title: Levels of asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, and risk of coronary artery disease: A meta-analysis based on 4713 participants.
abstract: BACKGROUND
  Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of endothelial nitric oxide synthase by competing with L-arginine. As a result, the expression of nitric oxide decreases and endothelial dysfunction occurs. Studies have evaluated the association between the serum ADMA level and risk of coronary artery disease. However, conflicting results have been obtained.
  
  
  METHODS
  Pubmed, Web of Science, Embase, Ovid, Cochrane databases were searched to identify eligible studies published in English until December 2014. Association was assessed on the basis of weighted mean differences (WMD) with 95% confidence intervals (CIs). Publication bias was analysed using Begg's and Egger's tests. Sensitivity analysis was performed to evaluate result stability.
  
  
  RESULTS
  A total of 16 case-control studies with 2939 patients and 1774 controls were included in the meta-analysis. Pooled result indicated that patients with coronary artery disease yielded a higher ADMA level than healthy controls (WMD: 0.248, 95% CI: 0.156-0.340; p = 1.16 e-7). Sensitivity analysis suggested that our meta-analysis result was stable. Subgroup analysis found a similar pattern in patients with myocardial infarction (WMD: 0.397, 95% CI: 0.112-0.683; p = 0.0106), stable angina pectoris (WMD: 0.197, 95% CI: 0.031-0.364; p = 0.02) and unstable angina pectoris (WMD: 0.857, 95% CI: 0.293-1.420; p = 0.003).
  
  
  CONCLUSIONS
  Meta-analysis results indicated that an increased ADMA level is associated with an increased risk of coronary artery disease.
authors.affiliation: Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Xuan
authors.affiliation: Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, China.
authors.forename: Qing-Wu
authors.initials: QW
authors.lastname: Tian
authors.affiliation: Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.affiliation: Department of Molecular Microbiology, Oslo University Hospital, Norway.
authors.forename: Bei-Bei
authors.initials: BB
authors.lastname: Zhang
authors.affiliation: TEDA International Cardiovascular Hospital, Tianjin; The Affiliated Hospital of Hangzhou Normal University, China Department of Surgery, Oregon Health and Science University, Portland, USA.
authors.forename: Guo-Wei
authors.initials: GW
authors.lastname: He
authors.affiliation: Department of Clinical Laboratory, The Affiliated Hospital of Qingdao University, China lunlmqd@163.com.
authors.forename: Li-Min
authors.initials: LM
authors.lastname: Lun
mesh_terms: D000328:Adult; D000368:Aged; D001120:Arginine / Q000031:analogs & derivatives* / Q000097:blood; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D003324:Coronary Artery Disease / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D018570:Risk Assessment; D012307:Risk Factors; D015854:Up-Regulation
chemical_list: D015415:Biomarkers; C018524:N,N-dimethylarginine; D001120:Arginine
keywords: ADMA; coronary artery disease; meta-analysis; risk