title: Compositional lipoprotein changes and low-density lipoprotein susceptibility to oxidation in chronic renal failure patients with heavy proteinuria.
abstract: BACKGROUND
  There are limited data regarding qualitative lipoprotein abnormalities in undialysed uremic patients without proteinuria. In this report, we focused on lipoprotein changes observed in uremic patients with proteinuria as well as on the susceptibility of low-density lipoprotein (LDL) of these patients to oxidative modification in vitro.
  
  
  METHODS
  20 patients with chronic renal failure [serum creatinine >1.6 mg/dl (141.4 micromol/l)], but not yet on renal replacement therapy, and with heavy proteinuria (>2 g/24 h), and 18 age- and sex-matched healthy individuals participated in the study. In both patients and controls, venous blood was collected for determination of serum lipid and lipoprotein levels, lipoprotein subfraction profile and chemical composition, as well as the susceptibility of LDL subfractions to oxidation.
  
  
  RESULTS
  Patients exhibited a more atherogenic lipid profile compared with the control population. Furthermore, the total very LDL + intermediate-density lipoprotein mass was increased in patients compared with controls, while this subfraction was triglyceride enriched in uremic patients. The total LDL concentration was significantly higher in patients compared with controls due mainly to an increase in the mass of all lipoprotein subfractions. It is noteworthy that the mass of small dense LDL was significantly elevated in patients compared with controls (135 +/- 12 vs. 115 +/- 11 mg/dl, p = 0.01), an increase which was more pronounced in hypertriglyceridemic patients. Furthermore, the subfraction high-density lipoprotein-2 mass was significantly lower in uremic patients compared with controls. Finally, no significant differences in the lag time, the rate of oxidation and the relative electrophoretic mobility values in each LDL subfraction between the two groups were observed.
  
  
  CONCLUSIONS
  We conclude that uremic patients with heavy proteinuria exhibit compositional lipoprotein changes that are less marked than those observed in nonuremic patients with nephrotic syndrome. However, there is no evidence that circulating LDL isolated from these patients is more susceptible to oxidation in vitro than lipoprotein isolated from age- and gender-matched controls.
authors.affiliation: Department of Chemistry, Laboratory of Biochemistry, Medical School, University of Ioannina, Ioannina, Greece.
authors.forename: Sonia Athena
authors.initials: SA
authors.lastname: Karabina
authors.forename: Haralampos
authors.initials: H
authors.lastname: Pappas
authors.forename: George
authors.initials: G
authors.lastname: Miltiadous
authors.forename: Eleni
authors.initials: E
authors.lastname: Bairaktari
authors.forename: Dimitris
authors.initials: D
authors.lastname: Christides
authors.forename: Alexandros
authors.initials: A
authors.lastname: Tselepis
authors.forename: Moses
authors.initials: M
authors.lastname: Elisaf
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Siamopoulos
mesh_terms: D000328:Adult; D001055:Apolipoproteins B / Q000097:blood; D002784:Cholesterol / Q000097:blood; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications*; D008055:Lipids / Q000097:blood; D008074:Lipoproteins / Q000097:blood; D008075:Lipoproteins, HDL / Q000097:blood; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D010084:Oxidation-Reduction; D011507:Proteinuria / Q000097:blood* / Q000209:etiology; D012709:Serum Albumin / Q000032:analysis; D014511:Uremia / Q000097:blood* / Q000150:complications
chemical_list: D001055:Apolipoproteins B; D008055:Lipids; D008074:Lipoproteins; D008075:Lipoproteins, HDL; D008077:Lipoproteins, LDL; D012709:Serum Albumin; D002784:Cholesterol