Effect of apolipoprotein E polymorphism on serum lipid, lipoproteins, and atherosclerosis in hemodialysis patients.

Atherosclerosis and cardiovascular disease are the main causes of death in hemodialysis patients. Possession of the apolipoprotein E4 (ApoE4) allele has been associated with increased levels of serum lipids and with coronary and carotid artery atherosclerosis. We investigated the possible relationship between ApoE polymorphism and atherosclerosis risk factors in hemodialysis patients. Two hundred sixty-nine hemodialysis patients (115 women, 154 men) were included in our study. The mean patient age and mean hemodialysis duration were 45.8 +/- 15.3 years and 52.6 +/- 40.6 months, respectively. Testing was done on all patients to determine ApoE genotype and serum levels of total cholesterol (T-Cho), low-density lipoprotein (LDL-C), high-density cholesterol (HDL-C), triglyceride (TG), lipoprotein (a) (Lp[a]), intact parathormone (iPTH), and fibrinogen. ApoE genotype was identified with the polymerase chain reaction. Ultrasonographic measurement of carotid artery intima media thickness (IMT) was used to diagnose atherosclerosis. We also analyzed ApoE polymorphism and risk factors such as age, gender, duration of hemodialysis, smoking, and hypertension in relation to the presence of atherosclerosis. Serum T-Cho and LDL-C levels were higher in patients with the ApoE4/3 phenotype than in those with ApoE3/3 and ApoE3/2 phenotypes (P < 0.05). However, there was no statistically significant link between ApoE polymorphism and serum levels of TG, HDL-C, or Lp(a) (P > 0.05). Apart from a relationship with age and duration of hemodialysis (P < 0.05), we found no significant association between atherosclerosis and ApoE polymorphism or the other risk factors analyzed (P > 0.05). In conclusion, although ApoE polymorphism significantly affects serum levels of T-Cho and LDL-C in hemodialysis patients, this study indicates that ApoE polymorphism is not associated with the presence of atherosclerosis in these individuals. The high incidence of atherosclerosis in these patients underlines the need for further research on other possible causative factors.