Angiotensin converting enzyme and angiotensin II type 1-receptor gene polymorphisms and risk of ischaemic heart disease.

OBJECTIVE: Polymorphisms in several genes of the renin-angiotensin system have been implicated as risk factors for myocardial infarction and ischaemic heart disease. In particular, it has been suggested that the angiotensin converting enzyme insertion/deletion (I/D) polymorphism and the angiotensin II type 1 receptor A1166C polymorphisms might act synergistically to increase the risk of myocardial infarction. The aim of this study was to investigate associations between the angiotensin converting enzyme I/D polymorphism and angiotensin II type 1 receptor polymorphisms and ischaemic heart disease. METHODS: We screened 331 white European patients who were recruited for routine angiographic investigation of chest pain, and 287 healthy white European controls for the angiotensin converting enzyme I/D and angiotensin II type 1 receptor A1166C polymorphisms, and related the genotype frequencies to angiotensin converting enzyme levels and the clinical phenotypes of atheroma and history of myocardial infarction. RESULTS: Angiotensin converting enzyme levels were related to I/D polymorphism but not to angiotensin II type 1 receptor polymorphism genotypes. I/D polymorphism and angiotensin II type 1 receptor genotypes did not relate individually to risk of myocardial infarction or atheroma in univariate or multivariate analysis. However, evidence of a synergistic relationship between the AC/II and CC/DD genotypes and coronary stenosis in the major arteries was found. No evidence of any relationship between these polymorphisms and history of myocardial infarction by World Health organisation (WHO) criteria was detected. CONCLUSION: These findings suggest that there is a weak relationship between the angiotensin converting enzyme I/D and angiotensin II type 1 receptor A1166C polymorphisms and coronary atheroma, but no evidence of a relationship with history of myocardial infarction.     

Angiotensin converting enzyme in patients with sleep apnoea syndrome: plasma activity and gene polymorphisms.

The prevalence of several cardiovascular diseases is increased with obstructive sleep apnoea syndrome (OSAS), due to, as yet, unclear reasons. Angiotensin converting enzyme (ACE) abnormalities have been implicated in the pathogenesis of various cardiovascular diseases. In this study, plasma ACE activity and the distribution of an insertion (I)/deletion (D) polymorphism of the ACE gene were determined in OSAS patients and in healthy controls. A total of 63 patients with OSAS (mean+/-SEM 54.5+/-2.5 apnoea/hypopnoeas.h(-1)) and 32 healthy subjects were studied. To avoid potential confounding factors, patients treated with ACE inhibitors or continuous positive airway pressure were excluded, as well as controls in whom a blood sample was not obtained early in the morning. ACE activity was determined spectrophotometrically in 46 OSAS patients and 25 controls. The I/D ACE polymorphism was determined by polymerase chain reaction in 44 patients and 32 controls. ACE activity was higher in OSAS patients (53.9+/-2.5 IU.L(-1)) than in healthy controls (42.4+/-3.1 IU.L(-1), p<0.01). This was independent of the presence of arterial hypertension. The frequency distribution of the DD, II and ID genotypes in OSAS patients (30%, 16%, 54%, respectively) was not significantly different from that seen in healthy subjects (31%, 28%, 41%, respectively, p=0.356). These results indicate that ACE plasma activity is increased in untreated OSAS patients. This increased activity may contribute to the pathogenesis of the cardiovascular disease in these patients.     

Angiotensin converting enzyme insertion/deletion polymorphisms in vasovagal syncope.

Recent studies suggest vasovagal syncope (VVS) has a significant heritable component (crude estimate sibling relative risk (lambda(s)): 1080) indicating that at least some forms of VVS may have a genetic cause. Here we present the first study examining a potential genetic abnormality in VVS. METHODS: DNA was collected from consecutive patients attending our unit with head up tilt confirmed VVS (n=165). One hundred and fourteen affected and unaffected first-degree relatives of those with a definitive diagnosis of VVS and positive family history also provided DNA. RESULTS: DNA from 165 VVS index cases was genotyped for the ACE insertion/deletion polymorphism. Mean+/-SD age of cases was 56+/-19 years (103 (62%) females). There was no significant difference in distribution of ACE insertion or deletion gene frequencies in cases compared with a large (>6000 subjects) national control population. No preferential transmission of alleles in families was identified using tests of association (P=0.1789) CONCLUSION: We have shown using both a case control and a small family based association study that polymorphisms of ACE alone are not associated with increased risk of VVS. Further studies are planned to clarify the genotype/phenotype relationship in VVS and examine other candidate genes.     

血管紧张素Ⅰ转换酶基因与急性脑血管病的相关性研究

采用ＰＣＲ扩增方法鉴定１３７例急性脑血管病（脑出血７１例，脑血栓形成５２例，蛛网膜下腔出血１４例）病人和１８６例正常对照的血管紧张素Ⅰ转换酶（ＡＣＥ）基因多态性，以观察急性脑血管病的发病与ＡＣＥ基因多态性之间的关系。结果发现：脑出血病人ＡＣＥ插入／插入（ⅠⅠ）纯合型频率明显高于对照组（０．５０７ＶＳ０．３６），而缺失／缺失（ＤＤ）纯合型频率则明显低于对照组（０．０７ＶＳ０．１７２）（Ｐ＝０．０３５４）；脑血栓形成和蛛网膜下腔出血病人ＡＣＥ基因多态频率与对照组差别不大（Ｐ＞０．０５）。提示ＡＣＥ基因ⅠⅠ纯合型可能为脑出血患者发病的易感因子。     

Angiotensin I-converting enzyme gene polymorphism in a low-risk European population for coronary artery disease

An insertion/deletion (I/D) polymorphism of the angiotensin I-converting enzyme (ACE) has been associated with an increased risk of coronary artery disease (CAD) and myocardial infarction (MI). However, this finding has not been fully investigated in European populations with very low CAD risk. In a case-control study on a population from Southern Europe (Toulouse, France), we evaluated the ACE I/D polymorphism in 405 men, aged 35–65 years, who underwent coronary angiography and in 357 representative control men within the same age range. We also explored associations in the patients between this polymorphism and CAD severity. The ACE genotype was not associated with the presence of either CAD or MI. The ACE genotype was not a marker for angiographically assessed CAD severity. In a sample in one of the European populations with the lowest CAD risk, ACE I/D polymorphism was not associated with an increased risk for CAD or MI and did not influence the extent of CAD.     

Angiotensin converting enzyme inhibitors

This review focuses on the use of angiotensin converting enzyme (ACE) inhibitors in hypertensive diseases. Specifically discussed are: proposed mechanisms of action, the pharmacology of the commercially available ACE inhibitors (captopril, enalapril, and lisinopril), their renal effects, and their safety and efficacy. The ACE inhibitors are assuming a dominant role in our therapeutic armamentarium, in that they are well-tolerated and very effective in the treatment of mild, moderate or severe hypertension.     

Angiotensin converting enzyme gene polymorphism in type 2 diabetes mellitus

The aim of this study is the assessment of the association of human angiotensin-converting enzyme gene I/D polymorphism with type 2 diabetes in 155 diabetic patients and 139 healthy individuals. These polymorphism were studied using polymerase chain reaction. Angiotensin converting enzyme gene DD genotype associated with type 2 diabetes in overweight and obese patients and patients with normal total plasma cholesterol. There is also association of DD genotype with arterial hypertension and with myocardial infarction in type 2 diabetic patients.     

血管紧张素转换酶基因多态性与原发性高血压的关系

目的：探讨中国人血管紧张素转换酶（ＡＣＥ）基因的插入／缺失（Ｉ／Ｄ）多态性与原发性高血压（ＥＨ）发病的相关性。方法按ＷＨＯ标准确诊的ＥＨ患者６８例,正常对照组６２例。用多聚酶链式反应（ＰＣＲ）和琼脂糖电泳技术,检测两组个体ＡＣＥ基因的Ｉ／Ｄ多态性。结果高血压组与正常对照组检测出３例基因Ⅱ、ⅠＤ和ＤＤ,频率分布分别为０．４８、０．３７、０．１５和０．３９、０．４８、０．１３,Ｉ、Ｄ等位基因频率分别为     

D/D genotype of the gene for angiotensin converting enzyme as a risk factor for post-stent coronary restenosis]

INTRODUCTION: Although intracoronary stenting has decreased restenosis rate compared to percutaneous balloon angioplasty, still a high number of patients develop in-stent restenosis, which is an entity primarily due to tissue proliferation. Experimental studies have indicated that the renin-angiotensin system is involved in neointimal hyperplasia. Plasma and cellular levels of ACE are associated with an I/D polymorphism in the ACE gene. Indeed, DD subjects have the higher ACE levels. The purpose of this study was to explore the possibility that the I/D polymorphism might be related with in-stent restenosis. METHODS: We studied the ACE polymorphism in 48 consecutive patients who underwent successful implantation of an elective coronary stent in native coronary vessels and had a 6 month angiographic follow up. Restenosis (50% of the reference vessel) was observed in 23/48 patients. Patients with or without restenosis did not differ in demographic or clinical variables like diabetes, plasma cholesterol levels or in quantitative angiographic parameters such as vessel reference size or minimal lumen diameter after stent implantation. RESULTS: I/D polymorphism was distributed as follows: 22.9% of the patients were D/D; 14.5% were I/I and 62.5% of the patients were heterozygous I/D. The presence of restenosis was strongly related with the I/D polymorphism: 81.8% of the patients with D/D genotype had restenosis, compared with 40.0% of I/D patients and only 14.2% of the I/I patients (chi 2 p < 0.01). CONCLUSIONS: In this limited cohort, homocygous D/D of the ACE gene was significantly associated with in-stent restenosis, whereas restenosis was infrequent in patients with the I/I genotype.     

Angiotensin converting enzyme inhibitors in arterial hypertension

We review the different cardiovascular effects exerted by angiotensin converting enzyme inhibitors, obtained in several experimental and clinical studies in the last twenty years, in patients with arterial hypertension and different cardiovascular pathologies related to the hypertensive process. We will review the mechanistic basis of the cardiovascular protective effects of angiotensin converting enzyme inhibition. These drugs, as monotherapy or combined therapy, can achieve blood pressure control in a high proportion of hypertensive patients; in hypertensive patients with diabetes these drugs are especially indicated, and also are the drugs of choice in diabetic hypertensive patients with cardiac dysfunction due to ischaemic cardiomyopathy. This group of drugs has the highest effect among the drugs available today in reducing left ventricular hypertrophy associated with the hypertensive process. There are many experimental and clinical data that suggest the potential role of the angiotensin converting enzyme antagonists limiting the atherosclerotic process.     

Angiotensin converting enzyme gene deletion allele is independently and strongly associated with coronary atherosclerosis and myocardial infarction.

OBJECTIVE--To investigate the association of the three angiotensin converting enzyme (ACE) genotypes, DD, ID, and II, with the occurrence or absence of coronary atherosclerosis and with myocardial infarction and hypertension. DESIGN--Cohort analysis study. SETTING--North-Italy reference centre. SUBJECTS--388 white Italian patients (281 males; mean age 60.7 (SD 12.5) years) with proven coronary atherosclerosis (n = 255) or with angiographically normal coronary arteries (n = 133). A further group of 290 healthy blood donors was tested for allele frequency comparison. INTERVENTIONS--ACE/ID polymorphism was analysed with polymerase chain reaction on DNA from white blood cells. MAIN OUTCOME MEASURES--Coronary atherosclerosis, myocardial infarction, hypertension. RESULTS--The D and I allele frequencies were respectively 0.63 and 0.37 in the overall healthy blood donor group and 0.66 and 0.34 in the overall study group. In the latter, univariate analysis showed (1) that coronary atherosclerosis (255 patients) was associated with the deletion allele, with an odds ratio (OR) of 5.78 for DD/II, P < 0.001, and 2.39 for ID/II, P = 0.006; and (2) that myocardial infarction (154 patients) was associated with the DD genotype (OR DD/II = 2.56, P = 0.007), but not with the ID genotype (OR DD/II = 1.96, P = 0.056). Finally, hypertension proved to be unrelated with the ACE genotype. The distribution between the three genotypes of known risk factors for coronary artery disease was similar. Logistic regression modelling, performed to test the association of the selected risk factors simultaneously with coronary atherosclerosis and myocardial infarction, showed that the deletion allele (whether DD or ID) was the strongest risk factor for atherosclerosis, and that the D allele was significantly associated with the risk of infarction (although to a lesser extent than with coronary atherosclerosis). CONCLUSION--ACE deletion polymorphism is strongly and independently associated with coronary atherosclerosis and, to a lesser extent, with myocardial infarction. As such, the results are analogous to what has already been reported in French white, Japanese, and Welsh coronary patients.