Increased frequencies of apolipoprotein ε2 and ε4 alleles in patients with ischemic heart disease

It has been demonstrated that the genetic polymorphism of apolipoprotein (apo) E is associated with atherosclerosis. Thus, in this study, we have examined the apo E allele frequencies in 109 patients with ischemic heart disease (IHD) and 576 Japanese people as controls, and we have compared these frequencies between patients with IHD and controls. The frequencies of the epsilon 2 and epsilon 4 alleles were significantly higher in patients with IHD than in the controls (epsilon 2: 8.2% vs 3.7%, epsilon 4: 17.0% vs 11.7%), whereas the frequency of the epsilon 3 allele was significantly lower in patients with IHD than in the controls (74.8% vs 84.6%). The epsilon 2-carrying patients with IHD were characterized by type III (43.8%) and IV (25.0%) hyperlipoproteinemia (HLP), whereas the epsilon 4-carrying patients with IHD were characterized by hypercholesterolemia (type IIb HLP: 42.8%, type IIa HLP: 28.6%). It is concluded that both epsilon 2 and epsilon 4 alleles are more associated with IHD than the epsilon 3 allele.     

Association of apolipoprotein ɛ4 allele with hypertriglyceridemia in obesity

Hypertriglyceridemia is the most frequent lipid abnormality associated with obesity. Genetic polymorphism of apolipoprotein E (apoE) has been demonstrated to influence lipid levels. We wanted to assess the role of apoE alleles in the hypertriglyceridemias of the obese population. The apoE phenotypes and lipid status were investigated in a population of 172 obese French subjects. The frequencies of phenotypes E4/3, E4/4 and E4/2 were 29.7%, 8.1% and 2.1%, respectively, in a subgroup with triglycerides greater than or equal to 200 mg/dl (n = 37) versus 14.2%, 2.7% and 0.9% in the normolipidemic subgroup (p less than 0.005). The odds ratio of hypertriglyceridemia was 3.15 for obese subjects with epsilon 4; 27.7% of hypertriglyceridemias could be attributed to epsilon 4 allele. It is concluded that the genetic polymorphism of apoE modulates the effects of obesity on lipids and lipoproteins and that allele epsilon 4 increases the risk of obesity-induced hypertriglyceridemia.     

The effect of the apolipoprotein E polymorphism on lipid levels in patients with familial defective apolipoprotein B-100

Summary Serum lipid concentrations of patients with familial defective apolipoprotein B-100 (FDB) show a high interindividual variability although the underlying defect is caused by a single point mutation. On the other hand, several genetic factors modulating serum cholesterol levels are known, such as DNA polymorphisms of the apopolipoprotein B or the apolipoprotein E (apo E) gene. To assess the effect of the apo E polymorphism on serum cholesterol, lipid levels of FDB patients (n=36) were compared with those of a normolipidemic control group (n=272) according to their apo E genotype. For the FDB group mean values of low-density lipoprotein (LDL) cholesterol (mg/dl) were 225.7 ± 53.7 for E3/2 genotype (n = 3), 234.2±48.3 for E3/3 genotype (n=20), and 252.4±73.8 for E4/3 genotype (n=13). Means of triglycerides (mg/dl) were 121.0±21.2, 114.8± 60.7, and 110.0 ± 62.8 for the respective apo E genotypes. The calculated average effect of the apo E alleles on LDL cholesterol levels was –6.0% for allele e2 and +3.7% for e4 relative to the whole FDB group. The effect on triglyceride levels was +7.5% for e2 and –3.6% for e4. The control group showed a similar variation in LDL cholesterol depending on the different apo E genotypes. About 6% of the total variation in LDL cholesterol can be accounted for by the apo E locus in normolipidemic and hypercholesterolemic individuals alike.Abbreviations FDB familial defective apolipoprotein B-100 - apo apolipoprotein - LDL low-density lipoprotein - VLDL very low density lipoprotein - HDL high-density lipoprotein - PCR polymerase chain reaction Dedicated to Prof. Dr. N. Zöllner on the occasion of his 70th birthday     

Cholesterol ester transfer protein,apolipoprotein E and lipoprotein lipase genotypes in patients with coronary artery disease in the Turkish population

The aim of this study was to compare patients with coronary artery disease (CAD) to healthy objects, in order to explore a possible association between CAD and the variants in the gene encoding cholesterol ester transfer protein (CETP), apolipoprotein E (Apo E) and lipoprotein lipase (LPL). The relationship between CETP MspI, apo E and LPL PvuII gene polymorphisms and serum lipids were investigated in 173 patients with CAD and 111 healthy controls. The frequency of Apo epsilon4 (p < 0.05) and CETP M1 (p < 0.01) alleles were higher in the CAD group than in the control group. In the CAD group, those with the Msp M1 allele had higher levels of total cholesterol (TC) (p = 0026) and low-density lipoprotein cholesterol (LDL-C) than those with the Msp M2 allele. Subjects with an epsilon2 allele had the lowest levels of TC and LDL-C, while subjects with the epsilon4 allele had the highest. In the control group, CETP, the Msp M2 allele was associated with a higher level of high-density lipoprotein cholesterol (HDL-C) (p = 0.012) than the Msp M1 allele. The distributions of LPL genotype and allele did not differ between the CAD and control groups. The present study demonstrates that the CETP Msp1 and Apo E gene polymorphisms are associated with variations in lipids in patients with CAD and healthy controls in Turkish population.     

中国人内源性高甘油三酯血症载脂蛋白E基因多态性的研究

目的 探讨中国人内源性高城油三酯血症（endogenous hypertriglyceridemia,HTG)患者载脂蛋白E（apolipoprotein E,apoE)基因多态性及其与血脂和载脂蛋白水平的关系。方法 采用聚合酶链反应－限制性片段长度多态性分析方法,分别对225例HTG患者及230名血脂正常者的apoE基因型、空腹血脂及载脂蛋白AⅠ、AⅡ、B100、CⅡ、CⅢ、E进行了分析。结果 HTG患者的体重指数(BMI)` 清甘油三酯（TG）、总胆固醇（TC）、非高密度脂蛋白胆固醇（nHDLC)水平较对照组显著升高,血清高密度脂蛋白胆固醇（HDLC）则显著降低（P＜0．001）,并伴有载脂蛋白水平的异常。HTG组与对照组apoE基因型及等位基因频率分布均以E3／3和ε3最高,HTG组的ε2等位基因有增高的趋势（P＞0．05）。对照组ε2等位基因携带者血清TG和apoE水平较ε3和ε4等位基因携带者显著升高（P＜0．001）,其低密度脂蛋白胆固醇（LDLC）水平及apoE/ApoC Ⅲ比值则显著降低（P＜0．001）。结论 ε2等位基因与血清TG和apoE水平升高及LDLC水平降低有关,apoE/apoC Ⅲ比值降低可能与HTG患者血TG水平升高有关。     

载脂蛋白E基因多态性与早发冠心病的关系及其对血脂的影响

目的 研究载脂蛋白E（apolipoprotein E,apoE)基因多态性与早发冠心病（coronary heart disease,CHD)的相关关系及其对血脂水平的影响。方法 应用聚合酶链反应－限制性片段长度多态性（polymerase chain reaction-restricted fragment hength polymorphism,PCR-RFLP)基因分析方法,测定52例早发CHD、161例迟发CHD患者和180名对照者的apoE基因型;血脂水平按常规方法测定。结果 发现的5种apoE基因型,分别为E3／3、E4／4、E3／2、E4／3及E4／2。早发CHD组和迟发CHD组apoE4/3基因型和ε4等位基因频率均高于对照组（P＜0．01）;进一步对两组CHD患者的apoE多态性进行分析,发现早发组ε4等位基因频率较迟发组为高（P＜0．05）。apoE各等位基因型之间,TC和LDL－C水平之间存在统计学差异（P＜0．05）。结论 apoE基因多态性与早发CHD的发生发展有关并影响血脂的水平。     

A racial difference in apolipoprotein E allele frequencies between the Japanese and Caucasian populations

We have examined the apo E phenotype frequencies in the Japanese population (n = 576, 16-78 years of age). Apo E phenotypes were determined by the rapid flat gel isoelectric focusing method that we previously reported. The apo E phenotype frequencies in the Japanese were 0.3% for E2/2, 6.1% for E3/2, 71.9% for E3/3, 0.7% for E4/2, 19.3% for E4/3 and 1.7% for E4/4. The apo E allele frequencies were 0.037, 0.846 and 0.117 for the epsilon 2, epsilon 3 and epsilon 4 alleles, respectively. These frequencies were compared with those in the Caucasian populations (n = 3033) reported by Sing & Davignon (1985). There was a significant difference in the apo E phenotype frequencies between the Japanese and Caucasian populations. In addition, a significantly lower frequency of the epsilon 2 and epsilon 4 alleles and a significantly higher frequency of the epsilon 3 allele were found in the Japanese than those reported for the Caucasian populations. It is concluded that there is a racial difference in the apo E allele frequencies between the Japanese and Caucasian populations.     

Increased frequency of apolipoprotein ε2 allele in non-insulin dependent diabetic (NIDDM) patients with nephropathy

The genetic polymorphism of apolipoprotein E (ε2, ε3 and ε4) is associated with lipid abnormalities. It has been suggested that lipid abnormalities may contribute to the development and progression of kidney diseases, including diabetic nephropathy. Thus, in this study we compared the apo E allele frequencies among 146 non-insulin-dependent diabetic (NIDDM) patients with nephropathy, 135 NIDDM patients without nephropathy and 576 of the general Japanese population. The ε2 allele frequency was significantly higher in diabetic patients with nephropathy (7.2%) and with renal failure (9.7%) than in diabetic patients without nephropathy (2.6%) and in the general Japanese population (3.7%). It is concluded that there is a possibility that the ε2 allele is associated with nephropathy in NIDDM.     

Ⅳ型高脂血症患者高密度脂蛋白亚类组成与载脂蛋白E基因多态性关系的研究

目的探讨型高脂血症患者载脂蛋白E基因多态性与HDL亚类组成的关系。方法采用聚合酶链反应-限制性片段长度多态性和双向电泳-免疫印迹检测法,分析103例型高脂血症患者和146名血脂正常者的apoE基因型、HDL各亚类组成及相对含量。结果型高脂血症组和对照组apoE基因型及等位基因频率分布均以E3/3和ε3最高。型高脂血症患者中等位基因ε2携带者血清HDL-C、apoE、apoE/C、HDL2a较等位基因ε3、ε4携带者升高,而TG/HDL-C、apoC则下降,等位基因ε2携带者HDL3c较等位基因ε3携带者降低,其差异有统计学意义(P<0.05)。对照组中等位基因ε2携带者血清TG、apoE、apoE/C较等位基因ε3和ε4携带者升高,等位基因ε2携带者HDL3a较等位基因ε3携带者降低,其差异有统计学意义(P<0.05)。结论型高脂血症患者apoEε2等位基因与血清HDL亚类的成熟代谢有关。     

Population frequency of apolipoprotein E5 (Glu3→Lys) and E7 (Glu244→Lys, Glu245→Lys) variants in western Japana

Apolipoprotein (apo) E modulates the catabolism of chylomicrons and of very low density lipoprotein remnants. It has three major isoforms (apo E2, E3, E4) and some rare variants. To detect the variants of apo E, blood specimens from 1269 Japanese subjects were analyzed using isoelectric focusing with immunoblotting. The E5 and E7 variants were identified by IEF in 2 and 18 subjects, respectively. Both E5 (Glu3→Lys) carriers were confirmed by PCR-mediated site-directed mutagenesis, and all E7 (Glu244→Lys, Glu245→Lys) carriers were confirmed by the amplification refractory mutation system. The relative frequencies of the ε5 and ε7 alleles were 0.001 and 0.007, respectively. High concentrations of total cholesterol (>220 mg/dl) were detected in five of the subjects expressing apo E7 and one subject expressing apo E5, and eight subjects heterozygous for apo E7 showed elevated plasma triglyceride concentrations (>150 mg/dl). In 621 healthy subjects, the mean triglyceride concentration in subjects with apo E7/3 appeared to be higher than in those with apo E3/3, but the difference was not statistically significant.     

Apolipoprotein E5 and E7 in apparently healthy Japanese males: Frequencies and relation to plasma lipid levels

Summary In order to determine the frequencies of apolipoproteins (apo) E5 and E7 and their relation to plasma lipid levels, apo E phenotypes were determined in 608 healthy Japanese male adults by two-dimensional gel electrophoresis. Apo E5 and E7 were observed in 2.8% of the subjects, in addition to the three common apo E isoforms, E2, E3, and E4. Apo E5 was divided into two subtypes based on the migration rate on SDS/PAGE, E5f is the type with faster migration and E5s slower migration. The gene frequencies were: the 3 allele, 0.841; the 4 allele, 0.095; the 2 allele, 0.049; the 7 allele, 0.009; the 5 allele encoding apo E5f (the 5f allele), 0.004; and the 5 allele encoding apo E5s (the 5s allele), 0.001. The five individuals with apo E5f and the eleven with apo E7 were heterozygotes and normocholesterolemic. Also plasma apo B and apo E levels were not increased in any subjects with apo E5f or apo E7. The data suggests that apo E5f and E7 are not rare in the Japanese population but that neither apo E5f nor E7 are associated with hypercholesterolemia in most of the heterozygotes.     

The influence of apo E phenotypes on the plasma triglycerides response to hormonal replacement therapy during the menopause.

OBJECTIVE: To study the influence of apo E phenotype in plasma lipids, especially in triglycerides levels, in menopausal women receiving hormonal replacement therapy (HRT). METHODS: One hundred and ten postmenopausal women were studied. Plasma total cholesterol (TC), HDL-C and triglycerides (TG) were measured before and after 3 months of HRT and the apo E phenotype was determined. According to the apo E phenotype the sample was divided into three groups: E2/E3 (n=28), E3/E3 (n=96) and E4/E3 (n=25). RESULTS: In the pre-treatment state, higher plasma levels of TC and TC/HDL-C ratio were observed in women with phenotype E3/E4 (P<0.0001 and P<0.02, respectively), while higher plasma TG levels were found in the apo E2/E3 group (P<0.0001). After HRT, women with phenotype E3/E4 showed higher levels of TC and TC/HDL-C ratio (P<0.0001 and P<0.006, respectively). The apo E2/E3 phenotype group showed increased levels of TG (P<0.0001). In the multivariant analysis the changes of TG after HRT were related to the type of treatment used (P<0.001), age (P=0.05) and the apo E phenotype (E2/E3). CONCLUSION: Women with phenotype E2/E3 have higher plasma TG levels and show a significant post HRT increase compared with the other phenotypes. Other factors with a lower impact on TG levels are age and progestagen association.     

Effects of apolipoprotein A-I genetic variations on plasma apolipoprotein,serum lipoprotein and glucose levels

The present authors investigated the individual and combined associations of the apolipoprotein (apo) A-I -75 bp and +83 bp polymorphisms with plasma lipid, lipoprotein and apolipoprotein levels in 734 Caucasian men and women. The frequency of the A allele at position -75 bp (G-->A) was 0.14 in women and 0.17 in men. The frequencies for the rare M2 allele at position +83 bp and/or 84 bp (C-->T and G-->A, respectively) were 0.04 and 0.05 in women and men, respectively. In women, the A allele was associated with significantly higher levels of apo B (P = 0.016), total cholesterol (TC) (P = 0.005), low-density lipoprotein cholesterol (LDL-C) (P = 0.018) and TC:high-density lipoprotein (HDL) ratio (P = 0.026) compared to the G/G subjects. In men, no significant associations were detected between the -75 bp polymorphism and any lipid trait examined. The M2 allele for the +83 bp polymorphism was significantly associated in men with higher levels of apo A-I (P = 0.002) and TC (P = 0.046). In women, a significant effect was observed for TC (P = 0.036), with M2+/- subjects having lower levels than M2+/+ subjects. Significant linkage disequilibrium (P = 0.037) between the apo A-I -75 bp and +83 bp polymorphisms was detected. Women carrying both rare alleles (G/A M2+/-) had significantly higher TC:HDL ratios (P = 0.031) compared to the other haplotypes. In men, significant differences were observed for apo A-I (P = 0.021) and TC (P = 0.044), with carriers of the G/G M2+/- haplotype having the highest values compared to other genotype combinations. In conclusion, the -75 bp (G/A) polymorphism appears to have a significant effect on levels of apo B, plasma TC and LDL-C in women, while the +83 bp polymorphism seems to affect the apo A-I levels in men, and the plasma cholesterol levels in both genders.     

The use of measured genotype information in the analysis of quantitative phenotypes in man. II. The role of the apolipoprotein E polymorphism in determining levels, variability, and covariability of cholesterol, betalipoprotein, and triglycerides in a sample of unrelated individuals

Recent advances in molecular biology provide measures of genotypes at loci involved in lipid metabolism. Genotypes for apolipoprotein E (apo E) and quantitative levels of total plasma cholesterol, betalipoprotein, and triglycerides were measured in a sample of 223 unrelated individuals from Nancy, France. The frequencies of the epsilon 2, epsilon 3, and epsilon 4 alleles are 0.13, 0.74, and 0.13, respectively, in this sample. Significant differences among apo E genotypes were detected for these lipoprotein phenotypes. The average effect of the epsilon 2 allele was to reduce total plasma cholesterol and betalipoprotein levels by 0.52 mmol/L and 0.98, respectively, while the epsilon 4 allele raised these levels by 0.26 mmol/L and 0.61, respectively. Apo E genotype specific correlations suggest that this locus also has an effect on the coordinated metabolism between cholesterol and triglycerides. We infer that approximately 17% of the genetic variability in total plasma cholesterol may be attributable to this apo E polymorphism. No other single locus has been identified with such a large contribution to cardiovascular disease risk factors in the general population.     

Phenotype of apolipoprotein E influences the lipid metabolic response of postmenopausal women to hormone replacement therapy

Objectives: We investigated whether the phenotype of apolipoprotein E (apo E) would influence the response of postmenopausal Japanese women to hormone replacement therapy (HRT). Methods: We measured the plasma levels of lipoprotein and apolipoprotein in 242 postmenopausal women at baseline and again after 12 months of HRT. Patients were divided into three groups according to apo E phenotype: E2+ (E2/2 and E2/3, n=21), E3/3 (n=176), E4+ (E3/4 and E4/4, n=45). Results: We found that the E4+ group had the highest levels of total and low density lipoprotein (LDL) cholesterol and apolipoprotein B, being significantly higher than in the E2+ group at baseline. The plasma levels of total and LDL cholesterol showed a significant decrease only in the E2+ and E3/3 groups after 12 months of HRT (E2+ group, total cholesterol −8.9% and LDL cholesterol −21.5%; E3/3 group, total cholesterol −2.9% and LDL cholesterol −9.5%). No significant difference in the reduction of total and LDL cholesterol was found in the E4+ group. Other lipid parameters did not differ in the three groups. Conclusions: These data show that the apo E phenotype influenced the response of lipid metabolism in postmenopausal women to HRT, especially in the reduction of LDL cholesterol. Therefore, apo E phenotyping may be important in predicting the cholesterol-lowering effect of HRT.     

Apolipoprotein E polymorphism and lipid levels differ by gender and family history of diabetes: the Rancho Bernardo Study

Association between apolipoprotein E (apoE) gene polymorphism and lipid levels was studied in 164 nondiabetic first-degree relatives of persons with diabetes and 962 nondiabetic persons with no family history of diabetes. Sex-specific genotypic distribution of apoE polymorphism did not differ between persons with and without a family history of diabetes. In first-degree relatives, lipid levels did not differ among persons with apoE2 (E2/2, E2/3), apoE3/3, and apoE4 (E4/4, E3/4) after adjusting for age, waist circumference, smoking, and alcohol and estrogen use. In persons without a family history of diabetes, both men (p<0.01) and women (p<0.001) with apoE2 showed lower levels of total and low density lipoprotein cholesterol compared with persons with apoE3/3 and apoE4. In women with a family history of diabetes, persons with apoE4 had larger waist circumference (p<0.05). ApoE2 allele is associated with more favorable levels of total and low density lipoprotein cholesterol in men and women without a family history of diabetes. ApoE4 allele is associated with obesity independent of dyslipidemia in women but not men with a family history of diabetes. ApoE polymorphism is not associated with lipids in men or women with a family history of diabetes.     

Apolipoprotein E gene polymorphism in cerebrovascular disease: a case-control study

The association between apolipoprotein E (apo E) polymorphism and stroke has been controversial. So far there are no studies reported on the polymorphism of apolipoprotein E in cerebrovascular diseases in the Asian Indians. A blinded case-control study was therefore undertaken and the apo E genotypes and lipid profile of a total of 120 subjects (63 stroke patients and 57 healthy controls) were done. The frequency distribution of apo E alleles and genotypes were assessed and their relation with the occurrence of stroke in Asian Indian subjects was determined. A significantly high frequency of apo epsilon4 allele (30%) was observed in the stroke patients than the controls (11%) (p < 0.005), and patients with epsilon4 allele had a fourfold higher odds to develop stroke OR (95%CI) 4.2 (1.8-10.1) (p < 0.005). On multivariate analysis, after adjusting for age, triglycerides and hypertension, the association of epsilon4 allele with stroke was found to be no longer statistically significant, OR (95%CI) 1.2 (0.4-4.5) (p = NS). On multiple logistic regression analysis age, OR (95%CI) 1.1 (1.1-1.2) (p < 0.001), and hypertension OR (95%CI) 15.1 (2.6-89.1) (p < 0.005) were found to be independent risk factors for development of stroke. This is the first report to have examined the association of apo E gene polymorphism with stroke in the Asian Indians. This study suggests that apo epsilon4 allele, triglycerides, age and hypertension are the predictors for stroke development.     

Apolipoprotein E polymorphism in northwestern Greece: frequency and effect on lipid parameters

Apolipoprotein (apo) E gene polymorphism and its effect on serum lipid parameters were examined in a Greek population originating from northwestern Greece (n = 555). The allele frequencies were epsilon2: 6.3%, epsilon3: 80.7%, and epsilon4: 13.0%. The epsilon4 allele frequency was higher in our population than was previously reported in individuals from other parts of Greece. ApoE polymorphism was associated with significant differences in serum lipid, and lipoprotein levels. Particularly, individuals with the epsilon2 allele had higher serum triglyceride and apoE levels and lower levels of total cholesterol, low-density lipoprotein cholesterol, and apoB, compared to those with the alleles epsilon3 and epsilon4. However, the impact of the epsilon4 allele on lipid parameters seen in other populations was not observed in our population. Furthermore, the combination of apoE polymorphism and serum apoE concentration explained a larger percentage of serum lipid variability than the polymorphism alone. In conclusion, the results of our study suggest that ethnic differences, as well as alterations of serum apoE levels, significantly modify the relationship between apoE gene polymorphism and serum lipid variability.     

高脂血症患者载脂蛋白E基因多态性与血脂水平分析

目的:分析载脂蛋白E基因多态性和高脂血症患者的血脂水平。方法:应用等位基因特异性多重PCR技术对高脂血症患者和健康对照者载脂蛋白E基因多态性进行分析,并测定所有样本血清载脂蛋白E等血脂指标水平。结果:高脂血症患者总胆固醇、甘油三脂、低密度脂蛋白胆固醇、载脂蛋白E水平明显高于健康对照组(P<0.05),而高密度脂蛋白胆固醇,载脂蛋白AI明显低于正常对照组(P<0.05);血浆中载脂蛋白E含量顺序是E2/3>E3/3>E3/4,两两比较具有统计学差异(P<0.05);在载脂蛋白E的基因型中以载脂蛋白E3/3型多见;高脂血症患者中载脂蛋白Eε4等位基因频率明显高于健康对照组(P<0.05)。结论:载脂蛋白Eε4等位基因与高脂血症有关,载脂蛋白E基因多态性可能是高脂血症患者的遗传因素。     

冠心病家族史青少年载脂蛋白E、B的基因多态性

目的 探讨青少年载脂蛋白E(apolipoprotein E，apoE)、apoB基因多态性对冠心病的遗传易感性。方法 应用聚合酶链反应—限制性片段长度多态性技术，对244名健康汉族大学生(冠心病家族史阳性者109人，阴性者135人)的apoE、apoB XbaI、apoB 3’可变数目串联重复序列(variable number of tandem repeat ，VNTR)基因型进行分析。结果 阳性组的e4、x^ 、VNTR—B(hypervariable element，HVE＞38)等位基因频率显著高于阴性组(P＜0．05)，且与血总胆固醇、低密度脂蛋白—胆固醇、aPoBl00水平升高有显著相关(P＜0．05)。结论 apoE的e4、apoB Xba I的x^ 、apoB3’VNTR的VNTR—B可能为冠心病的重要遗传标记。