title: Serum oxidized LDL is inversely associated with HDL2-cholesterol subclass in renal failure patients on hemodialysis.
abstract: BACKGROUND
  Dyslipoproteinemia and oxidative modification of LDL (oxLDL) are common symptoms in patients suffering from chronic renal failure on hemodialysis (HD), and contribute to the development of oxidative stress. High-density lipoprotein cholesterol (HDL-C) protects against atherosclerosis by inhibiting the oxidation of lipoproteins and by supporting reverse cholesterol transport. This study intends to examine the association of oxLDL with HDL2 and HDL3 subclasses of HDL-C in HD patients, in order to elucidate whether oxidative stress influences HDL-C composition.
  
  
  METHODS
  Thirty-four patients on HD and 21 age- and sex-matched controls were studied. HDL2 and HDL3-C subclasses were isolated from serum according to a single-step precipitation method following a homogenous HDL-C assay. oxLDL was measured by ELISA.
  
  
  RESULTS
  In HD patients, oxLDL concentration was higher compared to the controls (1.40 +/- 0.47 vs. 0.21 +/- 0.05 mg/l, p = 0.017) and was significantly associated to total cholesterol (r = 0.480, p = 0.044), LDL-C (r = 0.544, p = 0.019), HDL-C (r = -0.589, p = 0.027) and C-reactive protein (r = 0.578, p = 0.024). Comparing HDL-C subclasses, only HDL2-C was negatively correlated to oxLDL levels (r = -0.565, p = 0.035).
  
  
  CONCLUSIONS
  In HD patients, high serum levels of oxLDL are associated with low HDL2-C subclass levels. This might suggest that oxidative stress affects the HDL subclass more related to the protecting activity of HDL-C, contributing to atherosclerosis development.
authors.affiliation: Department of Biochemistry, Alexandra Hospital, Athens, Greece. tkk @ otenet.gr
authors.forename: E
authors.initials: E
authors.lastname: Samouilidou
authors.forename: A
authors.initials: A
authors.lastname: Karpouza
authors.forename: E
authors.initials: E
authors.lastname: Grapsa
authors.forename: H
authors.initials: H
authors.lastname: Tzanatou-Exarchou
mesh_terms: D015415:Biomarkers / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood*; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000534:rehabilitation*; D008077:Lipoproteins, LDL / Q000097:blood*; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D006435:Renal Dialysis; D013223:Statistics as Topic
chemical_list: D015415:Biomarkers; D008076:Cholesterol, HDL; D008077:Lipoproteins, LDL