Correlation between IL-1β, IL-1Ra gene polymorphism and occurrence of polycystic ovary syndrome infertility

Diacerein mitigates endocrine and cardio-metabolic disruptions in experimental PCOS mice model by modulating AdipoR1/ PON 1

BACKGROUND

This study aimed to explore the impact of Diacerein (DIC) on endocrine and cardio-metabolic changes in polycystic ovarian syndrome (PCOS) mouse model.

METHODS

A total of 18 adult female mice (Parkes strain), aged 4-5 weeks, were randomly assigned to three groups, each comprising 6 animals, as follows: Group I (control), received normal diet and normal saline as vehicle for 51 days; Group II received Letrozole (LET; 6 mg/kg bw) for 21 days to induce PCOS; Group III received LET, followed by daily oral gavage administration of DIC (35 mg/kg bw) for 30 days.

RESULTS

This study indicates that treatment with LET resulted in PCOS with characteristics such as polycystic ovaries, elevated testosterone, weight gain, visceral adiposity, high levels of insulin as well as fasting blood glucose in addition to insulin resistance, improper handling of ovarian lipids, atherogenic dyslipidemia, impaired Na + /K + -ATPase activity and serum, cardiac, and ovarian oxidative stress. Serum/ovarian adiponectin levels were lowered in LET-treated mice. In mice treated with LET, we also discovered a reduction in cardiac and serum paraoxonase 1 (PON1). Interestingly, DIC restored ovarian andcardio-metabolic abnormalities in LET-induced PCOS mice. DIC prevented the endocrine and cardio-metabolic changes brought on by letrozole-induced PCOS in mice.

CONCLUSION

The ameliorative effects of DIC on letrozole-induced PCOS with concurrent oxidative stress, abdominal fat deposition, cardiac and ovarian substrate mishandling, glucometabolic dysfunction, and adiponectin/PON1 activation support the idea that DIC perhaps, restore compromised endocrine and cardio-metabolic regulators in PCOS.

Therapeutic Potential of Selenium Nanoparticles on Letrozole-Induced Polycystic Ovarian Syndrome in Female Wistar Rats

Polycystic ovarian syndrome (PCOS) is considered the most frequent gynecological endocrine disorder that causes anovulatory infertility. The current study aimed to investigate the potential significance of selenium nanoparticles (SeNPs), an IL-1 inhibitor, in the treatment of letrozole-induced PCOS in rats that satisfied the metabolic and endocrine parameters found in PCOS patients. Letrozole (2 ppm, per orally, p.o.) was given orally to female Wistar rats for 21 days to develop PCOS. After PCOS induction, rats were given SeNPs (25 ppm/day, p.o.), SeNPs (50 ppm/day, p.o.), or metformin (2 ppm/day, p.o.) for 14 days. PCOS was associated with an increase in body weight, ovarian weight, ovarian size, and cysts, as well as an increase in blood testosterone, luteinizing hormone (LH), and insulin, glycaemia, and lipid profile levels. The SeNP administration decreased all of these variables. Furthermore, SeNPs significantly reduced letrozole-induced oxidative stress in the ovaries, muscles, and liver by decreasing elevated levels of malondialdehyde and total nitrite while raising suppressed levels of superoxide dismutase and catalase. SeNPs increased the amounts of the protective proteins Kelch-like ECH-associated protein 1 (Keap-1), nuclear factor erythroid 2-related factor 2 (Nrf2), and OH-1. It was depicted from the study that SeNPs reduce the upregulation of inflammatory cytokines that are interleukin 6 (IL-6), tumour necrosis factor α (TNF-α), and the interleukin 1 (IL-1). Our findings show that SeNPs, through their antioxidant and anti-inflammatory characteristics, alleviate letrozole-induced PCOS.

Role of diacerein on steroidogenesis and folliculogenesis related genes in ovary of letrozole-induced PCOS mice

Polycystic ovary syndrome (PCOS), an intricate and multifaceted metabolic-endocrine disorder that typically affects 6-20% of women of reproductive age and accounts for 70-80% of all occurrences of infertility globally. In this study we focussed on the effect of diacerein (DIC) on steroidogenesis and follicle development in addition to the basic metabolic and endocrine problems which are associated with PCOS. Eighteen mature female parkes strain mice were separated into three groups at random with 6 animals in a group as follows: Group I, received water and normal diet for 66 days; group II received letrozole (LETZ) (6 mg/kg bw) for the induction of PCOS; Group III received LETZ (6 mg/kg) for 3 weeks followed by the administration of DIC (35mg/kg) for 45 days. In our study we observed that mice with PCOS had irregular estrous cycle with increased LH/FSH, estrogen level and decline in expression of Kitl, Bmp, Cyp11a1, CYP19a1, Ar, lhr, Fshr and Esr1 as well as decreased SOD and CAT activity in ovary. Moreover, we observed increase in the expression of CYP17a1, as well as increase in serum cholesterol, triglycerides, testosterone, LH, VEGF and insulin levels. All these changes were reversed after the administration of DIC in PCOS mice. Diacerin administration reversed abnormalities in mice with PCOS by modulating the regulation of genes which are related to steroidogenesis and folliculogenesis.

Key Genes Associated With Non-Alcoholic Fatty Liver Disease and Polycystic Ovary Syndrome

Background: Polycystic ovary syndrome (PCOS) is the most common metabolic and endocrinopathies disorder in women of reproductive age and non-alcoholic fatty liver (NAFLD) is one of the most common liver diseases worldwide. Previous research has indicated potential associations between PCOS and NAFLD, but the underlying pathophysiology is still not clear. The present study aims to identify the differentially expressed genes (DEGs) between PCOS and NAFLD through the bioinformatics method, and explore the associated molecular mechanisms. Methods: The microarray datasets GSE34526 and GSE63067 were downloaded from Gene Expression Omnibus (GEO) database and analyzed to obtain the DEGs between PCOS and NAFLD with the GEO2R online tool. Next, the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis for the DEGs were performed. Then, the protein-protein interaction (PPI) network was constructed and the hub genes were identified using the STRING database and Cytoscape software. Finally, NetworkAnalyst was used to construct the network between the targeted microRNAs (miRNAs) and the hub genes. Results: A total of 52 genes were identified as DEGs in the above two datasets. GO and KEGG enrichment analysis indicated that DEGs are mostly enriched in immunity and inflammation related pathways. In addition, nine hub genes, including TREM1, S100A9, FPR1, NCF2, FCER1G, CCR1, S100A12, MMP9, and IL1RN were selected from the PPI network by using the cytoHubba and MCODE plug-in. Then, four miRNAs, including miR-20a-5p, miR-129-2-3p, miR-124-3p, and miR-101-3p, were predicted as possibly the key miRNAs through the miRNA-gene network construction. Conclusion: In summary, we firstly constructed a miRNA-gene regulatory network depicting interactions between the predicted miRNA and the hub genes in NAFLD and PCOS, which provides novel insights into the identification of potential biomarkers and valuable therapeutic leads for PCOS and NAFLD.

Diacerein ameliorates letrozole-induced polycystic ovarian syndrome in rats

Polycystic ovary syndrome (PCOS) is the most common gynaecological endocrine disease that causes anovulatory infertility. The current study aimed to explore the possible role of diacerein (DIA), an IL-1β inhibitor, in treating letrozole-induced PCOS in rats that exhibit the metabolic and endocrinal criteria of PCOS patients. PCOS was induced in female Wistar rats by the oral administration of letrozole (1 mg/kg, per orally, p.o.) for 21 days. Rats were then treated with DIA (25 mg/kg/day, p.o.), DIA (50 mg/kg/day, p.o.), or metformin (2 mg/100 g/day, p.o.) for 14 days after the PCOS induction. PCOS resulted in a significantly higher body weight, ovarian weight, ovarian size, and cysts, as well as an elevation in serum testosterone, LH, insulin, glycemia, and lipid profile levels. All of these effects were significantly reduced by the DIA administration. Additionally, DIA remarkably inhibited the letrozole-induced oxidative stress in the ovaries, muscles, and liver by reducing the upraised levels of malondialdehyde and total nitrite and increasing the suppressed levels of superoxide dismutase and catalase. DIA enhanced the protective proteins Keap-1, Nrf2, and OH-1 levels. Finally, DIA inhibited the elevated mRNA levels of NLRP3 and caspase-1, the up-regulated inflammatory cytokines IL-6, TNF-α, and the IL-1β/NFκB signaling pathway. Our results proved that DIA ameliorates letrozole-induced PCOS through its antioxidant and anti-inflammatory properties.

The Role of Chronic Inflammation in Polycystic Ovarian Syndrome-A Systematic Review and Meta-Analysis

Although the current literature associates polycystic ovarian syndrome (PCOS) with chronic inflammation, the evidence for this link remains inconclusive and its causal nature remains unclear. The purpose of this systematic review was to assess the inflammatory status in PCOS women and to determine whether it is related to PCOS or to its associated adiposity. We searched electronic databases including PUBMED, EMBASE and MEDLINE, SCOPUS, DynaMed plus, TRIP, ScienceDirect and Cochrane Library, for studies investigating C-reactive protein (CRP) and other inflammatory makers in PCOS women versus healthy controls. Quality and risk of bias for selected studies were assessed using the modified Newcastle-Ottawa scale. CRP data were extracted and pooled using RevMan for calculation of the standardized mean difference (SMD) and 95% confidence interval (CI). Eighty-five eligible studies were included in the systematic review, of which 63 were included in the meta-analysis. Pooled analysis of the 63 studies revealed significantly higher circulating CRP in PCOS women (n = 4086) versus controls (n = 3120) (SMD 1.26, 95%CI, 0.99, 1.53). Sensitivity meta-analysis of 35 high quality studies including non-obese women showed significantly higher circulating CRP in PCOS women versus controls (SMD 1.80, 95%CI, 1.36, 2.25). In conclusion, circulating CRP is moderately elevated in PCOS women independent of obesity, which is indicative of low-grade chronic inflammation.

Association of IL-1β, IL-6, TNF-α, and TGFβ1 Gene Polymorphisms with Recurrent Spontaneous Abortion in Polycystic Ovary Syndrome

Recurrent spontaneous abortion (RSA) is a common pregnancy-associated complication of polycystic ovary syndrome (PCOS) which is an endocrine malfunction disease. Patients with PCOS may have several underlying contributing and interrelated factors, which have been reported in women with RSA. The incidence rate between PCOS and RSA remains uncertain. The aim of this study is to determine the possible association of IL-1β-511C/T, IL-6-174G/C, TNF-α-1031T/C, and TGFβ1-509T/C with RSA patients with or without PCOS. A total of 140 RSA patients, 70 of which were PCOS patients, and 140 healthy females with no history of RSA or PCOS were included in this study. PCR amplification, genotyping, and sequence analysis were employed to investigate the presence of the polymorphisms. The genotypic and allelic frequencies were calculated separately for each subject. Out of the four studied polymorphisms, the IL-1β-511C/T genotype in RSA without PCOS patients (12.7%) was significantly different compared with that in control subjects (p = 0.047). For IL-6-174C/G, there was a tendency towards more CC carriers among RSA with PCOS patients (10%) than in controls (3%). The GG genotype in RSA women with PCOS (60%) was significantly different compared with that in control subjects (p = 0.033), and the GC genotype in RSA with PCOS patients (30%) showed a marginal significant difference compared with that in control subjects (p = 0.050). Significant difference was identified in the allelic frequencies in RSA patients with PCOS compared to controls (p = 0.025). IL-6-174G/C and TNF-α-1031T/C polymorphisms are significantly associated with RSA patients in Saudi patients with PCOS, while the IL-1β-511C/T polymorphism is significantly associated with RSA patients without PCOS.

Association of IL-1β, IL-1Ra and FABP1 gene polymorphisms with the metabolic features of polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS), a highly prevalent endocrinopathy is currently being designated as chronic low grade inflammatory state. IL-1β, IL-1Ra and FABP1 are critical mediators of inflammatory processes and are speculated to play a role in the pathogenesis of PCOS. The aim of this study was to study the association of IL-β, IL-1Ra and FABP1 gene polymorphisms with PCOS and related metabolic features.

SUBJECTS

95 PCOS and 45 age matched healthy control subjects were enrolled in this study.

METHODS

Polymorphism in genes IL-1β, IL-1Ra and FABP1 was studied by PCR, PCR-RFLP and sequencing methods, respectively. Hormonal and lipid profiles were evaluated for all the subjects.

RESULTS

Hormonal and lipid profiles showed significant differences between PCOS and control subjects. Allele and genotype frequencies of IL-1β, IL-1Ra and FABP1 gene polymorphisms did not vary between the control and PCOS group. However, T allele of C[-511]T variant of IL-1β, allele II in intron 2 of IL-1Ra and A allele of A/G variant of FABP1 (rs2197076) showed significant association with many metabolic features associated with PCOS.

CONCLUSIONS

Polymorphism in genes encoding cytokines and proteins involved in lipid metabolism can provide insights into the genetics of the disease and may contribute to assess the associated risk of cardiovascular diseases (CVD), dyslipidemia and metabolic syndrome (MetS) associated with PCOS.

Polymorphisms of Cytokine Genes and Polycystic Ovary Syndrome: A Review

BACKGROUND

Polycystic ovary syndrome (PCOS) is the endocrinopathy that affects women in their reproductive age. The physiopathology involves multifactorial mechanisms, including cytokine gene regulation.

METHODS

The review was conducted in the database PubMed, with articles published between 2005 and 2015. The selected studies evaluated the single-nucleotide polymorphisms (SNPs) of cytokines genes in association with PCOS. Twenty-four studies met the inclusion criteria and showed the SNPs of cytokines that were associated or not with PCOS.

RESULTS

The disease susceptibility was associated with interleukin (IL) 1A, IL1B, IL1RN, and IL6 alleles and genotypes. The tumor necrosis factor (TNF) -1032 C/T genotype and C allele were risk factors and T/T genotype was a protector marker to disease. The IL18 SNPs were not associated with PCOS per se, but IL18-137 C and G alleles were related to the protection of insulin resistance and glucose tolerance, respectively. One research found association between TGFB1 and PCOS. However, the TNF -308, IL10, and interferon (IFN) SNPs did not appear to influence PCOS genetic susceptibility.

CONCLUSIONS

This study sought to contribute and clarify the SNPs in cytokine genes that influence the development of PCOS. Most studies occurred in Asia; most SNPs studied were in IL1B -511, TNF -1031, and IL6-174; and most of them were associated with the susceptibility to PCOS development. Nevertheless, further investigations based on genome-wide association studies and cytokine gene SNPs are needed to better characterize the risk factors to PCOS.

A cross-sectional study to assess any possible linkage of C/T polymorphism in CYP17A1 gene with insulin resistance in non-obese women with polycystic ovarian syndrome

BACKGROUND & OBJECTIVES

Insulin resistance (IR) is a major confounding factor in polycystic ovarian syndrome (PCOS) irrespective of obesity. Its exact mechanism remains elusive till now. C/T polymorphism in the -34 promoter region of the CYP17 gene is inconsistently attributed to elucidate the mechanism of IR and its link to hyperandrogenemia in obese PCOS patients. In the present study we aimed to evaluate any association of this polymorphism with IR in non-obese women with PCOS.

METHODS

Polymorphism study was performed by restriction fragment length polymorphism (RFLP) analysis of the Msp A1 digest of the PCR product of the target gene in 75 PCOS cases against 73 age and BMI matched control women. Serum testosterone, BMI and HOMA-IR (homeostatic model of assessment-insulin resistance) were analyzed by standard techniques. A realistic cut-off value for the HOMA-IR was obtained through receiver operating characteristic (ROC) curve for exploring any possible link between IR and T/C polymorphism in the case group.

RESULTS

Significant increases in serum testosterone and HOMA-IR values were observed among the case group (P<0.001) without any significant elevation in BMI and FBG compared to controls. Cut-off value for IR in the PCOS patients was 1.40 against a maximum sensitivity of 0.83 and a minimum false positivity of 0.13. The analysis revealed an inconclusive link between the C/T polymorphic distribution and insulin resistant case subjects.

INTERPRETATION & CONCLUSIONS

The results showed that CYP17A1 gene was not conclusively linked to either IR or its associated increased androgen secretion in non-obese women with PCOS. We propose that an increased sensitivity of insulin on the ovarian cells may be the predominant reason for the clinical effects and symptoms of androgen excess observed in non-obese PCOS patients in our region.

IL-1 receptor antagonist levels are associated with glucose tolerance in polycystic ovary syndrome

OBJECTIVE

To investigate serum interleukin-1 receptor antagonist (IL-1Ra) levels in women with polycystic ovary syndrome (PCOS).

SUBJECTS AND METHODS

Serum IL-1Ra levels were measured at baseline in 73 women with PCOS and 45 control subjects (18-47 years), and in 27 women with PCOS who underwent oral and intravenous glucose tolerance tests (OGTTs and IVGTTs).

RESULTS

IL-1Ra concentrations predicted OGTT 2-h glucose levels independently of BMI and insulin resistance (P ≤ 0·001) in women with PCOS. Serum IL-1Ra concentration was elevated in women with PCOS compared with controls [mean (SD): 309·5 (208·8) vs 199·1 (81·4) ng/l, P < 0·001], but the difference disappeared after adjusting for BMI. An increment of five BMI units raised IL-1Ra levels by 108·5 ng/l [95% confidence interval (CI): 85·5-131·5, r(2) = 0·603] in women with PCOS and only by 77·0 ng/l (95% CI: 50·5-103·5, r(2) = 0·512) in controls when adjusted for BMI and age. Levels of IL-1Ra in obese women with PCOS reflected decreasing OGTT-derived insulinogenic index (P = 0·032) and disposition index (P = 0·046) independently of BMI. Increased levels of IL-1Ra correlated with indices showing increasing insulin resistance and AUC insulin (P ≤ 0·002).

CONCLUSIONS

Increased IL-1Ra levels in women with PCOS were largely explained by increasing adiposity. However, serum IL-1Ra concentrations predicted 2-h glucose levels independently of BMI suggesting that increased IL-1Ra may be associated with disturbed glucose metabolism.

Associations between TNF-α and interleukin gene polymorphisms with polycystic ovary syndrome risk: a systematic review and meta-analysis

BACKGROUND

The associations between TNF-α and Interleukin gene polymorphisms and polycystic ovary syndrome (PCOS) risk have been studied in numerous epidemiological studies, but the results remain controversial. To investigate whether these polymorphisms facilitate susceptibility to PCOS, we conducted a comprehensive systematic review and meta-analysis.

METHODS

PubMed, Embase, Web of Science, Medline, CNKI, and Google Scholar were searched to obtain the genetic association studies according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Odds ratios (OR) with corresponding 95 % confidence intervals (CI) were used to assess the strengths of the associations. Funnel plots and Egger's tests were performed to test for possible publication bias. All statistical analyses were performed using Review Manager 5.2 and STATA11.0.

RESULTS

Eighteen articles were included in the final meta-analysis. The studies involved the following polymorphisms: TNF-α -308G > A, TNF-α -805C>T, TNF-α -1031 T>C, IL-1A -889C>T, IL-1B -511C>T, IL-1B +3953 T>C, IL-6 -174G>C, IL-10 -819C>T, IL-10 -1082A>G, IL-18 -607C>A, and IL-18 -137G>C. Our results show a significant association between PCOS risk and the TNF-α -1031 T>C polymorphism (For TC+CC vs. TT: OR=2.09, 95 % CI=1.58-2.76, p<0.0001. For C allele vs. T allele: OR=1.67, 95 % CI=1.33-2.09, p<0.0001) and between PCOS risk and the IL-6 -174>C polymorphism (For CC+GC vs. GG: OR=0.49, 95 % CI=0.25-0.95, p=0.03. For CC vs. GG: OR=0.48, 95 % CI=0.28-0.80, p=0.005. For C vs. G: OR=0.60, 95 % CI=0.42-0.87, p=0.007). No associations were found with the other genetic models.

CONCLUSION

The results of the meta-analysis suggest positive associations between the TNF-α -1031 T>C and IL-6 -174G>C polymorphisms and the risk of PCOS. No associations are found between PCOS risk and the TNF-α -308G>A, TNF-α -805C>T, IL-1A -889C>T, IL-1B -511C>T, IL-1B +3953C>T, IL-10 -819C>T, IL-10 -1082 A>G, IL-18 -607C>A, and IL-18 -137G>C polymorphisms. However, due to the heterogeneity and low quality of the studies related to PCOS polymorphisms in the meta-analysis, the results should be interpreted with caution. Future multi-ethnicity studies of homogeneous populations of PCOS patients with larger sample sizes and well-matched controls are needed.

N-acetyl cysteine reduces oxidative toxicity, apoptosis, and calcium entry through TRPV1 channels in the neutrophils of patients with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a common inflammatory and oxidant disease with an uncertain pathogenesis. N-acetyl cysteine (NAC) decreases oxidative stress, intracellular free calcium ion [Ca(2+)]i, and apoptosis levels in human neutrophil. We aimed to investigate the effects of NAC on apoptosis, oxidative stress, and Ca(2+) entry through transient receptor potential vanilloid 1 (TRPV1) and TRP melastatin 2 (TRPM2) channels in neutrophils from patients with PCOS. Neutrophils isolated from PCOS group were investigated in three settings: (1) after incubation with TRPV1 channel blocker capsazepine or TRPM2 channel blocker 2-aminoethyl diphenylborinate (2-APB), (2) after supplementation with NAC (for 6 weeks), and (3) with combination (capsazepine + 2-APB + NAC) exposure. The neutrophils in TRPM2 and TRPV1 experiments were stimulated by N-formyl-L-methionyl-L-leucyl-L-phenylalanine (fMLP; 1 μM) and capsaicin (10 μM) as concentration agonists, respectively. Neutrophil lipid peroxidation and capsaicin-induced increase in [Ca(2+)]i concentrations were reduced by capsazepine and NAC treatments. However, the [Ca(2+)]i concentration did not change by fMLP stimulation. Neutrophil lipid peroxidation, apoptosis, caspase-3, caspase-9, cytosolic reactive oxygen species production, and mitochondrial membrane depolarization values were decreased by NAC treatment although neutrophil glutathione peroxidase and reduced glutathione levels were increased by the NAC treatment. Serum lipid peroxidation, luteinizing hormone, testosterone, insulin, interleukin-1 beta, and homocysteine levels were decreased by NAC treatment although serum vitamin A, beta-carotene, vitamin E, and total antioxidant status were increased by the NAC treatment. In conclusion, NAC reduced oxidative stress, apoptosis, cytokine levels, and Ca(2+) entry through TRPV1 channel, which provide supportive evidence that oxidative stress and TRPV1 channel plays a key role in etiology of PCOS.

Association of TNF-alpha, IL-6 and IL-1beta gene polymorphisms with polycystic ovary syndrome: a meta-analysis

Background

Several studies on the association of TNF-alpha (−308 G/A), IL-6 (−174 G/C) and IL-1beta (−511 C/T) polymorphisms with polycystic ovary syndrome (PCOS) risk have reported conflicting results. The aim of the present study was to assess these associations by meta-analysis.

Results

A total of 14 eligible articles (1665 cases/1687 controls) were included in this meta-analysis. The results suggested that there was no obvious association between the TNF-alpha (−308 G/A) polymorphism and PCOS in the overall population or subgroup analysis by ethnicity, Hardy–Weinberg equilibrium (HWE) in controls, genotyping method, PCOS diagnosis criteria, and study sample size. Also, no obvious association was found between the TNF-alpha (−308 G/A) polymorphism and obesity in patients with PCOS (body mass index [BMI] ≥ 25 kg/m² vs. BMI < 25 kg/m²). Regarding the IL-6 (−174 G/C) polymorphism, also no association was found in the overall population in heterozygote comparison, dominant model, and recessive model. Even though an allelic model (odds ratio [OR] = 0.63, 95% confidence interval [CI] = 0.41–0.96) and a homozygote comparison (OR = 0.52, 95% CI = 0.30–0.93) showed that the IL-6 (−174 G/C) polymorphism was marginally associated with PCOS. Further subgroup analysis suggested that the effect size was not significant among HWE in controls (sample size ≤ 200) and genotyping method of pyrosequencing under all genetic models. Similarly, there was no association between the IL-1beta (−511 C/T) polymorphism and PCOS in the overall population or subgroup analysis under all genetic models. Furthermore, no significant association was found between the IL-1beta (−511 C/T) polymorphism and several clinical and biochemical parameters in patients with PCOS.

Conclusions

The results of this meta-analysis suggest that the TNF-alpha (−308 G/A), IL-6 (−174 G/C), and IL-1beta (−511 C/T) polymorphisms may not be associated with PCOS risk. However, further case–control studies with larger sample sizes are needed to confirm our results.

Electronic supplementary material

The online version of this article (doi:10.1186/s12863-015-0165-4) contains supplementary material, which is available to authorized users.