Candidate gene region for polycystic ovary syndrome on chromosome 19p13.2

CONTEXT: Polycystic ovary syndrome (PCOS) is a common endocrine disorder that is believed to have a genetic basis. However, no specific susceptibility gene or region has been conclusively identified. OBJECTIVE: The objective of this study was to duplicate a previous study that localized a PCOS susceptibility region to chromosome 19p13.2 and to narrow the susceptibility region. DESIGN: This study was designed to test for genetic linkage and association between PCOS and short tandem repeat polymorphisms in 367 families, by analysis of linkage and family-based association. SETTING: The study was conducted at academic medical centers. PATIENTS OR OTHER PARTICIPANTS: We studied 367 families of predominantly European origin with at least one PCOS patient. Families included 107 affected sibling (sister) pairs (ASPs) in 83 families, and 390 trios with both parents and an affected daughter. The data set comprises two independent groups. Set 1 consists of 44 ASPs and 163 trios. Set 2 consists of 63 ASPs and 227 trios. INTERVENTION(S): The intervention was the drawing of blood for DNA extraction. MAIN OUTCOME MEASURE: We employed measures of evidence for linkage and association between PCOS and 19 STRs. RESULTS: Linkage with PCOS was observed over a broad region of chromosome 19p13.2. The strongest evidence for association was observed with D19S884 (chi2 = 11.85; nominal P < 0.0006; permutation P = 0.034) and duplicated our earlier findings. CONCLUSIONS: The present analysis suggests that a PCOS susceptibility locus maps very close to D19S884. Additional studies that systematically characterize DNA sequence variation in the immediate area of D19S884 are required to identify the PCOS susceptibility variant.     

Evidence for association of polycystic ovary syndrome in caucasian women with a marker at the insulin receptor gene locus

The polycystic ovary syndrome (PCOS) is one of the commonest female endocrinopathies affecting 5-10% of women of reproductive age. The disorder, characterized by chronic anovulation and signs of hyperandrogenism, results from a complex interaction between genetic predisposing factors and environmental triggers. We have studied 85 Caucasian PCOS patients and 87 age-matched Caucasian control women for associations with four candidate genes: follistatin, CYP19 (aromatase), CYP17a, and the insulin receptor (INSR). These genes were analyzed using microsatellite markers located near or inside the genes. We found that only the insulin receptor gene marker D19S884 was significantly associated with PCOS (p=0.006 and even after a conservative correction p=0.042). The INSR gene region was then fine mapped with an additional panel of 9 markers but only marker D19S884, located 1 cM telomeric to the INSR gene, was again associated with PCOS. In conclusion, our results suggested that a susceptibility gene for PCOS was located on chromosome 19p13.3 in the insulin receptor gene region. It remains to be determined if this susceptibility gene is the insulin receptor gene itself or a closely located gene. Since insulin stimulates androgen secretion by the ovarian stroma it is likely that INSR function in the ovary is involved in the genetic susceptibility ot PCOS.     

Polycystic ovary syndrome: syndrome XX?

Polycystic ovary syndrome (PCOS) is now recognized as an important metabolic and reproductive disorder. It is associated with substantial defects in insulin action and secretion that confer a markedly increased risk for type 2 diabetes mellitus. Insulin resistance modifies reproductive function both by the direct actions of insulin on steroidogenesis and by disruption of insulin signaling pathways in the central nervous system. These insights have led to a new therapy for PCOS with insulin-sensitizing agents. Hyperandrogenemia and insulin resistance cluster in PCOS families, consistent with a genetic susceptibility to these abnormalities. There is evidence for both linkage and association of the hyperandrogenemia phenotype with an allele of a marker locus on chromosome 19, in the region of the gene encoding the insulin receptor.     

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.     

Hyperinsulinaemia in the polycystic ovary syndrome confirmed with a specific immunoradiometric assay for insulin

OBJECTIVE Hyperinsulinaemia in the polycystic ovary syndrome (PCOS) has previously been defined using polyclonal radioimmunoassays (RIA) in which partially processed insulin-like molecules cross-react. This study aimed to reassess hyperinsulinaemia in women with PCOS using specific immunoradiometric assays (IRMA) for insulin, proinsulin and 32–33 spilt proinsulin. DESIGN Patients attended for 75 g oral glucose tolerance tests and were divided into groups depending on their degree of obesity and fasting insulin status determined by RIA. IRMA measurements for insulin-like molecules in plasma from patients with PCOS and controls were compared. PATIENTS Thirty-four patients with ultrasound diagnosed PCOS presented to a reproductive endocrinology clinic. A control group comprised women with normal ovaries on ultrasound. Four groups were constructed, two with normal fasting insulin concentrations (lean PCOS and controls) and two with hyperinsulinaemia (lean and obese PCOS). MEASUREMENTS Plasma glucose, insulin (RIA and IRMA), proinsulin and 32–33 split proinsulin concentrations were measured at time 0, 30 and 120 minutes of an oral glucose tolerance test. RESULTS Hyperinsulinaemia determined by RIA in lean and obese women with PCOS was confirmed using a specific IRMA assay for insulin. Plasma proinsulin and 32–33 split proinsulin concentrations were higher in hyper-insullnaemic women with PCOS compared with women with normal insulin concentrations. The proportion of circulating insulin-like molecules represented by proinsulin and 32–33 split proinsulin was similar in all groups studied. CONCLUSIONS Hyperinsulinaemia in PCOS is likely to reflect insulin resistance because the raised concentrations of proinsulin and 32–33 split proinsulin were in proportion to the raised insulin concentrations. Hyperinsulinaemia in PCOS, defined by RIA, therefore differs from that in non-Insulin dependent diabetes mellitus where it Is largely accounted for by disproportionate hyperproinsulinaemla.     

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.     

Evidence for pancreatic beta-cell dysfunction in brothers of women with polycystic ovary syndrome

Hyperandrogenemia and insulin resistance are heritable traits in sisters of women with polycystic ovary syndrome (PCOS). Hyperandrogenemia also appears to be the male reproductive phenotype; however, it is less clear whether male relatives are at risk for the metabolic disorders associated with PCOS. In this study, we tested the hypothesis that brothers of women with PCOS have defects in insulin action and/or secretion. Twenty-three non-Hispanic white brothers of women with PCOS and 23 non-Hispanic white control men of comparable age matched for body mass index underwent a modified frequently sampled intravenous glucose tolerance test. Parameters of insulin sensitivity and secretion were determined using minimal-model Bergman protocol. Disposition index was significantly decreased (2540 [1080, 3172] vs 2901 [2096, 4487], P = .009) independent of a family history of diabetes mellitus, and glucose effectiveness was significantly increased (2.4 [1.9, 2.7] vs 2.0 [1.8, 2.2], P = .02) in brothers compared with control men. We conclude that brothers of women with PCOS have evidence for pancreatic β-cell dysfunction and may be at increased risk for type 2 diabetes mellitus.     

Metabolic profile in sons of women with polycystic ovary syndrome

CONTEXT: Polycystic ovary syndrome (PCOS) is a common endocrine-metabolic disorder with strong familial aggregation. It has been demonstrated that parents and brothers of PCOS women exhibit insulin resistance and related metabolic defects. However, metabolic phenotypes in sons of PCOS women have not been described. OBJECTIVE: Our objective was to assess the metabolic profiles in sons of women with PCOS during different stages of life: early infancy, childhood, and adulthood. DESIGN: Eighty sons of women with PCOS (PCOS(S)) and 56 sons of control women without hyperandrogenism (C(S)), matched for age, were studied. In early infancy, glucose and insulin were determined in the basal sample. In children and adults, a 2-h oral glucose tolerance test was performed with measurements of glucose and insulin. Adiponectin, leptin, C-reactive protein, SHBG, and serum lipids were determined in the basal sample during the three periods. RESULTS: During early infancy, PCOS(S) showed higher weight (P = 0.038) and weight sd score (P = 0.031) than C(S). During childhood, weight (P = 0.003), body mass index (BMI) (P < 0.001), BMI sd score (P < 0.001), waist circumference (P = 0.001), total cholesterol (P = 0.007), and low-density lipoprotein cholesterol (P = 0.022) were higher in PCOS(S) compared with C(S), but after adjusting for BMI, these differences were nonsignificant. During adulthood, PCOS(S) exhibited higher weight (P = 0.022), BMI (P = 0.046), and waist circumference (P = 0.028) than C(S). Fasting insulin (P = 0.030), homeostasis model assessment for insulin resistance (P = 0.034), total cholesterol (P = 0.043), low-density lipoprotein cholesterol (P = 0.034), and 2-h insulin (P = 0.006) were also significantly higher and insulin sensitivity index composite significantly lower in PCOS(S) than in C(S) (P = 0.003). After adjusting for BMI, only 2-h insulin and insulin sensitivity index composite remained significantly different. CONCLUSIONS: This study indicates that sons of PCOS women exhibit higher body weight from early infancy. In addition, insulin resistance became evident as the subjects got older, which may place them at risk for the development of type 2 diabetes and cardiovascular disease.     

Insulin resistance and polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in humans, affecting approximately 7-8% of women of reproductive age. Despite the criteria adopted, PCOS is considered to be a predominantly hyperandrogenetic syndrome and the evaluation of metabolic parameters and insulin sensitivity is not mandatory. Most women with PCOS also exhibit features of the metabolic syndrome, including insulin resistance, obesity and dyslipidaemia. While the association with type 2 diabetes is well established, whether the incidence of cardiovascular disease is increased in women with PCOS remains unclear. Acknowledging the strong impact of insulin-resistance in the genesis of PCOS could be helpful not only to make the diagnosis more robust, but also for conferring better cardiovascular risk prevention. Several current studies support a strong recommendation that women with PCOS should undergo comprehensive evaluation for the metabolic syndrome and recognized cardiovascular risk factors, and receive appropriate treatment as needed. Lifestyle modifications remain the first-line therapy for all obese women with PCOS. However, many of these women do not lose weight easily. Insulin-sensitizing drugs are discussed as a promising and unique therapeutic option for the chronic treatment of PCOS.     

Melanocortin-3 receptor gene variants in a Maori kindred with obesity and early onset type 2 diabetes

Genetic studies suggest a diabetes susceptibility locus on human chromosome 20, near the melanocortin receptor-3 (MC3-R) gene. We examined the MC3-R as a candidate gene for type 2 diabetes in 12 members of a large Maori kindred with multiple affected members. The coding region of the MC3-R gene was sequenced for both diabetic and non-diabetic individuals. Two separate single base pair substitutions were found in the MC3-R coding sequence and these resulted in amino acid changes, Lysine6Threonine and Isoleucine81Valine. Neither of these MC3-R variants tracked with the presence of diabetes. Furthermore, the variant and wild type MC3-R showed similar functional coupling to adenylyl cyclase. A polymorphic marker (D20S32e) close to the human MC3-R (hMC3-R) coding sequence was investigated in a 60-member pedigree for association with diabetes and other metabolic parameters. There was an association between D20S32e genotype and fasting insulin (P=0.0085) and the insulin resistance index, HOMA-R (P=0.0042). An association was also found between genotype and HDL levels during oral glucose tolerance testing (P=0.0037). These associations were independent of BMI, age, gender and diabetes. Our data do not support a role for variations in the coding region of the hMC3-R in the development of type 2 diabetes in this Maori kindred, but suggest that a locus on chromosome 20 q, close to D20S32e, may contribute to both insulin secretion and action in the Maori kindred.     

Evidence for linkage of familial Diamond-Blackfan anemia to chromosome 8p23.3-p22 and for non-19q non-8p disease

Diamond-Blackfan anemia (DBA) is a rare congenital hypoplastic anemia that usually presents early in infancy and is inherited in 10% to 20% of cases. Linkage analysis has shown that DBA in many of both dominant and recessive DBA families mapped to chromosome 19q13.2 leading to the cloning of a gene on chromosome 19q13.2 that encodes a ribosomal protein, RPS19. However, subsequently, mutations of the RPS19 gene have only been identified in 25% of all patients with DBA. This study analyzed 14 multiplex DBA families, 9 of which had 19q13.2 haplotypes inconsistent with 19q linkage. A genome-wide search for linked loci suggested the presence of a second DBA locus in a 26.4-centimorgan (cM) interval on human chromosome 8p. Subsequently, 24 additional DBA families were ascertained and all 38 families were analyzed with additional polymorphic markers on chromosome 8p. In total, 18 of 38 families were consistent with linkage to chromosome 8p with a maximal LOD score with heterogeneity of 3.55 at D8S277 assuming 90% penetrance. The results indicate the existence of a second DBA gene in the 26.4-cM telomeric region of human chromosome 8p23.3-p22, most likely within an 8.1-cM interval flanked by D8S518 and D8S1825. Seven families were inconsistent with linkage to 8p or 19q and did not reveal mutations in the RPS19 gene, suggesting further genetic heterogeneity. (Blood. 2001;97:2145-2150)     

Genetic determinants of insulin action in polycystic ovary syndrome.

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

Elevated dehydroepiandrosterone sulfate levels as the reproductive phenotype in the brothers of women with polycystic ovary syndrome

There is an inherited susceptibility to polycystic ovary syndrome (PCOS). Some investigators have suggested that premature male-pattern balding is a male phenotype in PCOS families, but this remains controversial. We recently reported evidence for an autosomal monogenic abnormality in ovarian and adrenal steroidogenesis in the sisters of women with PCOS. We performed this study to determine whether we could identify a clinical or biochemical phenotype in the brothers of women with PCOS. One hundred nineteen brothers of 87 unrelated women with PCOS and 68 weight- and ethnicity-comparable unrelated control men were examined and had fasting blood samples obtained. The odds of balding (Hamilton score > or = V) did not differ in the brothers of PCOS women compared with control men. Brothers of women with PCOS had significantly elevated dehydroepiandrosterone sulfate (DHEAS) levels [brothers 3035 +/- 1132 ng/ml (mean +/- SD) vs. control men 2494 +/- 1172 ng/ml; P < 0.05]. There was a significant positive linear relationship between DHEAS levels in PCOS probands and their brothers (r = 0.35; P = 0.001). There was no significant bimodal distribution in DHEAS levels, and there were no significant differences in other parameters in brothers of PCOS women with high DHEAS levels compared with those with low DHEAS levels. There is familial clustering of elevated DHEAS levels in the brothers of women with PCOS, suggesting that this is a genetic trait. This might reflect the same underlying defect in steroidogenesis that we found in the sisters of women with PCOS. Balding was not increased in the brothers of women with PCOS. We conclude that there is a biochemical reproductive endocrine phenotype in men in PCOS families.     

Dyslipidemia and metabolic syndrome in the sisters of women with polycystic ovary syndrome

CONTEXT: Dyslipidemia is a feature of polycystic ovary syndrome (PCOS), but its pathogenesis remains controversial. OBJECTIVE: The objective of this study was to test the hypothesis that dyslipidemia is a heritable trait in sisters of women with PCOS. DESIGN: A case-control design was used. SETTING: The study took place at General Clinical Research Centers in four academic medical centers in the United States. PATIENTS: The subjects included 385 sisters of women with PCOS with the following reproductive phenotypes: sisters with PCOS (n = 51), sisters with hyperandrogenemia and regular menses (HA) (n = 38), unaffected sisters (n = 143), and unknown phenotypes (n = 153). One hundred twenty-five control women of comparable age, body mass index, and ethnicity to women with PCOS were included. INTERVENTIONS: Fasting blood was obtained for measurements of lipid profile, reproductive hormones, glucose, and insulin levels. MAIN OUTCOME MEASURES: The main outcome measures included lipid and lipoprotein levels and prevalence of metabolic syndrome. RESULTS: Sisters with PCOS and HA phenotypes had higher total (P < or = 0.001) and low-density lipoprotein cholesterol levels (P < or = 0.01) compared with unaffected sisters and control women. Triglyceride levels were elevated only in sisters with the PCOS phenotype (P < 0.05). The prevalence of metabolic syndrome was increased in sisters with the PCOS (n = 29) and HA (n = 17) phenotypes compared with unaffected sisters (n = 85) (P < 0.001 and P < 0.05, respectively). CONCLUSIONS: Low-density lipoprotein levels are increased in affected sisters of women with PCOS consistent with a heritable trait. The prevalence of metabolic syndrome is increased in affected sisters.     

Unravelling the phenotypic map of polycystic ovary syndrome (PCOS): a prospective study of 634 women with PCOS

BACKGROUND: The phenotypic spectrum of PCOS has been broadened but the prevalence and clinical significance of PCOS phenotypes continue to challenge the scientific community. OBJECTIVE: Analysis of the phenotypic spectrum of PCOS and determination of the association between metabolic, hormonal and new ultrasonographic criteria. DESIGN: Clinical prospective study. PATIENTS: Six hundred and thirty-four women with PCOS (18-35 years) and comparable body mass index (BMI), diagnosed by ESHRE/ASRM criteria, were categorized into two major groups of phenotypes: classic (NIH) and nonclassic (ESHRE/ASRM), and then subdivided into phenotypes with all possible combinations of diagnostic characteristics. One hundred and eight healthy women of reproductive age, matched for BMI, were recruited as the control group. MEASUREMENTS: Ultrasonographic (ovarian follicle number and volume), hormonal and metabolic parameters. RESULTS: Classic PCOS phenotype was more frequent (85.96%) than the nonclassic phenotype (14.04%). The patients were also classified according to the presence of biochemical (80.60%) or clinical hyperandrogenaemia (12.62%), and, in the newly introduced group, to absence of evidence of hyperandrogenaemia (6.78%). Subjects with classic PCOS with biochemical hyperandrogenaemia (74.76%) were more insulin resistant than controls. In women with PCOS, follicle number was positively related to both insulin resistance and biochemical hyperandrogenaemia. Additionally, women with PCOS had a 6.58-fold increased relative risk (RR) of > 12 follicles on intravaginal ultrasound and a 2.94-fold increased RR of ovarian volume > 10 cm(3) compared to controls. CONCLUSION: The most frequent PCOS phenotype is the subgroup with biochemical hyperandrogenaemia only within the classic phenotype, which is more insulin resistant than the control group. The follicle number, a newly introduced ultrasonographic marker, is related to both metabolic and hormonal features of PCOS.     

Thirty-seven candidate genes for polycystic ovary syndrome: Strongest evidence for linkage is with follistatin

Polycystic ovary syndrome (PCOS) is a common endocrine disorder of women, characterized by hyperandrogenism and chronic anovulation. It is a leading cause of female infertility and is associated with polycystic ovaries, hirsutism, obesity, and insulin resistance. We tested a carefully chosen collection of 37 candidate genes for linkage and association with PCOS or hyperandrogenemia in data from 150 families. The strongest evidence for linkage was with the follistatin gene, for which affected sisters showed increased identity by descent (72%; chi(2) = 12.97; nominal P = 3.2 x 10(-4)). After correction for multiple testing (33 tests), the follistatin findings were still highly significant (P(c) = 0.01). Although the linkage results for CYP11A were also nominally significant (P = 0.02), they were no longer significant after correction. In 11 candidate gene regions, at least one allele showed nominally significant evidence for population association with PCOS in the transmission/disequilibrium test (chi(2) >/= 3.84; nominal P < 0.05). The strongest effect in the transmission/disequilibrium test was observed in the INSR region (D19S884; allele 5; chi(2) = 8.53) but was not significant after correction. Our study shows how a systematic screen of candidate genes can provide strong evidence for genetic linkage in complex diseases and can identify those genes that should have high (or low) priority for further study.     

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

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

An association between non-alcoholic fatty liver disease and polycystic ovarian syndrome

Objectives: The aim of this study was to determine if there is an association between non‐alcoholic fatty liver disease (NAFLD) and polycystic ovarian syndrome (PCOS). NAFLD and PCOS are both known to be associated with metabolic syndrome/insulin resistance. Method: Fourteen consecutive female patients of reproductive age (20–45) either with liver biopsy proven NAFLD (50%) or abdominal ultrasound (US) consistent with steatosis together with elevated ALT levels (50%) were screened for PCOS using 2003 Rotterdam consensus meeting criteria. Other causes of hyperandrogenism were excluded. All subjects underwent relevant questionnaire and clinical exam together with hormonal assays, pelvic (1) or transvaginal US (13) and were screened for evidence of the metabolic syndrome. Results: Ten out of fourteen women matched 2003 Rotterdam consensus meeting diagnostic criteria for PCOS (71%). Eight women suffered from oligo/amenorrhoea, nine women manifested presence of hyperandrogenism and six had history of infertility. Seven women had evidence of biochemical hyperandrogenism with low SHBG, raised free testosterone and elevation of serum LH concentration. Seven women fulfilled US criteria for PCOS. Three of ten patients with PCOS also had type 2 diabetes mellitus. Women with PCOS and NAFLD had higher triglyceride and cholesterol and lower HDL level than group without PCOS. Five patients with NAFLD and PCOS had documented fibrosis on liver biopsy, indicative of more advanced liver disease. Implications: Despite limitations of the study due to the sample size, we found evidence of PCOS in the majority of subjects with NAFLD. Women with NAFLD should be routinely screened for presence of PCOS, diabetes mellitus and metabolic risk factors for cardiovascular disease. Equally, women with PCOS should be screened for NAFLD. Evaluation for liver disease should be considered at an earlier age in some women with PCOS particularly those with an evidence of metabolic syndrome.     

Obese but not normal-weight women with polycystic ovary syndrome are characterized by metabolic and microvascular insulin resistance

Context: Polycystic ovary syndrome (PCOS) and obesity are associated with diabetes and cardiovascular disease, but it is unclear to what extent PCOS contributes independently of obesity. Objective: The objective of the study was to investigate whether insulin sensitivity and insulin's effects on the microcirculation are impaired in normal-weight and obese women with PCOS. Design and Population: Thirty-five women with PCOS (19 normal weight and 16 obese) and 27 age- and body mass index-matched controls (14 normal weight and 13 obese) were included. Metabolic Insulin sensitivity (isoglycemic-hyperinsulinemic clamp) and microvascular insulin sensitivity [endothelium dependent (acetylcholine [ACh])] and endothelium-independent [sodium nitroprusside (SNP)] vasodilation with laser Doppler flowmetry was assessed at baseline and during hyperinsulinemia. Main Outcome Measures: Metabolic insulin sensitivity (M/I value) and the area under the response curves to ACh and SNP curves were measured to assess microcirculatory function at baseline and during insulin infusion (microvascular insulin sensitivity). Results: Obese women were more insulin resistant than normal-weight women (P < 0.001), and obese PCOS women were more resistant than obese controls (P = 0.02). In contrast, normal-weight women with PCOS had similar insulin sensitivity, compared with normal-weight women without PCOS. Baseline responses to ACh showed no difference in the four groups. ACh responses during insulin infusion were significantly greater in normal-weight PCOS and controls than in obese PCOS and controls. PCOS per se had no significant influence on ACh responses during insulin infusion. During hyperinsulinemia, SNP-dependent vasodilatation did not significantly increase, compared with baseline in the four groups. Conclusion: PCOS per se was not associated with impaired metabolic insulin sensitivity in normal-weight women but aggravates impairment of metabolic insulin sensitivity in obese women. In obese but not normal-weight women, microvascular and metabolic insulin sensitivity are decreased, independent of PCOS. Therefore, obese PCOS women in particular may be at increased risk of metabolic and cardiovascular diseases.     

Drug insight: insulin-sensitizing drugs in the treatment of polycystic ovary syndrome--a reappraisal

The recognition that insulin resistance has a pivotal role in the pathogenesis of polycystic ovary syndrome (PCOS) revolutionized our understanding of this complex disorder. PCOS causes major metabolic and reproductive morbidities, including substantially increased risk for type 2 diabetes mellitus and the metabolic syndrome. Insulin-sensitizing drugs (ISDs) ameliorate reproductive abnormalities, restore ovulation and regular menses, increase pregnancy rates and reduce androgenic symptoms in affected women with PCOS. Accordingly, ISDs, specifically metformin, have been widely adopted as therapy for this condition. A recent, large, randomized, multicenter, clinical trial that assessed live-birth rates rather than surrogate end points suggested that metformin alone is inferior to clomiphene citrate in treating infertility associated with PCOS. There is, furthermore, no evidence to support the use of metformin during pregnancy to prevent spontaneous abortions or gestational diabetes mellitus in women with PCOS. Renewed safety concerns about thiazolidinediones followed recent studies that reported increased cardiovascular morbidity with these agents. These concerns might preclude thiazolidinedione use in otherwise healthy women with PCOS. Finally, although ISDs improve insulin action and cardiovascular disease risk, there is no evidence that they provide long-term health benefits in PCOS. This article discusses the role of ISDs in PCOS in light of these new data.