Abstract:
This research investigated associations between the three Apolipoprotein E isoforms (ApoE, E2, E3 and E4) and clinical outcomes over a median 2.5yr (0.25-5.4yrs) follow-up in a coronary disease (CD) cohort (n=1362). Participants were genotyped for both the rs429358 and rs7412 variants of the ApoE gene. PHASE software for haplotype estimation was used to assign ApoE isoform combinations. Levels of circulating prognostic neurohormone markers, clinical history, circulating lipids, and discharge medications were documented. The median age of CD onset was 68yrs (71% male). Patients were predominantly of European descent (84%). The ApoE isoform frequencies were 59.6% e3/e3, 10.8% e3/e2, 23.7% e3/e4, 1.0% e2/e2, 2.3% e2/e4 and 2.6% e4/e4. The CD patients carrying at least one E3 isoform developed their disease at a significantly older age than the other participants (68yrs vs 64yrs, p=0.005). Despite an earlier age of CD onset, those carrying one or more E2 isoform had greater HDL/LDL ratios than the e3/e3 patient group (e2/e2, 0.54; e2/e3 0.52 and e2/e4; 0.53). Those carrying 1 or more E4 isoform had lower HDL/LDL ratios (e4/e4, 0.41: e3/ e4, 0.40) compared to e3/e3 (0.48, p=0.011). There were no significant associations between ApoE isoforms and age-adjusted plasma amino-terminal BNP levels (p=0.13), gender (p=0.53) or drug treatment (p=0.70). There was no difference in survival when adjusting for established independent predictors of mortality (P=0.70). This research suggests that theApoE E2 isoform is associated with developing CD at a younger age. In spite of this, once CD is established they do not have poorer clinical outcome.