Ischemic stroke and the gene for angiotensin-converting enzyme in Japanese hypertensives

Clinical Utility of Amplification Refractory Mutation System-Based PCR and Mutation-Specific PCR for Precise and Rapid Genotyping of Angiotensin-Converting Enzyme 1 (ACE1-rs4646996 D>I) and Angiotensin-Converting Enzyme 2 (ACE2-rs4240157T>C) Gene Variations in Coronary Artery Disease and Their Strong Association with Its Disease Susceptibility and Progression

Background: Experimental clinical and research studies demonstrated that the renin−angiotensin system (RAS) affects the pathogenesis of atherosclerosis and the prognosis of coronary heart disease (CHD). The results show that ACE2 (angiotensin I-converting enzyme 2) might act as a protective protein for cardiovascular diseases; however, only a few studies in human populations have been carried out. The aim of this study was to develop, optimize, and validate a direct T-ARMS-based PCR assay for the precise and rapid genotyping of ACE1-rs4646996 D>I and ACE2-rs4240157T>C and study their association with coronary artery disease susceptibility and progression. Methodology: This study included 149 consecutive coronary artery disease patients and 150 healthy controls. We utilized T-ARMS for the precise and rapid genotyping of ACE2-rs4240157; rs4646994. Results: Our results indicated that the ACE1-rs4646996 D>I genotypes observed between CAD cases and controls were statistically significant (p < 0.008) and, similarly, the ACE2-rs4240157T>C genotypes observed were significant (p < 0.0001). Moreover, the frequency of the D allele (ACE1-D>I) and C allele (ACE2-rs4240157T>C) was found to be higher among CAD patients than the HC. Our results indicated that in the codominant model, the ACE2-ID genotype was strongly associated with increased CAD susceptibility in a codominant model with an OR of 2.37, (95%) CI = (1.023−5.504), and p < 0.04. Similarly, the ACE2-DD genotype was strongly associated with an increased CAD susceptibility with an OR of 3.48, (95%) CI = (1.49 to 8.117), and p < 0.003. Similarly, in allelic comparison, the D allele was strongly associated with CAD susceptibility with an OR of 1.59, (95%) CI = (1.12−2.24), and p < 0.003. Our results revealed that there was a significant correlation between ACE2-I/D genotypes and hypertension, T2D, and obesity (p < 0.05). The results of ACE2 rs4240157 genotyping indicated a strong association in the codominant model with an increased CAD susceptibility with an OR of 3.62, (95%) CI = (2.027 to 6.481), and p < 0.0001. Similarly, in a dominant inheritance model, a strong association is observed between the ACE2 rs4240157 (CT+CC) genotype with an OR of 6.34, (95%) CI = (3.741 to 10.749), and p < 0.0001. In allelic comparison, the T allele was strongly associated with CAD susceptibility with an OR of 5.56, (95% CI = (3.56 to 7.17), and p < 0.0001. Similarly, our results revealed that there was a significant association of the ACE2-rs4240157T>C genotypes with Triglycerides (mg/dL), HDL-C (mg/dL), total Cholesterol (mg/dL), and C-reactive protein (mg/L) in CAD. Conclusion: It was indicated that the ARMS technique and MS-PCR assay proved to be fast, accurate, and reliable for ACE2-rs4240157T>C and ACE1-rs4646996 D>I, respectively, and can be used as a potential molecular tool in the diagnosis of genetic diseases in undeveloped and developing countries—where there might be a shortage of medical resources and supplies. ACE1-I>D genotypes were strongly associated with T2D, hypertension, and obesity (p < 0.002). Besides the ACE2-rs4240157 CT heterozygosity genotype, the T allele was strongly associated with CAD susceptibility. Future longitudinal studies in different ethnic populations with larger sample sizes are recommended to validate these findings

A meta-analysis on the association of genetic polymorphism of the angiotensin-converting enzyme and coronary artery disease in the chinese population

OBJECTIVE

To investigate the association between genotype insertion or deletion polymorphism of the angiotensin-converting enzyme gene (ACE) and susceptibility to coronary artery disease (CAD) in Chinese Han population.

METHODS

We conducted a comprehensive search for the OR value of contrast between the group of genotype insertion or deletion polymorphism of the ACE and the group of CAD as an effective index. A meta-analysis (Stata 12.0) was used to test the heterogeneity of the results, combine the values for effect, conduct sensitivity analysis, and basic evaluation.

RESULTS

A total of 638 studies were found on the association between polymorphisms of the angiotensin-converting enzyme gene and CAD, of which 44 studies met the inclusion criteria. In total, our study included 5619 cases and 4865 controls. The heterogeneity test of each study (P < 0.001) was carried out using a random effect model. The OR value of DD/ID+II was 1.95, 95% confidence interval (95%CI) (1.66-2.29). The OR value of II/DI+DD was 0.63, 95%CI (0.55-0.72). The funnel figure is basically symmetrical and the results of the sensitivity analysis were stable.

CONCLUSION

The DD genotype of the angiotensin converting enzyme gene may be a weaker risk factor for CAD in the Chinese Han population.

Exploring Overlaps Between the Genomic and Environmental Determinants of LVH and Stroke: A Multicenter Study in West Africa

BACKGROUND

Whether left ventricular hypertrophy (LVH) is determined by similar genomic and environmental risk factors with stroke, or is simply an intermediate stroke marker, is unknown.

OBJECTIVES

We present a research plan and preliminary findings to explore the overlap in the genomic and environmental determinants of LVH and stroke among Africans participating in the SIREN (Stroke Investigative Research and Education Network) study.

METHODS

SIREN is a transnational, multicenter study involving acute stroke patients and age-, ethnicity-, and sex-matched control subjects recruited from 9 sites in Ghana and Nigeria. Genomic and environmental risk factors and other relevant phenotypes for stroke and LVH are being collected and compared using standard techniques.

RESULTS

This preliminary analysis included only 725 stroke patients (mean age 59.1 ± 13.2 years; 54.3% male). Fifty-five percent of the stroke subjects had LVH with greater proportion among women (51.6% vs. 48.4%; p < 0.001). Those with LVH were younger (57.9 ± 12.8 vs. 60.6 ± 13.4; p = 0.006) and had higher mean systolic and diastolic blood pressure (167.1/99.5 mm Hg vs 151.7/90.6 mm Hg; p < 0.001). Uncontrolled blood pressure at presentation was prevalent in subjects with LVH (76.2% vs. 57.7%; p < 0.001). Significant independent predictors of LVH were age <45 years (adjusted odds ratio [AOR]: 1.91; 95% confidence interval [CI]: 1.14 to 3.19), female sex (AOR: 2.01; 95% CI: 1.44 to 2.81), and diastolic blood pressure > 90 mm Hg (AOR: 2.10; 95% CI: 1.39 to 3.19; p < 0.001).

CONCLUSIONS

The prevalence of LVH was high among stroke patients especially the younger ones, suggesting a genetic component to LVH. Hypertension was a major modifiable risk factor for stroke as well as LVH. It is envisaged that the SIREN project will elucidate polygenic overlap (if present) between LVH and stroke among Africans, thereby defining the role of LVH as a putative intermediate cardiovascular phenotype and therapeutic target to inform interventions to reduce stroke risk in populations of African ancestry.

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.

Insertion/deletion polymorphism of the angiotensin-converting enzyme gene and the risk of hypertension among residents of two cities, South-South Nigeria

BACKGROUND

Hypertension is a public health challenge due to its high prevalence, and is a major risk factor for cardiovascular diseases. This study was designed to determine the frequency of the I/D polymorphism of the angiotensin-converting enzyme gene and its association with hypertension in a sample population of Calabar and Uyo, South-South Nigeria.

MATERIALS AND METHODS

A population-based case control design consisting of total of 1224 participants, 612 each of patients and controls, were randomly recruited from hypertension clinics and the general population. The I/D polymorphism was investigated using polymerase chain reaction. Multiple regression and odds ratio (OR) was applied to test whether the ID genotypes were predictors of hypertension.

RESULTS

The I/D genotype frequencies were 73(12%), 262(43%) and 277(45%); 74(12%), 303(50%) and 235(38%) for the II, ID, DD genotype in patient and control groups, respectively. A higher frequency of the ID genotype was observed in controls of which 208(61%) were females. By multiple regression analysis, age was a predictor for SBP in patients, r = 0.596, and DBP in controls, r = 0.555. Gender, Body mass index, I/D genotypes were not significant predictors for hypertension but the I/D polymorpism was associated with an increased risk for hypertension with an OR of 1.15 95%CI (0.924-1.456).

CONCLUSION

The I/D polymorphism of the angiotensin-converting enzyme gene was a risk factor for hypertension in the sample population of Calabar and Uyo. This research will form baseline information for subsequent molecular studies in this population.

Angiotensin converting enzyme insertion/deletion (I/D) (rs4646994) and Vegf polymorphism (+405G/C; rs2010963) in type II diabetic patients: Association with the risk of coronary artery disease

HYPOTHESIS

Little is known about the concomitant presence of the angiotensin-converting enzyme (ACE) (rs4646994) D allele and vascular endothelial growth factor(VEGF) (+405G/C; rs2010963) G allele on the susceptibility of coronary artery disease (CAD). Here we examined the hypothesis that ACE-D and VEGF-G alleles act synergistically to increase the severity of CAD in patients with type II diabetes mellitus (T2DM).

MATERIALS AND METHODS

The VEGF (rs2010963) and ACE (rs4646994) genotypes were detected by polymerase chain reaction - restriction fragment length polymorphism (PCR-RFLP) and PCR, respectively in 510 T2DM patients undergoing their first coronary angiography. Diabetic patients were classified as T2DM patients with and without CAD (control).

RESULTS

The crude odds ratio (OR) for the presence of CAD in ID+DD and D allele carriers were 1.98 (p=0.01) and 1.55 (p=0.001), respectively. Also, adjusted ORs in the presence of normolipidemia and the absence of history of hypertension for the risk of CAD in the either ACE(rs4646994) D allele or VGEF(rs2010963)-G alleles were 2.08 (p=0.004) and 1.75 (p=0.024), respectively. In addition, the concomitant presence of the ACE-D and VEGF-G alleles increased the risk of CAD 2.25-fold (p=0.043).

CONCLUSION

Our results indicated that ACE(rs4646994)-D allele alone and in the presence of VEGF(rs2010963)-G allele can be an important independent risk factor for susceptibility of CAD in T2DM patients even after correcting for conventional risk factors in a population of Iran.

Large-scale meta-analysis of genetic studies in ischemic stroke: Five genes involving 152,797 individuals

BACKGROUND:

Ischemic stroke descent has a genetic basis. Stroke represents a complex trait, which is assumed to be polygenic. On this topic, the role of a wide number of candidate genes has been investigated in stroke through association studies.

MATERIALS AND METHODS:

We performed a literature-based systematic review of genetic association studies in stroke abound several populations. Odds ratios (ORs) and 95% confidence intervals (CIs) were determined for each gene-disease association. Following a review of 300 manuscripts, five candidate gene variants were analyzed among 152,797 individuals (45,433 cases and 107,364 controls).

RESULTS:

For these five candidate genes studied, the prothrombin OR is 1,57 (1,23-2,89), the factor V Leiden OR is 1,43 (0,67-6,24), the mean OR of angiotensin I converting enzyme (ACE) insertion/deletion (I/D) polymorphism is 1,11 (1,02-1,25), the summary OR for the C677T variant of 5,10-methylenetetrahydrofolate reductase (MTHFR) is 1,23 (0,61-1,47) and the pooled OR for the apolipoprotein E (APOE) gene is 0,95 (0,77-1,14) .

CONCLUSION:

These data suggest the genetic associations of some genes with ischemic stroke and it is necessary to compete with other genes. Our findings could represent an epidemiological base and a useful tool to address further molecular investigations and to realize more detailed meta-analyses.

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.

Role of Genetic Polymorphism of Angiotensin-Converting Enzyme, Plasminogen Activator Inhibitor-1 and Endothelial Nitric Oxide Synthase in the Prognosis of Coronary Artery Disease

Background

This study was to investigate the effects of multiple genetic polymorphisms and conventional risk factors in the prognosis of coronary artery disease (CAD).

Methods

One hundred and fifty five patients with CAD were prospectively recruited, they were subgrouped as single vessel disease (SVD) and multiple vessel disease (MVD). All patients were detected I/D polymorphism of angiotensin-converting enzyme (ACE) gene, 4G/5G polymorphism of plasminogen activator inhibitor-1 (PAI-1) gene, and G894→T mutation of endothelial nitric oxide synthase (eNOS) gene. The patients were followed up for 10-65 months, mean 35 months. End points were major adverse cardiovascular events (MACE), including angina, myocardial infarction, and cardiac sudden death.

Results

During the follow-up period, MACE developed in 81 patients, 73 patients with angina, seven with myocardial infarction, and one with cardiac sudden death. CAD patients with MVD were more probable of developing MACE during follow-up. Distribution of PAI-1 gene polymorphism was significantly different between SVD and MVD patients, p < 0.001. The frequency of DD genotype of ACE and 4G/4G genotype of PAI-1 in patients with MACE were significantly higher than those in patients without MACE, p < 0.001 and p = 0.002, respectively. Incidence of diabetes mellitus was significantly higher in patients with MACE than in patients without MACE, P = 0.03. Cox regression analysis showed that diabetes mellitus (HR 2.36, 95% CI 1.33-4.46, p = 0.003), 4G/4G polymorphism of PAI-1 gene (HR 3.45, 95% CI 1.71-6.56, p = 0.009), and D/D polymorphism of ACE gene (HR 2.99, 95% CI 1.84-5.76, p = 0.005), were independent predictors of the MACE.

Conclusions

Our results showed that the conventional risk factors and genetic polymorphisms have significant influence on prognosis of CAD patients. CAD patients with diabetes mellitus, DD genotype of ACE, and 4G/4G genotype of PAI-1 suggested poor prognosis.

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

BACKGROUND AND PURPOSE

Stroke is a heterogeneous multifactorial disease. Hence, a large number of candidate genes are involved in stroke pathophysiology, such as blood pressure regulation and atherosclerosis. Although angiotensin-converting enzyme insertion/deletion (ACE I/D) polymorphism is considered to have a role in hypertension, coronary artery disease, and myocardial infarction, its relationship with cerebrovascular disease and hypertension in stroke in different ethnic populations is still inconsistent.

METHODS

ACE I/D polymorphism, detected by polymerase chain reaction (PCR), was studied in 97 patients with large-vessel and 60 patients with small-vessel atherosclerotic stroke (44 asymptomatic, 16 symptomatic lacunes) and 85 healthy subjects with normal brain imaging. The demographic data, lipid profile and risk factors of patients and controls were obtained retrospectively.

RESULTS

ACE genotypes were in Hardy-Weinberg equilibrium in both patients and controls. Prevalences of DD, ID and II genotype were 41%, 40%, and 19%, respectively, in the stroke group. Differences in ACE I/D polymorphism distribution were statistically insignificant between the groups. This lack of association between stroke and ACE I/D polymorphism did not change in the presence of traditional risk factors (hypertension, diabetes mellitus, smoking, and dyslipidemia). Although hypertension was significantly more common in the patient groups, ACE I/D polymorphism showed no effect on hypertension risk. This lack of association also did not change according to groups or in the presence of diabetes mellitus, male gender or smoking.

CONCLUSION

ACE I/D polymorphism did not predict the risk of stroke or hypertension in our population living in the western Black Sea region of Turkey.

Prevalence of Thrombophilic Mutations and ACE I/D Polymorphism in Turkish Ischemic Stroke Patients

The aim of this study was to evaluate the prevalence of factor V Leiden (FVL), prothrombin G20210A, methylenetetrahydrofolate reductase ( MTHFR) C677T gene mutations, and angiotensin-converting enzyme (ACE) I/D polymorphism in ischemic stroke (IS) patients. A total of 162 Turkish IS patients were included and analyzed according to stroke subtype by the TOAST classification. Their genotype data were compared with those of the control group, representing the healthy population, using the χ2 test. The frequency of FVL heterozygocity was 12.3% in this series—higher than that in the normal population (9.8%; statistically insignificant, P = .478). The frequency of the ACE D/D genotype in all stroke patients and those with stroke of undetermined etiology was higher than that in our population (52.5% and 59.2%, respectively, vs 39.3%; statistically significant, P = .034, P = .020). Our results may suggest that ACE D/D genotype is a risk factor for IS, particularly in those with stroke of undetermined etiology in the Turkish population.

Genetics of ischaemic stroke among persons of non-European descent: a meta-analysis of eight genes involving approximately 32,500 individuals

BACKGROUND

Ischaemic stroke in persons of European descent has a genetic basis, but whether the stroke-susceptibility alleles, the strength of any association, and the extent of their attributable risks are the same in persons of non-European descent remains unanswered. Whether ethnicity itself has a relevant or substantial contribution on those effect estimates is controversial. Comparative analyses between the ethnic groups may allow general conclusions to be drawn about polygenic disorders.

METHODS AND FINDINGS

We performed a literature-based systematic review of genetic association studies in stroke in persons of non-European descent. Odds ratios (ORs) and 95% confidence intervals (CIs) were determined for each gene-disease association using fixed and random effect models. We further performed a comparative genetic analysis across the different ethnic groups (including persons of European descent derived from our previous meta-analysis) to determine if genetic risks varied by ethnicity. Following a review of 500 manuscripts, eight candidate gene variants were analysed among 32,431 individuals (12,883 cases and 19,548 controls), comprising mainly Chinese, Japanese, and Korean individuals. Of the eight candidate genes studied, three were associated with ischaemic stroke: the angiotensin I converting enzyme (ACE) insertion/deletion (I/D) polymorphism with a mean OR of 1.90 (95% CI 1.23-2.93) in the Chinese and 1.74 (95% CI 0.88-3.42) in the Japanese; the summary OR for the C677T variant of 5,10-methylenetetrahydrofolate reductase (MTHFR) was 1.18 (95% CI 0.90-1.56) in Chinese and 1.34 (95% CI 0.87-2.06) in Koreans; and the pooled OR for the apolipoprotein E (APOE) gene was 2.18 (95% CI 1.52-3.13) in Chinese and 1.51 (95% CI 0.93-2.45) in Japanese. Comparing the commonly investigated stroke genes among the Asian groups against studies in persons of European descent, we found an absence of any substantial qualitative or quantitative interaction for ORs by ethnicity. However, the number of individuals recruited per study in the studies of persons of non-European descent was significantly smaller compared to studies of persons of European descent, despite a similar number of studies conducted per gene.

CONCLUSIONS

These data suggest that genetic associations studied to date for ischaemic stroke among persons of non-European descent are similar to those for persons of European descent. Claims of differences in genetic effects among different ethnic populations for complex disorders such as stroke may be overstated. However, due to the limited number of gene variants evaluated, the relatively smaller number of individuals included in the meta-analyses of persons of non-European descent in stroke, and the possibility of publication bias, the existence of allele variants with differential effects by ethnicity cannot be excluded.

Angiotensin-converting enzyme and angiotensin II type 1 receptor gene polymorphisms in children with subacute sclerosing panencephalitis

Subacute sclerosing panencephalitis (SSPE) is a progressive, debilitating, and fatal brain disorder caused by mutant measles virus infection. Although both viral and host factors seem to be involved in SSPE, the exact pathogenesis remains to be determined. Autoimmune demyelination is characteristic of SSPE. The blood angiotensin-converting enzyme (ACE) activity and angiotensin II (Ang II) levels are associated with the ACE gene polymorphism. Proinflammatory effects of Ang II may contribute to the development of SSPE. The aim of this study was to investigate whether the ACE and Ang II type 1 receptor (AT1R) (A1166C) gene polymorphisms were associated with SSPE. The polymorphisms were investigated by polymerase chain reaction (PCR) in 43 patients with SSPE and 100 healthy controls. The genotype distribution of the SSPE children and healthy controls were as follows: DD 58.1% versus 34.0, ID 37.2% versus 48.0%, and II 4.7% versus 18.0, respectively (P = 0.012). Allele frequencies of patients and controls were D 76.7% versus 58.0%, and I 23.3% versus 42.0%, respectively (P = 0.004). The frequency of DD genotype and D allele were significantly higher in SSPE children compared with controls (P < 0.05). AT1R gene polymorphism distribution was found to be similar in SSPE children and control subjects: AA 55.8% versus 60.7%, AC 37.2% versus 32.1%, and CC 7.0% versus 7.2%, respectively (P > 0.05). In conclusion, the results of this study suggest that the DD genotype of ACE I/D polymorphism may be related to SSPE. Due to small size of this study, further studies with more patients are needed to confirm these results.

Sequence variants of ACE, AGT, AT1R, and PAI-1 as genetic risk factors for vascular dementia

Sequence variants of angiotensin converting enzyme (ACE) insertion/deletion (I/D), angiotensinogen (AGT) T235M, angiotensin II type 1 receptor (AT1R) A1166C, and plasminogen activator inhibitor-1 (PAI-1) 4G/5G were analyzed to see their genetic associations with vascular dementia as its candidate genetic risk factors involving renin-angiotensin and fibrin systems. While the ACE I/D, AT1R A1166C, and PAI-1 4G/5G did not contribute to the genetic susceptibility to vascular dementia (P>0.05), a significant association with vascular dementia was shown in the T235M polymorphism of AGT. The frequency of the M allele in patients was higher than in controls with the odds ratio (OR) estimate of 1.51 (P<0.05). In a dominant model, the TM+MM genotypes increased the risk of vascular dementia compared to the TT genotype (OR=2.01; P<0.001). The current results suggested that AGT T235M polymorphism might be a risk factor of vascular dementia.

Are the angiotensin-converting enzyme gene and activity risk factors for stroke?

Stroke is a multifactorial disease in which genetic factors play an important role. This study was carried out to determine angiotensin-converting enzyme (ACE) gene polymorphism in Turkish acute stroke patients and to establish whether there is an association of angiotensin-converting enzyme gene I/D polymorphism with clinical parameters. In this study 185 patients and 50 controls were recruited. We have investigated the association among the allelic distribution of the insertion/deletion (I/D) polymorphism of the ACE gene identified by polymerase chain reaction. Distribution of ACE gene I/D genotypes and allele frequencies in patients were not significantly different from controls. D allele frequencies were 57.8% in patients versus 53.0% in controls and I allele 42.2% versus 47% respectively. History of hypertension, stroke, renal, heart and vessel diseases incidence and age, gender, systolic-diastolic blood pressures and creatinine levels were significantly high in patients. But these results and ACE activities had no significant differences among the ACE genotypes in patients and controls. Our results suggest that the ACE gene polymorphism is not associated with the pathogenesis of stroke in Turkish stroke patients.

Apolipoprotein E, angiotensin-converting enzyme and kallikrein gene polymorphisms and the risk of Alzheimer's disease and vascular dementia

Lipoproteins and vascular factors may play roles in the development of Alzheimer's disease (AD) and/or vascular dementia (VaD). In this study, odd ratios (ORs) and 95% confidence intervals (CIs) for apolipoprotein E (APOE), angiotensin-converting enzyme (ACE), and kallikrein (KLK1) polymorphisms were computed to test their association with the disease by a case-control study. The risk of AD was significantly increased for individuals with APOE varepsilon4 allele (OR = 3.73, 95% CI = 2.38-5.98). The risk of AD was also significant for people with ACE DD genotype, D allele, or T-D haplotype [OR (95% CI) = 4.29 (1.96-10.23), 1.90 (1.35-2.70), or 2.91 (1.71-5.10), respectively]. The above association between ACE-VaD was also strong (p = 0.0012, 0.0050, 0.0007, respectively). Reporter constructs containing the -240 A or T allele displayed similar transcriptional activity in both HEK-293 and IMR-32 cells. Thus, another putative pathogenic marker that is linked with the Alu D allele might affect the risk of AD and VaD in Taiwan.

Antihypertensive medications for risk reduction of first and recurrent ischemic stroke

It is increasingly clear that even a small reduction in blood pressure results in a substantial risk reduction of vascular events including ischemic stroke. Recently, several comparative prospective trials of angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers have demonstrated that, for equivalent reductions in blood pressure, these drugs may confer a greater effect on the prevention of primary and recurrent ischemic stroke compared with other antihypertensive medications. Given this information from prospective randomized trials, it appears that this class of drugs should be the first-line treatment for hypertension in patients at risk of a first or recurrent ischemic stroke. This review will critically assess the scientific basis and rationale of the use of angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers in primary and secondary stroke prevention.

Possible synergic effect of angiotensin-I converting enzyme gene insertion/deletion polymorphism and angiotensin-II type-1 receptor 1166A/C gene polymorphism on ischemic heart disease in patients with Kawasaki disease

ACE I/D and AT1R 1166A/C polymorphisms are considered to comprise individual risk factors for the development of coronary disease. We sought to demonstrate that the ACE I/D and AT1R 1166A/C polymorphisms affect coronary artery stenosis in patients with Kawasaki disease (KD). We examined 147 healthy controls and 281 Japanese children with KD. The patients were further divided into group N (n = 246, no ischemia) and group I (n = 35, severe coronary artery stenosis with myocardial ischemia), and we studied the genotype of ACE I/D and AT1R 1166A/C polymorphisms. We also examined ACE activity in patients with acute KD. We did not detect any prevalent genotypes of the ACE and AT1R polymorphisms between controls and KD patients. However, the prevalence of the D allele in the ACE polymorphism and of the C allele in the AT1R polymorphism tended to be higher in group I than in group N (odds ratios, 2.00 and 2.32, respectively). In addition, the presence of the D and/or C alleles significantly increased the relative risk of developing myocardial ischemia (odds ratio, 2.71; p = 0.038). During the convalescent phase of KD, ACE activity was increased despite significant attenuation during the acute phase. These results suggested that the renin-angiotensin system is associated with the formation of severe coronary artery stenosis and myocardial ischemia.

Frequency of angiotensin-converting enzyme gene polymorphism in Turkish hypertensive patients

Hypertension is a multifactorial disease, in which genetic factors play an important role. This study was carried out to determine angiotensin-converting enzyme levels and angiotensin-converting enzyme gene polymorphism in Turkish hypertensive patients, and to establish whether there is an association of angiotensin-converting enzyme gene polymorphism with clinical and echocardiographic parameters. We have investigated the association among the allelic distribution of the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme gene identified by polymerase chain reaction, angiotensin-converting enzyme activity determined spectrophotometrically, cardiac morphology and function assessed by means of echocardiography. Distribution of angiotensin-converting enzyme gene I/D polymorphism and allele frequencies in hypertensive patients was not significantly different from controls. D allele frequency was 51.7% in hypertensives vs. 51.9% in controls and I allele 48.3 vs. 48.1%, respectively. The level of angiotensin-converting enzyme activity was significantly higher in the patients homozygotes for D allele (DD = 59.93 U/l) than in heterozygotes (ID = 39.49) and in homozygotes for I allele (II = 40.28 U/l). In addition to these, the level of angiotensin-converting enzyme activity was significantly lower in the ID and especially II patients receiving ACE inhibitors than the others. Also, it was determined that left atrium diameter was larger in the patients homozygotes for I allele than the others.

GNB3 gene C825T and ACE gene I/D polymorphisms in essential hypertension in a Kazakh genetic isolate

The Kazakh inhabitants living in Barkol pasture of northeast China belong to a genetic isolate characterized by ethnically homogeneous and a communal pastoral lifestyle. To investigate whether the polymorphisms in the G-protein beta-3 subunit (GNB3) gene and angiotensin-converting enzyme (ACE) gene are associated with essential hypertension (EH), we carried out a case-control study of 290 hypertensive subjects and 244 normotensive (NT) controls randomly selected from Kazakh populations of Barkol. A previous medical history of diabetes and hypertension, and body mass index (BMI) was recorded. Plasma glucose, triglyceride, and cholesterol were measured. The insertion/deletion (I/D) polymorphism of the ACE gene and the C825T polymorphism of the GNB3 gene were determined by the polymerase chain reaction (PCR) technique. The distributions of genotypes and alleles for the two polymorphisms did not differ significantly between the case and control populations, and odds ratio of EH related to the ACE gene D allele and GNB3 gene T allele was not significantly different from 1.0. Logistic regression analysis shows the variation at the GNB3 and ACE did not have any statistically significant synergistic effect on blood pressure (BP). Stratification of NT and untreated hypertensives according to I/D polymorphism of ACE gene and C825T polymorphism of GNB3 gene disclosed no significant difference across genotypes with respect to BMI, glucose, triglyceride, cholesterol, systolic and diastolic BP. In conclusion, the polymorphisms in the GNB3 gene and ACE gene, solely or combined, did not confer a significantly increased risk for the development of EH in the Kazakh isolate of northeast China.

Angiotensin converting enzyme gene polymorphism and traditional Sasang classification in Koreans with cerebral infarction

Sasang constitutional medicine is a major branch of Korean traditional oriental medicine. Constitutions of Sasang medicine refer to Taeyangin, Taeumin, Soyangin, and Soumin. The differences of disease severity to be shown in the constitution may be due to genetic factors. Therefore, we examined interrelationship among cerebral infarction, CI, angiotensin converting enzyme (ACE) gene polymorphism, and Sasang constitutional classification. We investigated the association between ACE genotype and CI by case-control study in a Korean population. We also classified CI patients and control group into groups according to Sasang constitutional medicine. 208 CI patients and 643 controls without CI were examined. ACE genotype was determined by 7.5 % polyacrylamide gel separation after DNA amplification. The ACE/DD genotype was not associated with CI. The frequency of Taeumin of Sasang constitutional medicine in patients with CI was significantly higher than that in controls (chi2=41.202, p<0.001). However, the Taeumin constitution did not enhance the relative risk for CI in the subjects with ACE/DD genotype. Although we did not find any association between ACE gene polymorphism and CI in Koreans, there were significant differences in allele frequencies between Koreans and Europeans, but not Japanese and Chinese populations. Furthermore, we first attempted to evaluate the efficacy of Sasang constitutional medicine, and to find an association with CI.

Apolipoprotein E, angiotensin-converting enzyme and alpha-1-antichymotrypsin genotypes are not associated with post-stroke dementia

There is evidence that indicates the involvement of environmental and genetic factors in the pathogenesis of post-stroke dementia (PSD). In the present work, we examined different polygenic influences on the risk of PSD in a series of stroke patients. We studied 150 consecutive patients evaluated 3 months after suffering acute strokes. All patients were evaluated with a prospective standard protocol and genotyped for vascular disease-associated polymorphisms in the genes coding for apolipoprotein E (including apoE coding and apoE promoter polymorphisms), angiotensin-converting enzyme (ACE) and alpha-1-antichymotrypsin (ACT). Thirty-two cases (21.3%) resulted in dementia 3 months after the stroke. In patients with PSD, the frequency of apoE epsilon 4 (0.08), ACE-D (0.64), ACT-A (0.62) alleles and apoE gene promoter polymorphisms (-491/A, 0.88; -427/C, 0.02) was similar to that of patients without PSD (apoE epsilon 4: 0.10, p=0.79; ACE-D: 0.56, p=0.36; ACT-A: 0.51, p=0.21; -491/A: 0.86, p=1.00; -427/C: 0.08, p=0.29). Our data indicate that PSD is not associated with the genetic risk factors of vascular dementia (VD) that were studied, and that additional factors may contribute to the pathogenesis of PSD.

Gender, ethnicity and genetics in cardiovascular disease: part 1: Basic principles

Prior to 1993, most drug efficacy and safety trials were conducted in white males, although gender and racial differences in pharmacodynamics and pharmacokinetics have been documented since the early 1900s. Over the last 2 decades, supported by the FDA and legislation, attempts to include more women and minorities in clinical drug trials have been made, with limited success. Yet, there are important differences in pathophysiology and pharmacogenetics, as well as pharmacotherapeutic effectiveness. This is the first of 2 articles that review the basic scientific principles of such differences. In particular, genetic polymorphisms of cardiovascular candidate genes and drug metabolism are described. The pharmacodynamic and pharmacokinetic variations among genders and ethnicities are summarized.

Genetic susceptibility to ischemic cerebrovascular disease in Koreans

Ischemic cerebrovascular disease (ICVD) is a multifactorial disease caused by the interactions of several genetic and environmental factors. Tobacco smoke is a major cause of both cancer and vascular disease. Although its carcinogenic role via induction of DNA damage and mutation is well established, the mechanisms involved in vascular disease remain unclear. One possibility is that DNA damage causes smooth muscle cell proliferation in the intima of arteries, thereby contributing to atherothrombotic processes. The binding of chemicals to DNAis modulated by detoxification enzymes, including glutathione S-transferase (GST). We examined whether polymorphisms in this gene, as well as the angiotensin-converting enzyme (ACE) gene influence the risk of ICVD on smoking status. DNA was analyzed for deletions in the GST M1, T1, and ACE genes by polymerase chain reaction (PCR). No significant association was observed between GST null genotype and ICVD, even in smokers. However, a significant association between ACE and ICVD was observed only in smokers (chi(2) = 0.023, p < 0.05). We conclude that GST polymorphism is not a risk factor for the development of ICVD through smoking and suggest a high probability that ACE polymorphism may contribute to the odds of ICVD in smokers.

Genetics of leukoaraiosis

Computed tomography and magnetic resonance imaging of the brains of elderly individuals frequently show areas of altered signal intensity in the periventricular and subcortical white matter, referred to as leukoaraiosis. Although mildly affected individuals appear asymptomatic, larger burdens of leukoaraiosis are associated with deficits of cognition and gait. Histopathologically, areas of leukoaraiosis invariably show sclerosis, luminal narrowing, and tortuosity of small arteries and arterioles, accompanied by variable degrees of gliosis, demyelination, and axonal loss resulting from ischemia. Genetic variation plays a substantial role in interindividual differences in the volume of leukoaraiosis and its associated adverse clinical outcomes. Characterizing genetic factors contributing to interindividual differences in leukoaraiosis has the potential to enhance understanding of molecular determinants of ischemic brain injury and lead to new approaches to the diagnosis, evaluation, treatment, and prevention of this common form of vascular dementia.

Genetic aspects of stroke: human and experimental studies

As one of the leading causes of death within both the developed and developing world, stroke is a worldwide problem. Risk factors can be identified and controlled at the level of lifestyle changes; however, genetic components of stroke have yet to be identified. The identification of such genetic components is critical in the understanding, diagnosis, and treatment of stroke in the future. This review focuses on the genetic determinants of stroke in both human and experimental systems. Mendelian disorders, candidate genes, and twin studies provide evidence for a strong genetic component of stroke. Genome-wide scanning in both human and animal models has led to the identification of regions of the genome that contain genes for stroke susceptibility and sensitivity. Animal models of stroke allow for environmental control and genetic homogeneity, not possible within a human population, and therefore are essential for the dissection of this complex, multifactorial disorder. Future genetic and genomic strategies and their role in ultimate causative gene identification are discussed.

Cerebrovascular disorders and genetic polymorphisms: mitochondrial DNA5178C is predominant in cerebrovascular disorders

We studied polymorphisms of mitochondrial DNA 5178cytosine/adenine (mt5178C/A) and angiotensin I-converting enzyme (ACE) genes (DCP1) in 127 cerebrovascular disorder (CVD) patients and 294 age-matched normal controls to clarify the genetic background of Japanese patients with CVD. Mt5178C was predominant in CVD patients compared with controls (P<0.01). The frequency of DCP1 insertion (I) and deletion (D) alleles showed no significant difference between the CVD patients and controls or between each CVD subgroup. Although the number of CVD patients in the present study was too small to make a final conclusion, mt5178C might be one of the genetic factors to be considered in Japanese patients with CVD.

Angiotensin-converting enzyme gene and longevity in the Xin Jiang Uighur autonomous region of China: an association study

BACKGROUND

Longevity can be regarded as a multifactorial trait that results from an interaction between environmental factors and sets of epistatic alleles that have pleiotropic age-dependent effects. The Hotan district in the Xin Jiang Uighur Autonomous region of China is relatively isolated and is well known for an ethnic group that displays marked longevity.

METHODS

We performed a correlation study between the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene and longevity by comparing distributions of the polymorphism between three different ethnic groups in this region. We obtained data from 424 subjects comprising 227 Uighur individuals, 108 Kazakh individuals, and 89 Han individuals. All subjects in the latter two groups ranged in age from 65 to 70 years, whereas the Uighur subjects actually comprised two different age groups: those ranging in age from 59 to 70 years (Uighur older group in Hotan [UOH]) and those ranging in age from 90 to 113 years (Uighur longevity group in Hotan [ULH]). Genomic DNA was extracted from peripheral white blood cells. Polymerase chain reaction was performed to amplify the I/D polymorphic region of the ACE gene.

RESULTS

Frequencies of the insertion (I) and deletion (D) alleles were 0.596 (243/408) and 0.404 (165/408) in the Uighur group, 0.606 (130/216) and 0.394 (85/216) in the Kazakh group, and 0.657 (117/178) and 0.343 (61/178) in the Han group. The overall distributions of alleles in these three groups did not differ significantly (chi(2) = 4.6, p =.33). Within the Uighur group, frequency of the D allele was significantly higher in the ULH group (0.448) than in the UOH group (0.355) (p <.04).

CONCLUSIONS

This association reflects a genetic influence on differential survival and may point to pleiotropic age-dependent effects on longevity. Our data may help elucidate the relationship between natural longevity and race difference among individuals in the Xin Jiang Uighur Autonomous region of China.

Cerebral white matter lesions in essential hypertension

The pathogenesis and clinical significance of cerebral white matter lesions (WML) remain controversial. Most studies have shown that age, hypertension, diabetes mellitus, and a history of stroke or heart disease are the most important factors related to the presence of cerebral WML. Moreover, some studies suggest that the presence of WML are closely related to cerebrovascular disease and cognitive impairment in elderly patients with vascular risk factors, particularly hypertension. In this review, different points of view about cerebral WML are discussed, with special focus on the presence of WML in essential hypertension. Some authors suggest that the presence of WML in hypertensive patients could be considered an early marker of brain damage.

MRI and genetic correlates of cognitive function in elders with memory impairment

The present study investigated the relationship between genetic variation, MRI measurements and neuropsychological function in a sample of 58 elders exhibiting memory decline. In agreement with previous reports, we found that the epsilon4 allele of the apolipoprotein E (APOE) and the D allele of the angiotensin converting enzyme (ACE) polymorphisms negatively modulated the cognitive performance. Further, we found an association between the A allele of the apolipoprotein C1 (APOC1) polymorphism and poorer memory and frontal lobe function. No clear associations emerged between MRI measures of white matter lesions (WML) or hippocampal sulcal cavities (HSC) and the cognitive performance after controlling for age effects. Further, the degree of WML or HSC lesions was in general not predisposed genetically except for the presence of the A allele of the APOC1 polymorphism that was related to a higher severity of HSC scores. Our results suggest that WML or HSC do not represent important brain correlates of genetic influences on cognitive performance in memory impaired subjects.

Polymorphism insertion/deletion of the ACE gene and ambulatory blood pressure circadian variability in essential hypertension

OBJECTIVE

The objective of the present study was to analyze the influence of the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme on ambulatory blood pressure values and circadian variability in untreated patients with hypertension.

MATERIAL AND METHODS

Ninety-nine essential hypertensive patients, less than 50 years old (mean age 39.5+/-7.0 years), previously untreated with antihypertensive drugs were included. Twenty-four hour ambulatory blood pressure monitoring (ABPM) was performed with a Spacelabs (90202 and 90207) monitor, during a regular working day in unrestricted ambulatory conditions. The I/D polymorphism of the ACE was determined by PCR.

RESULTS

The distributions of genotypes were in Hardy-Weinberg equilibrium: I=17 (17%), ID=41 (41.5%), DD=41 (41.5%). No significant differences were present among the groups in terms of age, sex, and biochemical and lipid profiles. The average of 24-h ambulatory blood pressure was slightly higher in patients with the DD genotype as compared with patients with the II and ID genotypes. This was the result of higher nighttime blood pressure values, because no differences in blood pressure were observed during daytime. The systolic blood pressure (SBP) day:night ratio, as an estimate of circadian variability, was significantly lower in subjects homozygous for the D allele than it was in patients carrying the I allele (1.13+/-0.09 vs. 1.17+/-0.08, P=0.014). The subjects in the lowest tertile of the SBP day:night ratio, exhibited a higher frequency of the D allele when compared with those in the middle tertile (0.74 vs. 0.59, P<0.05) or with those in the highest tertile (0.74 vs. 0.54, P<0.01). By using two-way ANOVA with repeated measures, significant differences in SBP variation over time were observed when comparing homozygous for the D allele with subjects carrying the I allele (F=2.11, P=0.002).

CONCLUSIONS

Among the genotypes of the I/D polymorphism, subjects carrying DD genotype showed a blunted decline of the physiological nocturnal fall of blood pressure that was significant for SBP.

Genetic polymorphisms in the renin-angiotensin system: relevance for susceptibility to cardiovascular disease

The renin-angiotensin system plays an important role in the pathogenesis of cardiovascular disease. Cloning of the human genes coding for the angiotensin-converting enzyme, angiotensinogen, and angiotensin II type 1 receptor has led to the discovery of several polymorphisms, which may be implicated in the pathogenesis of cardiovascular disease. The deletion/insertion (D/I) polymorphism of the angiotensin-converting enzyme gene is associated with hypertension in men, left ventricular hypertrophy in untreated hypertensive patients, various atherosclerotic cardiovascular complications, and microvascular disorders. The M235T polymorphism of the angiotensinogen gene may be associated with a higher risk of hypertension. The A1166C polymorphism of the angiotensin II type 1 receptor gene is probably correlated with hypertension and through an epistatic interaction with the D/I polymorphism of the angiotensin-converting enzyme gene possibly also with coronary heart disease. Several other gene polymorphisms, in particular those in the promoter area of the angiotensinogen gene, have been studied in relation to cardiovascular disease. Based on the insights gained from the reports summarized in this review article, population-based genetic studies of nuclear families are currently being conducted in Belgium and in the People's Republic of China with blood pressure and hypertension as the main outcome variables.

Angiotensinogen and angiotensin converting enzyme gene polymorphisms and the risk of bipolar affective disorder in humans

A possible participation of the renin-angiotensin system (RAS) components with mood disturbances has been suggested in both animal and pharmacological models. In this cross-sectional study, we examined the association between functional polymorphisms in the angiotensin converting enzyme (ACE) and angiotensinogen (AGT) genes in 115 bipolar affective disorder (BPAD) patients and 323healthy control subjects. The ACE I/D variant did not show any difference in allelic frequencies and genotypic distribution between the groups. In contrast, when studying the AGT M235T polymorphism we found that the M allele was more frequently observed in BPAD patients than in controls (chi(2)=6.766, d.f.=1, P=0.009). Using multivariate logistic models the strongest odds ratio resulted from a dominant genetic model (OR=3.0; CI (95%) 1.7-5.3] Our data suggest an association between the AGT M235 genotype and increased susceptibility for BPAD in these Brazilian patients. These findings are consistent with the hypothesis that the RAS system plays a role in regulating the mood

Gene polymorphism of the renin-angiotensin system associates with risk for lacunar infarction. The Ohasama study

The polymorphism of the angiotensin-converting enzyme gene is considered to be associated with increased risk for stroke, but there is a diversity in the results obtained. The genetic involvement of the renin-angiotensin system in stroke also remains unclear. To predict the genetic risk of lacunar infarction, we conducted an association study in an Ohasama population, which is the cohort in a rural region of northern Japan. A total of 134 subjects without major neurological, cardiovascular, or metabolic disorders were recruited. Using brain magnetic resonance imaging, the number of lacunae in each of four brain regions were calculated, and periventricular hyperintensity was classified into five grades. We used the following four candidate gene polymorphisms: angiotensin converting enzyme (ACE)/Insertion(I)-Deletion(D), angiotensinogen (AGT)/M235T, angiotensin II type 1 receptor (AT1)/ A1166C, type 2 receptor (AT2)/C3123A, to examine the association between polymorphisms and the severity of lacunar infarction. AGT/M235T was significantly associated with the number of lacunae in the brain stem, the basal ganglia (P < .05), and whole brain (P < .005) regions. The AT1 polymorphism was also significantly associated with the number of lacunae in the basal ganglia and whole brain regions (P < .05), and with periventricular hyperintensity grade (P < .005) in the younger population. However, ACE and AT2 polymorphisms failed to show an association with either the number of lacunae or the PVH grade. We concluded that AGT and AT1 polymorphisms are independent genetic risk factors for lacunar infarction.

Larger anastomoses in angiotensinogen-knockout mice attenuate early metabolic disturbances after middle cerebral artery occlusion

Abnormalities in the homeostasis of the renin-angiotensin system have been implicated in the pathogenesis of vascular disorders, including stroke. The authors investigated whether angiotensinogen (AGN) knockout mice exhibit differences in brain susceptibility to focal ischemia, and whether such differences can be related to special features of the collateral circulation. Wild-type and AGN-knockout mice were submitted to permanent suture occlusion of the middle cerebral artery (MCA). The collateral vascular system was visualized by systemic latex infusion, and the ischemic lesions were identified by cresyl-violet staining. The core and penumbra of the evolving infarct were differentiated by bioluminescence and autoradiographic imaging of ATP and protein biosynthesis, respectively. In wild-type mice, mean arterial blood pressure was 95.0 +/- 8.6 mm Hg, and the diameter of fully relaxed anastomotic vessels between the peripheral branches of the anterior and middle cerebral arteries 26.6 +/- 4.0 microm. In AGN knockouts, mean arterial blood pressure was significantly lower, 71.5 +/- 8.5 mm Hg (P < .01), and the anastomotic vessels were significantly larger, 29.4 +/- 4.6 microm (P < .01). One hour after MCA occlusion, AGN-knockout mice exhibited a smaller ischemic core (defined as the region of ATP depletion) but a larger penumbra (the area of disturbed protein synthesis with preserved ATP). At 24 hours after MCA occlusion, this difference disappeared, and histologically visible lesions were of similar size in both strains. The observations show that in AGN-knockout mice the more efficient collateral blood supply delays ischemic injury despite the lower blood pressure. Pharmacologic suppression of angiotensin formation may prolong the therapeutic window for treatment of infarcts.

Angiotensin I-converting enzyme gene polymorphism, coronary artery disease and myocardial infarction. An angiographically controlled study

OBJECTIVES

We investigated the association between insertion/deletion polymorphism of the angiotensin I-converting enzyme (ACE) gene, the presence and extent of coronary artery disease, and myocardial infarction.

BACKGROUND

The D allele of the ACE gene has been associated with coronary artery disease and myocardial infarction, but this association has been challenged in epidemiological studies.

METHODS

Nine hundred and sixty-nine men and 341 women undergoing coronary angiography were studied. The ACE genotypes were assessed by polymerase chain reaction from genomic deoxyribonucleic acid, homozygosity for the D allele was controlled using an insertion-specific primer. Coronary artery disease was defined by angiographic criteria, the extent of coronary artery disease by the number of coronary arteries with >/=50% lumen narrowing.

RESULTS

The ACE genotypes did not differ in terms of age, sex, body mass index, blood pressure, plasma lipids or lipoproteins. We found no association between the ACE genotypes and coronary artery disease (odds ratio, 95% confidence interval in DD genotypes for coronary artery disease in men 0.97, 0.70-1.36; in women 1.56, 0.95-2.57), extent of coronary artery disease (men 1.17, 0.85-1.61; women 1.24, 0.65-2.34), or myocardial infarction among the patients with coronary artery disease (men 1.07, 0.78-1.48; women 0.95, 0.50-1.76). The ACE genotype was not associated with coronary artery disease or myocardial infarction in hypertensives (n=771; odds ratio for coronary artery disease 0.93, 0.65-1.34; odds ratio for myocardial infarction 0.94, 0.66-1.33), or in patients </=60 years (n=649; odds ratio for coronary artery disease 1.05, 0.72-1.52; odds ratio for myocardial infarction 0.96, 0.63-1.47).

CONCLUSION

ACE insertion/deletion gene polymorphism is associated neither with the prevalence nor the extent of coronary artery disease, nor with myocardial infarction in this relatively large sample of Caucasian men and women. Genotyping for ACE insertion/deletion polymorphism is not useful in assessing the individual risk of coronary artery disease or myocardial infarction.

An angiotensin-converting enzyme gene polymorphism suggests a genetic distinction between ischaemic stroke and carotid stenosis

BACKGROUND

Ischaemic cerebrovascular disease (ICVD) is a heterogeneous syndrome to which different genetic factors may contribute. We have investigated the distribution of alleles of the angiotensin-converting enzyme (ACE) gene, which has been suggested to be of possible importance in ischaemic stroke or cardiovascular disease, in groups of patients with ischaemic stroke and carotid artery stenosis (CS).

MATERIALS AND METHODS

One hundred and thirty patients with ischaemic stroke and 68 patients with more than 50% stenosis of the internal carotid artery were investigated and compared with age- and sex-matched healthy control subjects. Alleles of an insertion/deletion polymorphism of the ACE gene were determined by one-stage polymerase chain reaction and visualized on agarose gels.

RESULTS

There was a significant difference (P < 0.05) in the distribution of ACE alleles, homozygosity for the presumed susceptibility deletion allele being more common in patients with CS than in healthy control subjects. There was also a significant difference (P < 0.05) in patients with CS in comparison with matched ICVD patients without CS, both in allelic frequencies and in homozygosity for the deletion allele.

CONCLUSIONS

Our results indicate that the ACE gene polymorphism may be a risk factor for the development of CS. The observed difference in ACE allele distribution may be seen as evidence for a genetic distinction between ICVD and CS, two clinically related conditions, which further supports the hypothesis that genetic factors are of importance for this group of diseases.

Genetic susceptibility and ischaemic stroke

In the past year the search for genetic susceptibility factors involved in ischaemic stroke has motivated a number of important studies in humans and animals. These have been focused on genetic susceptibility as a risk factor for ischaemic stroke, or as a determinant of ischaemic stroke outcome. Because there is increasing evidence that genetic factors play a role, it seems that epidemiological studies assessing both environmental and genetic risk factors may help to understand the cause of ischaemic stroke better. This may have therapeutic and preventive implications.

A polymorphism of angiotensinogen gene codon 174 and coronary artery disease in Japanese subjects

The relationship between coronary artery disease (CAD) and polymorphisms of genes encoding angiotensinogen (AGT) and angiotensin converting enzyme (ACE) was analyzed in Japanese subjects. One hundred and four patients with CAD and 170 healthy subjects were enrolled in the study. CAD was defined as having a luminal diameter stenosis > or =50% in at least one of three major coronary arteries by coronary angiography. The genotypes (determined by polymerase chain reaction) of AGT gene codon 174 were not significantly associated with CAD in the total study population. However, the frequency of T/T homozygotes of AGT codon 174 was significantly higher in CAD patients compared to controls in each of three subgroups: 1) body mass index (BMI) below the median value of 24.1 kg/m2; 2) not more than two CAD risk factors out of five (hypercholesterolemia, hypertension, diabetes mellitus, smoking, and family history of CAD); and 3) the ACE I/I genotype. The M/M genotype of AGT codon 235 was negatively associated, and the ACE D/D genotype was positively associated, with CAD in the total study population. Our results indicate that the T/T genotype of AGT codon 174 may be a risk factor for CAD in Japanese individuals with low BMI, lesser CAD risk factors, or ACE I/I genotype.

Association between angiotensin I-converting enzyme genotypes, extracranial artery stenosis, and stroke

The insertion(I)/deletion(D) polymorphism of the angiotensin-converting-enzyme (ACE) gene has been associated with an increased risk of myocardial infarction, lacunar stroke, and with an increased intimal-medial thickness in several populations. The aim of this study was to evaluate whether the ACE I/D genotype is associated with stenosis of extracranial arteries and stroke in middle-aged and aged men and women. We studied 388 patients (247 male, 141 female) using Doppler and Duplex ultrasound of the extracranial arteries. Patients' history was obtained by standard questionnaire and by the hospital case records. Genomic DNA was analyzed by polymerase chain reaction (PCR) to identify the I/D polymorphism, with a second insertion specific PCR in samples classified as homozygous DD genotypes to prevent mistyping. The ACE genotype groups (DD 132, ID 164, II 92) were well matched for the basic characteristics. The DD genotype was more common in patients with extracranial artery stenosis > or = 50%, compared with patients without stenosis (59/147 versus 73/241, odds ratio 1.54, 95%-CI 1.01-2.37), but was not associated with a history of stroke (30/91 versus 102/297, odds ratio 0.94, 95%-CI 0.57-1.54). The association of the DD genotype with extracranial artery stenosis was also present in hypertensive subjects (n = 206, odds ratio 1.76, 95%-CI 0.99-3.17). In the whole group multiple logistic regression analysis revealed that the association of the DD genotype with extracranial artery stenosis was independent of age, gender, hypertension, hyperlipidemia, and diabetes. In conclusion, the ACE DD genotype is a weak risk factor for hemodynamically relevant stenosis of extracranial arteries, but not for stroke.