Apolipoprotein E gene polymorphism modifies fasting total cholesterol concentrations in response to replacement of dietary saturated with monounsaturated fatty acids in adults at moderate cardiovascular disease risk

Abstract

Background: Consumption of ≤10% total energy from fat as saturated fatty acids (SFA) is recommended for cardiovascular disease risk reduction in the UK; however there is no clear guidance on the optimum replacement nutrient. Lipid-associated single-nucleotide polymorphisms (SNPs) have been shown to modify the lipid responses to dietary fat interventions. Hence, we performed a retrospective analysis in 120 participants from the Dietary Intervention and VAScular function (DIVAS) study to investigate whether lipoprotein lipase (LPL) and apolipoprotein E (APOE) SNPs modify the fasting lipid response to replacement of SFA with monounsaturated (MUFA) or n-6 polyunsaturated (PUFA) fatty acids.

Methods: The DIVAS study was a randomized, single-blinded, parallel dietary intervention study performed in adults with a moderate cardiovascular risk who received one of three isoenergetic diets rich in SFA, MUFA or n-6 PUFA for 16 weeks.

Results: After the 16-week intervention, a significant diet-gene interaction was observed for changes in fasting total cholesterol (P = 0.001). For the APOE SNP rs1064725, only TT homozygotes showed a significant reduction in total cholesterol after the MUFA diet (n = 33; -0.71 ± 1.88 mmol/l) compared to the SFA (n = 38; 0.34 ± 0.55 mmol/l) or n-6 PUFA diets (n = 37; -0.08 ± 0.73 mmol/l) (P = 0.004). None of the interactions were statistically significant for the other SNPs.

Conclusions: In summary, our findings have demonstrated a greater sensitivity of the APOE SNP rs1064725 to dietary fat composition, with a total cholesterol lowering effect observed following substitution of SFA with MUFA but not n-6 PUFA. Further large intervention studies incorporating prospective genotyping are required to confirm or refute our findings.

Trial registration: The trial was registered at www.clinicaltrials.gov as NCT01478958.

Keywords: Apolipoprotein E polymorphism; DIVAS; Gene-diet interaction; Monounsaturated fatty acids; Saturated fatty acids; Total cholesterol.

Conflict of interest statement

Ethics approval and consent to participate

The West Berkshire Local Research ethics committee (09/ H0505/56) and the University of Reading Research Ethics Committee (09/40) gave a favourable ethical opinion for conduct. The trial was registered at www.clinicaltrials.gov as NCT01478958. All participants provided written informed consent before participating.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Figures

Fig. 1

Mean (±SE) of changes in total cholesterol concentrations following three intervention diets [rich in either saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and n-6 polyunsaturated fatty acids (PUFA)] according to the APOE SNP rs1064725 genotype (Pinteraction = 0.001). A general linear model analysis was performed with adjustments for age, sex, body mass index, and ethnicity. Individuals carrying the ‘TT’ genotype had lower total cholesterol levels after consuming the MUFA diet compared to the SFA or n-6 PUFA diets (Passociation = 0.004)