APOE Genotypes, Lipid Profiles, and Associated Clinical Markers in a Finnish Population with Cardiovascular Disease Risk Factors

Introduction: The APOE epsilon 4 allele predisposes to high cholesterol and increases the risk for lifestyle-related diseases such as Alzheimer's disease and cardiovascular diseases (CVDs). The aim of this study was to analyse interrelationships of APOE genotypes with lipid metabolism and lifestyle factors in middle-aged Finns among whom the CVD risk factors are common. Methods: Participants (n = 211) were analysed for APOE epsilon genotypes, physiological parameters, and health- and diet-related plasma markers. Lifestyle choices were determined by a questionnaire. Results: APOE genotypes epsilon 3/epsilon 4 and epsilon 4/epsilon 4 (epsilon 4 group) represented 34.1% of the participants. Genotype epsilon 3/epsilon 3 (epsilon 3 group) frequency was 54.5%. Carriers of epsilon 2 (epsilon 2 group; epsilon 2/epsilon 2, epsilon 2/epsilon 3 and epsilon 2/epsilon 4) represented 11.4%; 1.9% were of the genotype epsilon 2/epsilon 4. LDL and total cholesterol levels were lower (p < 0.05) in the epsilon 2 carriers than in the epsilon 3 or epsilon 4 groups, while the epsilon 3 and epsilon 4 groups did not differ. Proportions of plasma saturated fatty acids (SFAs) were higher (p < 0.01), and omega-6 fatty acids lower (p = 0.01) in the epsilon 2 carriers compared with the epsilon 4 group. The epsilon 2 carriers had a higher (p < 0.05) percentage of 22:4n-6 and 22:5n-6 and a lower (p < 0.05) percentage of 24:5n-3 and 24:6n-3 than individuals without the epsilon 2 allele. Conclusions: The plasma fatty-acid profiles in the epsilon 2 group were characterized by higher SFA and lower omega-6 fatty-acid proportions. Their lower cholesterol values indicated a lower risk for CVD compared with the epsilon 4 group. A novel finding was that the epsilon 2 carriers had different proportions of 22:4n-6, 22:5n-6, 24:5n-3, and 24:6n-3 than individuals without the epsilon 2 allele. The significance of the differences in fatty-acid composition remains to be studied.

Automated summary

The APOE epsilon 4 allele is associated with high cholesterol and increased risk of lifestyle-related diseases. This study found that APOE genotypes are related to lipid metabolism and influenced by lifestyle factors. Compared to the epsilon 3 and epsilon 4 groups, carriers of the epsilon 2 allele had lower cholesterol levels and different fatty acid proportions.