Meta-based evidence for apolipoprotein E epsilon2/epsilon3/epsilon4 polymorphism in association with hypertension among Chinese

E2/E3 and E3/E4 Genotypes of the Apolipoprotein E are Associated with Higher Risk of Diabetes Mellitus in Patients with Hypertension

Objective

Apolipoprotein E (APOE) plays an important role in the lipid metabolism. APOE polymorphisms have been implicated in susceptibility to diabetes mellitus (DM). However, the association between APOE polymorphisms and the risk of DM among the hypertensive patients remains unclear. Our study aimed to evaluate this relationship to provide clues for further developing DM in hypertensive patients.

Methods

The study included 808 hypertensive patients with DM and 1226 hypertensive patients without DM as controls. The APOE 388T>C (rs429358) and 526C>T (rs7412) polymorphisms were genotyped by polymerase chain reaction (PCR) - microarray. Differences in APOE genotypes between subjects and controls were compared. To analyze the relationship between APOE genotypes and DM risk, multiple logistic regression analysis was performed after adjusting for gender, age, smoking history, and drinking history.

Results

The APOE E2/E4, E3/E3 genotype and ε2, ε3 allele frequency had significant difference between DM patients and controls (P<0.05). The DM patients with ɛ4 allele had lower level in high-density lipoprotein cholesterol (HDL-C) and higher level in apolipoprotein B (ApoB) than those with ɛ2 allele. The results of logistic regression analysis indicated that the APOE genotype of E2/E3 with adjusted OR=1.350 (95% Cl=1.009-1.806, P=0.043) and E3/E4 with adjusted OR=1.325 (95% Cl=1.034-1699, P=0.026) may be independent risk factors for DM.

Conclusion

APOE E2/E3 and E3/E4 genotypes may be risk factors for developing diabetes mellitus in hypertensive patients.

Association between eNOS rs1799983 polymorphism and hypertension: a meta-analysis involving 14,185 cases and 13,407 controls

BACKGROUND

Essential hypertension is a complex disease determined by the interaction of genetic and environmental factors, eNOS is considered to be one of the susceptible genes for hypertension. Our study aimed to evaluate the association between eNOS rs1799983 polymorphism and hypertension, and to provide evidence for the etiology of hypertension.

METHODS

Case-control studies of eNOS rs1799983 polymorphism and hypertension were included by searching PubMed, Embase, Web of Science, Medline, Scopus, WanFang datebase, Vip datebase, and CNKI database according to PRISMA guideline. Eligible data were extracted and pooled, and were analyzed using R software based on five different genetic models.

RESULTS

A total of 60 eligible articles involving 14,185 cases and 13,407 controls were finally selected. We found significant association between eNOS rs1799983 polymorphism and hypertension under any genetic model (T vs G: OR = 1.44, 95% CI 1.26-1.63; GT vs GG: OR 1.34, 95% CI 1.18-1.52; TT vs GG: OR 1.80, 95% CI 1.41-2.31; GT + TT vs GG: OR 1.42, 95% CI 1.25-1.63; TT vs GG + GT: OR 1.68, 95% CI 1.35-2.08; GT vs GG + TT: OR 1.24, 95% CI 1.11-1.40).

CONCLUSIONS

We found that eNOS rs1799983 polymorphism is associated with the increased risk of hypertension under any genetic model. Moreover, investigations of gene-gene and gene-environment interactions are needed to give more insight into the association between eNOS rs1799983 polymorphism and hypertension.

Association between ApoE polymorphism and hypertension: A meta-analysis of 28 studies including 5898 cases and 7518 controls

Hypertension is one of the most common chronic diseases, constituting an independent risk factor for many diseases. Our study aimed to evaluate the association between apolipoprotein E (ApoE) genetic polymorphism and hypertension, and to provide evidence for the etiology of hypertension. Case-control studies of ApoE polymorphism and hypertension, which were included in PubMed, Embase, Web of Science, Medline, WanFang, Vip, and CNKI information databases, were selected and evaluated according to criteria of inclusion and exclusion. Eligible data were extracted and pooled, and were analyzed and assessed using Stata 12.0. Random-effect models were used when heterogeneity existed in between-study, and fixed-effect models were applied otherwise. A total of 28 studies that consisted of 5898 cases with hypertension and 7518 controls were selected. Alleles and genotypes of ApoE between cases and controls were compared. For ApoE alleles, we observed the contrast of ApoE ε2 versus ε3 allele yielded a pooled OR of 0.99 (95% CI: 0.87-1.11; P = 0.823), whereas the contrast of ε4 versus ε3 allele yielded a pooled OR of 1.95 (95% CI: 1.50-2.54; P < 0.001). For ApoE genotypes, compared with ε3/ε3 genotype, genotypes (ε2/ε2 and ε2/ε3) showed a possible association with hypertension (OR = 0.88; 95% CI: 0.79-0.99; P = 0.033), and genotypes (ε3/ε4 and ε4/ε4) had a 2.08-fold risk of developing hypertension (OR = 2.08; 95% CI: 1.58-2.74; P < 0.001). There is the association between ApoE polymorphism and hypertension: the genotypes carrying ε2 allele may be a protective factor, and the ApoE ε4 allele and the genotypes carrying ε4 allele may be risk factors for hypertension.

Age-related trends of blood pressure levels by apolipoprotein E genotype: the Bambuì Cohort Study of Ageing (1997-2008)

The role of apolipoprotein E (apoE) polymorphisms in regulating blood pressure (BP) is still not clear. The aim of this study was to examine longitudinal changes in BP levels by apoE genotypes in a population-based prospective cohort of elderly subjects, and explore interactions with plasma lipids and uric acid. Subjects whose apoE genes had been genotyped at baseline (1408, representing 80.8% of all the elderly residents in Bambuì city, south-eastern Brazil; age range 60-95 years) were included in the analysis. Repeated BP measurements were obtained in four waves. Multi-level random-effects pattern-mixture models were used to evaluate the age-related BP trajectories, accounting for non-ignorable dropouts/deaths and handling heterogeneities as random parameter variations. Subjects with the ɛ4/4 genotype and high levels of low-density lipoprotein cholesterol had higher systolic BP levels at 60 years of age than those with the other genotypes (154.5 vs. 133.2 mm Hg, P=0.020), but this was not the case among the older subjects. Systolic BP increased more rapidly with age in the ɛ2 carriers, leading to significantly higher levels among the oldest. This relationship seemed to be modulated by uric acid levels, as it was present in the subjects with the ɛ2/3 genotype and high uric acid levels, and in those with the ɛ2/4 genotype and low or normal uric acid levels. The differences in systolic BP between the genotypes were age dependent, and the shift between the ɛ4 and ɛ2 alleles suggest that these alleles are involved in the different mechanisms leading to increased BP in middle-aged and elderly subjects.

The association between apolipoprotein E gene polymorphisms and essential hypertension: a meta-analysis of 45 studies including 13,940 cases and 16,364 controls

The apolipoprotein E single-nucleotide polymorphisms are among the potential candidate genes that may serve as modulators in susceptibility to essential hypertension. In an effort to clarify earlier inconclusive results, we performed a meta-analysis of population-based case-control genetic association studies. Random-effects methods were applied on summary data in order to combine the results of the individual studies. We identified in total 45 studies, including 13 940 hypertensive cases and 16 364 controls. The contrast of E4 carriers versus non-carriers yielded an overall odds ratio (OR) of 1.16 (95% confidence interval (CI): 1.02, 1.31), whereas the contrast of E4 allele versus the others in a subtotal of 6617 cases and 7330 controls, yielded an OR of 1.39 (95% CI: 1.12, 1.72). There was moderate evidence of publication bias in both contrasts, which was eliminated after excluding studies not in Hardy-Weinberg equilibrium. Subgroup analyses revealed that significant estimates arose from studies on Asian populations, as opposed to the Caucasian ones. Furthermore, no evidence of publication bias was demonstrated in the comparisons within this subgroup. Our results are consistent with recent meta-analyses but show that the association is weaker than that has been previously demonstrated. Further studies are needed in order to fully address questions about the etiological mechanism of the particular association, as well as to study the effect in populations of African descent.

ApoE gene polymorphism and vascular dementia in Chinese population: a meta-analysis

Vascular dementia is the second common cause of dementia, only second to Alzheimer's disease in later life. The Apolipoprotein E (ApoE) gene polymorphism as a risk factor in vascular dementia has been suggested, but direct evidence from genetic association studies remains inconclusive even in Chinese population. Therefore, we performed this meta-analysis in order to evaluate the relationship between ApoE gene polymorphism and susceptibility to vascular dementia in Chinese population by pooling data from all relevant case-control studies published domestically and abroad from January 1990 to May 2011. 18 case-control studies were selected. Meta-analysis results showed that the pooled OR value of vascular dementia subjects in Chinese population with ε4 allele carriers was 2.07 [95% CI (1.69, 2.53)], and the pooled OR value of vascular dementia subjects with E4/E4 genotype was 3.34 [95% CI (1.89, 5.88)]. These results suggest that ApoE polymorphism is significantly associated with susceptibility to vascular dementia in Chinese population. The subject with at least one ε4 allele or E4/E4 genotype has higher risk suffering from vascular dementia than others.