Apolipoprotein E genotype and sex influence C-reactive protein levels regardless of exercise training status

Impact of the Apolipoprotein E (epsilon) Genotype on Cardiometabolic Risk Markers and Responsiveness to Acute and Chronic Dietary Fat Manipulation

Apolipoprotein (APO) E (ε) genotype is considered to play an important role in lipid responses to dietary fat manipulation but the impact on novel cardiometabolic risk markers is unclear. To address this knowledge gap, we investigated the relationship between the APOE genotype and cardiometabolic risk markers in response to acute and chronic dietary fat intakes. Associations with fasting (baseline) outcome measures (n = 218) were determined using data from the chronic DIVAS (n = 191/195 adults at moderate cardiovascular disease risk) and acute DIVAS-2 (n = 27/32 postmenopausal women) studies examining the effects of diets/meals varying in saturated, polyunsaturated and monounsaturated (MUFA) fatty acid composition. Participants were retrospectively genotyped for APOE (rs429358, rs7412). For baseline cardiometabolic outcomes, E4 carriers had higher fasting total and low-density lipoprotein-cholesterol (LDL-C), total cholesterol: high-density lipoprotein-cholesterol (HDL-C) and LDL-C: HDL-C ratios, but lower C-reactive protein (CRP) than E3/E3 and E2 carriers (p ≤ 0.003). Digital volume pulse stiffness index was higher in E2 carriers than the E3/E3 group (p = 0.011). Following chronic dietary fat intake, the significant diet × genotype interaction was found for fasting triacylglycerol (p = 0.010), with indication of a differential responsiveness to MUFA intake between the E3/E3 and E4 carriers (p = 0.006). Test fat × genotype interactions were observed for the incremental area under the curve for the postprandial apolipoprotein B (apoB; p = 0.022) and digital volume pulse reflection index (DVP-RI; p = 0.030) responses after the MUFA-rich meals, with a reduction in E4 carriers and increase in the E3/E3 group for the apoB response, but an increase in E4 carriers and decrease in the E3/E3 group for the DVP-RI response. In conclusion, baseline associations between the APOE genotype and fasting lipids and CRP confirm previous findings, although a novel interaction with digital volume pulse arterial stiffness was observed in the fasted state and differential postprandial apoB and DVP-RI responses after the MUFA-rich meals. The reported differential impact of the APOE genotype on cardiometabolic markers in the acute and chronic state requires confirmation.

ApoE genotype: from geographic distribution to function and responsiveness to dietary factors

ApoE is a key protein in lipid metabolism with three major isoforms.ApoEallele frequencies show non-random global distribution especially in Europe with highapoEε3frequency in the Mediterranean area, whereas theapoEε4genotype is enriched in Northern Europe. TheapoEε4genotype is one of the most important genetic risk factors for age-dependent chronic diseases, including CVD and Alzheimer's disease (AD). The apoE polymorphism has been shown to impact on blood lipids, biomarkers of oxidative stress and chronic inflammation, which all may contribute to the isoform-dependent disease risk. Studies in mice and human subjects indicate that theapoEε3but not theapoEε4genotype may significantly benefit from dietary flavonoids (e.g. quercetin) andn-3 fatty acids. Metabolism of lipid soluble vitamins E and D is likewise differentially affected by theapoEgenotype. Epidemiological and experimental evidence suggest a better vitamin D status inapoEε4than ε3subjects indicating a certain advantage of ε4over ε3. The present review aims at evaluation of current data available on interactions between apoE polymorphism and dietary responsiveness to flavonoids, fat soluble vitamins andn-3 fatty acids. Likewise, distinct geographic distribution and chronic disease risk of the different apoE isoforms are addressed.

Apolipoprotein E gene polymorphisms are strong predictors of inflammation and dyslipidemia in rheumatoid arthritis

OBJECTIVE

Rheumatoid arthritis (RA), a condition with a strong genetic etiology, is associated with excess cardiovascular disease (CVD). Dyslipidemia in RA may be driven by inflammation and genetic factors. Apolipoprotein E (ApoE) is important for the regulation of lipid levels and CVD risk and immune function in the general population. We compared the frequency of 2 ApoE single-nucleotide polymorphisms (SNP) in patients with RA and controls, and studied the relationship of ApoE genotypes with lipids and inflammation in RA.

METHODS

A total of 387 patients with well-characterized RA and 420 non-RA controls were studied. Two ApoE SNP, rs7412 (ApoE2) and rs429358 (ApoE4), were identified.

RESULTS

Genotypic (p = 0.908) and allelic (p = 0.894) frequencies did not differ between RA and controls. Within RA, the E2 allele was associated with the lowest and E4 allele with the highest levels of total cholesterol (p = 0.007), low-density lipoproteins (p = 0.004), and apolipoprotein B (p = 0.009). The E4 allele was also associated with lower C-reactive protein (p = 0.007), erythrocyte sedimentation rate (p = 0.001), and Disease Activity Score (p = 0.015) compared to the E3 allele. E2 or E4 alleles were not associated with CVD in RA, although a trend was observed (p = 0.074).

CONCLUSION

The frequency of ApoE polymorphisms did not differ between patients with RA and controls. ApoE genotypes are strongly linked to inflammation and lipid levels in RA, raising interest in the prognostic implications of ApoE genotypes.

APOE polymorphism and its effect on plasma C-reactive protein levels in a large general population sample

The published data remain inconsistent on association between apolipoprotein E (APOE) gene variations and plasma levels of C-reactive protein (CRP), mainly because of low statistical power of previous studies. To clarify this question, we analyzed data from large population sample of randomly selected individuals from seven Czech towns (2,886 males and 3,344 females, the HAPIEE [Health, Alcohol, and Psychosocial factors In Eastern Europe] study). In both males and females, the lowest levels of plasma hsCRP were observed in the carriers of the APOE epsilon 4 epsilon 4 and epsilon 4 epsilon 3 genotypes. The median (interquartile range, IQR) concentration of hsCRP in carriers of the most common APOE epsilon 3 epsilon 3 genotype (two-thirds of participants) was 1.13 mg/l (IQR, 0.56-2.33) in men and 1.23 mg/l (IQR, 0.61-2.65) in women, compared with 0.72 mg/l (IQR, 0.61-0.86) in male and 0.72 mg/l (IQR, 0.61-0.85) in female carriers of APOE epsilon 4 epsilon 3/epsilon 4 epsilon 4 genotypes; the differences were statistically significant (p < 0.001). The association between APOE and CRP was not materially affected by adjustment for age, sex, history of cardiovascular disease, or cardiovascular risk factors. This study, the largest to date, provides robust evidence of an association between plasma hsCRP and the APOE genotype, an association not explained by history of cardiovascular disease nor its risk factors.

Apolipoprotein E genotype is associated with serum C-reactive protein but not abdominal aortic aneurysm

OBJECTIVE

Apolipoprotein E (ApoE) genotype has been associated with systemic inflammation and athero-thrombosis however the association with abdominal aortic aneurysm (AAA) has not been previously examined. We assessed the association between ApoE genotype with AAA presence and growth, and serum C-reactive protein (CRP).

METHODS

Serum concentrations of CRP (in 1358 men) and 6 single nucleotide polymorphisms (SNPs) for ApoE (in 1711 men) were examined in subjects from the Health In Men Study. 640 men with small AAAs were followed by ultrasound surveillance for a mean of 4.1 years.

RESULTS

There was no association between ApoE genotype and AAA presence. Men heterozygote for the ApoE p.Arg176Cys polymorphism had slower AAA growth, odds ratio for AAA progression> or =median 0.41, 95% confidence intervals 0.21-0.80, p=0.01. Men heterozygote for the ApoE g.50093756A>G polymorphism had slightly more rapid AAA growth, odds ratio for AAA progression> or =median 1.48, 95% confidence intervals 1.02-2.14, p=0.04. None of the ApoE SNPs were associated with AAA growth however taking into account multiple testing. Two SNPs in ApoE were associated with serum CRP under a co-dominant model, ApoE p.Cys130Arg (SNP ID rs429358), p=0.00003 and ApoE g.50114786A>G (SNP ID rs4420638), p=0.00013. Adjusting for other risk factors plus serum creatinine the varepsilon4 allele was associated with lower serum CRP under a dominant model, coefficient 0.089, p=0.002.

CONCLUSION

We found no consistent association between ApoE genotype and AAA. We confirmed an association between ApoE genotype and serum CRP.