Apolipoprotein E polymorphism and carotid artery intima-media thickness ina random sample of middle-aged men

Genetic polymorphism of apolipoprotein E (apoE) is an important factor in t he development of coronary artery disease but the results concerning apoE g enotype and carotid artery atherosclerosis remain controversial. We investi gated a random sample of 189 Finnish middle aged men (mean age 54 years, ra nge 50-59) to assess the role of apoE in the process of carotid atheroscler osis. Intima-media thickness (IMT) of the carotid artery wall was measured at three standardised segments (common carotid artery, bifurcation and inte rnal carotid artery) by B-mode ultrasonography. Overall mean IMT value was also calculated. The carriers of E3/2 (n = 20) genotype had significantly l ower (P < 0.01) total cholesterol and LDL cholesterol concentrations than c arriers of E3/3 genotype (rl = 109) or the E4 allele (n = 60). ApoE polymor phism was associated with common carotid artery IMT (P = 0.034) when adjust ed for age and body-mass index (model 1). The carriers of E3/2 had on avera ge 9%, (95% CI 0.8-16%, P = 0.028) lower common carotid IMT values than the carriers of E3/3. After further adjustment with LDL and HDL cholesterol, s ystolic blood pressure, lipoprotein (a), apolipoprotein B and pack-years of smoking (model 2) the association was not statistically significant. The o verall mean IMT varied significantly with apoE genotype (P = 0.03 for model 1 and P = 0.07 for model 2), and it was also lowest in the carriers of E3/ 2 genotype. This suggests that apoE E3/2 genotype is a protective factor in the development of carotid artery atherosclerosis in randomly selected mid dle-aged men. The favourable effect might be mediated at least partly by th e lowering effect of E3/2 genotype on serum cholesterol. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.