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.

Significance of Homocysteine Levels in the Management of Polycystic Ovarian Syndrome: A Literature Review

Polycystic ovarian syndrome (PCOS) is a complex disorder involving cardiovascular, metabolic, endocrine, and reproductive systems. Even though the exact etiology is not clear, many studies suggest genetic and environmental factors play a role. Homocysteine (Hcy) is considered to be an independent risk factor for atherogenic and thrombotic components of various systems. Many studies in the past have evaluated Hcy levels in the PCOS population. This article aims to elaborate on the importance of Hcy levels in the overall management of PCOS. We conducted a PubMed data search using combined keywords PCOS and homocysteine levels and manually screened relevant articles for the review while avoiding duplication of data. After the literature review, we analyzed the relationship between homocysteine levels and various components of PCOS. Most of the studies identified a statistically significant elevation in Hcy levels in PCOS women with insulin resistance, androgen excess, elevated markers of cardiovascular risk, recurrent pregnancy loss, and metformin treatment. We also examined studies that focused on treating hyperhomocysteinemia (Hhcy) in PCOS women. However, because of the limited sample sizes and various inclusion criteria used for subjects in the studies, their clinical implication is unclear in routine practice. Furthermore, we encourage clinicians to follow up on Hcy levels in PCOS women at high risk for any complications in their management course. We believe an observational study on a larger scale in a well-defined PCOS population would be useful to uncover the prevalence of elevated Hcy levels in PCOS women, which would help pave the way for establishing treatment guidelines on serum Hcy levels in PCOS management.

Metabolic and carbohydrate characteristics of different phenotypes of polycystic ovary syndrome

OBJECTIVE

To compare the prevalence of various metabolic and cardiovascular risk factors and insulin resistance between polycystic ovary syndrome (PCOS) patients with or without hyperandrogenism.

MATERIAL AND METHODS

This is a retrospective cross-sectional study involving women with PCOS as diagnosed according to the Androgen Excess (AE) Society definition (n=504) and women with normoandrogenemic PCOS (n=183). Anthropometrics, lipid profile, glucose, insulin, oral glucose tolerance test (OGTT), and reproductive hormone levels were evaluated.

RESULTS

Women with PCOS diagnosed according to the AE Society had a significantly higher prevalence of metabolic syndrome compared with the normoandrogenemic PCOS phenotype: odds ratio (OR) 2.95 [95% confidence interval (CI) 1.21-7.21]. There was no significant difference in the prevalence glucose intolerance test between the groups [OR: 2.15, 95% CI 0.71-6.56]. The prevalence of low high density lipoprotein (HDL)-cholesterol in the group under the AE-PCOS Society criteria was higher than that of the normoandrogenemic PCOS group [OR: 2.82, 95%CI 1.29-3.36].

CONCLUSION

The risks of metabolic syndrome and cardiovascular disease may vary among the phenotypes of PCOS based on the Rotterdam criteria. This new data may be of reference in informing women with PCOS, although further prospective studies are needed to validate this proposition.

Circulating markers of oxidative stress and polycystic ovary syndrome (PCOS): a systematic review and meta-analysis

BACKGROUND Oxidative stress might be associated with polycystic ovary syndrome (PCOS), but relatively small studies published to date do not permit reaching a definitive conclusion. We aimed at conducting a systematic review and meta-analysis of studies evaluating circulating markers of oxidative stress in patients with PCOS. METHODS We conducted a systematic review of studies reporting circulating markers of oxidative stress in women with PCOS and controls published up to June 2012, using Entrez PubMed and EMBASE online facilities. Meta-analysis calculated standardized mean differences (SMDs) and 95% confidence intervals (95CI). RESULTS From 1633 potential studies identified electronically, 68 studies, including 4933 PCOS patients and 3671 controls, were selected. For each of nine circulating markers of oxidative stress, an individual meta-analysis was conducted. Compared with control women, patients with PCOS presented higher circulating concentrations of homocysteine (23% increase, SMD 0.6, 95CI, 0.4-0.8), malondialdehyde (47% increase, SMD 1.9, 95CI 1.2-2.6) and asymmetric dimethylarginine (36% increase, SMD 1.1, 95CI 0.6-1.6), and increased superoxide dismutase activity (34% increase, SMD 1.0, 95CI 0.5-1.4) and decreased glutathione levels (50% decrease, SMD -3.7, 95CI -6.2 to -1.2) and paraoxonase-1 activity (32% decrease, SMD -0.9, 95CI -1.3 to -0.4). Similar results were found when restricting the analyses to studies in which patients and controls were matched for age and body mass index. CONCLUSIONS Circulating markers of oxidative stress are abnormal in women with PCOS independent of weight excess. This finding suggests that oxidative stress may participate in the pathophysiology of this common disorder.

Mediators of chronic inflammation in polycystic ovarian syndrome

Polycystic ovarian syndrome (PCOS) is an endocrine disorder affecting 5-10% of reproductive-age women. Hyperandrogenemia, which characterizes the syndrome, stimulates the maturation of adipocytes and favors central obesity. The linking hub between obesity and other metabolic manifestations of the syndrome seems to be chronic low-grade inflammation. We discuss the most reliable current data regarding the role of inflammatory mediators in PCOS, with particular focus on the genetic mechanisms implicated. C-reactive protein levels are 96% higher in PCOS patients than in healthy controls. Patients with the -308A polymorphism of the tumor necrosis factor-α gene have elevated androgens in comparison with carriers of the -308G. Interleukin 18 (IL-18) is elevated in lean patients, with a further rise in the presence of obesity and insulin resistance. Polymorphisms of the IL-1a, IL-1b and IL-6 genes have also been associated with PCOS. Plasminogen activator inhibitor-1 levels are positively associated with the syndrome, and carriers of the 4G allele of the 4G/5G polymorphism are at risk of developing PCOS. Other mediators discussed include adhesion molecules, osteoprotegerin, asymmetric dimethylarginine, homocysteine and advanced glycation end-products. The elucidation of the pathogenetic mechanisms implicated in PCOS and their connection with low-grade inflammation may in the future offer the opportunity for the formulation of novel therapeutic strategies and individualized therapy for these patients.

Homocysteine metabolism in polycystic ovary syndrome

Homocysteine, a sulfur-containing amino acid formed during the metabolism of methionine, exert cytotoxic effects on vascular endothelium. Molecular mechanisms of homocysteine-induced cellular dysfunction include increased inflammatory cytokine expression, altered nitric oxide bioavailability, induction of oxidative stress, activation of apoptosis and defective methylation. Hyperhomocysteinemia is associated with an increased risk of atherosclerotic and thromboembolic disorders, as well as hyperinsulinemia and may partially account for increased risk of cardiovascular disease associated with insulin resistance. Women with PCOS are more likely to develop components of the metabolic syndrome such as disturbances of carbohydrate metabolism, obesity, hypertension and dyslipidemia, which in turn are risk factors for cardiovascular disease. A number of studies confirmed the presence of increased serum homocysteine concentration in PCOS patients and the possible determinants of this observation are still debated. PCOS treatment options can influence homocysteine levels.

Is the risk for cardiovascular disease increased in all phenotypes of the polycystic ovary syndrome?

Polycystic ovary syndrome (PCOS) is a common disorder in women of reproductive age, affecting around 10% of them. Polycystic ovary syndrome is considered to be related to increased risk for type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). There are 2 definitions for PCOS: one adopted in 1990 (classical PCOS with phenotypes A and B) and the other in 2003 (Rotterdam criteria with 4 phenotypes A to D). The latter is a wider definition including the 1990 phenotypes. There is mounting data suggesting that phenotypes C and D are not actually related to increased CVD risk, and thus screening for CVD risk factors of intervening for primary CVD prevention in young women is not cost-effective. There is an increasing number of suggestions to return to the 1990 criteria plus some metabolic parameters to identify real CVD risk in this population. However, such a strategy needs verification by large, prospective studies.

Meta-analysis of cardiovascular disease risk markers in women with polycystic ovary syndrome

BACKGROUND

The relation between polycystic ovary syndrome (PCOS) and cardiovascular disease (CVD) remains unclear. In an attempt to provide high-quality evidence on the relation between PCOS and CVD, relevant literature for CVD risk markers [C-reactive protein (CRP), homocysteine (Hcy), tumor necrosis factor-alpha (TNF-α), plasminogen activator inhibitor-1 (PAI-1), lipoprotein (a) [Lp(a)], advanced glycation end-products (AGEs), vascular endothelial growth factor (VEGF), interleukin-6 (IL-6), asymmetric dimethylarginine (ADMA), endothelin-1 (ET-1) and fibrinogen] in women with PCOS was reviewed and analyzed.

METHODS

A systematic search was conducted electronically using specific eligibility criteria. Weighted mean differences (WMDs) and 95% confidence intervals (CIs) were calculated and combined appropriately. To ensure synthesis of the best available evidence, sensitivity analyses were performed. RESULTS A total of 130 data sets were included in 11 different outcomes, involving 7174 and 5076 CVD markers in women with PCOS and controls, respectively. Women with PCOS demonstrated significantly elevated CRP [WMD (95% CI) 0.99 (0.77-1.21)], Hcy [2.25 (1.46-3.03)], PAI-1 antigen [16.96 (7.25-26.28)], PAI-1 activity [0.71 (0.18-1.23)], VEGF [1.72 (0.96-2.48)], ADMA [0.19 (0.08-0.3)], AGEs [3.91 (2.36-5.45)] and Lp(a) [0.81 (0.58-1.04)] concentrations compared with controls, yet with significant between-study heterogeneity. Borderline significance (not robust in the sensitivity analyses) was detected for TNF-α [0.75 (0.07-1.44)], ET-1 [1.06 (0.52-1.59)] and fibrinogen [0.20 (0.01-0.39)], whereas no difference was detected for IL-6 [0.71 (-0.16 to 1.59)]. CONCLUSIONS Women with PCOS have increased serum concentrations of CVD risk markers compared with controls. Whether this apparent risk is translated into increased incidence of CVD in later life remains to be elucidated.