Angiotensin-converting enzyme insertion/deletion polymorphism has no effect on the risk of atherosclerotic stroke or hypertension

Angiotensin-converting enzyme gene insertion/deletion polymorphism and risk of ischemic stroke complication among patients with hypertension in the Ethiopian population

Background

Ischemic stroke is a complicated, multifaceted condition brought on by a confluence of vascular, environmental, and genetic variables. The burden of ischemic stroke is currently rising in terms of death, morbidity, and disability worldwide. Genetic variables also play significant roles in the pathophysiology of hypertension and ischemic stroke in addition to the greatest effects of demographic, clinical, and behavioral risk factors. The key functional variation of the ACE gene that has drawn the most interest is the ACE I/D variant. Even though the ACE gene I/D polymorphism has been widely studied, the findings of investigations on the involvement of this polymorphism in ischemic stroke were contradictory and provide conflicting data. The goal of this study was to look into the effect of the ACE gene I/D polymorphism on the risk of ischemic stroke in patients with hypertension.

Methods

A hospital-based case-control study was carried out in 36 cases of patients with hypertensive IS and 36 age- and sex-matched healthy controls. Clinical and biochemical parameters were measured to assess the associated risk factors. The DNA was isolated from blood samples, and the ACE I/D genotypes were identified using polymerase chain reaction and analyzed by agarose gel electrophoresis.

Results

The ACE-DD genotype (OR = 3.71, 95% CI = 1.02-13.5; P < 0.05) and D allele (OR = 2.07, 95% CI = 1.06-4.03; P < 0.05) were significantly more common in patients than in controls, indicating that it is a risk factor for the development of ischemic stroke in hypertensive individuals.

Conclusion

There is a significant correlation between the ACE gene I/D polymorphism and the development of ischemic stroke in patients with a history of hypertension in the Ethiopian population.

Analysis of the Pattern, Alliance and Risk of rs1799752 (ACE I/D Polymorphism) with Essential Hypertension

Studies in spontaneously hypertensive rat had revealed an elevated level of ACE gene expression in the tissues and is substantiated by experimental clinical studies for a positive correlation between ACE I/D polymorphism and hypertension. Aim: To determine whether the polymorphic variant of ACE gene in intron 16 confers susceptibility to essential hypertension. I/D polymorphism at the locus intron 16 of the ACE gene were amplified from the genomic DNA of the total 571 (hypertensive patients, n: 279; controls, n: 292) participants using polymerase chain reaction and gel electrophoresis methods and were examined in a case-control approach. Suitable descriptive statistics was used for different variables. Result revealed significant heterogeneity under the allele (p: 0.0002) and genotype (p: 0.0001) contrast in hypertensive patients than in normal controls, with an increased frequency of D allele (62.72%; p < 0.0001; OR: 1.8144; 95% CI: 1.4327-2.2979) and DD genotype (41.93%; p: < 0.0001). A significant association was found in the DD variant with disease phenotype (p: 0.0018, 95% CI: 1.3303-3.4907; OR: 2.1549; Table 31) and is substantiated by the data of multivariate analysis, demonstrating a statistically significant increase in odds of hypertension with the ACE D/D genotype (OR: 2.09; 95% CI: 1.24-2.91). Conspicuously, subgroup analysis by gender did not change this pattern of results. Albeit the allele distribution resulted in a higher frequency of the D/D genotype in the cases than controls, testing genetic equilibrium between the observed and expected genotypes using Hardy-Weinberg equilibrium showed ACE gene variants were confirming to the law in hypertensive as well as in non-hypertensive participants. I/D polymorphism in the angiotensin-I-converting enzyme gene at the 16th intron can be useful for outcome predictions during diagnostic processes can be implicated in an individual's propensity for hypertension and thus implies that genetic variants of ACE I/D might serve as a predictor for the susceptibility to hypertension.

Association Between the Angiotensin-Converting Enzyme I/D Polymorphism and Risk of Cerebral Small Vessel Disease: A Meta-Analysis Based on 7186 Subjects

INTRODUCTION

Cerebral small vessel disease (CSVD) causes a quarter of all strokes and is the most common pathology underlying vascular dementia. However, the mechanism of CSVD remains unclear. Numerous studies have investigated whether the angiotensin-converting enzyme (ACE) intersection/deletion (I/D) polymorphism influences the risk of CSVD, but the results are controversial.

METHODS

We searched English and Chinese databases and calculated the odds ratio (OR) and 95% confidence interval (CI) to examine the existence of genetic associations between the ACE I/D polymorphism and the risk of CSVD. All relevant studies were screened and meta-analyzed using Review Manager 5.4.

RESULTS

A total of 27 studies involving 7,186 subjects were identified for the meta-analysis. The results of five genetic models showed a significantly increased risk of CSVD (allelic, OR=1.30; recessive, OR=1.41; dominant, OR=1.34; homozygous, OR=1.55 and heterozygous OR=1.22) in the overall analysis. Furthermore, in subgroup analysis, increased CSVD risks were also observed in Asian and Caucasian populations. We also found no relationship between ACE I/D and leukoaraiosis (LA) in patients with lacunar infarction (LI).

CONCLUSION

The ACE I/D polymorphism was positively associated with CSVD in both populations. However, this polymorphism did not increase the risk of LA in LI patients.

Promoter methylation changes in ALOX12 and AIRE1: novel epigenetic markers for atherosclerosis

BACKGROUND

Atherosclerosis is the main cause of cardiovascular diseases such as ischemic stroke and coronary heart disease. Gene-specific promoter methylation changes have been suggested as one of the causes underlying the development of atherosclerosis. We aimed to identify and validate specific genes that are differentially expressed through promoter methylation in atherosclerotic plaques. We performed the present study in four steps: (1) profiling and identification of gene-specific promoter methylation changes in atherosclerotic tissues; (2) validation of the promoter methylation changes of genes in plaques by comparison with non-plaque intima; (3) evaluation of promoter methylation status of the genes in vascular cellular components composing atherosclerotic plaques; and (4) evaluation of promoter methylation differences in genes among monocytes, T cells, and B cells isolated from the blood of ischemic stroke patients.

RESULTS

Upon profiling, AIRE1, ALOX12, FANK1, NETO1, and SERHL2 were found to have displayed changes in promoter methylation. Of these, AIRE1 and ALOX12 displayed higher methylation levels in plaques than in non-plaque intima, but lower than those in the buffy coat of blood. Between inflammatory cells, the three genes were significantly less methylated in monocytes than in T and B cells. In the vascular cells, AIRE1 methylation was lower in endothelial and smooth muscle cells. ALOX12 methylation was higher in endothelial, but lower in smooth muscle cells. Immunofluorescence staining showed that co-localization of ALOX12 and AIRE1 was more frequent in CD14(+)-monocytes than in CD4(+)-T cell in plaque than in non-plaque intima.

CONCLUSIONS

Promoter methylation changes in AIRE1 and ALOX12 occur in atherosclerosis and can be considered as novel epigenetic markers.

ACE-Triggered Hypertension Incites Stroke: Genetic, Molecular, and Therapeutic Aspects

Stroke is the second largest cause of death worldwide. Angiotensin converting enzyme (ACE) gene has emerged as an important player in the pathogenesis of hypertension and consequently stroke. It encodes ACE enzyme that converts the inactive decapeptide angiotensin I to active octapeptide, angiotensin II (Ang II). Dysregulation in the expression of ACE gene, on account of genetic variants or regulation by miRNAs, alters the levels of ACE in the circulation. Variable expression of ACE affects the levels of Ang II. Ang II acts through different signal transduction pathways via various tyrosine kinases (receptor/non-receptor) and protein serine/threonine kinases, initiating a downstream cascade of molecular events. In turn these activated molecular pathways might lead to hypertension and inflammation thereby resulting in cardiovascular and cerebrovascular diseases including stroke. In order to regulate the overexpression of ACE, many ACE inhibitors and blockers have been developed, some of which are still under clinical trials.

Blood and CSF biomarkers in brain subcortical ischemic vascular disease: Involved pathways and clinical applicability

Vascular dementia is the second most common type of dementia after Alzheimer’s disease (AD). Subcortical ischemic vascular disease refers to a form of vascular cognitive impairment characterized by the presence of diffuse white matter hyperintensities (WMHs) and multiple lacunar infarcts. These neuroimaging findings are mainly caused by cerebral small-vessel disease (cSVD) and relate to aging and cognitive impairment, but they can also be silent and highly prevalent in otherwise healthy individuals. We aimed to review studies on blood and cerebrospinal fluid (CSF) markers related to the presence of WMHs and lacunar infarcts that have been conducted in the past in large population-based studies and in high-risk selected patients (such as those with vascular risk factors, vascular cognitive impairment, or AD). Relevant associations with the presence and progression of cSVD have been described in the blood for markers related to inflammatory processes, endothelial damage and coagulation/fibrinolysis processes, etc. Also, different combinations of CSF markers might help to differentiate between etiologic types of dementia. In the future, to translate these findings into clinical practice and use biomarkers to early diagnosis and monitoring vascular cognitive impairment would require the replication of candidate markers in large-scale, multicenter, and prospectively designed studies.

Angiotensin converting enzyme (I/D) gene polymorphism contributes to ischemic stroke risk in Caucasian individuals: a meta-analysis based on 22 case-control studies

BACKGROUND

Stroke is a multifactorial disease in which genetic factors play an important role. Previous studies associated angiotensin converting enzyme (ACE) (insertion/deletion, I/D) gene polymorphism with ischemic stroke risk in Caucasian individuals reported conflicting results. The purpose of this study was to evaluate the association between ACE (I/D) gene polymorphism and ischemic stroke risk by a meta-analysis.

METHODS

The related studies were searched in MEDLINE, EMBASE and HuGEnet databases. The odds ratios (ORs) and corresponding 95% confidence intervals (CIs) for ischemic stroke risk associated with this polymorphism were estimated using fixed-effect or random-effects model. Twenty-two studies (5528/5081 cases/controls) were eligible in our meta-analysis.

RESULTS

Overall, statistical associations of the ACE (I/D) polymorphism with ischemic stroke risk were found in dominant model (DD + ID versus II) : OR = 1.21, 95% CI = (1.06,1.38), P = 0.006, recessive model (DD versus ID + II): OR = 1.28, 95% CI = (1.05,1.55), P = 0.01, and homozygote comparison (DD versus II): OR = 1.37, 95% CI = (1.14,1.65), P = 0.001 for Caucasians. When stratifying according to stroke subtypes, there were similarly significant differences for small vessel disease in dominant model (DD + ID versus II) : OR = 1.44, 95% CI = (1.01,2.05), P = 0.04, recessive model (DD versus ID + II): OR = 1.30,95% CI = (1.09,1.55), P = 0.004, and homozygote comparison (DD versus II): OR = 1.44, 95% CI = (1.15,1.80), P = 0.001.

CONCLUSION

This analysis suggests that the ACE (I/D) polymorphism may be a risk factor for ischemic stroke, genotype DD of ACE could increase the risk of ischemic stroke in Caucasians. Subgroup analyses indicate that stroke subtypes may be a genetic risk factor of ischemic stroke, and there might be a greater genetic liability with small vessel disease.

ACE-II genotype and I allele predicts ischemic stroke among males in south India

Two hundred ischemic stroke patients and 193 age and sex matched healthy controls were studied for the presence of Angiotensin Converting Enzyme Insertion/Deletion (ACE I/D) gene polymorphism. The PCR studies revealed that ACE 'II' (OR = 2.055; p = 0.004) genotype and 'I' (OR = 1.411; p = 0.018) alleles were significantly associated with IS patients. Gender specific analysis revealed a strong association of 'II' (OR = 2.044; p = 0.014) genotype and 'I' (OR = 1.531; p = 0.011) allele with male sex. Classification of patients based on TOAST criteria, revealed a significant association for 'II' genotype (OR = 1.713; p = 0.043) and 'I' (OR = 1.382; p = 0.039) allele in LVD patients only. When the data was stratified based on age and sex, a statistically significant association was observed for ACE 'II' genotype (OR = 2.288; p = 0.006) and 'I' allele (OR = 1.395; p = 0.054) in IS male patients of > 50 years of age. The ACE 'D' allele was found to be increased in controls (OR = 0.709; p = 0.018) than IS patients. Multivariate logistic regression analysis showed that smoking and diabetes were the most powerful independent risk factor in LVD type of stroke. Thus, we presented here an evidence for a strong association of ACE 'II' genotype and 'I' allele compounded by factors such as smoking and diabetes among south Indian IS patients.

Angiotensin-converting enzyme gene polymorphisms and hypertension in occupational noise exposure in Egypt

BACKGROUND

The gene-environment interaction in the pathogenesis of hypertension has not been extensively studied in occupational noise.

OBJECTIVES

The aim of this study was to determine the relationship between noise and hypertension in Egyptian workers, the interaction of angiotensin-converting enzyme (ACE) gene polymorphisms as modifiers, and the possible relationship between noise hearing impairment and hypertension.

METHODS

Study subjects were divided into two groups depending on noise exposure level. The control group (n = 161) was exposed to noise intensity <85 dB and the exposed group (n = 217) was exposed to noise intensity ≧85 dB. A polymerase chain reaction was used to differentiate the various genotypes of ACE insertion/deletion (I/D) and ACE G2350A.

RESULTS

Noise significantly increased the likelihood of hypertension. Carriers of the genotypes AG, GG, and DD were vulnerable to hypertension on noise exposure. No association between hypertension and hearing impairment or noise-induced hearing loss (NIHL) was found.

CONCLUSION

Our results support the association between ACE gene polymorphisms and occurrence of hypertension in noise-exposed workers.

Association between the ACE I/D polymorphism and risk of ischemic stroke: an updated meta-analysis of 47,026 subjects from 105 case-control studies

BACKGROUND

The association between the angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphism and risk of ischemic stroke (IS) remains controversial and ambiguous. To clarify this association, a large meta-analysis was performed.

METHODS

Electronic databases in both English and Chinese were used to identify relevant studies (updated in February 2014). Odds ratios (ORs) and 95% confidence intervals (95% CIs) were used to describe the strength of the association.

RESULTS

One hundred and fifty eligible studies, including 18,258 IS cases and 28,768 controls, were identified. Meta-analysis of these studies pointed to a significant association between the ACE I/D polymorphism and IS risk: (D vs. I: OR=1.354, 95% CI=1.272-1.440, P<0.001; DD vs. II: OR=1.755, 95% CI=1.561-1.973, P<0.001; ID vs. II: OR=1.178, 95% CI=1.098-1.263, P<0.001; DD vs.

ID/II

OR=1.535, 95% CI=1.399-1.684, P<0.001; DD/ID vs. II: OR=1.353, 95% CI=1.251-1.463, P<0.001). Subgroup analysis revealed a significantly elevated risk among Asians, but with borderline statistical significance among Caucasians.

CONCLUSION

This meta-analysis indicated that the ACE I/D polymorphism may be a genetic susceptibility factor for IS, especially among Asians, but with borderline statistical significance for Caucasians. Further investigations are needed to validate our conclusions.

Association study of angiotensin converting enzyme gene polymorphism with elderly diabetic hypertension and lipids levels

OBJECTIVE

To investigate the relationship between angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and diabetic essential hypertension in elderly population.

METHODS

Polymerase chain reaction (PCR) technique was used in 260 elderly normal control patients, 205 elderly hypertensive patients and 138 elderly diabetic hypertensive patients to detect the I/D polymorphism in ACE gene.

RESULTS

DD genotype frequency (0.352) and D allele frequency (0.543) in elderly hypertensive patients were higher than those in the normal control patients. DD genotype (0.421) and D allele frequency (0.579) in elderly diabetic hypertensive patients were significantly higher than those in the control patients (0.133 and 0.250). The differences of DD genotype and D allele frequency between the elderly hypertensive patients and the elderly diabetic hypertensive patients were not significant (P > 0.05).

CONCLUSION

ACE gene deletion is a risk factor for hypertension but is not a risk factor for diabetes in elderly population.

Associations of ACE gene insertion/deletion polymorphism, ACE activity, and ACE mRNA expression with hypertension in a Chinese population

Background

The present study was designed to explore the association of angiotensin converting enzyme (ACE) gene insertion/deletion (I/D, rs4646994) polymorphism, plasma ACE activity, and circulating ACE mRNA expression with essential hypertension (EH) in a Chinese population. In addition, a new detection method for circulating ACE mRNA expression was explored.

Methods

The research was approved by the ethics committee of Zhejiang Provincial Center for Disease Prevention and Control. Written informed consent was obtained prior to the investigation. 221 hypertensives (cases) and 221 normotensives (controls) were interviewed, subjected to a physical examination, and provided blood for biochemical and genetic tests. The ACE mRNA expression was analyzed by real time fluorescent quantitative Reverse Transcription PCR (FQ-RT-PCR). We performed logistic regression to assess associations of ACE I/D genotypes, ACE activity, and ACE mRNA expression levels with hypertension.

Results

The results of the multivariate logistic regression analysis showed that the additive model (ID, DD versus II) of the ACE genotype revealed an association with hypertension with adjusted OR of 1.43(95% CI: 1.04-1.97), and ACE ID genotype with adjusted OR of 1.72(95% CI: 1.01-2.92), DD genotype with adjusted OR of 1.94(95% CI: 1.01-3.73), respectively. In addition, our data also indicate that plasma ACE activity (adjusted OR was 1.13(95% CI: 1.08-1.18)) was significantly related to hypertension. However, the plasma ACE mRNA expressions were not different between the cases and controls.

Conclusion

ACE I/D polymorphism and ACE activity revealed significant influence on hypertension, while circulating ACE mRNA expression was not important factors associated with hypertension in this Chinese population. The detection of circulating ACE mRNA expression by FQ-RT-PCR might be a useful method for early screening and monitoring of EH.

ACE I/D and eNOS E298D gene polymorphisms in Saudi subjects with hypertension

BACKGROUND

Hypertension has a multifactorial background based on genetic and environmental interactive factors.

OBJECTIVES

We aimed to test for the association of the angiotensin-converting enzyme (ACE) and endothelial nitric oxide synthase (eNOS) gene polymorphisms with hypertension.

SUBJECTS AND METHODS

Participants included 120 Saudi patients with hypertension and 250 normal healthy controls. For all participants, DNA was processed for characterization of ACE I/D and eNOS E298D gene polymorphisms.

RESULTS

Hypertensive cases showed a significantly higher frequency of the ACE mutant D allele carriage (98.3% vs. 92.4%, p = 0.028, OR = 4.8). Cases with hypertension associated with diabetes and obesity showed 100% mutant D allele carriage. Regarding the eNOS E298D polymorphism, the frequency of the mutant D allele carriage was only observed to be higher among cases with hypertension associated with diabetes and obesity, in comparison with controls, yet not reaching statistical significance (41.2% vs. 34%, p > 0.05).

CONCLUSIONS

There is increased frequency of ACE and eNOS mutant allele carriage among Saudi patients affected with hypertension, particularly if accompanied by obesity and diabetes.

Angiotensin-converting enzyme insertion/deletion polymorphism contributes to ischemic stroke risk: a meta-analysis of 50 case-control studies

Background

Many studies have investigated the association between the angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and risk of ischemic stroke. However, the evidence is inadequate to draw robust conclusions because most studies were generally small and conducted in heterogeneous populations. To shed light on these inconclusive findings, we conducted a large meta-analysis of studies relating the ACE I/D polymorphism to the risk of ischemic stroke.

Methods

Relevant studies were identified by searching PubMed and Embase through February 2012 and by reviewing the references of retrieved articles. We included studies that reported odds ratio (OR) with 95% confidence interval (CI) for the association between this polymorphism and ischemic stroke risk.

Results

Fifty independent publications, with 10 070 stroke cases and 22 103 controls, were included. The results indicated that the DD homozygote carriers had a 37% higher risk of ischemic stroke when compared with the homozygotes II and heterozygote ID [odds ratio (OR) = 1.37, 95% confidence interval (CI): 1.22–1.53]. Subgroup analyses indicated that this higher risk was more pronounced among Asians, hospital-based studies, and small vessel disease (SVD). Potential publication bias may exist, but correction for this bias using a formal statistical method did not materially alter the combined risk estimate.

Conclusion

The results of our meta-analysis indicate that the D allele of ACE I/D polymorphism is a low-penetrance susceptibility marker of ischemic stroke.

Rat Ace allele variation determines susceptibility to AngII-induced renal damage

INTRODUCTION

Ace b/l polymorphism in rats is associated with differential tissue angiotensin-converting enzyme (ACE) expression and activity, and susceptibility to renal damage. Same polymorphism was recently found in outbred Wistar rat strain with b allele accounting for higher renal ACE, and provided a model for studying renin-angiotensin-aldosterone system (RAAS) response behind the innate high or low ACE conditions.

METHODS

We investigated the reaction of these alleles on chronic angiotensin II (AngII) infusion. Wistar rats were selected to breed male homozygotes for the b (WU-B) or l allele (WU-L) (n = 12). For each allele, one group (n = 6) received AngII infusion via an osmotic minipump (435 ng/kg/min) for 3 weeks. The other group (n = 6) served as a control.

RESULTS

WU-B had higher ACE activity at baseline then WU-L. Interestingly, baseline renal ACE2 expression and activity were higher in WU-L. AngII infusion induced the same increase in blood pressure in both genotypes, no proteinuria, but caused tubulo-interstitial renal damage with increased α-SMA and monocyte/macrophage influx only in WU-B (p < 0.05). Low ACE WU-L rats did not develop renal damage.

CONCLUSION

AngII infusion causes proteinuria-independent renal damage only in rats with genetically predetermined high ACE while rats with low ACE seemed to be protected against the detrimental effect of AngII. Differences in renal ACE2, mirroring those in ACE, might be involved.

Rat Ace allele variation determines susceptibility to AngII-induced renal damage

INTRODUCTION

Ace b/l polymorphism in rats is associated with differential tissue angiotensin-converting enzyme (ACE) expression and activity, and susceptibility to renal damage. Same polymorphism was recently found in outbred Wistar rat strain with b allele accounting for higher renal ACE, and provided a model for studying renin-angiotensin-aldosterone system (RAAS) response behind the innate high or low ACE conditions.

METHODS

We investigated the reaction of these alleles on chronic angiotensin II (AngII) infusion. Wistar rats were selected to breed male homozygotes for the b (WU-B) or l allele (WU-L) (n = 12). For each allele, one group (n = 6) received AngII infusion via an osmotic minipump (435 ng/kg/min) for 3 weeks. The other group (n = 6) served as a control.

RESULTS

WU-B had higher ACE activity at baseline then WU-L. Interestingly, baseline renal ACE2 expression and activity were higher in WU-L. AngII infusion induced the same increase in blood pressure in both genotypes, no proteinuria, but caused tubulo-interstitial renal damage with increased α-SMA and monocyte/macrophage influx only in WU-B (p < 0.05). Low ACE WU-L rats did not develop renal damage.

CONCLUSION

AngII infusion causes proteinuria-independent renal damage only in rats with genetically predetermined high ACE while rats with low ACE seemed to be protected against the detrimental effect of AngII. Differences in renal ACE2, mirroring those in ACE, might be involved.

Effect of ACE polymorphisms on the association between noise and hypertension in a Pakistani population

Introduction: This study investigates the effect of angiotensin converting enzyme (ACE) polymorphisms on the association between noise and hypertension.

Subjects and methods: A cross sectional study was conducted involving 385 male volunteers. In the control group 156 participants were exposed to a sound level of ≤80 dB; in the exposed group 229 individuals were exposed to a sound level ≥80 dB. Both groups were subdivided into categories on the basis of blood pressure. A polymerase chain reaction (PCR)-based strategy was used to differentiate the various genotypes of ACE ID and ACE G2350A. Association of noise with genotypes as modifiers was estimated after adjustment of data for age and body mass index.

Results: These showed the following odds ratios (OR) with 95% confidence interval (CI) indicating that noise is associated with hypertension in a Pakistani population (OR: 3.196; CI: 1.803–5.666). ACE ID and ACE G2350A polymorphism affects this association. ID (OR: 2.844: CI: 1.32–6.110) and DD allele carriers (OR: 4.487; CI: 1.549–12.99) were at increased risk of hypertension. GG (OR: 3.970; CI: 1.628–9.681) and GA (OR: 3.705; CI: 1.407–9.758) carriers were also at increased risk of hypertension associated with noise. However II and AA allele carriers were not found to be at increased risk of hypertension.

Conclusion: ACE ID polymorphism and ACE G2350A polymorphism modulates the effects of noise on blood pressure.

E-selectin gene polymorphisms are associated with essential hypertension: a case-control pilot study in a Chinese population

Background

Genetic variation is thought to contribute to the etiology of hypertension, and E-selectin is a candidate essential hypertension-associated gene. This study thus sought to investigate possible genetic associations between the T1880C, C602A and T1559C polymorphisms of E-selectin and essential hypertension.

Methods

Hypertensive patients (n = 490) and healthy normotensive subjects (n = 495) were screened for the genotypes T1880C, C602A and T1559C using real-time quantitative polymerase chain reaction after DNA extraction to identify representative variations in the E-selectin gene. The associations between genotypes and alleles of the three mutations and essential hypertension were then analyzed using a case-control study.

Results

Hypertensive patients and normotensive subjects were significantly different with respect to the genotypes CC, CA and AA (P = 0.005) and the C-allele frequency of C602A (P = 0.001). A comparison of dominant versus recessive models also revealed significant differences between the two groups (P = 0.004 and P = 0.02). When subgrouped by gender, these indexes differed significantly between normotensive and essential hypertensive males, but not in females. The additive model of the T1559C genotype did not differ between essential hypertensive and normotensive groups overall (P = 0.39), but it was different between hypertensive and normotensive males (P = 0.046) and females (P = 0.045). The CC + TC versus TT frequency of T1559C was also different in the recessive model of male hypertensive and normotensive groups (P = 0.02). Further analysis showed that C602A and T1559C were significantly associated with hypertension (C602A: OR = 7.58, 95%CI = 1.53-11.97, P < 0.01; and T1559C: OR = 6.77, 95%CI = 1.07-1.83, P < 0.05). The frequency of the C-C-C haplotype was significantly higher in hypertensive patients than in control individuals as well as in hypertensive and normotensive males (P = 0.008 and 0.01). The frequency of the C-A-T haplotype was higher only in male hypertensives and normotensives (P = 0.015). Furthermore, there was a significant interaction between E-selectin and gender (P = 0.02 for C602A and 0.04 for T1559C).

Conclusion

C602A and T1559C may be independent risk factors for essential hypertension in the Chinese population, whereas T1880C is not.