👤 Erin M Humphries

Apolipoprotein A-IV (apoA-IV) has been postulated to be antiatherogenic. Transgenic APOA4/Apoe-/- mice are protected against atherosclerosis, with plasma apoA-IV displaying antioxidant activity in vitro. In humans, there is an inverse relationship between apoA-IV levels and risk of coronary heart disease (CHD). Furthermore, the APOA4 T347S rare allele has been associated with increased risk of CHD and reduced apoA-IV levels. Reduced total antioxidant status (TAOS) due to increased oxidative stress is implicated in the process of atherogenesis. Thus, this study aimed to examine the association between the APOA4 T347S variant and TAOS in diabetic patients with (n = 196) or without (n = 509) cardiovascular disease (CVD). A higher percentage of CVD patients were present in the lowest quartile of TAOS, compared with the rest (P = 0.04). Overall, there was no association between genotype and TAOS. However, in patients with CVD, homozygotes for the S347 allele had significantly lower TAOS compared with TT and TS subjects (31.2 +/- 9.89% and 42.5 +/- 13.04% TAOS, respectively; P = 0.0024), an effect that was not seen in the patients without CVD. This study offers direct support for an antioxidant capacity of apoA-IV, thus providing some explanation for the antiatherogenic role of apoA-IV and the higher CVD risk in S347 homozygotes. Show less

A new apolipoprotein (apo) gene, APOA5, was recently identified on chromosome 11q23, and common variants in the gene have been associated with plasma triglyceride (TG) levels in several studies. The purpose of the present study was to examine the association of five single nucleotide polymorphisms (SNPs) and haplotypes in the APOA5 gene with low-density lipoprotein (LDL) particle size using a community-based sample of Japanese American families, including examining whether the associations with LDL size are independent of, or primarily reflecting, TG levels. Genetic association analyses were performed using 154 unrelated individuals, quantitative transmission disequilibrium tests (TDT) in 238 nuclear families, a sample of 24 hypertriglyceridemic subjects with matched, normotriglyceridemic controls, and using haplotype analyses. There was a high degree of allelic association between several of the SNPs, with complete linkage disequilibrium (LD) between -1131C>T and the -3A>G SNP which alters a potential Kozak sequence. All approaches demonstrated associations between the -3A>G APOA5 variant and both decreased LDL size and increased TG levels. The frequency of the rare allele was higher than reported for Caucasian, Hispanic, and African Americans, but similar to that in Japan and China. Therefore, the haplotype containing the -1131C and -3G variants, and possibly specifically the -3A>G SNP in APOA5, may be a major genetic determinant of LDL particle size and TG levels among ethnic Asians. Show less

Animal and human studies support a role for apolipoprotein A-V (apoA-V) in triglyceride (TG) metabolism. We examined the relationship of APOA5 -1131T>C and S19W with lipid subfractions and progression of atherosclerosis in the Lopid Coronary Angiography Trial. Compared with -1131TT men (n = 242), carriers of the -1131C allele (n = 54) had significantly higher total TG (P = 0.03), reflected in significantly increased VLDL mass [higher VLDL-TG, VLDL-cholesterol, VLDL-protein, and surface lipids (all P < 0.05)]. Because apoB levels were unaffected by genotype, this suggests an increase in VLDL size and not number. Compared with 19SS men (n = 268), 19W carriers (n = 44) had higher intermediate density lipoprotein (IDL)-TG, IDL-cholesterol (P = 0.04), and IDL-surface components [free cholesterol (P = 0.005) and phospholipids (P = 0.017)] but not protein content, suggesting an increase in IDL lipid enrichment resulting in an increase in IDL size. 19W carriers also showed a trend toward increased progression of atherogenesis, as measured by change in average diameter of segments (-0.46 +/- 0.011 mm compared with -0.016 +/- 0.006 mm) in 19SS men (P = 0.08). There was no effect of genotype on the response of these parameters to gemfibrozil treatment. These results shed new light on the role of APOA5 variants in TG metabolism and coronary heart disease risk. Show less

Cohort and case-control genetic association studies offer the greatest power to detect small genotypic influences on disease phenotypes, relative to family-based designs. However, genetic subdivisions could confound studies involving unrelated individuals, but the topic has been little investigated. We examined geographical and interallelic association of SNP and microsatellite haplotypes of the Y chromosome, of regions of chromosome 11, and of autosomal SNP genotypes relevant to cardiovascular risk traits in a UK-wide epidemiological survey. We show evidence (p = 0.00001) of the Danelaw history of the UK, marked by a two-fold excess of a Viking Y haplotype in central England. We also found evidence for a (different) single-centre geographical over-representation of one haplotype, both for APOC3-A4-A5 and for IGF2. The basis of this remains obscure but neither reflect genotyping error nor correlate with the phenotypic associations by centre of these markers. A panel of SNPs relevant to cardiovascular risks traits showed neither association with geographical location nor with Y haplotypes. Combinations of Y haplotyping, autosomal haplotyping, and genome-wide SNP typing, taken together with phenotypic2 associations, should improve epidemiological recognition and interpretation of possible confounding by genetic subdivision. Show less

Upstream stimulatory factor 1 (USF 1), is a transcription factor controlling expression of several genes involved in lipid and glucose homeostasis and co-localizes with familial combined hyperlipidemia (FCHL) and type 2 diabetes on chromosome 1q22-23. We sequenced USF1 in 24 UK FCHL probands, but found no rare or common cSNPs. Three common intronic single nucleotide ploymorphisms (SNP), 306A>G, 475C>T and 1748C>T, were identified and their association was examined with fasting and postprandial lipids and after an oral glucose tolerance test (OGTT) in the European Atherosclerosis Research Study II offspring study. There were no significant differences in allelic frequencies of the SNPs between cases and controls. Individually none of the SNPs showed significant associations with any parameter. In haplotype analysis, compared with other haplotypes, 475C/1748T showed significantly higher and 475T/1748T showed lower peak glucose (P=0.004 and 0.07, respectively) during the OGTT. There was significant case-control heterogeneity in the interaction of genotype with body mass index, on fasting low density lipoprotein with 306A>G and 1748C>T, and on borderline significance with fasting glucose with 475C>T (P=0.002, 0.0007 and 0.015, respectively). Furthermore, 475C>T showed interaction with both HSL-60C>G (case-control heterogeneity P=0.0002) on AUC TG and APOC3 -482C>T on plasma apoE levels (P=0.0012). Thus, in these healthy young men, variation in USF1 was the influencing feature of both glucose and lipid homeostasis showing case-control heterogeneity. Show less

The aim of this study was to investigate the influence of APOA5 variants on fasting lipids and to the response to both an oral fat tolerance test (OFTT) and an oral glucose tolerance test (OGTT). The association of two APOA5 SNPs [S19W (SNP5), -1131T>C (SNP3)] and an APOA4/A5 intergenic SNP [-12238T>C (SNP4)] were examined in healthy young men (n=774) who had undergone both an OFTT and an OGTT. Both -1131T>C and S19W rare alleles were associated with triglyceride (TG)-raising effects (11%, P=0.008; 21% (in cases), P<0.026, respectively) and showed additive effects on TG. None of the variants influenced the responsiveness to the OFTT after correcting for baseline TG. Homozygosity for the -12238T>C rare allele was associated with higher waist to hip ratio (P<0.0006), systolic blood pressure (P=0.012) and AUC and peak of insulin after OGTT (P=0.003 and P=0.027, respectively), traits that define the metabolic syndrome. Our results strongly support the role of APOA5 in determining plasma TG levels in an age-independent manner and highlight the importance of the APOC3/A4/A5 gene cluster in both TG and metabolic homeostasis. Show less

The impact of common variants in the apolipoprotein gene cluster (APOC3-A4-A5) on prospective coronary heart disease (CHD) risk was examined in healthy UK men. Of the 2808 men followed over 9 years, 187 had a clinically defined CHD event. Examination of 9 single nucleotide polymorphisms (SNPs) in this group revealed that homozygotes for APOA4 S347 had significantly increased risk of CHD [hazard ratio (HR) of 2.07 (95%CI 1.04 to 4.12)], whereas men homozygous for APOC3 1100T were protected [HR 0.28 (95%CI 0.09 to 0.87)]. In stepwise multiple regression analysis, after entering all the variants and adjusting for established risk factors APOA4 T347S alone remained in the model. Using all nine SNPs, the highest risk-estimate haplotypes carried APOA4 S347 and rare alleles of the two flanking intergenic markers. The protective effect of APOC3 1100T could be explained by negative linkage disequilibrium with these alleles. To determine the association of APOA4 T347S with apoAIV levels, the relationship was examined in 1600 healthy young European men and women. S347 homozygotes had significantly lower apoAIV plasma levels (13.64+/-0.59 mg/dL) compared with carriers of the T347 allele (14.90+/-0.12 mg/dL) (P=0.035). These results demonstrate that genetic variation in and around APOA4, independent of the effects of triglyceride, is associated with risk of CHD and apoAIV levels, supporting an antiatherogenic role for apoAIV. Show less

Variation in the insulin responsive element (IRE) of the APOC3 promoter has been shown to be associated with insulin and glucose concentrations after an oral glucose tolerance test (OGTT) in young healthy men. We evaluated two variants in the IRE (-455T>C and -482C>T) in the Ely study, a prospective cohort study of middle-aged men (n=223) and women (n=279), to determine if the effect of these variants on glucose homeostasis could be explained by altered nonesterified fatty acid (NEFA) levels and if these effects are modulated by age and gender. Both variants had significant effects on the 30-min insulin incremental response in men alone (-482C>T, P=0.007; -455T>C, P=0.0155), with rare allele homozygotes having a 33.3% and 23.3% lower insulin increment as compared to common allele homozygotes, respectively. Thirty-minute NEFA concentrations were also significantly associated with genotype in men and levels were approximately 10% higher in carriers homozygous for the rare alleles as compared to subjects homozygous for the common alleles (-482C>T, P=0.04; -455T>C, P=0.006). In addition, there was a strong interaction between both variants and cigarette smoking affecting fasting triglyceride levels in both men (interaction: -455T>C, P=0.02; -482C>T, P=0.008) and women (interaction: -455T>C, P=0.007; -482C>T, P=0.013). Taken together, the data shows that men who carry the rare alleles of the IRE variants have disturbed glucose homeostasis and an unfavourable lipid phenotype. The finding of an elevated 30-min NEFA may be an important mechanistic link between triglyceride-rich lipoprotein (TRL) metabolism and glucose homeostasis. Show less

Since triglycerides (TG) are a major independent risk factor for coronary heart disease, understanding their genetic and environmental determinants is of major importance. Mouse models indicate an inverse relationship between levels of the newly identified apolipoprotein AV (APOAV) and TG concentrations. We have examined the relative influence of human APOA5 variants on plasma lipids, compared to the impact of variation in APOC3 and APOA4 which lie in the same cluster. Single nucleotide polymorphisms (SNPs) in APOA5 (S19W, -1131T>C) and APOA4 (T347S, Q360H) and an APOA4/A5 intergenic T>C SNP were examined in a large study of healthy middle-aged men (n=2808). APOA5 19WW and -1131CC men had 52% and 40% higher TG (P<0.003) compared to common allele homozygotes, respectively, effects which were independent and additive. APOA4 347SS men had 23% lower TG compared to TT men (P<0.002). Haplotype analysis was carried out to identify TG-raising alleles and included, in addition, four previously genotyped APOC3 SNPs (-2845T>G, -482C>T, 1100C>T, and 3238C>G). The major TG-raising alleles were defined by APOA5 W19 and APOC3 -482T. This suggests that the TG-lowering effect of APOA4 S347 might merely reflect the strong negative linkage disequilibrium with the common alleles of these variants. Thus variation in APOA5 is associated with differences in TGs in healthy men, independent of those previously reported for APOC3, while association between APOA4 and TG reflects linkage disequilibrium with these sites. The molecular mechanisms for these effects remain to be determined. Show less

The effect of genetic variation on plasma lipoproteins and their subfraction distribution was examined. Forty Hispanic men and 223 women and 42 non-Hispanic white men and 53 women participated in the study. Genotypes for cholesteryl ester transfer protein (CETP TaqIB), hepatic lipase (LIPC -480 C > T), lipoprotein lipase (LPL S447X), and apolipoprotein CIII (APOC3--455T > C) were determined by polymerase chain reaction. Lipoprotein particle size distribution was determined by nuclear magnetic resonance. For all but APOC3, genotype effects were homogeneous in the ethnic/racial groups and men and women. Effects were seen primarily in the women. Compared to women carriers of the common CETP B1 allele, B2B2 women had significantly higher plasma levels of high-density lipoprotein cholesterol (HDL-C) (16.4.0%, p = 0.001), reflected in the level of larger HDL particles (21.9%, p = 0.001), and larger mean particle size of HDL (2.3%, p = 0.01) and low-density lipoproteins (LDL) (1.3%, p = 0.02). Compared to LPL 447S homozygous women carriers of the LPL 447X allele had significantly lower levels of very-low-density lipoprotein-triglyceride (VLDL-TG) (21.0%, p = 0.02). For APOC3, there was significant gender:genotype interaction with the genotype differences seen only in the men. Compared to men homozygous for the -455T allele, carriers of -455C had higher levels of VLDL-TG (71.4%, p = 0.0001), reflected in a larger mean VLDL particle size (13.7%, p = 0.009). LIPC genotype was not associated with significant effects on any of these traits. These data confirm the role of genetic variants of CETP, LPL and APOC3 in determining the relationship between VLDL, LDL and HDL particles. Show less

Genetic determinants of baseline levels and the fall in plasma triglyceride and fibrinogen levels in response to bezafibrate treatment were examined in 853 men taking part in the lower extremity arterial disease event reduction (LEADER) trial. Three polymorphisms in the peroxisome proliferator activated receptor alpha (PPARalpha) gene were investigated (L162V, G>A in intron 2 and G>C in intron 7), two in the apolipoprotein CIII (APOC3) gene (-482C>T and -455T>C) and one in the beta-fibrinogen (FIBB) gene (-455G>A). The presence of diabetes (n=158) was associated with 15% higher triglyceride levels at baseline compared to non-diabetics (n=654) (P<0.05). Among the diabetic group, carriers of the PPARalpha intron 7 C allele had 20% lower triglyceride levels compared to homozygotes for the common G allele (P<0.05), with a similar (non-significant) trend for the L162V polymorphism, which is in linkage disequilibrium with the intron 7 polymorphism. For the APOC3 gene, carriers of the -482T allele had 13% lower baseline triglyceride levels compared to -482C homozygotes (P<0.02), but no effect was observed with the -455T>C substitution. In the non-diabetic patients, the PPARalpha V162 allele was significantly associated with 9% higher baseline triglyceride levels (P<0.03) and a similar, but non-significant trend was seen for the intron 7 polymorphism. Overall, triglyceride levels fell by 26% with 3 months of bezafibrate treatment, and current smokers showed a poorer response compared to ex/non-smokers (23% fall compared to 28% P=0.03), but none of the genotypes examined had a significant influence on the magnitude of response. Carriers of the -455A polymorphism of the FIBB gene had, as expected, marginally higher baseline fibrinogen levels, 3.43 versus 3.36 g/l (P=0.055), but this polymorphism did not affect response to treatment. Overall, fibrinogen levels fell by 12%, with patients with the highest baseline fibrinogen levels showing the greatest decrease in response to bezafibrate. For both the intron 2 and the L162V polymorphisms of the PPARalpha gene there was a significant interaction (both P<0.01) between genotype and baseline levels of fibrinogen on the response of fibrinogen levels to bezafibrate, such that individuals carrying the rare alleles in the lowest tertile showed essentially no overall decrease compared to a 0.18 g/l fall in homozygotes for the common allele. Thus while these genotypes are a minor determinant of baseline triglyceride and fibrinogen levels, there is little evidence from this study that the magnitude of response to bezafibrate treatment in men with peripheral vascular disease is determined by variation at these loci. Show less

To examine the genotype:phenotype association in children compared with their parents. Variations at 4 key gene loci, namely lipoprotein lipase (LPL S447X), hepatic lipase (HL -480C>T), cholesteryl ester transfer protein (CETP TaqIB), and apolipoprotein CIII (APOC3 -455T>C and -482C>T), were examined in children (n = 495) and their parents (n = 353) in the Columbia University BioMarkers Study, 1994 to 1998. The frequencies of the rare alleles of the HL -480C>T and APOC3 -455T>C and -482C>T (but not LPL S447X or CETP TaqIB) were significantly lower in non-Hispanic white participants compared with Hispanics. Overall, genotype effects seen in the adults were weaker in the children, although similar trends were seen. In an examination of the effect of body fat on the genotypic effects in the children, there was significant HL -480C>T:sum of skinfold interaction. All genotypes were associated with clear relationships to plasma lipid levels in adults, but the effects were weaker in their children, unless stressed by body fat. atherosclerosis, cardiovascular disease, child, lipids, genetics. Show less

To evaluate the association between plasma lipids and insulin and variation in the genes for apolipoproteins (APO) E (CfoI), B (insertion/deletion), C1 (HpaI), and C3 (C-482T, C3238G) in a population-based Czech Slavonic study. In 131 men and 154 women, polymorphisms were investigated using PCR. In the same subjects plasma lipid levels and insulin were measured. In the women, carriers of the e4 allele had higher apoB (p = 0.03) and triglyceride (p = 0.03) compared to e3 homozygotes, whereas in the men, the effect of the e4 allele was seen on total cholesterol (p = 0.02), LDL cholesterol (p = 0.003) and apoB (p = 0.001). Compared with SP27 (insertion) homozygotes of the APOB polymorphism, women SP24 (deletion) homozygotes had higher levels of total (p = 0.003) and LDL cholesterol (p = 0.007) and apoB (p = 0.05). No significant effect was seen in the men. Women homozygous for the APOC3 -482T allele had higher insulin levels than -482C homozygotes (p = 0.03). Men homozygous for APOC3 -482T allele have the highest plasma triglyceride level (p = 0.02). The APOC1 polymorphism exhibited no significant effect on any of the parameters studied. In this sample, variation at the APOE, APOB and APOC3 genes play a role in determining plasma levels of insulin and lipids, and emphasize the importance of gender-associated effects in the genetic determinations. Show less

The apolipoprotein C3-482C> T variant modulates insulin and glucose concentrations after an oral glucose tolerance test (OGTT) in young healthy white men. We evaluated the effect of this variant in different ethnic groups with different rates of Type II (non-insulin-dependent) diabetes mellitus and coronary heart disease. We investigated the -482C > T in a population-based cross-sectional study of white subjects (n = 462), South Asians (n = 442) and subjects of West African and Afro-Caribbean origin (n = 462), whose OGTT and fasting plasma triglyceride concentrations had been measured. The -482T allele frequency differed between the three groups: 0.25 (95 % CI 0.22-0.28) in white subjects, 0.44 (0.41-0.47) in South Asians and 0.71 (0.68-0.74) in black subjects (p < 0.0001). A positive association was found between body mass index and genotype in black women (p = 0.009) and in black men (p = 0.056) but not in white subjects or South Asians. Associations between -482C > T and fasting insulin were found in white subjects, where -482T allele carriers had higher concentrations (adjusted for age and sex, p = 0.007, also including smoking and body mass index, p = 0.038). Higher triglyceride concentrations (p = 0.004 and p = 0.007 in the two models) but not glucose concentrations were also associated with -482C > T. In black subjects, decreased fasting insulin (p = 0.04) and fasting glucose (p = 0.004) were associated with -482C > T. No relation was observed between genotype and any post-load measured. CONCLUSIONS/INTERPRETATION. Allele frequencies of the -482C > T and associations with insulin, glucose and triglyceride concentrations vary considerably among ethnic groups. Although the results are consistent among white subjects across different studies, the associations among black subjects and South Asians differ. Show less

Variation within and around the apolipoprotein C-III (APOC3) gene has been associated with elevated triglyceride (Tg) levels and cardiovascular disease. The associations of 4 polymorphic variants in the APOC3 gene (3238C>G in the 3' untranslated region [SST:I], 1100C>T in exon 3, -482C>T in the insulin-responsive element, and -2854T>G in the APOC3-A4 intergenic region) with plasma Tg and cholesterol levels and their interaction with smoking have been investigated in the Second Northwick Park Heart Study (NPHSII), a large cohort of healthy men (n=2745). Analyzing the variants separately showed that 3238G, 1100T, and -482T alleles were all associated with raised Tg levels. For the 3238C>G and -482C>T sites, the Tg-raising effect appeared to depend on smoking status (test for interaction, P:=0.042 and P:=0.009, respectively), but for the 1100C>T site, the effect was constant irrespective of smoking status (test for interaction, P:=0.27). The -2854T>G site was not associated with effects on Tg levels in this sample. Because all of the variants showed significant allelic association, regression modeling was used to quantify the relative size of each effect and to assess whether the effects of the separate variants were independent. The 1100C>T variant had an independent effect on Tg levels that was not influenced by smoking status (increase of 8.2% in Tg with each T1100 allele), whereas the -482C>T variant had a separate effect that was dependent on smoking (increase of 13.7% in Tg for each -482T allele in current smokers, 8.6% in exsmokers, and -7.4% in those who never smoked). The 3238C>G variant did not show a separate independent effect on Tg concentration. Thus, by use of the regression model, it was possible to estimate how mean Tg levels would vary in groups of individuals with respect to APOC3 genotype and smoking information. Analysis in this large group of healthy men has allowed the identification of a statistically robust APOC3 genotype-smoking interaction, which now warrants further molecular study. Show less

We have identified a G-to-A transition in exon 3 of the APOC3 gene resulting in a novel Ala23Thr apolipoprotein (apo) C-III variant, associated with apoC-III deficiency in three unrelated Yucatan Indians. The Ala23Thr substitution modifies the hydrophobic/hydrophilic repartition of the helical N-terminal peptide and hence could disturb the lipid association. In vitro expression in Escherichia coli of wild-type and mutant apoC-III enabled the characterization of the variant. Compared with wild-type apoC-III-Ala23, the mutant apoC-III-Thr23 showed reduced affinity for dimyristoylphosphatidylcholine (DMPC) multilamellar vesicles with higher amounts of free apoC-III. Displacement of apoE from discoidal apoE:dipalmitoylphosphatidycholine (DPPC) complex by apoC-III-Thr23 was comparable to wild type but the less efficient binding of the apoC-III-Thr23 to the discoidal complex resulted in a higher apoE/apoC-III (mol/mol) ratio (34%) than with wild-type/apoE:DPPC mixtures. The inhibition of lipoprotein lipase (LPL) by apoC-III-Thr23 was comparable to that of wild type, and therefore effects on LPL activity could not explain the lower triglyceride (Tg) levels in Thr-23 carriers. Thus, these in vitro results suggest that in vivo the less efficient lipid binding of apoC-III-Thr23 might lead to a faster catabolism of free apoC-III, reflected in the reduced plasma apoC-III levels identified in Thr-23 carriers, and poorer competition with apoE, which might enhance clearance of Tg-rich lipoproteins and lower plasma Tg levels seen in Thr-23 carriers. Show less

Remnant particles of triglyceride-rich lipoproteins (RLP) are known to be a strong predictor of atherogenicity. The serum concentrations of remnant-like particle triglyceride (RLPTG) and remnant-like particle cholesterol (RLPC) have been determined in a representative sample of the Czech MONICA study (n = 285). The relationship was investigated between remnant particle triglyceride/cholesterol concentrations and polymorphisms in the genes APOC3 (-482C-->T/3238C-->G), APOE (epsilon2/epsilon3/epsilon4), APOCI (-317-321ins), APOB (signal peptide), hepatic lipase (LIPE, -480C-->T), and lipoprotein lipase (LPL, S447X). Univariate analysis showed significant effects on RLPTG associated only with the APOE genotype (P = 0.009), the APOC3 -482C-->T genotype (P = 0.018), and the APOCI -317-321ins (P = 0.014) genotype and significant effects on RLPC with APOE (P = 0.01) and APOCI -317-321ins (P = 0.021). The raising effect of the APOE genotype for both remnant cholesterol and triglyceride was confined to the epsilon2/4 (n = 6) and varepsilon4/4 (n = 3) groups, and thus when the epsilon2/4 group was omitted in order to analyze by allele (epsilon2+/epsilon3+/epsilon4+), significance was lost (P = 0.6). There was strong linkage disequilibrium between the APOE and APOCI alleles (chi(2), P < 0.001) and a multivariate ANOVA of RLPTG with all three significantly associated variants as factors demonstrated that while the APOC3 -482C-->T effect was independent of the others (P = 0.003), the APOCI -317-321ins and APOE effects were not. This was also true for the APOCI -317-321ins and APOE effects on RLPC. To assess whether APOE-CI effects on RLPC were independent of their effects on total cholesterol and triglyceride levels, multiple linear regression was used. Using multiple linear regression, it appeared that the APOE-CI effects on RLPC were independent of their effects on plasma cholesterol, but the effects of APOC3 and APOE-CI on RLPTG could not be separated from their effects on plasma Tg levels. Further characterization of this remnant particle phenotype and its genetic determinants may lead to a better understanding of its metabolism and contribution to atherosclerosis. Show less

The aims of the study were to investigate associations of the apolipoprotein (apo) A-IV polymorphisms Thr347Ser and Gln360His with anthropomorphic measurements and fasting and postprandial lipids in subjects participating in the European Atherosclerosis Research Study II (EARS II). The allelic frequencies of Ser347 and His360 were 0.185 and 0.067, respectively, in the sample as a whole. There were no significant differences in rare allele frequency between cases (offspring of fathers who suffered a myocardial infarction before the age of 55 years) and controls. Control subjects who were carriers of Ser347 had significantly higher body mass indices (BMIs), waist:hip ratios, total and low density lipoprotein cholesterol and triacylglycerol (TG) concentrations (all P < or = 0.02) than control subjects who were non-carriers, but these effects were not seen in the cases. Control subjects who were carriers of His360 had lower BMIs (P = 0.04), cholesterol and TG concentrations (both P < or = 0.07) compared to non-carriers, but these effects were not seen in the cases. After consumption of an oral fat load, carriers of His360 who were most obese (subjects in the third tertile of BMI) had significantly reduced postprandial lipemia (P < 0.03, as assessed by area under the curve).-Fisher, R. M., H. Burke, V. Nicaud, C. Ehnholm, and S. E. Humphries. Effect of variation in the apoA-IV gene on body mass index and fasting and postprandial lipids in the European Atherosclerosis Research Study II. Show less