title: Circulating irisin levels are positively associated with endothelium-dependent vasodilation in newly diagnosed type 2 diabetic patients without clinical angiopathy.
abstract: OBJECTIVE
  Irisin is a newly identified myokine that can promote energy expenditure and alleviate insulin-resistance in animal model. It has been established that insulin resistance is frequently associated with endothelial dysfunction. Therefore, we hypothesize that circulating irisin levels are associated with endothelial dysfunction in type 2 diabetes.
  
  
  METHODS
  One hundred and eighty eight patients with newly diagnosed type 2 diabetes and 40 healthy subjects were recruited. Serum irisin concentrations were measured by using enzyme-linked immunosorbent assay, and flow-mediated dilation (FMD) was evaluated by using high-resolution ultrasound.
  
  
  RESULTS
  The mean value of circulating irisin levels in newly diagnosed type 2 diabetes was 13.25 ng/ml, which was significantly lower than that in controls (25.98 ng/ml, p < 0.001). By dividing the distribution of FMD levels into quartiles, serum irisin levels were increased gradually with the increase of FMD levels (p < 0.001). Multivariate stepwise regression analysis demonstrated that serum irisin levels were independently associated with FMD (p = 0.009). By logistic regression analysis the odds ratio for lower FMD levels was reduced by 11.8% per 1 ng/ml increase in serum irisin concentration after adjustment for multivariate metabolic factors [OR (95% CI); 0.882 (0.709-0.969)].
  
  
  CONCLUSIONS
  These results demonstrated that circulating irisin levels were decreased in newly diagnosed Chinese type 2 diabetic patients without clinical angiopathy and positively associated with FMD levels.
authors.affiliation: Graduate School, Southern Medical University, Guangzhou Avenue North 1838, Guangzhou 510515, China; Department of Endocrinology, Wuhan General Hospital of Guangzhou Command, Wuluo Road 627, Wuhan 430070, Hubei Province, China. Electronic address: xianglin832010@hotmail.com.
authors.forename: Lin
authors.initials: L
authors.lastname: Xiang
authors.affiliation: Department of Endocrinology, Wuhan General Hospital of Guangzhou Command, Wuluo Road 627, Wuhan 430070, Hubei Province, China. Electronic address: Guangda64@hotmail.com.
authors.forename: Guangda
authors.initials: G
authors.lastname: Xiang
authors.affiliation: Department of Endocrinology, Wuhan General Hospital of Guangzhou Command, Wuluo Road 627, Wuhan 430070, Hubei Province, China. Electronic address: Yueling1@medmail.com.cn.
authors.forename: Ling
authors.initials: L
authors.lastname: Yue
authors.affiliation: Department of Endocrinology, Wuhan General Hospital of Guangzhou Command, Wuluo Road 627, Wuhan 430070, Hubei Province, China. Electronic address: Zhangjx666@gmail.com.
authors.forename: Junxia
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Endocrinology, Wuhan General Hospital of Guangzhou Command, Wuluo Road 627, Wuhan 430070, Hubei Province, China. Electronic address: ZLS7111@yahoo.com.cn.
authors.forename: Linshuang
authors.initials: L
authors.lastname: Zhao
mesh_terms: D000328:Adult; D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000503:physiopathology; D004108:Dilatation, Pathologic / Q000097:blood*; D005260:Female; D005353:Fibronectins / Q000097:blood*; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D008875:Middle Aged; D012039:Regional Blood Flow; D014664:Vasodilation
chemical_list: C577593:FNDC5 protein, human; D005353:Fibronectins
keywords: Circulating irisin; Endothelial dysfunction; Type 2 diabetes