cells fail to secrete the excess insulin needed, diabetes mellitus type 2 emerges, which is, besides coronary heart disease, the main complication of insulin resistance and associated diseases.

PCOS according to the Rotterdam consensus criteria: change in prevalence among WHO-II anovulation and association with metabolic factors

OBJECTIVE

The current report aims to compare the prevalence of polycystic ovary syndrome (PCOS) diagnosed according to the new Rotterdam criteria (Rott-PCOS) versus the previous criteria as formulated by the National Institutes of Health (NIH) (NIH-PCOS) in women with normogonadotropic (WHO-II) anovulation and assess the frequency of obesity and related factors determined in these women.

DESIGN

Cohort study based on large anovulation screening database.

SETTING

Two large tertiary referral centres for reproductive medicine.

POPULATION

WHO-II normogonadotropic, anovulatory, infertility cases.

METHODS

WHO-II cases were extracted from the screening database and classified according to both the Rotterdam and NIH criteria for PCOS. Within these two classes, the prevalence of obesity, hyperglycaemia and insulin resistance was assessed and compared and their relation to the difference in diagnostic criteria applied was analysed.

MAIN OUTCOME MEASURES

Prevalence of diagnosis PCOS in the WHO-II anovulation group. Prevalence of obesity, hyperglycaemia and insulin resistance in the two diagnostic classes.

RESULTS

The Rott-PCOS group appeared to be more than 1.5 times larger than the group classified as NIH-PCOS (91 versus 55% of the WHO-II cohort). Especially, women with ovarian dysfunction and polycystic ovaries at ultrasound scan, but without hyperandrogenism, were added to the PCOS diagnostic group. The Rott-PCOS exhibited a lower frequency of obesity, hyperglycaemia and insulin resistance compared with the NIH-PCOS group. Obese women in the Rott-PCOS group without androgen excess had a different metabolic profile compared with obese women in the NIH-PCOS group, with lower rates of hyperglycaemia and hyperinsulinism, despite comparable distributions of body weight.

CONCLUSION

The present findings indicate that with the new Rotterdam consensus criteria, oligo/anovulatory women with less severe metabolic derangement will be added to the heterogeneous group of women with PCOS.

Selecting controls is not selecting “normals”: Design and analysis issues for studying the etiology of polycystic ovary syndrome

INTRODUCTION

Polycystic ovary syndrome (PCOS) is a highly prevalent disorder among postmenarcheal premenopausal women, accounting for much of anovulatory infertility, and it is associated with several comorbidities. The natural history of PCOS, as well as hypotheses regarding its etiology, facilitates employment of the case-control study design. However, a review of the literature suggested that inconsistency of research findings in relation to the etiology of PCOS might be, in part, due to the different choice of controls for case-control design and application.

DESIGN

Investigators have often employed "healthy" control groups and neglected to consider the tenability of the "rare disease" assumption in the analysis when instituting the case-control strategy. This might result in the introduction of a positive bias or overestimation of odds ratios, producing an effect estimate that is more extreme than that in the underlying population. Using several quantitative, though hypothetical, literature-driven examples, this bias is described and demonstrated. In addition, recommendations are provided with regard to case-sampling strategy when the rare disease assumption is untenable, as it may frequently be in studies of PCOS.

CONCLUSION(S)

It is hoped that more consistent case-control methodology, in concert with recent consensus on case definition, will more effectively facilitate the elucidation of the causes and consequences of PCOS.

Epigenetic modification of the X chromosome influences susceptibility to polycystic ovary syndrome

CONTEXT

The cause of polycystic ovary syndrome (PCOS) is unknown, although genetic and environmental influences are clearly implicated. Some genetic studies have suggested the involvement of X-linked genes in PCOS, but the influence of X chromosome inactivation (XCI) on manifestation of this disorder has not previously been examined.

OBJECTIVE

The objective of the study was to test the null hypothesis that XCI has no influence on clinical presentation of PCOS.

DESIGN

We examined patterns of XCI between sister pairs with the same genotype at a polymorphic locus on the X chromosome in families with PCOS.

SETTING

The study was conducted at a private practice.

PARTICIPANTS

PCOS was defined as hyperandrogenemia with chronic anovulation. Forty families were studied in which DNA was obtained from at least one parent, the proband, and one sister that could be accurately diagnosed as being affected or unaffected.

MAIN OUTCOME MEASURE(S)

Relative expression of two X-linked alleles was determined, and the ratio of one to the other represented the pattern of XCI.

RESULTS

The statistical odds on a different clinical presentation between sisters was approximately 29 times higher in sister pairs with different patterns of XCI, compared with sister pairs with the same pattern of XCI (odds ratio 28.9; 95% confidence interval 4.0-206; P = 0.0008).

CONCLUSIONS

This study provides evidence to refute the null hypothesis and propose a closer inspection of X-linked genes in PCOS, one in which both genotype and epigenotype are considered. Environmental determinants of PCOS may alter clinical presentation via epigenetic modifications, which currently remain undetected in traditional genetic analyses.

A microsatellite polymorphism (tttta)n in the promoter of the CYP11a gene in Chinese women with polycystic ovary syndrome

A (tttta)n microsatellite polymorphism in the promoter of CYP11a gene was investigated in 201 Chinese Han women with polycystic ovary syndrome (PCOS) and 147 control women. The 6/6 genotype was defined with significant difference of CYP11a polymorphism between women with PCOS and control women, and associated with greater BMI in PCOS patients, suggesting a certain role of the six-repeat allele variant in the pathogenesis of Chinese women with PCOS.

Diagnosis, epidemiology, and genetics of the polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a heterogeneous disorder, and its definition remains fluid and controversial. PCOS is characterized by clinical and/or biochemical hyperandrogenism, and is frequently accompanied by ovulatory dysfunction and polycystic ovaries. PCOS is a diagnosis of exclusion, with other androgen excess and related disorders to be excluded. The prevalence of PCOS is 6.5-8.0% of unselected women of reproductive age, using the NIH 1990 criteria. Genetically, PCOS is a common, complex disorder. Despite repeated attempts to identify the putative gene or genes responsible for this disorder, the PCOS gene(s) remain elusive.

Family size in women with polycystic ovary syndrome

Given that polycystic ovary syndrome (PCOS) is associated with oligo-ovulatory infertility and is an inherited trait, we hypothesized that the families of patients with PCOS are smaller than those of matched controls. However, our study of 106 white patients with PCOS, ages 18-45, and 53 healthy eumenorrheic nonhirsute white controls did not indicate a difference in family size between the groups; these results have important implications for the design of prospective studies of the heritability and genetics of PCOS.

The origins and sequelae of abnormal neuroendocrine function in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common clinical disorder characterized by ovulatory dysfunction and hyperandrogenaemia. A neuroendocrine hallmark of PCOS is persistently rapid LH (GnRH) pulsatility, which favours pituitary synthesis of LH over that of FSH and contributes to the increased LH concentrations and LH : FSH ratios typical of PCOS. Inadequate FSH levels contribute to impaired follicular development, whereas elevated LH levels augment ovarian androgen production. Whereas luteal phase elevations in progesterone normally slow GnRH pulse frequency, women with PCOS do not experience normal progesterone-mediated slowing, due in part to impaired hypothalamic progesterone sensitivity. This reduction in hypothalamic progesterone sensitivity appears to be mediated by elevated androgens because sensitivity can be restored with the androgen receptor blocker flutamide. The ovulatory and hormonal abnormalities associated with PCOS generally present during puberty, typically associated with hyperandrogenaemia. Along with elevated LH concentration and pulsatility, some girls with hyperandrogenaemia have impaired hypothalamic progesterone sensitivity similar to that seen in adult women with PCOS. We propose that peripubertal hyperandrogenaemia may lead to persistently rapid GnRH pulse frequency via impaired hypothalamic feedback inhibition. The subsequent abnormalities in gonadotropin secretion, androgen production and ovulatory function may support progression towards the adult PCOS phenotype.

Evidence for metabolic and reproductive phenotypes in mothers of women with polycystic ovary syndrome

Dyslipidemia is a feature of polycystic ovary syndrome (PCOS), but its pathogenesis remains controversial. We performed this study of mothers of women with PCOS to test the hypothesis that dyslipidemia is a heritable trait in families of women with PCOS and to investigate the impact of age on reproductive and metabolic phenotypes. Fasting blood was obtained in 215 non-Hispanic white mothers of women with PCOS and 62 control women. The prevalence of metabolic syndrome was compared with that in non-Hispanic white women of comparable age from the National Health and Nutrition Examination Survey III. Mothers had higher total (P < 0.001) and low-density lipoprotein (LDL) cholesterol levels (P = 0.007), whereas high-density lipoprotein and triglyceride levels did not differ compared with control women. The only predictors of LDL levels in mothers were their daughters' LDL levels (r2 = 0.11, P < 0.001) and their own unbound testosterone levels (r2 = 0.04, P = 0.03). The prevalence of metabolic syndrome was increased in obese (body mass index > or = 30 kg/m2) mothers compared with obese non-Hispanic white women from the National Health and Nutrition Examination Survey III (P = 0.04). Thirty-one percent of mothers reported a history of menstrual irregularity. These mothers had higher androgen levels, markers of insulin resistance, and LDL levels than mothers with regular menses. LDL levels are increased in mothers of women with PCOS, suggestive of a heritable trait. A history of menstrual irregularity identifies mothers with features of PCOS. Obese mothers have a very high prevalence of metabolic syndrome. These findings suggest that both the reproductive and metabolic abnormalities persist with age in PCOS.

A novel SNP at exon 17 of INSR is associated with decreased insulin sensitivity in Chinese women with PCOS

To investigate the association of single-nucleotide polymorphisms (SNPs) in exon 17 of the insulin receptor (INSR) gene with insulin resistance and INSR beta-subunit expression in polycystic ovary syndrome (PCOS) patients, a case-control study was carried out in an academic endocrinology clinic of China. One hundred and nine Chinese patients with PCOS and 107 healthy Chinese women as control were recruited. Their leukocytes and red blood cells were separated from blood samples, for SNP analysis with single-stranded conformation polymorphism and for the INSR beta-subunit expression detection by western blot analysis, respectively. A novel T/C SNP at codon Cys1008 (position 3128 of NM_000208) of INSR was found in two allele genotypes, i.e. the homozygous CC and the heterozygous TC. A higher frequency of the mutant homozygous CC was observed in the PCOS women with PCOS than that in the controls (21.1 versus 5.6%, P < 0.01). In contrast with the women with wild-type genotype, a significantly lower insulin sensitivity index in the women with each of the two mutant genotypes was revealed (CC: 0.335 +/- 0.026/TC: 0.346 +/- 0.027 versus TT: 0.367 +/- 0.029, P < 0.05). No relationship was found between the novel SNP and the INSR beta-subunit expression. We concluded that the novel T/C SNP at codon Cys1008 of INSR is associated with decreased insulin sensitivity in Chinese women with PCOS and that the association is not by the change of synthesis or secretion of INSR beta-subunit, but most possibly by the effects of this novel SNP on the function of INSR beta-subunit.

Adolescent girls with polycystic ovary syndrome have an increased risk of the metabolic syndrome associated with increasing androgen levels independent of obesity and insulin resistance

CONTEXT

Adult women with polycystic ovary syndrome (PCOS) have an increased prevalence of the metabolic syndrome (MBS). The prevalence of MBS is also increasing in adolescents.

OBJECTIVE

Our objective was to test the hypothesis that the prevalence of MBS is increased in adolescent girls with PCOS compared with the general population and to determine the factors associated with an increased risk of the MBS in PCOS.

DESIGN AND SETTING

We conducted a cross-sectional case-control study at academic medical centers with general clinical research centers.

PARTICIPANTS

Participants included 49 adolescent girls with PCOS and 165 girls from the Third National Health and Nutrition Examination Survey (NHANES III) adolescent population of similar age and ethnic background.

MAIN OUTCOME MEASURE

We assessed the prevalence of MBS according to currently proposed adolescent MBS criteria.

RESULTS

Thirty-seven percent of adolescent girls with PCOS had MBS compared with 5% of NHANES III girls (P < 0.0001). None of the girls of normal body mass index (BMI) had MBS, whereas 11% of overweight and 63% of obese girls with PCOS had MBS compared with 0 and 32% of NHANES III girls, respectively. Girls with PCOS were 4.5 times more likely to have MBS than age-matched NHANES III girls after adjusting for BMI (odds ratio, 4.5; 95% confidence interval, 1.1-17.7; P = 0.03). The odds of having the MBS were 3.8 times higher for every quartile increase in bioavailable testosterone in girls with PCOS after adjusting for BMI and insulin resistance (odds ratio, 3.8; 95% confidence interval, 1.4-10.2; P = 0.008).

CONCLUSIONS

Adolescent girls with PCOS have a higher prevalence of MBS than the general adolescent population. Hyperandrogenemia is a risk factor for MBS independent of obesity and insulin resistance.

Specific haplotypes of the CALPAIN-5 gene are associated with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common endocrine disorder in women of reproductive age. The aim of the present study was to investigate the role of CALPAIN-5 (CAPN5) gene in PCOS susceptibility.

METHODS

We analysed four intronic polymorphisms of the CAPN5 gene in 148 well-characterized women with PCOS and 606 unrelated controls. We performed a case-control study and an intracohort analysis of clinical characteristics associated with PCOS.

RESULTS

Analysis of haplotypes distribution between PCOS population compared to controls showed a strong deviation (P = 0.00029). The haplotypes GGCA and GGTG were overrepresented in PCOS patients (P = 0.009 and P = 0.001, respectively). In addition, we identified several CAPN5 haplotypes associated with phenotypic differences observed between PCOS patients, such as the presence of obesity (P = 0.02), cardiovascular complications (P = 0.02), familial antecedents of obesity (P = 0.003) and of hypertension (P = 0.007) and type 2 diabetes mellitus aggregation (P = 0.04).

CONCLUSIONS

These results suggest a role of CAPN5 gene in PCOS susceptibility in humans. Moreover, novel candidate risk alleles have been identified, within CAPN5 gene, which could be associated with important phenotypic and prognosis differences observed in PCOS patients.

No association between the microsatellite polymorphism (TTTTA)n in the promoter of the CYP11A gene and ovarian hyperstimulation syndrome

PURPOSE

Women with ultrasonic evidence of polycystic ovaries are at higher risk of ovarian hyperstimulation syndrome (OHSS). We focused on investigating a possible association of the (TTTTA)(n) microsatellite polymorphism in the promoter of the CYP11A gene with OHSS during controlled ovarian hyperstimulation (COH).

METHODS

We evaluated 58 patients at high risk of OHSS (study group) and 58 control patients undergoing controlled ovarian hyperstimulation.

RESULTS

The difference in the allele distribution between both groups of patients was not statistically significant. The genotype distribution of 4+ (with at least one copy of the four-repeat-unit allele) and 4- (without the four-repeat-unit allele) genotypes was identical in the two groups.

CONCLUSION

An association between the (TTTTA)(n) microsatellite polymorphism in the promoter of the CYP11A gene and the pathogenesis of OHSS could not be confirmed.

Thiazolidinediones for the Therapeutic Management of Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) is a diagnosis made between late adolescence and the menopause in 5-10% of women. PCOS is a heterogeneous disorder of unknown etiology characterized by hyperandrogenic chronic anovulation. This syndrome consists of a diverse constellation of signs and symptoms, such as hirsutism, acne, acanthosis nigricans, obesity, menstrual irregularities, anovulation, and/or infertility. Features of the metabolic syndrome, including obesity, insulin resistance, and dyslipidemia, are common in this patient population. Recent insights into the pathophysiology of PCOS have shown insulin resistance and hyperinsulinemia to play a substantial role. Insulin resistance is increasingly recognized as a chronic, low-level, inflammatory state. Recent studies show that serum levels of inflammatory mediators, such as tumor necrosis factor-alpha and interleukin-6, are increased in the insulin-resistant conditions of obesity and PCOS. The optimal modality for long-term treatment should have positive effects on androgen synthesis, sex hormone-binding globulin production, the lipid profile, insulin sensitivity, inflammatory mediators, and clinical symptoms including acne, hirsutism, and irregular menstrual cycles. Treatment with insulin-sensitizing agents is a relatively new therapeutic strategy in women with PCOS. Current research has shown that the use of diabetes mellitus management practices aimed at reducing insulin resistance and hyperinsulinemia (such as weight reduction and the administration of oral antidiabetic drugs) can not only reverse testosterone and luteinizing hormone abnormalities and restore menstrual cycles, but can also improve glucose, insulin, proinflammatory cytokine, and lipid profiles.Clinical treatment with troglitazone, a member of the thiazolidinedione family, for the management of PCOS complications such as insulin resistance, hyperandrogenism, and anovulation was found to have beneficial effects; however, it was taken off the market over concerns of hepatotoxicity. Although troglitazone is no longer available in the US, numerous clinical trials have established the role of thiazolidinediones in the treatment of women with PCOS. Clinical data emerging regarding the utility of two of the newer, safer thiazolidinediones, pioglitazone and rosiglitazone, for this patient population, consistently demonstrate effective improvements of endocrine and ovulatory performance in women with PCOS. The benefit and importance of lifestyle modification and weight reduction, when it can be achieved, is still an important component in the long-term treatment of PCOS. Pharmacologic reduction in insulin levels using thiazolidinediones appears to offer another therapeutic modality for PCOS, which may ameliorate the progress of both hyperinsulinemia and hyperandrogenism. However, additional studies of patients so treated are necessary before these agents can be considered first-line treatment for PCOS. Convincing data from randomized controlled trials with sufficient power to detect both the benefits and risks of long-term treatment with thiazolidinediones in women with PCOS remain to be obtained.

Identification of a functional polymorphism of the human type 5 17beta-hydroxysteroid dehydrogenase gene associated with polycystic ovary syndrome

CONTEXT

Polycystic ovary syndrome (PCOS) is characterized by chronic hyperandrogenic anovulation and is associated with insulin resistance. Its pathogenesis is believed to be multifactorial, and abnormal gene regulation could be one contributing factor. Type 5 17beta-hydroxysteroid dehydrogenase (17beta-HSD5) appears to be the major testosterone-forming 17beta-HSD isoenzyme in females.

OBJECTIVE

Our objective was to investigate the role of a potentially activating 17beta-HSD5 gene (HSD17B5) variant in hyperandrogenism.

DESIGN AND SETTING

We conducted a case study and case-control cohort study in our General Clinical Research Center.

STUDY SUBJECTS

Subjects included a case of PCOS who had hyperthecosis associated with profound type B insulin resistance and an unusual, frankly male testosterone response to a GnRH agonist test, as well as 121 PCOS patients and 128 population controls.

INTERVENTIONS

Interventions were diagnostic.

MAIN OUTCOME MEASURES

Main outcome measures included sequencing of HSD17B5 5'-flanking region and nine exons, genotype/phenotype studies, and in vitro functional studies.

RESULTS

Our case had a previously undescribed homozygous HSD17B5 variant (G-to-A substitution) -71 bp in the promoter region. Genotyping controls showed this to be a single-nucleotide polymorphism (SNP)-71G. Luciferase activity of a SNP-71G promoter construct was significantly higher than that of the wild type, and EMSAs revealed that SNP-71G possessed significantly increased affinity to nuclear transcription factors. SNP-71G allele frequency (32.2 vs. 22.3%) and SNP-71G allele presence (53.7% vs. 38.3%) were significantly increased in PCOS (P = 0.01) [corrected] SNP-71G homozygosity tended to contribute about 20% to the plasma testosterone level.

CONCLUSIONS

SNP-71G is a functional polymorphism that may contribute to testosterone excess in a subset of PCOS patients.

Development of polycystic ovary syndrome: involvement of genetic and environmental factors

We have recently proposed that polycystic ovary syndrome (PCOS) has its origin in fetal life. This hypothesis is based on data from animal models (rhesus monkey or sheep that have been exposed prenatally to high doses of androgen) and is supported by clinical studies. It is suggested that, in human females, exposure to excess androgen, at any stage from fetal development of the ovary to the onset of puberty, leads to many of the characteristic features of PCOS, including abnormalities of luteinizing hormone secretion and insulin resistance. It is likely that, in humans with PCOS, the development of the PCOS phenotype results primarily from a genetic predisposition for the fetal ovary to hypersecrete androgen. At present, it is unclear whether the maternal environment directly influences the development of PCOS in the offspring. Maternal androgen excess is unlikely to affect the fetus, because the placenta presents an effective barrier, but metabolic disturbances during pregnancy could affect development of the syndrome in the fetus. In postnatal life, the natural history of PCOS can be further modified by factors affecting insulin secretion and/or action, most importantly, nutrition. We now have evidence for a disorder of early follicular development in the polycystic ovary that is consistent with an increased population of primordial follicles in the fetal ovary. It remains to be determined whether this phenomenon is the cause or the effect of increased exposure to androgen within the ovary. PCOS is the commonest endocrine disorder in women. It is not only a very prevalent cause of anovulatory infertility, menstrual disturbances and hirsutism, but it is also a major risk factor for the development of type 2 diabetes mellitus in later life. The aetiology of the syndrome remains uncertain but there is increasing evidence for a genetic basis. PCOS very often becomes clinically manifest during adolescence with maturation of the hypothalamic-pituitary-ovarian axis but the genesis of the syndrome may be during very early development - perhaps even in utero. In this review, this hypothesis is explored in the light of clinical, biochemical and genetic research.

Adrenal hyperandrogenism is induced by fetal androgen excess in a rhesus monkey model of polycystic ovary syndrome

CONTEXT

Adrenal androgen excess is found in approximately 25-60% of women with polycystic ovary syndrome (PCOS), but the mechanisms underlying PCOS-related adrenal androgen excess are unclear.

OBJECTIVE

The objective of this study was to determine whether adrenal androgen excess is manifest in a nonhuman primate model for PCOS.

PARTICIPANTS

Six prenatally androgenized (PA) and six control female rhesus monkeys of similar age, body weight, and body mass index were studied during d 2-6 of two menstrual cycles or anovulatory 30-d periods.

INTERVENTIONS

Predexamethasone adrenal steroid levels were assessed in the first cycle (cycle 1). In a subsequent cycle (cycle 2), occurring one to three cycles after cycle 1, adrenal steroids were determined 14.5-16.0 h after an i.m. injection of 0.5 mg/kg dexamethasone (postdexamethasone levels) and after an i.v. injection of 50 microg ACTH-(1-39).

RESULTS

Both before and after dexamethasone, serum levels of dehydroepiandrosterone (DHEA) in PA females exceeded those in controls. After ACTH injection, PA females exhibited higher circulating levels of DHEA, androstenedione, and corticosterone but comparable levels of 17alpha-hydroxyprogesterone, cortisol, the sulfoconjugate of DHEA, and testosterone compared with controls.

CONCLUSION

Enhanced basal and ACTH-stimulated adrenal androgen levels in PA female monkeys may reflect up-regulation of 17,20 lyase activity in the adrenal zona reticularis, causing adrenal androgen excess comparable with that found in PCOS women with adrenal androgen excess. These findings open the possibility that PCOS adrenal hyperandrogenism may have its origins in fetal androgen excess reprogramming of adrenocortical function.

Female precocious puberty, obesity and polycystic-like ovaries

OBJECTIVE

To evaluate the characteristics of obese girls with gonadotropin releasing hormone-dependent precocious puberty with and without polycystic-like ovaries.

METHODS

Forty-seven overweight (> 75(th) centile of the Italian reference data) girls with a diagnosis of isosexual precocious puberty underwent auxological analysis, hormonal assay and utero-ovarian sonographic and Doppler evaluation. On the basis of sonography the patients were subdivided into two groups, girls presenting normal ovaries (Group I; n = 31) and those with polycystic-like ovaries (Group II; n = 16).

RESULTS

The mean body weight was significantly higher (P = 0.003) in Group II than it was in Group I. In addition, the patients with polycystic-like ovaries fell within our definition of superobese (> or = 97(th) centile of the Italian reference data) in 44% of cases. The uterine and ovarian volumes were significantly greater in Group II compared with Group I patients. The Doppler evaluation showed intraparenchymal ovarian vascularization and low downstream impedance to flow in all patients in Group II.

CONCLUSIONS

Girls with precocious puberty and polycystic ovaries, compared with those without polycystic ovaries, have a higher incidence of body weight exceeding the 85(th) centile of the Italian reference data (obesity).

Ovarian steroids modulate neuroendocrine dysfunction in polycystic ovary syndrome

OBJECTIVE

Neuroendocrine dysfunction in polycystic ovary syndrome (PCOS) was addressed by studying the steroid hormone changes in women with PCOS with either high or normal LH levels leading to inferences regarding the primacy of elevated LH in the pathophysiology of PCOS.

METHODS

A cross-sectional study was designed in an academic clinical facility involving 234 women with PCOS. Patients were divided into two groups based on an LH/FSH ratio < or >1 and hormonal and metabolic studies were performed in both groups. Factors were determined by binomial logistic regression that predicted group membership of these women.

RESULTS

Higher follicular phase estradiol (E2) and androstenedione (A4) levels as well as greater insulin sensitivity were the only factors that predicted the presence of neuroendocrine dysfunction with elevated A4 being necessary for neuroendocrine dysfunction.

CONCLUSIONS

It was concluded that uncoupling of hypothalamic E2 inhibition by elevated ovarian A4 associated with E2 related sensitization of pituitary LH leads to neuroendocrine dysfunction in PCOS.

Pro12Ala polymorphism of the peroxisome proliferator-activated receptor-gamma gene in first-degree relatives of subjects with polycystic ovary syndrome

AIM

This study was designed to examine the relationship between the Pro12Ala polymorphism of the peroxisome proliferator-activated receptor-gamma (PPAR-gamma) gene and insulin resistance (IR) in first-degree relatives of subjects with polycystic ovary syndrome (PCOS).

MATERIALS AND METHODS

One hundred and twenty family members of 55 patients with PCOS and 80 unrelated healthy control subjects without a family history of diabetes or PCOS were studied. IR was assessed by homeostatic model assessment (HOMA-IR) and area under the curve (AUC) for insulin during an oral glucose tolerance test in subjects with normal glucose tolerance and controls. Genetic analysis of the PPAR-gamma gene Pro12Ala polymorphism was performed by restriction fragment length polymorphism.

RESULTS

Fasting insulin, HOMA-IR and AUC insulin were significantly higher in first-degree relatives of PCOS subjects than in controls. A significantly different allele distribution of the Pro12Ala polymorphism of PPAR-gamma was observed between the two groups, with the frequency of the variant Ala isoform being significantly reduced in the first-degree relatives of PCOS subjects (10.8%, 13 subjects) compared with the control group (22.5%, 18 subjects). All Pro12Ala polymorphisms of the PPAR-gamma gene were heterozygous. Compared with first-degree relatives of PCOS subjects with the Pro12Pro polymorphism of PPAR-gamma, first-degree relatives of PCOS subjects with the Pro12Ala polymorphism had low fasting insulin, HOMA-IR and AUC insulin levels. The combined prevalence rate for impaired glucose tolerance, impaired fasting glucose and diabetes was 40% (16 subjects) in mothers and 52% (20 subjects) in fathers of PCOS women.

CONCLUSION

Our findings suggest that Pro12Ala PPAR-gamma gene polymorphism may be protective against IR and might prevent the development of diabetes mellitus in the first-degree relatives of subjects with PCOS.

Androgen excess fetal programming of female reproduction: a developmental aetiology for polycystic ovary syndrome?

The aetiology of polycystic ovary syndrome (PCOS) remains unknown. This familial syndrome is prevalent among reproductive-aged women and its inheritance indicates a dominant regulatory gene with incomplete penetrance. However, promising candidate genes have proven unreliable as markers for the PCOS phenotype. This lack of genetic linkage may represent both extreme heterogeneity of PCOS and difficulty in establishing a universally accepted PCOS diagnosis. Nevertheless, hyperandrogenism is one of the most consistently expressed PCOS traits. Animal models that mimic fetal androgen excess may thus provide unique insight into the origins of the PCOS syndrome. Many female mammals exposed to androgen excess in utero or during early post-natal life typically show masculinized and defeminized behaviour, ovulatory dysfunction and virilized genitalia, although behavioural and ovulatory dysfunction can coexist without virilized genitalia based upon the timing of androgen excess. One animal model shows particular relevance to PCOS: the prenatally androgenized female rhesus monkey. Females exposed to androgen excess early in gestation exhibit hyperandrogenism, oligomenorrhoea and enlarged, polyfollicular ovaries, in addition to LH hypersecretion, impaired embryo development, insulin resistance accompanying abdominal obesity, impaired insulin response to glucose and hyperlipidaemia. Female monkeys exposed to androgen excess late in gestation mimic these programmed changes, except for LH and insulin secretion defects. In utero androgen excess may thus variably perturb multiple organ system programming and thereby provide a single, fetal origin for a heterogeneous adult syndrome.

Oral contraceptives and the management of hyperandrogenism-polycystic ovary syndrome in adolescents

Appropriate management of polycystic ovary syndrome in adolescents depends on recognizing the syndrome, which can have a variety of presenting complaints and must be differentiated from other causes of hyperandrogenism, as well as not dismissed as "normal adolescence." Oral contraceptives have long been considered the first line of treatment by obstetrician/gynecologists and have many advantages in treating the aspects of PCOS that are most bothersome to teens. Because of the potential risk for cardiovascular disease, early diagnosis and management may be helpful in minimizing the risk of the early metabolic correlates of adult disease.

Polycystic ovary syndrome in adolescence

Polycystic ovary syndrome (PCOS) is a syndrome of variable combinations of menstrual irregularity, hirsutism or acne, and obesity. It can be diagnosed in adolescence and has early childhood antecedents. PCOS is the single most common endocrine cause of an ovulatory infertility and a major risk factor for the metabolic syndrome and, in turn, development of type 2 diabetes mellitus in women. Thus, it appears that PCOS increases a woman's risk of developing cardiovascular disease. Therefore, identifying girls at risk for PCOS and implementing treatment early in the development of PCOS may be an effective means of preventing some of the long-term complications associated with this syndrome. This article reviews the definition, clinical features, diagnosis, and treatment of PCOS.