title: Interleukin-6 Levels in Women with Polycystic Ovary Syndrome: A Systematic Review and Meta-Analysis.
abstract: BACKGROUND
  The change of serum interleukin-6(IL-6) levels in women with polycystic ovary syndrome (PCOS), as well as the relations between IL-6 levels and body mass index (BMI), insulin resistance(IR) and androgen status of PCOS patients, are not fully understood.
  
  
  METHODS
  A literature search was performed in October 2015 using PubMed, Embase and the Cochrane Library databases to identify studies. Random-effects model was used to estimate the standardized mean differences (SMDs) with 95% confidence intervals (CIs).
  
  
  RESULTS
  Twenty articles with 25 case-control studies included 1618 women (922 PCOS patients and 696 controls) were included in this study. IL-6 levels in controls were significantly lower than that of PCOS patients (SMD = 0.78, 95%CI = 0.41-1.16, P<0.001), with significant heterogeneity across studies (I2 = 91% and P<0.001). Meta-regression analysis model indicated IR status was the main source of heterogeneity (P = 0.005). Results from group analysis suggested that high IL-6 levels in PCOS were significantly associated with Homeostasis Model Assessment of Insulin Resistance (HOMA2-IR) ratio and total testosterone ratio (T ratio), and was found in both lean and obese women with PCOS. Cumulative meta-analysis results indicated the total effect size (SMD) had tend to be stable since 2012(0.79 to 0.92).
  
  
  CONCLUSIONS
  A high IL-6 level is not an intrinsic characteristic of PCOS, but may be a useful monitoring biomarker for the treatment of PCOS.
authors: Department of Clinical Laboratory, the Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou, Guangxi, China.
authors: Zheng
authors: Z
authors: Peng
authors: Department of Clinical Laboratory, Liuzhou Hospital of Traditional Chinese Medicine, Liuzhou, Guangxi, China.
authors: Yifan
authors: Y
authors: Sun
authors: Department of Clinical Laboratory, Liuzhou Maternal and Child Health Care Hospital, Liuzhou, Guangxi, China.
authors: Xiaolan
authors: X
authors: Lv
authors: Department of Clinical Laboratory, Liuzhou Hospital of Traditional Chinese Medicine, Liuzhou, Guangxi, China.
authors: Hongyu
authors: H
authors: Zhang
authors: Department of Clinical Laboratory, Liuzhou Hospital of Traditional Chinese Medicine, Liuzhou, Guangxi, China.
authors: Chunming
authors: C
authors: Liu
authors: Department of Clinical Laboratory, the Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou, Guangxi, China.
authors: Shengming
authors: S
authors: Dai
mesh_terms: D015992:Body Mass Index; D005260:Female; D006801:Humans; D007333:Insulin Resistance; D015850:Interleukin-6 / Q000097:blood*; D015999:Multivariate Analysis; D009765:Obesity / Q000097:blood; D011085:Polycystic Ovary Syndrome / Q000097:blood; D013739:Testosterone / Q000097:blood
chemical_list: C508600:IL6 protein, human; D015850:Interleukin-6; D013739:Testosterone