Apolipoprotein E genotype and plasma levels in coronary artery disease. A case-control study in the Italian population.

OBJECTIVES: To investigate the role of the apolipoprotein B and apolipoprotein E polymorphisms in coronary artery disease (CAD) susceptibility in the Italian population and their relation to plasma lipid and apolipoprotein levels. METHODS: APOB (APOB Xbal, EcoRI, Ins/Del), and APOE (APOE Cfol) polymorphisms were analyzed in 150 male CAD patients and 110 matched controls. In the same subjects plasma lipid, apoB, and apoE levels were measured. RESULTS: No differences in the distribution of the APOB polymorphisms were observed between patients and controls. Among patients the number of e*4-carriers was significantly higher than in controls. e*4-carriers were more frequent among the hypertensive patients and had a higher systolic blood pressure (p = 0.007) than the non-e*4 carriers. The APOB Xbal polymorphism was found to influence the distribution of HDL-cholesterol. Patients showed significantly lower levels of apoE (39.29 mg/L) than controls (54.32 mg/dL) and the lowest concentrations were associated to the E4/E3 and E4/E4 genotypes. CONCLUSION: Quantitative data are consistent with the hypothesis that apoE has an anti-atherosclerotic role and suggest that the apoE quantitation could be a useful parameter for defining cardiovascular risk. e*4 allele appears to be a risk factor for CAD in the Italian population and could act by its association with low apoE levels.     

Apolipoprotein B gene polymorphisms: prevalence and impact on serum lipid concentrations in hypercholesterolemic individuals from Brazil

Genetic polymorphisms at the apolipoprotein B (apo B) have been associated with elevated plasma concentrations of low-density lipoprotein (LDL) cholesterol, atherosclerosis and increased risk for coronary artery disease (CAD). In the present study, four apo B gene polymorphisms (MspI, XbaI, Ins/Del and 3'HVR) have been investigated to determine their frequencies and influence on the lipid profile of 177 hypercholesterolemic white Brazilian subjects (HG) and 100 control individuals (CG). The genotype distribution and allele frequency of MspI, XbaI and Ins/Del polymorphisms of apo B gene were similar between HG and CG groups. The frequency of the alleles smaller than 43 repeats (< or =43) of 3'HVR polymorphism in the HG group was higher when compared to controls (16.4 vs. 8.5%, P<0.05). Moreover, these alleles were associated with higher total cholesterol concentrations in serum of hypercholesterolemic individuals (P<0.05). In addition, an association between Ins/Del and 3'HVR polymorphism was observed. The alleles < or =43 and Del were more frequent in the HG when compared to the CG individuals (P<0.05). We concluded that 3'HVR polymorphism at the apo B gene may be an important genetic marker to evaluate atherosclerotic disease risk.     

Association of the insertion/deletion gene polymorphism of the apolipoprotein B signal peptide with myocardial infarction in Tunisian patients

BACKGROUND: Numerous polymorphisms of the apolipoprotein B (APOB) gene have been described. Particularly, the insertion/deletion (Ins/Del) polymorphism located in the coding part of the signal peptide of apoB, associated with modification of lipid concentrations and the risk of coronary artery disease and/or myocardial infarction (MI), has been reported in the general population. Moreover, conflicting results emerge from the literature and suggest that the effect is context-dependent. In the present study, the first investigation of the Ins/Del polymorphism of the APOB gene in Tunisian patients with MI, we examined a possible association between this polymorphism and MI in a subgroup of the Tunisian population. METHODS: A total of 318 Tunisian patients with MI and 368 healthy controls were included in the study. Genomic DNA was extracted from white blood cells, and the Ins/Del polymorphism was determined by electrophoresis in polyacrylamide gels after PCR amplification. A binary logistic regression analysis was performed to test how the association between MI and Ins/Del polymorphism is independent from confounding factors. RESULTS: A significant difference in genotype distribution and allele frequency was observed between patients and controls. Patients with MI had a frequency of 7.2% for the Del/Del genotype, 39.6% for the Ins/Del genotype, and 53.1% for the Ins/Ins genotype. Controls had a frequency of 3.0% for the Del/Del, 32.1% for the Ins/Del and 64.9% for the Ins/Ins genotype (chi2=12.93, p=0.002). The MI patient group showed a significantly higher frequency of the Del allele compared to controls (27.1% vs. 19.1%; chi2=12.50, p=0.0004). In comparison to the Ins/Ins homozygotes, the odds ratio (95% confidence interval) for MI was 1.51 (1.09-2.07) for Ins/Del heterozygotes and 2.95 (1.40-6.22) for Del/Del homozygotes. In multivariate analysis, age (p=0.001), smoking (p<0.001), hypertension (p=0.001), diabetes mellitus (p<0.001), and dyslipidemia (p=0.01) were independent correlates of the presence of MI, whereas the Ins/Del polymorphism (p=0.330) was not an independent predictor of MI. CONCLUSIONS: The present study shows a significant but not independent association between the Ins/Del polymorphism of the APOB gene and MI in the Tunisian population.     

Apo B gene haplotype is associated with lipid profile of higher risk for coronary heart disease in Caucasian Brazilian men

We investigated using haplotype analysis whether genetic variation of the apo B gene is associated with a higher risk for coronary heart disease in a Brazilian population. Ins/Del, XbaI, and EcoRI polymorphic sites of the apolipoprotein B (apo B) gene were studied in 67 patients with CHD and in 67 age-matched healthy individuals selected from a population of Brazilians. The allelic frequency of apo B polymorphisms did not differ between the CHD patients and controls. However, a significant linkage disequilibrium was observed between the XbaI site and Ins/Del polymorphism of the apo B gene in CHD individuals (chi2, P < 0.01). The simultaneous presence of the rare X+ and Del alleles (X+Del haplotype) in males of CHD group was associated with significantly higher serum levels of total cholesterol (P < 0.01), triglycerides (P < 0.05), and LDL-cholesterol (P < 0.05), and with a higher TC/HDL-C ratio (P < 0.05). These data indicate that a single haplotype, X+Del, within the apo B gene exerts an impact on lipid metabolism and may contribute to the susceptibility to development of CHD in males from a population of Brazilians.     

Association of the apolipoprotein B gene polymorphisms with cholesterol levels and response to fluvastatin in Brazilian individuals with high risk for coronary heart disease.

The influence of genetic polymorphism of the apolipoprotein B on lipid metabolism and coronary heart disease (CHD) risk has been demonstrated in different populations, but few studies have shown the contribution of this risk factor in individuals from Brazil. The Ins/del, Xbal and EcoRI polymorphisms of apo B were evaluated in 93 controls and in 104 Caucasian individuals presenting with a high risk lipid profile (HR1) for CHD; 54 of these subjects (HR2) were treated with fluvastatin during 16 weeks. DNA polymorphisms of the apo B gene were analyzed by polymerase chain reaction-restriction fragment length polymorphism. The X(-)X(-) genotype for Xbal polymorphism was associated with higher serum concentrations of total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) (p<0.01) in women of the HR1 group. The Ins/del and EcoRI polymorphisms were not associated with variation of lipid profile. After treatment with fluvastatin, TC and LDL-C levels of HR2 individuals were reduced by 23% and 30%, respectively. Individuals with II genotype had significantly greater reduction (34%) of LDL-C than those with ID/DD genotypes (27%). These results indicate that the Xbal polymorphism is associated with variation of serum TC and LDL-C levels in Brazilian women with lipid profile of risk for CHD and the Ins/del polymorphism is associated with the therapeutic response to fluvastatin.     

Linkage between cholesterol 7alpha-hydroxylase and high plasma low-density lipoprotein cholesterol concentrations.

Interindividual differences in plasma low-density lipoprotein cholesterol (LDL-C) levels reflect both environmental variation and genetic polymorphism, but the specific genes involved and their relative contributions to the variance in LDL-C are not known. In this study we investigated the relationship between plasma LDL-C concentrations and three genes with pivotal roles in LDL metabolism: the low-density lipoprotein receptor (LDLR), apolipoprotein B (APOB), and cholesterol 7alpha-hydroxylase (CYP7). Analysis of 150 nuclear families indicated statistically significant linkage between plasma LDL-C concentrations and CYP7, but not LDLR or APOB. Further sibling pair analyses using individuals with high plasma LDL-C concentrations as probands indicated that the CYP7 locus was linked to high plasma LDL-C, but not to low plasma LDL-C concentrations. This finding was replicated in an independent sample. DNA sequencing revealed two linked polymorphisms in the 5' flanking region of CYP7. The allele defined by these polymorphisms was associated with increased plasma LDL-C concentrations, both in sibling pairs and in unrelated individuals. Taken together, these findings indicate that polymorphism in CYP7 contributes to heritable variation in plasma LDL-C concentrations. Common polymorphisms in LDLR and APOB account for little of the heritable variation in plasma LDL-C concentrations in the general population.     

DNA polymorphisms of apolipoprotein B and AI/CIII genes and response to gemfibrozil treatment.

Apolipoprotein B XbaI polymorphism and apolipoprotein AI/CIII SstI polymorphism have been found to be associated with variations in serum lipoprotein levels. We investigated whether these gene polymorphisms are involved in determining the lipid-modulating action of gemfibrozil. Of the 221 male subjects with hyperlipidemia studied, 121 responded well to the treatment with more than a 25% reduction in the non-high-density lipoprotein cholesterol level, whereas 100 were nonresponders. Among responders, but not nonresponders, homozygosity for the apolipoprotein B X2 allele (XbaI site present) and heterozygosity for the apolipoprotein AI/CIII S2 allele (SstI site present) were associated with elevated baseline serum low-density lipoprotein cholesterol and triglyceride levels, respectively. However, the hypolipidemic effect of gemfibrozil among the responders was independent of these gene polymorphisms. These data indicate that common polymorphisms of the apolipoprotein B and apolipoprotein AI/CIII gene loci influence serum lipid levels by mechanisms that are amenable to an intervention with gemfibrozil.     

载脂蛋白B基因EcoRI、XbaI、MspI及载脂蛋白AI基因-75bp、+83bp位点多态性与哈萨克族血脂异常的关系

目的:分析载脂蛋白B(apoB)基因EcoRI、XbaI、MspI位点和载脂蛋白AI(apoAI)基因-75bp、+83bp位点多态性与哈萨克族(哈族)人血脂异常的关系。方法:采用聚合酶链式反应-限制性片段长度多态性分析法检测275例哈族血脂异常患者(血脂异常组)和252例哈族血脂正常对照者(对照组)的apoB基因EcoRI、XbaI、MspI位点和apoAI基因-75bp、+83bp位点多态性。检测甘油三酯、血浆总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、apoB、apoAI的水平。结果:(1)各个位点各基因型及等位基因频率在两组之间差异无显著性。(2)血脂异常组和对照组各基因型联合的总体分布不同(χ2=19.26,P<0.05)。E+-/X--/Ms++/M1/M2(联合10)的比率在血脂异常组(45/275)显著高于对照组(22/+-++252,χ2=5.37,P<0.05)。E++/X+-/Ms+-/M1/M2(联合11)的比率在血脂异常组(30/275)显著高于对照组+-++(13/252,χ2=4.94,P<0.05)。(3)血脂异常组中基因型联合10和11(基因型联合10～11)的TC均值显著高于本组中除基因型联合10及11(基因型联合1～9)的均值,apoAI/apoB均值显著低于本组中基因型联合1～9的均值。对照组中基因型联合10～11的apoAI/apoB水平也显著低于本组中基因型联合1～9。(4)E++/X+-/Ms++/M1/M2(基因型联合2)的TC在两组中都分别低于基因型联合10～11,apoAI/apoB在两组+-+-中都分别高于基因型联合10～11。(5)apoAI/apoB无论在血脂异常组还是在对照组都与TC、LDL-C负相关,与HDL-C正相关。结论:apoB基因EcoRI、XbaI、MspI位点和apoAI基因-75bp、+83bp各位点基因型多态联合中,基因型联合10及11与哈族人血脂异常相关。基因型联合2可能是预防血脂异常的因素。其中的机制可能与载脂蛋白基因变异引起apoAI/apoB的改变进而引起血脂的变化有关。     

Factor VII –323 decanucleotide D/I polymorphism in atrial fibrillation: Implications for the prothrombotic state and stroke risk

There are limited data on the influence of genetic polymorphisms in atrial fibrillation (AF) stroke risk. We hypothesized that a functional haemostatic polymorphism, that is, the factor VII ?323 Del/Ins polymorphism, would influence the prothrombotic state associated with AF, as well as stroke risk. Other functional polymorphisms were also tested.

Methods. We performed a cross-sectional study of 119 AF patients, who were compared to 96 patients with stroke secondary to AF. In the first patient group, we analysed plasma prothrombin fragment 1+2 levels (F1+2, an index of thrombin generation) to reflect the prothrombotic state of AF.

Results. AF patients carrying the ?323 Ins allele had lower plasma F1+2 levels (P=0.015). After multivariate analysis adjusted by age, sex and clinical risk factors, advanced age and 807C/T polymorphism of glycoprotein Ia (GPIa) gene were associated with higher risk of ischaemic stroke (OR: 1.06; P=0.003 and OR: 1.91; P=0.025), whilst FVII Ins ?323 allele was associated with lower stroke risk (OR: 0.41; P=0.017).

Conclusion. FVII ?323 Ins allele may modulate the prothrombotic state associated with AF. Despite the small sample size, we found that FVII Ins ?323 allele could be associated with a lower stroke risk in AF, whereas the 807C/T polymorphism may increase the risk.     

中国人群载脂蛋白E基因多态性与他汀类药物疗效关系的Meta分析

目的：评价中国人群载脂蛋白 E(APOE)基因多态性对他汀类药物降脂疗效的影响。方法在数据库中检索,获取 APOE 基因多态性与他汀类药物疗效关系的文献,筛选并对纳入文献进行质量评分和数据提取,使用RevMan 5.3软件进行 Meta 分析。结果ε2等位基因携带者低密度脂蛋白胆固醇(LDL-C)降低水平显著大于ε3ε3基因型(高脂血症组 P <0.05;阿托伐他汀组 P <0.01)和ε4等位基因(冠心病组 P =0.01;阿托伐他汀组 P =0.01)。ε2等位基因总胆固醇(TC)降低水平显著大于ε3ε3基因型(高脂血症组 P <0.01)和ε4等位基因(高脂血症组 P <0.01;冠心病组 P =0.02;阿托伐他汀组 P <0.01)。ε3ε3基因型甘油三酯(TG)降低水平显著大于ε4等位基因(总体 P <0.01;高脂血症组 P =0.03;辛伐他汀组 P =0.03)。ε2等位基因高密度脂蛋白胆固醇(HDL-C)升高水平显著大于ε3ε3基因型(高脂血症组 P =0.02)。结论 APOE 基因多态性与他汀类药物疗效相关,ε2等位基因携带者具有更好的降脂效果。     

Synergistic effect between apolipoprotein E and angiotensinogen gene polymorphisms in the risk for early myocardial infarction

BACKGROUND: Several studies based on different populations worldwide have described an association between cardiovascular diseases and genetic variations in the apolipoprotein E (A:POE), angiotensinogen (A:GT), angiotensin receptor type 1 (A:T1R), and angiotensin-converting enzyme (A:CE) genes. In addition, there is growing evidence of an interaction between hypercholesterolemia and the renin-angiotensin system in the risk for hypertension and atherosclerosis. METHODS: To determine whether the DNA polymorphisms in A:POE (epsilon2, epsilon3, and epsilon4 alleles), A:GT (M235T), A:T1R (1166 A:/C:), and ACE (I:/D:) are associated with early onset of myocardial infarction (MI), we genotyped 220 patients and 200 controls <55 years of age. Patients and controls were males from the same homogeneous Caucasian population. Data concerning hypertension, diabetes, and tobacco consumption were recorded. The lipid profiles of patients and controls were also determined. RESULTS: APOE, ACE, AGT, and AT1R allele and genotype frequencies did not differ between patients and controls. None of these polymorphisms was related to the biochemical values in patients or controls. The frequency of individuals who were both APOE epsilon4 allele carriers and AGT-TT homozygotes was significantly higher in patients than in controls (11% vs 3.5%; P: = 0.0037). In patients, the frequency of epsilon4 carriers was significantly higher (P: <0.00001) in those who were AGT-TT (46%) than those who were AGT-MT/MM (14%). Mean cholesterol was significantly higher in AGT-TT + APOE epsilon34/44 patients than in the TM/MM + epsilon34/44 or TT + epsilon23/33 genotypes (P: = 0. 029). CONCLUSIONS: Our data suggest a synergistic effect between the APOE and AGT polymorphisms and early MI. The increased risk could be mediated in part through higher cholesterol concentrations among individuals who are AGT-TT + APOE epsilon4 allele carriers.     

The presence of apolipoprotein epsilon4 and epsilon2 alleles augments the risk of coronary artery disease in type 2 diabetic patients

OBJECTIVE: It has been suggested that there is a relationship between apolipoprotein E polymorphism and the severity of coronary artery disease in type II diabetes mellitus (T2DM). The current study specifically aimed to examine whether APOE polymorphism in association with serum lipids-lipoproteins level is a risk factor for developing coronary artery disease (CAD) in diabetic patients living in western of Iran. METHODS: The APOE genotypes were detected by PCR-RFLP in 152 angiographically documented diabetic CAD patients, 262 non-diabetic (ND) individuals with CAD and 300 unrelated controls (normal coronary artery cases without diabetes) and serum lipid level was measured enzymatically. RESULTS: The APOE-epsilon4 and epsilon2 allele frequencies were significantly higher in the CAD/T2DM and CAD/ND patients than in the control group (p<0.001). Our study demonstrated a significant association between APOE polymorphism and the level of plasma lipids with CAD/T2DM (p=0.001) and CAD/ND (p=0.026) patients. The CAD subjects with T2DM and ND patients carrying APOE-epsilon4 allele had lower plasma HDL-C level (p<0.001), (p=0.008) but had higher plasma LDL-C (p=0.01), total cholesterol (p=0.002), (p=0.03) and TG (p<0.001), (p=0.042) than that of the APOE-epsilon3 carriers, respectively. However, carriers of APOE-epsilon2 had significantly higher levels of plasma TG only. OR of APOE-epsilon4 and epsilon2 alleles in CAD/T2DM and CAD/ND patients were found to be 2.98 (p=0.001),1.86 (p=0.001), 2 (p=0.001), and 1.65 (p=0.001), respectively. CONCLUSIONS: The major finding of the present case-control study is that T2DM patients carrying APOE-epsilon2 and epsilon4 alleles have a higher risk of developing CAD than ND patients in the western population of Iran, with APOE-epsilon4 being more closely associated with CAD than the APOE-epsilon2 allele. These results indicated that carriers of APOE-epsilon4 allele have a distinct plasma lipids profile and carrier of this allele with low levels of HDL-C and with high levels of LDL-C may be susceptible to CAD and myocardial infarction specially in diabetic patients. This suggests that a therapeutic modality should be considered for these patients.     

ApoE基因多态性与慢性心血管疾病及患者血脂水平的相关性研究

目的分析载脂蛋白E(ApoE)基因多态性与慢性心血管疾病及患者血脂水平的相关性。方法采用基因芯片分析系统及生化分析仪,检测1 414例慢性心血管疾病患者(实验组)和374例健康者(对照组)ApoE基因多态性及血脂水平。结果实验组和对照组ApoE基因型分布构成比比较差异有统计学意义(P0.05),对照组E2/3基因型构成比高于实验组。实验组总胆固醇(TC)、三酰甘油(TG)、低密度脂蛋白胆固醇(LDL-C)水平明显高于对照组,对照组高密度脂蛋白胆固醇(HDL-C)水平明显高于实验组,差异有统计学意义(P0.05)。E2/3基因型实验组患者HDL-C水平明显高于E3/4基因型患者,而E3/4基因型患者TC、LDL-C水平明显高于E2/3基因型患者,差异有统计学意义(P0.05)。不同ApoE基因型在脑梗死、脑出血、高血压、冠心病、2型糖尿病、脂肪肝等患者中的构成比有所差异,E3/4基因型在脑梗死、脑出血、高血压、冠心病、2型糖尿病、脂肪肝患者中所占比例高于E2/3基因型,差异有统计学意义(P0.05)。结论 ApoE基因多态性可能是导致个体血脂水平差异的重要原因之一,也是导致慢性心血管疾病发生、发展的危险因素。     

Association between apolipoprotein E polymorphism and coronary artery disease in the Kermanshah population in Iran

OBJECTIVE: Coronary artery disease (CAD) is the major cause of death in developing countries, such as Iran. The apolipoprotein E gene (APOE) is considered an important genetic determinant of CAD. In this study, the relationship between APOE polymorphism with lipid variation in CAD patients in Kermanshah, Iran was investigated. METHODS: This case-control study consisted of 115 CAD patients who angiographically had at least 30% stenosis and 135 unrelated controls. APOE polymorphism was detected by PCR-RFLP and serum lipid level was measured enzymatically. RESULTS: The APOE-epsilon4 and -epsilon2 allele frequencies were significantly higher in the CAD patients than in the control group (P < 0.001). The CAD patients with epsilon3/epsilon4 genotype had also higher TC (P < 0.001) and LDL-C (P < 0.01) and lower HDL-C (P < 0.03) levels than that of the control group. CONCLUSIONS: APOE-epsilon4 allele is a risk factor for CAD, so that carriers of this allele with high levels of LDL-C may be susceptible to CAD and myocardial infarction.     

Relation of genetic polymorphisms of apolipoprotein E, angiotensin converting enzyme, apolipoprotein B-100, and glycoprotein IIIa and early-onset coronary heart disease.

OBJECTIVE: Apolipoprotein E (APOE) E4, apolipoprotein B-100 (APOB) Q3611 allele, the angiotensin converting enzyme (ACE) deletion (D) allele and glycoprotein IIIa (GP3A) P33 mutant allele are reported to predispose to early-onset coronary heart disease (CHD). These associations were not all confirmed in more recent studies. To determine the impact of these alleles on CHD, we examined the prevalence of these mutations in patients presenting with early-onset CHD and compared them to those manifesting CHD later in life. The delayed-onset was considered a sign of longevity and would serve as a comparative group to assess prevalence of the biochemical and genetic risk factors. METHODS: 300 patients with a history of myocardial infarction or angina pectoris and angiographically documented CHD were studied. Patients were divided into two groups: group 1 (G1 = 150 patients) presenting with these findings under the age of 50 years; while group 2 (G2 = 150 patients) were patients presenting for the first time over the age of 65 years. Prevalence of the alleles of APOE, APOB, ACE and GP3A was assessed by molecular analysis. An association of any of these genotypes with early onset CHD could lead to a higher prevalence in the younger age group. RESULTS AND CONCLUSIONS: None of the suspected alleles namely APOB Q3611 [G1: 10.7% vs. G2: 9.0%, p = 0.57], ACE D (G1: 52.0% vs. G2: 49.7%, p = 0.57), or the GP3A P33 (G1: 17.3% vs. G2: 15.7%; p = 0.58) showed any significant difference between the two groups. Subjects with APOE E4 were more frequent in the younger age group (G1: 18.3% vs. G2: 13.7%; p = 0.047), while APOE E2 was more frequent in G2 (G2: 10.0% vs. G1: 2.7%; p = 0.0002). Multivariate analysis showed an odds ratio of APOE E2 allele in G1 of 0.27 with a confidence interval of 0.10-0.73.     

Candidate gene polymorphisms in cardiovascular disease: a comparative study of frequencies between a French and an Italian population.

A multilocus assay was used to genotype up to 27 variable sites in 15 genes in French and Italian, presumed to be healthy populations (n=1480, n=162, respectively). These genes are involved in lipid metabolism (APOE, APOB, APOC3, CETP, LPL, PON), homocysteine metabolism (CBS, MTHFR), blood viscosity (Fibrinogen, FV), platelet aggregation (GpIIIa), leukocyte adhesion (SELE), and renin-angiotensin system (AT1R, ACE, AGT). Allele frequencies for all the markers were compared between the two populations. Five allele frequencies differed between the two European countries: APOB 71Ile (p < 0.001), SELE 98T (p < 0.001), SELE 128Arg (p < or = 0.01), APOE E4 (p < or = 0.01) and MTHFR 677T (p < or = 0.01), suggesting the existence of a north-south gradient in European allele frequencies. The other allele frequencies : APOC3 -482T, -455C, 1100T, 3175G, 3206G; LPL -93G, 9Asn, 291Ser; CETP 405Val; PON 192Arg; ACE Del; AGT 235Thr; AT1R 1166C; CBS 278Thr, GpIIIa P1A2; Fibrinogen -455A, FV 506Gln and SELE 554Phe, were similar between the two populations. They were also similar to those observed in other European countries.     

Apolipoprotein B gene 3'VNTR polymorphism: association with plasma lipids and coronary heart disease in Han Chinese.

BACKGROUND: Studies that considered polymorphisms within the apolipoprotein B (APOB) gene as risk factors for coronary heart disease (CHD) have reported conflicting results. METHODS: The phenotypic effects of the 3'VNTR polymorphism of the APOB gene on the susceptibility to CHD were investigated in 120 unrelated healthy individuals and 137 CHD patients. The internal structure of APOB gene 3'VNTR alleles was also analyzed by the methods of SspI restriction mapping and DNA sequencing of the allele fragments. RESULTS: In total, 14 segregating alleles and 32 genotypes of APOB gene 3'VNTR were characterized in the pooled total of 257 subjects. The frequency of 3'VNTR-B alleles [hypervariable element (HVE) > or =38)] in the CHD cases was higher than that of the controls (10.95% vs. 5.00%, p<0.05). 3'VNTR-B allele was dependently related to total cholesterol levels (p<0.05). Compared with SS homozygotes, 3'VNTR-B allele carriers were associated with an increased risk of CHD (OR=2.137, 95% CI=1.055-4.328, p=0.0349). No significant differences in the internal structure and sequences of APOB gene 3'VNTR alleles were found between cases and controls. CONCLUSIONS: APOB gene 3'VNTR polymorphism exerts an impact on lipid metabolism and may contribute to the susceptibility to the development of CHD in Han Chinese.     

Genetic determination of plasma lipids and insulin in the Czech population

OBJECTIVES: 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. DESIGN AND METHODS: In 131 men and 154 women, polymorphisms were investigated using PCR. In the same subjects plasma lipid levels and insulin were measured. RESULTS: 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. CONCLUSIONS: 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.     

载脂蛋白E基因多态性与高血压肾损害及肾实质性高血压

目的　探讨载脂蛋白E(ApoE)基因多态性与高血压 (EH)肾损害及肾实质性高血压 (RH)的关系。方法　采用PCR技术 ,对黑龙江地区 4 8例高血压 -肾功能正常病人 (EH -NRF)、4 6例高血压 -肾功能衰竭病人 (EH -CRF)和 5 2例肾实质性高血压 -肾功能正常病人 (RH -NRF)、5 6例肾实质性高血压 -肾功能衰竭病人 (RH -CRF)及 5 0例健康对照者 (NC)的ApoE基因多态性进行检测。结果　共检测出 3种基因型 ,纯合子缺失型 (DD)、纯合子插入型 (II)、杂合子插入 /缺失型 (ID)。EH -NRF组与NC组比较D等位基因及DD基因型差异无显著意义 (P >0 0 5 )。EH -CRF、RH -NRF、RH -CRF组D等位基因及DD基因型频率明显高于EH -NRF、NC组 ,差异有显著意义 (P <0 0 5 ,P <0 0 0 1)。结论　ApoE基因I/D多态性与EH发生无关 ,而与EH并发症呈明显相关 ,可能参与肾损害过程。D等位基因可能是黑龙江地区汉族人肾损害的遗传危险因素 ,但不能用ApoE基因多态性来解释EH ,说明高血压并发尿毒症与尿毒症并发高血压存在不同的遗传基础。     

载脂蛋白E基因多态性与高血压胰岛素抵抗的相关性研究

目的:探讨载脂蛋白E基因多态性与原发性高血压胰岛素抵抗及脂代谢异常的相关性。方法:高血压患者142例,分为胰岛素抵抗组59例和非胰岛素抵抗组83例,采集静脉血,提取DNA,采用基因测序法检测载脂蛋白E基因多态性。结果:高血压胰岛素抵抗患者中E4等位基因频率要明显高于非胰岛素抵抗患者,E2等位基因频率低于非胰岛素抵抗患者。携带E4等位基因者(E3/4+E4/4)空腹血糖、空腹胰岛素、HOMA胰岛素抵抗指数均高于携带E2基因者(E2/2+E2/3),携带E4等位基因总胆固醇、低密度脂蛋白、三酰甘油均明显高于携带E2基因者,而高密度脂蛋白明显低于携带E2基因者。结论:载脂蛋白E基因E4等位基因影响高血压患者胰岛素抵抗程度及脂代谢水平。