Genetic variations of apolipoprotein A5 gene is associated with the risk of coronary artery disease among Chinese in Taiwan

Recently, a T/C polymorphism of the promoter region of the APOA5 gene at position -1131 and a G/T polymorphism at position 553 were found to be associated with increased levels of plasma triglyceride. Triglyceride plays a role in coronary artery disease (CAD), so this case-control study tested for a possible link between these two APOA5 polymorphisms, their common haplotypes and the risk of CAD. The subjects included 211 CAD patients and 677 unrelated controls. A significantly higher level of triglycerides and a lower level of high-density lipoprotein cholesterol (HDL-C) were noted for carriers with -1131C than for non-carriers (P<0.001 and 0.013, respectively) among controls. Plasma triglyceride levels were significantly higher (P=0.014) in controls with genotypes that contained the c.553T allele than in homozygotes for the G allele. Subjects homozygous for the wild-type haplotype had significantly lower triglyceride levels and higher HDL-C levels than subjects with all other haplotype pairs. The -1131C homozygous carriers and c.553T heterozygous carriers were found more frequently in 211 patients with CAD than in the 317 age/sex-matched controls (P=0.008 and 0.023, respectively) in univariate analysis. The significant association between c.553T allele carriers with CAD remained in multivariate regression analysis (OR, 1.79; CI, 1.07-3.00; P=0.028), after adjustments were made for other risk factors. Notably, haplotype analysis further verified that the APOA5 -1131C and c.553T bi-loci haplotype was significantly overpresented in CAD, as compared to the controls. These results indicate that the variants of APOA5 gene modulate plasma triglyceride and may use them to predict CAD susceptibility in Taiwanese Chinese.     

Longitudinal analysis of haplotypes and polymorphisms of the APOA5 and APOC3 genes associated with variation in serum triglyceride levels: the Bogalusa Heart Study

Polymorphisms in the APOC3 and APOA5 genes, from the APOA1/APOC3/APOA4/APOA5 gene cluster on chromosome 11q23, have been associated with interindividual variation in plasma triglycerides. APOA5 polymorphisms implicated include 2 in the promoter region (-1131 T/C and -3 A/G) and 1 in exon 2 (+56 C/G). APOC3 polymorphisms implicated include 1 (SstI) in the 3' untranslated region and 1 (-2854 G/T) in the APOC3-APOA4 intergenic region. We analyzed the associations of haplotypes and multilocus genotypes of these polymorphisms on longitudinal serum triglyceride profiles in 360 African American and 823 white subjects from the Bogalusa Heart Study. Subjects were examined from 2 to 8 times (mean +/- SD, 5.4 +/- 1.3) between 1973 and 1996, at ages ranging from 4 to 38 years, with 1978 observations in African Americans and 4465 in whites. Serum triglycerides were significantly higher among whites across all ages. Allele frequencies differed significantly between African Americans and whites at all but the APOA5 +56 C/G locus. Linkage disequilibrium among the loci was higher in whites and haplotype diversity lower: 6 haplotypes had estimated frequencies of more than 1% in African Americans, 5 in whites. Individually, all polymorphisms except APOC3 -2854 G/T showed significant associations with triglyceride levels in the full sample. However, genotype models including all 5 loci showed significant triglyceride associations for only 3 (APOC3 SstI, APOA5 -1131 T/C, and APOA5 +56 C/G); significant interactions among them indicated their effects were not independent. Neither APOC3 -2854 G/T nor APOA5 -3 A/G had significant effects when the other 3 loci were in the models. The EM algorithm was used to estimate haplotype frequencies and assign haplotype probabilities to individuals, which is conditional on their genotypes; individuals' haplotype probability vectors were then used as predictors in multilevel mixed models of longitudinal triglyceride profiles. Of haplotypes comprising, in order, APOC3 SstI and -2854 G/T and APOA5 -1131 T/C, -3 A/G, and +56 C/G, 3 were significantly associated with higher triglycerides, even after adjusting for multiple tests: GGTAG (P = .002), GTTAG (P < .0001), and CGCGC (P = .0002). Each GGTAG haplotype carried would be expected to raise triglyceride levels (relative to those of GTTAC homozygotes) by approximately 19 mg/dL, each GTTAG haplotype by approximately 15 mg/dL, and each CGCGC haplotype by approximately 7 mg/dL. Haplotypes comprising the 3 loci implicated by genotype analyses (SstI, -1131 T/C, and +56 C/G) were also tested: haplotypes C_C_C and G_T_G significantly raised triglycerides, even after adjustment for multiple comparisons (P < .002 for both), with each copy of C_C_C expected to raise triglycerides by approximately 7 mg/dL and each copy of G_T_G by approximately 15 mg/dL. Overall, our findings support those of others in associating specific polymorphisms and haplotypes in the APOA1/C3/A4/A5 gene cluster with higher serum triglyceride levels. However, the degree to which polymorphisms in the APOC3 and APOA5 genes may be independently associated with triglyceride levels remains to be determined.     

Two independent apolipoprotein A5 haplotypes modulate postprandial lipoprotein metabolism in a healthy Caucasian population

BACKGROUND: Apolipoprotein A5 (APOA5) plays an important role in plasma triacylglycerol (TG) homeostasis. Five polymorphisms (1131T>C, c.-3A>G, c.56C>G, IVS3+476G>A, and c.1259T>C) in the APOA5 gene define three common haplotypes (APOA5*1, APOA5*2, and APOA5*3) in Caucasian individuals. Our aim was to determine whether these haplotypes could modulate the postprandial response in young healthy males. DESIGN AND METHODS: Eighty-eight APO E3/3 volunteers [67 with (-1131T and 56C) APOA5*1 haplotype, 12 with (-1131C and 56C) APOA5*2 haplotype, and nine with (-1131T and 56G) APOA5*3 haplotype] underwent a fat load test consisting of the consumption of 1 g of fat per kilogram body weight and 60,000 IU vitamin A. Blood samples were taken at time 0, at every hour until the sixth hour, and at every 2.5 h until the 11th hour. Total plasma cholesterol (C) and TG, and C, TG, apolipoprotein B-100, apolipoprotein B-48, and retinyl palmitate in lipoprotein fractions were determined. RESULTS: Subjects with the APOA5*2 and APOA5*3 haplotypes had a higher area under the curve of total plasma TG (P = 0.03), large TG-rich lipoprotein (TRL)-TG (P = 0.02), small TRL-TG (P = 0.04), small TRL-C (P = 0.04), large TRL-C (P = 0.03), and small apolipoprotein B100 (P = 0.04) than subjects with the APOA5*1 haplotype. CONCLUSIONS: Our findings show that the presence of the APOA5*2 and APOA5*3 haplotypes in the APOA5 gene is associated with a higher postprandial response that could be involved in the higher risk of coronary heart disease associated with the 56G and -1131C alleles.     

Associations of the apolipoprotein A1/C3/A4/A5 gene cluster with triglyceride and HDL cholesterol levels in women with type 2 diabetes

The apolipoprotein gene cluster (APOA1/C3/A4/A5) was recently associated with triglycerides (TG) and high-density lipoprotein cholesterol (HDL-C) in non-diabetic population. Little is known whether the variations in these genes affect lipid homeostasis in patients with type 2 diabetes. We examined the associations of 10 polymorphisms at APOA1/C3/A4/A5 gene cluster with blood lipids among 902 diabetic women. A linkage disequilibrium (LD) breakdown was observed between APOA5 and other genes. APOA5 S19W was associated with significantly higher fasting TG levels (P=0.001). Two common haplotypes encompassing four APOA5 polymorphisms (SNP1, SNP2, S19W, and SNP3) were associated with 35.6 mg/dL (haplotype 2212, APOA5*2, P=0.016) and 57.8 mg/dL (haplotype 1121, APOA5*3, P=0.0002) higher fasting TG levels compared with the most common (haplotype 1111, APOA5*1), respectively. Adjustment for age, BMI, and other covariates did not appreciably change such associations. In addition, APOC3 promoter polymorphism -455T/C showed significant associations with fasting TG levels (P=0.006), whereas APOA4 +347T/A showed significant associations with lower levels of HDL-C (P=0.017). Our results indicate that the variability in APOA1/C3/A4/A5 gene cluster may affect TG and HDL levels in women with type 2 diabetes.     

Variant in the glucokinase regulatory protein (GCKR) gene is associated with fatty liver in obese children and adolescents

Recently, the single nucleotide polymorphism (SNP) identified as rs1260326, in the glucokinase regulatory protein (GCKR), was associated with hypertriglyceridemia in adults. Because accumulation of triglycerides in hepatocytes represents the hallmark of steatosis, we aimed to investigate whether this variant might be associated with fatty liver (hepatic fat content, HFF%). Moreover, because recently rs738409 in the PNPLA3 and rs2854116 in the APOC3 were associated with fatty liver, we explored how the GCKR SNP and these two variants jointly influence hepatosteatosis. We studied 455 obese children and adolescents (181 Caucasians, 139 African Americans, and 135 Hispanics). All underwent an oral glucose tolerance test and fasting lipoprotein subclasses measurement by proton nuclear magnetic resonance. A subset of 142 children underwent a fast gradient magnetic resonance imaging to measure the HFF%. The rs1260326 was associated with elevated triglycerides (Caucasians P = 0.00014; African Americans P = 0.00417), large very low-density lipoprotein (VLDL) (Caucasians P = 0.001; African Americans, P = 0.03), and with fatty liver (Caucasians P = 0.034; African Americans P = 0.00002; and Hispanics P = 0.016). The PNPLA3, but not the APOC3 rs2854116 SNP, was associated with fatty liver but not with triglyceride levels. There was a joint effect between the PNPLA3 and GCKR SNPs, explaining 32% of HFF% variance in Caucasians (P = 0.00161), 39.0% in African Americans (P = 0.00000496), and 15% in Hispanics (P = 0.00342). CONCLUSION: The rs1260326 in GCKR is associated with hepatic fat accumulation along with large VLDL and triglyceride levels. GCKR and PNPLA3 act together to convey susceptibility to fatty liver in obese youths.     

Apolipoprotein A5 gene polymorphisms are associated with non-alcoholic fatty liver disease

Background: Several studies have reported that apolipoprotein A5(APOA5) is involved in the development of non-alcoholic fatty liver disease(NAFLD). However, no research has been performed regarding the association between APOA5 polymorphisms and the risk of NAFLD. This study aimed to explore the association between APOA5 gene polymorphisms and NAFLD in a Chinese Han population.Methods: Genotypes of the SNPs(rs10750097, rs1263173, rs17120035, rs3135507 and rs662799) of APOA5 in 232 NAFLD patients and 188 healthy controls were determined using polymerase chain reaction(PCR)analysis. Clinical characteristics were measured using biochemical methods.Results: The five single nucleotide polymorphisms(SNPs)(rs10750097, rs1263173, rs17120035, rs3135507 and rs662799) of APOA5 showed no significant association with NAFLD(P 0.05). The rs10750097 with G allele showed a higher serum level of alkaline phosphatase(ALP) compared with C allele in overall series and NAFLD patients(P 0.05). The rs1263173(A/A) carriers showed a higher level of glucose compared to the non-carriers in overall series(P 0.05). The rs17120035(T/T) carriers showed a lower plasma TG level in overall series and NAFLD patients(P 0.05), and the rs662799(G/G) carriers showed higher levels of plasma triglyceride(TG), ALP, and lower level of high-density lipoprotein(HDL) compared to non-carriers in NAFLD patients(P 0.05). No significant difference were observed on the clinic parameters of APOA5 rs3135507(T/T) carriers in both group of overall series and NAFLD patients(P 0.05).Conclusions: The five SNPs(rs10750097, rs1263173, rs17120035, rs3135507 and rs662799) of APOA5 gene are not associated with the risk of NAFLD in the Chinese Han population. The genotypes of rs10750097(G/G), rs1263173(A/A), rs17120035(T/T), and rs662799(G/G) performed a significant effect on clinic characteristics in overall series and NAFLD patients, indicating that these polymorphisms may be associated with NAFLD.     

载脂蛋白A5-1131T>C(rs662799)多态性与中国汉族非心源性缺血性脑卒中的关联研究

目的探讨中国汉族人群中载脂蛋白A5(APOA5)-1131T>C(rs662799)多态性与缺血性脑卒中的关系。方法选择1119例缺血性脑卒中患者和1027例健康居民作为对照,采用Taqman-MGB探针对载脂蛋白A5-1131T>C位点基因多态性进行检测,并通过文献检索,对符合标准的文献进行荟萃分析,全面探讨中国人群中载脂蛋白A5-1131T>C多态性与缺血性脑卒中的关系。结果研究表明载脂蛋白A5-1131T>C单核苷酸多态性不同等位基因频率和基因型在缺血性脑卒中组和正常对照组分布未见显著统计学差异。校正传统危险因素logistic回归分析显示在隐性模型下,APOA5-1131T>C与血栓性脑卒中相关(p=0.036),荟萃分析结果表明APOA5-1131C等位基因与中国汉族人群脑卒中发生的危险性无相关关系(OR=1.18,95%CI=0.90-1.54)。结论在中国人群中,APOA5-1131T>C多态性与缺血性脑卒中无相关性。     

Association between DNA variant sites in the apolipoprotein A5 gene and coronary heart disease in Chinese

The recently discovered apolipoprotein A5 ( APOA5 ) gene has been shown to be important in determining plasma triglyceride levels, a major cardiovascular disease risk factor. We searched for possible associations of the APOA5 gene polymorphisms S19W and -1131T>C with coronary heart disease (CHD) in a Chinese population. A total of 483 Chinese CHD patients and 502 control non-CHD subjects were genotyped by polymerase chain reaction-restriction fragment length polymorphism for these 2 single nucleotide polymorphisms. We found that the minor allele 19W was observed only in CHD patients and not in controls, with allelic frequencies of 0.047 and 0.000, respectively ( P < .000001), and the minor allele -1131C was significantly higher in CHD patients than in controls (0.391 vs 0.299, P < .0001). These results suggest that both the S19W and -1131T>C variations in the APOA5 gene are associated with the CHD and appear to be 2 genetic risk factors for CHD susceptibility in Chinese. Moreover, we found that triglyceride levels were significantly higher in -1131C carriers than in -1131T subjects of the control group and that high-density-lipoprotein cholesterol was decreased in -1131C carriers among CHD patients.     

Associations of polymorphisms in the apolipoprotein A1/C3/A4/A5 gene cluster with familial combined hyperlipidaemia in Hong Kong Chinese

BackgroundFamilial combined hyperlipidaemia (FCH) is the most common genetic dyslipidaemia associated with coronary artery disease. Single nucleotide polymorphisms (SNPs) and haplotypes in the APOA1/C3/A4/A5 gene cluster are associated with FCH in Caucasians and with elevated triglycerides (TG) in various ethnic groups. We examined these associations with FCH in Hong Kong Chinese.MethodsFifty-six Chinese FCH patients and 176 unrelated controls were studied. Thirteen SNPs in the APOA1/C3/A4/A5 cluster were genotyped.ResultsFour alleles in APOA5 were associated with FCH (P < 0.001). The ?1131T > C (rs662799) and ?3A > G (rs651821) SNPs in APOA5 were in almost complete linkage disequilibrium (LD, r² = 0.99), and their minor alleles were more frequent (P < 0.001) in FCH than controls (0.60 vs. 0.24). The odds ratio (OR) for FCH was 6.2 (95% CI, 2.6–14.8) and 6.1 (2.6–14.6) per copy of ?1131C and ?3G, respectively, and 24.6 (8.4–72.0) and 24.4 (8.4–70.9) in ?1131C and ?3G homozygotes, respectively, as compared to wild-type homozygotes. The 1891T > C (rs2266788) SNP was in LD (r² = 0.68) with ?1131T > C and ?3A > G, and the minor allele was more frequent in FCH than controls (0.42 vs. 0.19, P < 0.001). The 553G > T (rs2075291) nonsynonymous variant was also associated with FCH (0.15 vs. 0.04, P = 0.001) and, along with ?3A > G (or ?1131T > C) and 1891T > C, contributed to haplotypes predicting FCH. The two tightly linked SNPs, ?1131T > C and ?3A > G polymorphism were significantly associated with lipid traits in all subjects combined, with variant homozygous subjects having higher TG and LDL-C and lower HDL-C levels.ConclusionsSome common polymorphisms and haplotypes in APOA5 are closely associated with FCH in Hong Kong Chinese, and these differ from those found in Caucasians.     

A genetic variant c.553G > T in the apolipoprotein A5 gene is associated with an increased risk of coronary artery disease and altered triglyceride levels in a Chinese population

Elevation in plasma triglycerides (TG) has been widely accepted as a coronary artery disease (CAD) risk predictor. Recently, a new apolipoprotein playing an important role in TG metabolism named apolipoprotein AV (apoAV) was discovered, which is encoded by the APOA5 gene. Several single nucleotide polymorphisms (SNPs) of APOA5 associated with increased TG concentrations have been identified. We here report that a recently identified genetic variant, c.553G>T in the APOA5 gene which causes a substitution of a cysteine for a glycine residue at amino acid residue 185(G185C) is also associated with increased TG levels. To investigate the association between this genetic variation and the risk of CAD, a case-control study comprising 232 patients with CAD and 302 controls from the same area of China was performed. The minor allele frequencies of c.553G > T for the CAD and control groups were 7.76 and 3.97%, respectively (P = 0.008). In both the CAD and control groups, the T allele carriers had higher serum TG levels than homozygous carriers of the major G allele (CAD group: 2.67 +/- 1.48 mmol/l versus 1.95 +/- 1.02 mmol/l, P = 0.021; controls: 2.31 +/- 1.20 mmol/l versus 1.68 +/- 0.95 mmol/l, P = 0.002). After adjustment for age, gender, body mass index, smoking status, glucose and presence of hypertension, the odds ratio (OR) for CAD in the T allele carriers was 2.089 (95% CI = 1.140-3.830, P = 0.017), in comparison to the individuals without the T allele. These results suggest that the APOA5 c.553G > T polymorphism is an important predictor for hypertriglyceridemia and CAD.     

冠心病患者载脂蛋白A5和载脂蛋白C3基因多态性的研究

目的研究中国北方汉族人群中载脂蛋白A5基因(APOA5)-1131F／C、56C／G多态性和载脂蛋白C3基因(APOC3)-482C／T多态性与冠心病的关系。方法采用聚合酶链反应．限制性片段长度多态性(PCR-RFLP)结合聚丙烯酰胺凝胶电泳(PAGE)技术检测了312例经冠状动脉造影确诊的冠心病患和317例健康对照APOA5-1131T／C、56C／G和APOC3-482C／T多态性基因型和等位基因的分布,同时采用生化方法检测了研究对象的血脂水平。结果冠心病组APOA5-1131C等位基因频率明显高于对照组(39．9％比33．3％,P=0．02)。CC纯合子患冠心病的风险是TT纯合子的1.93倍(95％CI：1．12～3．32),且通过Logistie回归分析发现该相关性独立于性别、年龄、体重指数、吸烟史、高血压糖尿病患病史及血清TC、HDK-C、IDL-C水平;冠心病组CC纯合子的TG水平明显高于TC杂合子,而TT纯合子TG水平最低。虽然APOA5-1131T／C和APOC3—482C／T多态性存在连锁不平衡,但前的作用与后无关。结论APOA5-1131T／C基因多态性对人群血清TG水平有影响,APOA5-1131C等位基因可能与我国北方汉族人冠心病的发生相关联。     

Association of apolipoprotein A5 gene polymorphisms and serum lipid levels

Background and aims

Apolipoprotein (APO) A5 gene polymorphisms have been associated with increased plasma triglyceride (TG), but the results are inconsistent. The present study was undertaken to detect the APOA5 gene polymorphisms and their associations with lipid profiles in the Guangxi Hei Yi Zhuang and Han populations.

Methods and results

Genotyping of the APOA5 −1131T>C, c.553G>T and c.457G>A was performed in 490 subjects of Hei Yi Zhuang and 540 participants of Han Chinese aged 15-89 years. The −1131C allele frequency was higher in high total cholesterol (TC) than in normal TC subgroups in both the ethnic groups (P < 0.05). The c.553T allele frequency was higher in high TG than in normal TG subgroups (P < 0.01), in high APOB than in normal APOB subgroups in Hei Yi Zhuang (P < 0.05), or in females than in males in Han (P < 0.01). The c.457A allele frequency in Han was higher in high TG than in normal TG subgroups, in low APOA1 than in normal APOA1 subgroups, in males than in females, or in normal APOB than in high APOB subgroups (P < 0.05-0.01). The levels of TC, low-density lipoprotein cholesterol and APOB in Hei Yi Zhuang were correlated with −1131T>C genotype or allele, and the levels of TG were associated with c.553G>T genotype (P < 0.05). The levels of TG, APOA1 and APOB in Han were correlated with c.457G>A genotype or allele, and the levels of TC were associated with −1131T>C allele (P < 0.05).

Conclusions

The differences in the lipid profiles between the two ethnic groups might partly result from different APOA5 gene-environmental interactions.     

The -1131 T>C and S19W APOA5 gene polymorphisms are associated with high levels of triglycerides and apolipoprotein C-III, but not with coronary artery disease: an angiographic study

High plasma concentrations of triglycerides (TG) and apolipoprotein C-III (ApoC-III) are well-known risk factors for cardiovascular disease. Two variants of the recently discovered APOA5, 1131 C>T and S19W, have been associated with hypertriglyceridemia, whereas their relation with coronary artery disease (CAD) remains controversial. Nine hundred and thirteen angiografically defined patients (669 CAD and 244 CAD-free) were genotyped for APOA5 -1131 C>T and S19W polymorphisms. Carriership of the APOA5 -1131 C allele was identified, by multiple linear regression models, as a significant independent predictor for both TG (standardized beta-coefficient=0.112; p=0.010) and ApoC-III variability (standardized beta-coefficient=0.113; p=0.013). Similarly, APOA5 19W allele carriership was a significant independent predictor for both TG (standardized beta-coefficient=0.113; p=0.007) and ApoC-III variability (standardized beta-coefficient=0.088; p=0.045). Despite the association with at-risk lipid profile, no significant difference was detected in the distribution of both APOA5 gene polymorphisms between subjects with or without CAD. Moreover, homozygous carriers of the APOC3 -455 C, another TG- and ApoC-III raising variant, showed a significant increased risk for CAD (OR 1.90 with 95% CI 1.002-3.62; p=0.049; by multiple logistic regression). Different genotypes, i.e., APOA5 and APOC3 variants, may lead to similar biochemical phenotypes, namely hypertriglyceridemia, but to contrasting clinical phenotypes such as the presence of angiographically proven CAD.     

载脂蛋白A5 c553G/T基因多态性与急性冠状动脉综合征的相关性

目的:探讨载脂蛋白A5(APOA5)c553G/T基因多态性与急性冠状动脉综合征(ACS)的相关性。方法:以254例ACS患者(ACS组)和229名健康对照者(对照组)为研究对象,用聚合酶链反应限制性片段长度多态性分析G/T位点多态性的分布,并用酶法检测血脂水平。结果:APOA5c553T等位基因在ACS组中的分布频率明显高于对照组(P<0.05),对ACS具有独立的影响(OR=2.344,P<0.01)。2组APOA5c553TT纯合子及GT杂合子个体比GG纯合子个体具有高TG、TC、LDL水平和低HDL水平。结论:APOA5c553G/T基因多态性与血浆TG、TC、HDL和LDL具有相关性。APOA5c553T等位基因可能为ACS的危险因素。     

Association of glucokinase regulatory gene polymorphisms with risk and severity of non-alcoholic fatty liver disease: an interaction study with adiponutrin gene

Background

Recent genome-wide association studies demonstrated an association between single nucleotide polymorphisms (SNPs) on the glucokinase regulatory gene (GCKR) with hepatic steatosis. This study attempted to investigate the association of GCKR rs780094 and rs1260326 with susceptibility to non-alcoholic fatty liver disease (NAFLD) and its severity.

Methods

The genotypes were assessed on 144 histologically confirmed NAFLD patients and 198 controls using a Sequenom MassARRAY platform.

Results

The GCKR rs1260326 and rs780094 allele T were associated with susceptibility to NAFLD (OR 1.49, 95 % CI 1.09–2.05, p = 0.012; and OR 1.51, 95 % CI 1.09–2.09, p = 0.013, respectively), non-alcoholic steatohepatitis (NASH) (OR 1.55, 95 % CI 1.10–2.17, p = 0.013; and OR 1.56, 95 % CI 1.10–2.20, p = 0.012, respectively) and NASH with significant fibrosis (OR 1.50, 95 % CI 1.01–2.21, p = 0.044; and OR 1.52, 95 % CI 1.03–2.26, p = 0.038, respectively). Following stratification by ethnicity, significant association was seen in Indian patients between the two SNPs and susceptibility to NAFLD (OR 2.64, 95 % CI 1.28–5.43, p = 0.009; and OR 4.35, 95 % CI 1.93–9.81, p < 0.0001, respectively). The joint effect of GCKR with adiponutrin rs738409 indicated greatly increased the risk of NAFLD (OR 4.14, 95 % CI 1.41–12.18, p = 0.010). Histological data showed significant association of GCKR rs1260326 with high steatosis grade (OR 1.76, 95 % CI 1.08–2.85, p = 0.04).

Conclusion

This study suggests that risk allele T of the GCKR rs780094 and rs1260326 is associated with predisposition to NAFLD and NASH with significant fibrosis. The GCKR and PNPLA3 genes interact to result in increased susceptibility to NAFLD.     

Interactions of the apolipoprotein A5 gene polymorphisms and alcohol consumption on serum lipid levels

Objectives Apolipoprotein(Apo) A5 gene poly-morphisms and alcohol consumption have been associated with increased serum triglyceride(TG) levels,but little is known about their interactions on serum lipid levels.The present study was undertaken polymorphismsand alcohol consumption on serum lipid levels.Methods A total of 516 unrelated nondrinkers and 514 drinkers aged 15 -89 were randomly selected from our previous stratified randomized cluster samples.Genotyping of the ApoA5was performed by polymerase chain reaction and restriction fragment length polymorphism,and then confirmed by direct sequencing.Interactions of the ApoA5alcohol consumption were assessed by using a cross-product term between genotypes and the aforementioned factor.Results The levels of total cholesterol (TC),TG,high-density lipoprotein cholesterol(HDL-C), ApoA1 and ApoB were higher in drinkers than in nondrinkers (P<0.05-0.001).The genotypic and allelic frequencies of the three single nucleotide polymorphisms(SNPs) were not different between the two groups.The levels of TG in non-drinkers, and TC,TG,low-density lipoprotein cholesterol (LDL-C)and ApoB in drinkers were different among the three -1131T>C genotypes(P<0.05-0.001).The -1131C allele carriers had higher serum TC,TG,LDL-C and ApoB levels than the allele noncarriers.The levels of TG,HDL-C and ApoB in nondrinkers,and TG and HDL-C in drinkers were different between the two c.553G>T genotypes(P<0.05-0.01).The C.553T allele carriers had higher serum TG and ApoB levels,and lower HDL-C levels than the allele noncarriers.Serum lipid levels in nondrinkers were not different among the three c.457G>A genotypes(P<0.05 for all), but the levels of HDL-C,LDL-C,ApoA1 and ApoB in drinkers were different between the GG and GA/AA geno-types (P<0.05-0.001).The C.457A allele carriers had lower serum HDL-C,LDL-C,ApoAl and ApoB levels than the allele noncarriers.We also observed four haplotypes:G-G-T, G-G-C,G-A-T,and T-G-C with frequencies ranging from 0.06 to 0.87,representing 100%o     

冠心病痰证与载脂蛋白A5 c.553G>T基因多态性的关系研究

目的探讨载脂蛋白A5(APOA5)c.553G>T基因多态性与冠心病痰证的关系。方法运用聚合酶链反应-限制性片段长度多态性分析技术(PCR-RFLP)对湖南地区58例冠心病痰证、51例冠心病非痰证、73例非冠心病痰证患者及74名健康人的APOA5c.553G>T基因型进行检测,同时检测所有研究对象的血脂、血压及体质量指数。结果 256例受检者中,APOA5c.553G>T位点GG型221例(86.33%),GT型35例(13.67%),TT型0;G等位基因频率93.16%,T等位基因频率6.84%。c.553GT型血清TG水平明显高于GG型。病例-对照研究提示c.553T等位基因是冠心病痰证发生的危险因素,但多因素Logistic回归分析不支持c.553T是上述病证发生的独立危险因素。结论 APOA5c.553G>T基因多态性不是冠心病痰证的独立危险因素,c.553GT基因型可能与血清三酰甘油水平升高有关。     

Plasma apoAV levels are markedly elevated in severe hypertriglyceridemia and positively correlated with the APOA5 S19W polymorphism

OBJECTIVE: The recently discovered apoAV is hypothesized to affect triglyceride metabolism by stimulating the lipolysis of triglycerides in VLDL and chylomicrons. We set out to determine the association between increased serum TG levels, plasma apoAV levels, and polymorphism of the APOA5 gene, with specific emphasis on the APOA5 S19W variation. This mutation alters the endoplasmic reticulum signal peptide and is hypothesized to impair apoAV secretion into the circulation. METHODS AND RESULTS: Two haplotype-tagging APOA5 polymorphisms, APOA5 S19W and APOA5 -1131T>C and plasma apoAV levels were determined in a population of patients with severe hypertriglyceridemia (HTG). As compared to a random control population, the allele frequencies of the APOA5 S19W and -1131T>C rare variants were significantly increased in HTG patients. Furthermore, the HTG population exhibited markedly elevated plasma apoAV levels that were positively correlated with serum TG levels. Plasma apoAV levels were positively correlated with occurrence of the APOA5 S19W rare variant. CONCLUSIONS: The increased allele frequencies of the APOA5 S19W and -1131T>C rare variants in the HTG population are in agreement with previous reports. Our data show a positive correlation between apoAV and TG levels. Moreover the finding of a positive association between apoAV levels and the APOA5 S19W rare variant is in disagreement with the hypothesis that this variant is poorly secreted.     

Haplotype analysis of the apolipoprotein A5 gene in patients with the metabolic syndrome

Background and aimsIn recent studies, the T-1131C variant of apolipoprotein A5 (APOA5) gene was found to confer a risk for metabolic syndrome (MS). Here we determined four haplotype-tagging polymorphisms (T-1131C, IVS3+G476A, T1259C, and C56G), and studied the distribution of the naturally occurring major haplotype profiles in MS.Methods and resultsA total of 343 MS patients and 284 controls were genotyped using PCR–RFLP methods. Both in MS and control groups, we confirmed the already known association of –1131C, IVS3+473A and 1259C minor alleles with elevated triglyceride levels. The prevalence of the APOA5*2 haplotype (the combination of T-1131C, IVS3+G476A and T1259C SNPs) was 13.1% in MS patients, and 4.9% in controls (p < 0.001); multiple logistic regression analysis revealed that this haplotype confers risk for the development of MS (OR = 2.880; 95% CI: 1.567–5.292; p = 0.001). We also observed a gender effect: in males a more prominent degree of susceptibility was found. Contrary to the APOA5*2 haplotype, the prevalence rate of APOA5*4 (determined by the T-1131C SNP alone) did not differ between MS patients and controls. We identified a novel haplotype, designated here as APOA5*5 (1259C allele alone); which appears to be protective against MS.ConclusionOur results refined the role of SNP T-1131C in the development of MS. The susceptibility nature of this SNP is limited to the APOA5*2 haplotype, while in APOA5*4 haplotype it did not confer a risk for the disease. In addition, as our current data suggest, the novel APOA5*5 haplotype can confer protection against MS.     

Apolipoprotein A5 gene IVS3+G476A allelic variant confers susceptibility for development of ischemic stroke

BACKGROUND: T-1131C, T1259C and IVS3+G476A are naturally occurring variants of the apolipoprotein A5 (APOA5) gene and their possible impact on the development of ischemic stroke was investigated in the present study. METHODS AND RESULTS: PCR-RFLP assays were used to determine the distributions of the APOA5 alleles in small-vessel, large-vessel and mixed subgroups of 378 patients and in 131 stroke-free control subjects. Increased triglyceride levels were found in subjects carrying -1131C, 1259C, IVS3+476A alleles in all stroke groups and in the controls. The -1131C and IVS3+476A alleles, but not the T1259C variant, showed significant accumulation in all stroke subgroups. Logistic regression analysis adjusted for age, gender, body mass index, total cholesterol level, ischemic heart disease, hypertension, diabetes mellitus, smoking-and drinking habits revealed that the IVS3+476A allele represents independent susceptibility factor for stroke (odds ratio for small-vessel: 4.748; large-vessel: 3.905; mixed: 2.926; overall: 3.644 at 95% confidence interval; p<0.05), we could also confirm the previously verified pathogenic role of the -1131C variant. CONCLUSIONS: All of the 3 APOA5 variants are associated with elevated triglycerides, but only the -1131C and the IVS3+476A alleles confer risk for all types of ischemic stroke; such an association could not be detected for the 1259C allele.