Association of APOE gene polymorphism with lipid profile and coronary artery disease in Afro-Caribbeans

Laurent Larifla,Patrick Numeric,Christophe Armand,Fritz-Line Vélayoudom-Céphise,Anne Blanchet-Deverly,Carl-Thony Michel,Véronique Bourrhis,Christiane Fonteau,Séverine Ferdinand,Jacqueline Bangou,Ornit Chiba-Falek

doi:10.1371/journal.pone.0181620

Abstract

ObjectivesApolipoprotein E gene (APOE) polymorphism is associated with the lipid profile and cardio-vascular disease. However, these relationships vary between ethnic groups.We evaluated, for the first time in an Afro-Caribbean population, the distribution of APOE polymorphisms and their associations with coronary artery disease (CAD), the lipid profile and other cardio-metabolic risk factors.MethodsWe studied 712 Afro-Caribbean subjects including 220 with documented CAD and 492 healthy subjects. TaqMan assays were performed to genotype rs7412 and rs429358, the two variants that determine the APOE alleles ε2, ε3 and ε4. The association between APOE genotype and the lipid profile was analysed by comparing ε2 carriers, ε3 homozygotes and ε4 carriers.ResultsThe frequencies of ε2, ε3 and ε4 in the overall sample were 8%, 70% and 22%, respectively. CAD was not associated with APOE polymorphism. The total cholesterol level was higher in ε4 carriers compared with ε2 carriers: 5.07 vs 4.59 mmol/L (P = 0.016). The LDL-cholesterol level was lower in APOE ε2 carriers compared with ε3 homozygotes and ε4 carriers: 2.65 vs 3.03 and 3.17 mmol/L, respectively (p = 0.002). The total cholesterol/HDL-cholesterol and LDL-cholesterol/HDL-cholesterol ratios were similar in the three allelic groups. APOE polymorphism was not associated with diabetes, hypertension, waist circumference or body mass index.ConclusionsOur results indicate that APOE gene polymorphism is associated with the lipid profile but not with CAD in Afro-Caribbean people. This lack of association with CAD may be explained by the low atherogenic profile observed in ε4 carriers, which may warrant further investigation.

Highlights

Apolipoprotein E (ApoE) is a polymorphic glycoprotein that plays a multifunctional role in lipid metabolism
coronary artery disease (CAD) was not associated with Apolipoprotein E gene (APOE) polymorphism
Our results indicate that APOE gene polymorphism is associated with the lipid profile but not with CAD in Afro-Caribbean people

Summary

Introduction

Apolipoprotein E (ApoE) is a polymorphic glycoprotein that plays a multifunctional role in lipid metabolism. The APOE gene is located on chromosome 19 and encodes three alleles, ε2, ε3 and ε4, which have been shown to affect the lipid profile and the development of coronary artery disease (CAD) [2, 3] The distribution of these alleles varies between ethnic groups: Europeans and African-Americans have a high frequency of ε4; Asians have a low frequency of ε2 and ε4 [2]. Despite the high prevalence of several cardio-vascular risk factors such as type 2 diabetes (8.1%), hypertension (29.2%) and obesity (22.9%) in the general population [4, 5], data from the regional health observatory indicate a lower mortality rate from ischaemic heart disease (by 50% in men and 40% in women) compared with mainland France [6] This finding has been reported in Afro-Caribbean people living in the United Kingdom [7, 8] and may reflect, in part, a more favourable lipid profile in Afro-Caribbean people even in the context of insulin resistance or diabetes [9]

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