Association between apolipoprotein B gene polymorphisms and the risk of coronary heart disease (CHD): an update meta-analysis

Dietary acid load adopts the effect of ApoB ins/del genetic variant (rs11279109) on obesity trait, cardiovascular markers, lipid profile, and serum leptin level among patients with diabetes: a cross-sectional study

ApoB insertion/deletion (ins/del) genetic variant (rs11279109) is thought to be related to cardio-metabolic markers and obesity. This association has the potential to be modified by dietary patterns. Since the majority of studies concerned the role of dietary acid load (DAL) or ApoB in type 2 diabetes mellitus (T2DM) and its complications independently, and due to the insufficient data regarding the possible interactions between ApoB genetic variants and DAL on anthropometric and metabolic markers, we aimed to study the interaction between this genetic variant and dietary acid load (DAL) on cardio-metabolic markers, along with leptin among Iranian individuals with T2DM. 700 T2DM patients were randomly recruited. A validated semi-quantitative food frequency questionnaire was used for DAL calculation including potential renal acid load (PRAL) and net-endogenous acid production (NEAP). The polymerase chain reaction was used for genotyping the ApoB ins/del (rs11279109). The general linear model was applied to find the interactions in the crude and adjusted models. Patients with del/del genotype (rs11279109) with high PRAL intake have lower low-density lipoprotein cholesterol (LDL-C) (Pinteraction = 0.004), LDL/HDL ratio (Pinteraction = 0.02), total cholesterol (TC) (Pinteraction = 0.04), triglyceride (TG) (Pinteraction = 0.04), leptin (Pinteraction = 0.04) and interleukin-18 (IL-18) (Pinteraction = 0.04). Moreover, the interaction of gene and DAL in the PRAL method on TG concentration (P = 0.04), waist circumference (WC) (P = 0.04), and LDL/HDL ratio (P = 0.04) were significant. Eventually, a positive relationship was observed between the presence of the del/del genotype (rs11279109) and higher levels of TG, TC, LDL-C, IL-18, and LDL/HDL, in individuals with lower adherence to DAL, after adjusting for various covariates. Further studies are needed to investigate and confirm these findings.

Could Aneurysm and Atherosclerosis-Associated MicroRNAs (miR 24-1-5p, miR 34a-5p, miR 126-5p, miR 143-5p, miR 145-5p) Also Be Associated with Coronary Artery Ectasia?

Background: Coronary artery ectasia (CAE), known for localized or diffuse excessive dilatation of the coronary artery, has an unknown etiology, but it has been reported that the underlying cause may be atherosclerosis and genetic changes that may affect the arterial lumen. MicroRNAs have been shown to have an effect in aneurysm diseases and are known to contribute to vascular development and atherosclerosis. The purpose of this study was to investigate whether they are also associated with CAE. Methods: This cross-sectional study consisted of 25 patients with CAE and 25 subjects with normal coronary arteries. Blood was collected and miRNA expression was detected using the Rotor-GeneQ real-time polymerase chain reaction cycler (Qiagen) to investigate expression levels of miR-24-1-5p, miR-34a-5p, miR-126-5p, miR-143-5p, and miR-145-5p. Results: Demographic variables of CAE (mean age 59.5 ± 1.7; 12 women) and controls (mean age 57.2 ± 2.1; 16 women) were similar. miR-126-5p (p = 0.014) and miR-145-5p (p = 0.003) levels were found to be <2-fold upregulated in CAE compared to controls; miR-143-5p also showed upregulation, but it was not significant (p = 0.078). Conversely, miR-24-1-5p (p = 0.032) levels were downregulated in CAE compared to controls. miR-34a-5p was also downregulated, but this was not considered significant (p = 0.185). Conclusions: According to our study findings, miR-126-5p, miR-145-5p, and miR-24-1-5p may be associated with CAE. These microRNAs could be of diagnostic and therapeutic significance for further studies of CAE involving abnormal angiogenesis and vascular disorders and potentially serve as useful biomarkers.

The APOB rs693 polymorphism impacts the lipid profile of Brazilian older adults

The apolipoprotein B (APOB) gene contains several polymorphic sites described as risk modifiers for cardiovascular events. The objective of this study was to verify the association of the classic APOB Xba I polymorphism (rs693) with atherosclerotic risk factors in a segment of the Brazilian elderly population considering their usual dietary intake. Clinical and biochemical characteristics as well as total caloric and fat intake data were determined from 644 elderly individuals. Polymorphism analysis was performed by conventional polymerase chain reaction followed by enzyme restriction. Statistical analyses compared measures and proportions according to different APOB genotypic combinations. Statistically significant association was found between Xba I polymorphism and serum LDL, total cholesterol, and total lipid levels, with important elevations among T homozygotes compared to the other genotypes. There was homogeneity in all other parameters analyzed (including intake pattern), with a tendency for reduced levels of circulating apolipoprotein B among TT individuals. Our results pointed out that genetic variation in APOB affected the lipemic profile of elderly individuals in a context not biased by diet, generating a pattern suggestive of secretory disorder of lipoprotein particles, with possible implication in atherosclerotic risk.

Global genetic diversity of human apolipoproteins and effects on cardiovascular disease risk

Abnormal plasma apolipoprotein levels are consistently implicated in CVD risk. Although 30% to 60% of their interindividual variability is genetic, common genetic variants explain only 10% to 20% of these differences. Rare genetic variants may be major sources of the missing heritability, yet quantitative evaluations of their contribution to phenotypic variability are lacking. Here, we analyzed whole-genome and whole-exome sequencing data from 138,632 individuals across seven major human populations to present a systematic overview of genetic apolipoprotein variability. We provide population-specific frequencies of 38 clinically important apolipoprotein alleles and identify further 6,875 genetic variants, 33% of which are novel and 98.7% of which are rare with minor allele frequencies <1%. We predicted the functional impact of rare variants and found that their relative importance differed drastically between genes and among ethnicities. Importantly, we validated the clinical relevance of multiple variants with predicted effects by leveraging association data from the CARDIoGRAM (Coronary Artery Disease Genomewide Replication and Meta-analysis) and Global Lipids Genetics consortia. Overall, we provide a consolidated overview of population-specific apolipoprotein genetics as a valuable data resource for scientists and clinicians, estimate the importance of rare genetic variants for the missing heritability of apolipoprotein-associated disease traits, and pinpoint multiple novel apolipoprotein variants with putative population-specific impacts on serum lipid levels.

Increased Risk of the APOB rs11279109 Polymorphism for CHD among the Kuwaiti Population

Background

Coronary heart disease (CHD) is among the leading causes of death in Kuwait. This case-control study investigated the genetic association of APOB rs11279109 with CHD in Kuwaitis.

Methods

The polymorphism was genotyped in 734 Kuwaiti samples by direct amplification. Statistical analysis with genetic modeling was used to assess its association with CHD.

Results

A statistically significant association (P < 0.001) between the rs11279109 DD genotype (OR: 2.43, CI: 1.34–4.41) with CHD was observed. A codominant genetic model revealed a 2.69 risk increase (CI: 1.57–4.61) for the DD genotype (P = 0.009) independent of age, sex, BMI, smoking, hypercholesterolemia, and ethnicity suggesting APOB rs11279109 as an indicator for the increased risk of CHD.

Conclusion

The DD genotype may explain molecular mechanisms that underline increased LDL oxidation leading to arthrosclerosis. The findings emphasize the need to identify genetic markers specific to the CHD patient ethnic group in order to improve prognosis and help in early diagnosis and prevention.

Associations of the APOB rs693 and rs17240441 polymorphisms with plasma APOB and lipid levels: a meta-analysis

BACKGROUND

The associations of the apolipoprotein B gene (APOB) rs693 and rs17240441 polymorphisms with plasma levels of APOB and lipids have been widely explored, but the results were inconclusive. This meta-analysis aimed to clarify the associations of the rs693 and rs17240441 polymorphisms with fasting APOB and lipid levels.

METHODS

Sixty-one studies (50,018 subjects) and 23 studies (8425 subjects) were respectively identified for the rs693 and rs17240441 polymorphisms by searching in PubMed, Google Scholar, Web of Science, Cochrane Library, Wanfang, VIP and CNKI databases. The following information was collected for each study: first author, age, gender, ethnicity, health condition, sample size, genotyping, lipid assay method, mean and standard deviation or standard error of APOB and lipid variables by genotypes. A dominant model was used for this meta-analysis.

RESULTS

The carriers of the rs693 variant allele (T) had higher levels of APOB [standardized mean difference (SMD) = 0.26, 95% confidence interval (CI) = 0.16-0.36, P < 0.01], triglycerides (TG) (SMD = 0.12, 95% CI = 0.05-0.20, P < 0.01), total cholesterol (TC) (SMD = 0.24, 95% CI = 0.17-0.30, P < 0.01) and low-density lipoprotein cholesterol (LDL-C) (SMD = 0.22, 95% CI = 0.14-0.30, P < 0.01), and lower levels of high-density lipoprotein cholesterol (HDL-C) (SMD = -0.06, 95% CI = -0.11-0.01, P = 0.01) than the non-carriers. The carriers of the rs17240441 deletion allele had higher levels of APOB (SMD = 0.13, 95% CI = 0.06-0.20, P < 0.01), TC (SMD = 0.17, 95% CI = 0.07-0.26, P < 0.01) and LDL-C (SMD = 0.15, 95% CI = 0.07-0.23, P < 0.01) than the non-carriers.

CONCLUSIONS

The rs693 polymorphism is significantly associated with higher levels of APOB, TG, TC and LDL-C, and lower levels of HDL-C. The rs17240441 polymorphism is significantly associated with higher levels of APOB, TC and LDL-C. Further studies are needed to elucidate the underlying mechanisms.

The impact of APOA5, APOB, APOC3 and ABCA1 gene polymorphisms on ischemic stroke: Evidence from a meta-analysis

BACKGROUND AND AIMS

Genetic studies have been reported on the association between APOA5, APOB, APOC3 and ABCA1 gene polymorphisms and ischemic stroke, but results remain controversial. Hence, this meta-analysis aimed to infer the causal relationships of APOA5 (rs662799, rs3135506), APOB (rs693, rs1042031, rs1801701), APOC3 (rs4520, rs5128, rs2854116, rs2854117) and ABCA1 rs2230806 with ischemic stroke risk.

METHODS

A systematic review was performed for all the articles retrieved from multiple databases, up until March 2017. Data were extracted from all eligible studies, and meta-analysis was carried out using RevMan 5.3 and R package 3.2.1. The strength of association between each studied polymorphism and ischemic stroke risk was measured as odds ratios (ORs) and 95% confidence intervals (CIs), under fixed- and random-effect models.

RESULTS

A total of 79 studies reporting on the association between the studied polymorphisms and ischemic stroke risk were identified. The pooled data indicated that all genetic models of APOA5 rs662799 (ORs = 1.23-1.43), allelic and over-dominant models of APOA5 rs3135506 (ORs = 1.77-1.97), APOB rs1801701 (ORs = 1.72-2.13) and APOB rs1042031 (ORs = 1.66-1.88) as well as dominant model of ABCA1 rs2230806 (OR = 1.31) were significantly associated with higher risk of ischemic stroke. However, no significant associations were observed between ischemic stroke and the other five polymorphisms, namely ApoB (rs693) and APOC3 (rs4520, rs5128, rs2854116 and rs2854117), under any genetic model.

CONCLUSIONS

The present meta-analysis confirmed a significant association of APOA5 rs662799 CC, APOA5 rs3135506 CG, APOB rs1801701 GA, APOB rs1042031 GA and ABCA1 rs2230806 GG with increased risk of ischemic stroke.

Danshen (Salvia miltiorrhiza) Compounds Improve the Biochemical Indices of the Patients with Coronary Heart Disease

Danshen was able to reduce the risk of the patients with coronary heart disease (CHD), but the mechanism is still widely unknown. Biochemical indices (lipid profile, markers of renal and liver function, and homocysteine (Hcy)) are closely associated with CHD risk. We aimed to investigate whether the medicine reduces CHD risk by improving these biochemical indices. The patients received 10 Danshen pills (27 mg/pill) in Dashen group, while the control patients received placebo pills, three times daily. The duration of follow-up was three months. The serum biochemical indices were measured, including lipid profiles (LDL cholesterol (LDL-C), HDL-C, total cholesterol (TC), triglycerides (TG), apolipoprotein (Apo) A, ApoB, ApoE, and lipoprotein (a) (Lp(a))); markers of liver function (gamma-glutamyl transpeptidase (GGT), total bilirubin (TBil), indirect bilirubin (IBil), and direct bilirubin (DBil)); marker of renal function (uric acid (UA)) and Hcy. After three-month follow-up, Danshen treatment reduced the levels of TG, TC, LDL-C, Lp(a), GGT, DBil, UA, and Hcy (P < 0.05). In contrast, the treatment increased the levels of HDL-C, ApoA, ApoB, ApoE, TBil, and IBil (P < 0.05). Conclusion. Danshen can reduce the CHD risk by improving the biochemical indices of CHD patients.