title: Elevated plasma dityrosine in patients with hyperlipidemia compared to healthy individuals.
abstract: BACKGROUND
  Dityrosine, the modification of tyrosine residues, may contribute to metabolic disorders. This study was undertaken to investigate plasma dityrosine concentrations in patients with hyperlipidemia and to examine the correlation between dityrosine and lipid profiles.
  
  
  METHODS
  Fluorescence spectrophotometry was used to measure dityrosine in the plasma of healthy subjects (n = 203) and dyslipidemic subjects, which included patients with mild hyperlipidemia (n = 246) and hyperlipidemia (n = 179). Advanced oxidation protein products (AOPP) and malondialdehyde (MDA) were also assayed in all subjects.
  
  
  RESULTS
  Dityrosine levels were higher by 9.3 and 22.9% in mildly hyperlipidemic and hyperlipidemic patients, respectively, compared to controls after adjustment for age, gender, and BMI. AOPP and MDA levels showed similar trends. The levels of dityrosine related positively (p < 0.05) to total cholesterol (r = 0.362), triglycerides (r = 0.449), and low-density lipoprotein cholesterol (r = 0.359). Moreover, plasma dityrosine (r = 0.408), AOPP (r = 0.488), and MDA (r = 0.181) levels were elevated with an increase in the atherosclerosis index in the subjects.
  
  
  CONCLUSIONS
  These findings suggest that dityrosine formation may be an early event in the pathological process of hyperlipidemia. Dityrosine as a biomarker detected by fluorescence spectrophotometry might be a useful tool to evaluate the plasma redox state in hyperlipidemia.
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, China.
authors.forename: Gui-Rong
authors.initials: GR
authors.lastname: Wu
authors.forename: Maureen
authors.initials: M
authors.lastname: Cheserek
authors.forename: Yong-Hui
authors.initials: YH
authors.lastname: Shi
authors.forename: Li-Ye
authors.initials: LY
authors.lastname: Shen
authors.forename: Jing
authors.initials: J
authors.lastname: Yu
authors.forename: Guo-Wei
authors.initials: GW
authors.lastname: Le
mesh_terms: D000328:Adult; D062107:Advanced Oxidation Protein Products / Q000097:blood; D015415:Biomarkers; D002784:Cholesterol / Q000097:blood; D005260:Female; D006801:Humans; D006949:Hyperlipidemias / Q000097:blood*; D008077:Lipoproteins, LDL / Q000097:blood; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D013050:Spectrometry, Fluorescence; D014280:Triglycerides / Q000097:blood; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D062107:Advanced Oxidation Protein Products; D015415:Biomarkers; D008077:Lipoproteins, LDL; D014280:Triglycerides; D014443:Tyrosine; D008315:Malondialdehyde; D002784:Cholesterol; C007543:dityrosine