title: The influence of serum apolipoprotein E concentration and polymorphism on serum lipid parameters in hemodialysis patients.
abstract: BACKGROUND
  Apolipoprotein E (ApoE) polymorphism has been shown to influence serum lipid parameters and ApoE levels in both healthy subjects and hemodialysis (HD) patients. Conversely, ApoE concentration significantly affects serum lipid levels in the general population, independently of ApoE polymorphism, by modulating lipoprotein production, lipolytic conversion, and receptor-mediated clearance. Therefore, studying the effect of ApoE polymorphism on serum lipid levels without taking into account ApoE levels could lead to confounding results. However, such a combined study has not been performed in HD patients to date.
  
  
  METHODS
  Three hundred one patients without diabetes on long-term maintenance HD therapy and 200 matched healthy subjects were studied. Determination of levels of fasting serum ApoE and other lipid parameters, as well as common ApoE genotypes, was performed in all subjects.
  
  
  RESULTS
  HD patients had a significantly lower prevalence of the epsilon4 allele and greater levels of ApoE compared with the control population. ApoE2 allele carriers had significantly lower levels of ApoB and serum total, low-density lipoprotein, and non-high-density lipoprotein cholesterol, as well as increased ApoE levels. When ApoE levels were included in analysis, ApoE levels themselves were proven to be important determinants of serum lipid levels, whereas the effect of ApoE polymorphism became more pronounced. The combination of these 2 factors explains a much greater percentage of the variation in the studied parameters than each factor alone.
  
  
  CONCLUSIONS
  For the first time, our study provides data to support that ApoE concentration in combination with the ApoE polymorphism significantly influences serum lipid parameters in HD patients.
authors.affiliation: Department of Internal Medicine, School of Medicine, University of Ioannina, Ioannina, Greece.
authors.forename: Evagelos N
authors.initials: EN
authors.lastname: Liberopoulos
authors.forename: George A
authors.initials: GA
authors.lastname: Miltiadous
authors.forename: Marios
authors.initials: M
authors.lastname: Cariolou
authors.forename: Alexandros D
authors.initials: AD
authors.lastname: Tselepis
authors.forename: Kostas C
authors.initials: KC
authors.lastname: Siamopoulos
authors.forename: Moses S
authors.initials: MS
authors.lastname: Elisaf
mesh_terms: D000368:Aged; D000483:Alleles; D053329:Apolipoprotein E2; D053327:Apolipoprotein E4; D001055:Apolipoproteins B / Q000097:blood; D001057:Apolipoproteins E / Q000097:blood* / Q000235:genetics*; D001786:Blood Glucose / Q000032:analysis; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000235:genetics; D008055:Lipids / Q000097:blood*; D008074:Lipoproteins / Q000097:blood; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D006435:Renal Dialysis; D014280:Triglycerides / Q000097:blood
chemical_list: D053329:Apolipoprotein E2; D053327:Apolipoprotein E4; D001055:Apolipoproteins B; D001057:Apolipoproteins E; D001786:Blood Glucose; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D008055:Lipids; D008074:Lipoproteins; D014280:Triglycerides