title: Plasma/Serum Leptin Levels in Patients with Ankylosing Spondylitis: A Systematic Review and Meta-analysis.
abstract: Leptin is an adipokine that has several effects on metabolism and immune system in patients with ankylosing spondylitis (AS). The present investigations of the relationship between plasma/serum leptin levels and AS are contradictory. To derive a more precise estimation on the plasma/serum leptin levels in AS patients and related factors, a meta-analysis was performed.
  
  
  
  Published literature that compares plasma/serum leptin levels between AS group and control group from PubMed, Embase, Cochrane Library and other databases were searched. The study quality was assessed by the Newcastle-Ottawa scale. Pooled standardized mean difference (SMD) with its 95% confidence interval (CI) was calculated by fixed-effects or random-effect model analyses. Statistical heterogeneity within studies was examined by the Q statistic.
  
  
  
  A total of eight studies including 391 AS patients and 293 healthy controls were finally included in the meta-analysis. No significant differences in plasma/serum leptin levels was found between AS patients and healthy controls when all studies were pooled into the meta-analysis (pooled SMD = 0.384, 95% CI = -1.522 to 0.753). Meanwhile, subgroup analyses by gender also showed no significant differences in plasma/serum leptin levels between case group and controls.
  
  
  
  There is no significant difference in plasma/serum leptin levels between AS patients and controls.
authors.affiliation: Department of Rheumatology and Immunology, The First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui, China.
authors.forename: Yong-Jun
authors.initials: YJ
authors.lastname: Mei
authors.affiliation: Department of Epidemiology and Biostatistics, School of Public Health, Anhui Medical University, Meishan Road, Hefei, Anhui, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.affiliation: Department of Rheumatology and Immunology, The First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui, China.
authors.forename: Lin-Jie
authors.initials: LJ
authors.lastname: Chen
authors.affiliation: Department of Rheumatology and Immunology, The First Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui, China. Electronic address: lizhijun@medmail.com.cn.
authors.forename: Zhi-Jun
authors.initials: ZJ
authors.lastname: Li
mesh_terms: D054392:Adipokines; D016022:Case-Control Studies; D006801:Humans; D020738:Leptin / Q000097:blood*; D010949:Plasma; D044967:Serum; D013167:Spondylitis, Ankylosing / Q000097:blood*
chemical_list: D054392:Adipokines; D020738:Leptin
keywords: Ankylosing spondylitis; Leptin; Meta-analysis; Systematic review