Apolipoprotein E genotype and plasma lipid levels in Caucasian diabetic patients

Apo E polymorphism has been shown to affect lipid profiles in non-diabetic and diabetic populations. We evaluated the relationship between Apo E phenotype and fasting lipid plasma levels in type 2 diabetes patients.

Two hundred and ten French type 2 diabetic patients (115 men and 95 women) without any lipid lowering drugs were studied. Fasting lipids were measured by usual methods and Apo E genotype was established for each patient: PCR was followed by digestion of the amplification product with restriction enzymes and separation of the fragments by polyacrylamide gel.

Genotypes epsilon3/epsilon3, epsilon2/epsilon3 and epsilon3/epsilon4, epsilon2/epsilon2 and epsilon2/epsilon4 were found in 68.1%, 14.8%, 15.7%, 1.0% and 0.5%, respectively. No patient had the epsilon4/epsilon4 genotype. Lipid plasma levels were compared between E3 group (epsilon3/epsilon3) as a reference and E2 (epsilon2/epsilon2 or epsilon2/epsilon3) or E4 (epsilon3/epsilon4 or epsilon2/epsilon4). Total cholesterol, LDL cholesterol and Apo B levels were lower in the E2 group. Total cholesterol, LDL cholesterol and Apo B levels were higher in the E4 group. HDL cholesterol levels were increased in the E4 group, as only previously observed in Japanese populations.

These results agree with those already reported in diabetic patients of several western European countries. E4 allele carriers have a greater cardio-vascular risk and this could be partially explained by the metabolic variation in lipid metabolism induced by E4 with higher LDL cholesterol and Apo B levels. These results observed in French diabetic subjects without any lipid-lowering drugs may be used as a reference for other studies performed in France.