ACE gene polymorphism and long-term renal graft function

OBJECTIVES: The long-term outcome of transplanted kidneys has not changed substantially and only a minority of grafts survives more than 15 yr. The aim of this study was to determine the influence of ACE gene polymorphism on long-term outcome after renal transplantation. DESIGN AND METHODS: Using PCR, we evaluated ACE I/D gene polymorphism in a group of patients with long-term graft function (LTF) over 15 yr and compared it with control groups of transplant recipients and population sample. RESULTS: The distribution of genotypes in the LTF group differed from transplant controls (p < 0.05). Moreover, DD homozygotes in the LTF group had better creatinine clearance (DD: 1.1 +/- 0.3, ID: 0.96 +/- 0.3, II: 0.76 +/- 0.3 mL/s; p < 0.05). There were no differences in genotype distribution between transplant and population samples. CONCLUSIONS: Results of our study have demonstrated a possible connection between the DD variant of ACE I/D gene polymorphism and excellent long-term graft function.     

Angiotensin converting enzyme gene polymorphism and glomerular filtration rate changes in type 2 diabetic patients

It has been suggested that an insertion/deletion (I/D) polymorphism in intron 16 of the angiotensin-converting enzyme (ACE) gene may be associated with diabetic nephropathy The aim of this study was to investigate whether an association exists between ACE I/D polymorphism and glomerular filtration rate (GFR) in type 2 diabetes mellitus. A total of 128 type 2 diabetic patients were included in the study with the following ACE genotype distribution: DD 40, ID 58,11 30. I/D polymorphism was determined by polymerase chain reaction (PCR). Mean GFR was not statistically different according to ACE genotype (DD: 89.9 +/- 28.1 ml/min, ID: 99.5 +/- 25.1 ml/min, II: 96.6 +/- 19.6 ml/min). There was no significant difference in genotype distribution in normo-, micro- and macroalbuminuric patients (DD:ID:II [%], normo- 35:46:19, micro-28:55:17, macro- 31:55:14). ACE I/D polymorphism does not seem to be associated with GFR in type 2 diabetic patients.     

ACE gene insertion/deletion polymorphism associated with 1998 World Health Organization definition of metabolic syndrome in Chinese type 2 diabetic patients

OBJECTIVE: Because ACE insertion/deletion (I/D) polymorphism has been shown to be associated with diabetes, hypertension, coronary artery diseases, and diabetic nephropathy, and because plasma ACE concentration has been found to be associated with plasma triglyceride and total cholesterol levels in patients with type 2 diabetes, the goal of this study was to investigate whether ACE gene I/D polymorphism is associated with metabolic syndrome in Chinese subjects with type 2 diabetes. RESEARCH DESIGN AND METHODS: A total of 711 patients with type 2 diabetes and 750 control subjects were studied. The ACE I/D polymorphism was determined by PCR. The definition and criteria of metabolic syndrome used in this study matched those proposed in the 1998 World Health Organization classification. RESULTS: Of 711 patients with type 2 diabetes, 534 (75.1%) fulfilled the criteria for metabolic syndrome. The prevalence of metabolic syndrome in control subjects with II, ID, and DD genotype was 9.4, 11.5, and 15.4%, respectively, and in patients with type 2 diabetes, it was 68.6, 79.2, and 86.1%, respectively. The ACE I/D polymorphism was significantly associated with the syndrome in patients with type 2 diabetes (P = 0.001). When pooling the control subjects with diabetic patients, the prevalence of metabolic syndrome in the whole study group with II, ID, and DD genotype was 37.9, 44.5, and 51.0%, respectively, and ACE I/D polymorphism was still significantly associated with metabolic syndrome (P = 0.003). Diabetic patients with DD genotype were also found to have a higher prevalence of dyslipidemia (II/ID/DD = 43.1/53.1/65.8%, P < 0.001) and albuminuria (36.0/44.6/50.6%, P = 0.018) and to have higher serum triglyceride levels (II, ID, and DD = 155 +/- 114, 170 +/- 140, and 199 +/- 132 mg/dl, respectively, P < 0.05). Control subjects with DD genotype were also found to have a higher prevalence of albuminuria or more advanced nephropathy (II/ID/DD = 5.7/14.0/15.4%, P = 0.001), whereas the prevalence of dyslipidemia was not found to be statistically different in the control group. When pooling control with diabetic subjects, ACE genotype could still be significantly associated with dyslipidemia (II/ID/DD = 34.7/41.3/52.2%, P < 0.001) and albuminuria or more advanced nephropathy (20.3/28.9/33.1%, P < 0.001). Diabetic patients with metabolic syndrome were found to have higher serum uric acid levels than those without metabolic syndrome (6.4 +/- 1.8 vs. 5.3 +/- 1.4 mg/dl, P < 0.01). CONCLUSIONS: The ACE I/D polymorphism was found to be associated with metabolic syndrome in Chinese patients with type 2 diabetes. This finding may provide genetic evidence to explain the clustering of metabolic syndrome and suggests that the renin-angiotensin system is involved in the pathophysiology of metabolic derangement in patients with type 2 diabetes.     

血管紧张素转换酶基因多态性与高血压病血管内皮纤溶障碍的关系

目的 :探讨 ACE基因 I/ D多态性与原发性高血压 (EH)及高血压血管内皮纤溶功能障碍间的关系。方法 :PCR检测 6 1例原发性高血压患者和正常对照组 2 8例的 ACE基因 I/ D多态性 ;发色底物法测 t- PA、PAI- 1活性 ,酶联免疫吸附双抗夹心法 (EL ISA)测 v WF含量。结果 :高血压组 DD基因型频率显著高于对照组 (P<0 .0 5 ) ,但 D等位基因频率分布在高血压组和正常组之间无差异性 (P>0 .0 5 )。高血压组 t- PA活性降低 ,PAI- 1活性、v WF含量升高 (P均 <0 .0 0 1)。高血压组 DD型 t- PA活性明显低于 ID、II型 (P<0 .0 0 1) ,而 ID、II型之间无统计学差异 (P>0 .0 5 ) ,DD型 PAI-1活性明显高于 ID、 型 (P<0 .0 0 1) ,而 ID、II型之间无统计学差异 (P>0 .0 5 ) ,v WF在 DD、ID、II型三者之间无明显差异 (P均 >0 .0 5 )。结论 :DD型是原发性高血压发病的危险因素。原发性高血压存在血管内皮损伤、纤溶功能障碍。t- PA、PAI- 1的变化与血管紧张素转换酶基因 I/ D多态性有关 ,DD基因型可引起纤溶功能紊乱。     

Increased deformability of red blood cells is associated with a deletion polymorphism of the angiotensin-converting enzyme gene

Angiotensin-converting enzyme (ACE) plays important roles in the renin-angiotensin system. ACE converts angiotensin I to angiotensin II and also inactivates bradykinin, thereby modulating the vascular tone. A polymorphism of the ACE gene, located on chromosome 17, has been found in intron 16, and is characterized by the presence (insertion [I]) or absence (deletion [D]) of a 287-base-pair Alu repeat. Individuals with the D allele of the ACE gene have higher ACE levels and are at higher risk of cardiovascular events. We aimed to investigate the possible relationship between the I/D polymorphism of the ACE gene and hemorheological parameters, including red blood cell (RBC) deformability. The study was performed on 28 healthy young volunteers (13 women and 15 men, mean age 24 +/- 2). The prevalence of the I and D alleles was 30.4% and 69.6%, respectively. The I/I genotype (II) was found in 21.4%, I/D genotype (ID) in 17.9%, and D/D genotype (DD) in 60.7% of the subjects tested. No significant relationship between ACE I/D polymorphism and RBC aggregation or whole blood and plasma viscosity was observed. In contrast, RBC deformability was significantly increased in the subjects with the DD genotype compared with the II (p < 0.05) or the ID (p < 0.01) genotype, and in the subjects with the D allele compared with the I allele (p < 0.01). We suggest that RBC deformability of individuals with the D allele, who have higher risk for cardiovascular pathologies, may have been increased by a compensatory mechanism.     

The insertion/deletion polymorphism of the ACE gene is related to insulin sensitivity in overweight women

OBJECTIVE: The ACE insertion/deletion (I/D) polymorphism has been identified as a genetic risk factor for coronary heart disease (CHD). The deletion (D) allele of the ACE gene may be associated with higher insulin sensitivity. Individuals who are homozygous for the DD allele have higher ACE levels and possibly more angiotensin II, which, when infused exogenously, causes an increase in insulin sensitivity. The purpose of this study was to investigate the association of the I/D polymorphism of the ACE gene with insulin sensitivity and CHD risk factors. RESEARCH DESIGN AND METHODS: The study included 66 women (ages 57 +/- 1 years) who were overweight or obese (means +/- SEM, BMI = 33 +/- 1 kg/m(2)) and sedentary (VO(2max) = 19.6 +/- 0.4 ml. kg(-1). min(1)). Total body fat mass and percent fat were determined by dual-energy X-ray absorptiometry, and abdominal fat was by computed tomography. Insulin sensitivity was measured during the last 30 min of 3-h hyperinsulinemic-euglycemic clamps (40 mU. m(-2). min(-1)). Comparisons were made among women with the II (n = 9), ID (n = 36), and DD (n = 21) genotypes. RESULTS: Age, percent body fat, waist-to-hip ratio, visceral and subcutaneous abdominal fat areas, plasma lipid levels, and systolic and diastolic blood pressures did not differ by ACE genotype. Fasting glucose and 2-h glucose levels were similar among genotypes, but fasting plasma insulin levels were lower in DD women than in ID women (P < 0.05). Glucose utilization was higher in women with the DD genotype than in women with the II genotype (53.1 +/- 3.9 vs. 36.0 +/- 3.8 micromol. kg(-1) FFM. min(-1), P = 0.01) and was higher in ID women than in II women (48.5 +/- 2.5 micromol. kg(-1) FFM. min(-1), P = 0.04). CONCLUSIONS: These data suggest that the I/D polymorphism is not associated with risk factors for CHD in overweight sedentary women; however, women who are homozygous for the D allele of the ACE gene are more insulin sensitive, whereas women who are homozygous for the I allele of the ACE gene have greater insulin resistance and potential risk for type 2 diabetes.     

Frequency of angiotensin-converting enzyme gene polymorphism in Turkish type 2 diabetic patients

We aimed to investigate the angiotensin-converting enzyme (ACE) gene polymorphism, ACE activity and their associations with diabetic complications in Turkish patients with type 2 diabetes mellitus. A total of 143 patients and 133 controls were screened for ACE gene I/D polymorphism by using polymerase chain reaction. Serum ACE activities were determined spectrophotometrically. There was no significant difference in the distribution of ACE I/D genotypes between patients and controls. The patients with DD genotype had a higher ACE activity than those with ID and II. Hypertensive diabetic patients with DD genotype had higher ACE activities than those with ID and II. There was no significant difference in the distribution of ACE I/D genotypes between patients with and without nephropathy, retinopathy and hypertension except for patients with and without neuropathy. In patients with DD genotype, creatinine clearance correlated with duration of diabetes. The grade of retinopathy was correlated with duration of diabetes in DD and ID genotypes. The highest ACE activity was measured in hypertensive diabetics with DD genotype. ID genotype was suggested to be a risk factor and II was suggested to be protective for diabetic neuropathy. The DD and ID genotypes might be a predictor for the development of retinopathy in relation to duration of diabetes.     

Angiotensin-converting enzyme genotype, albuminuria and plasma fibrinogen in type 2 diabetes mellitus

AIMS: Increased fibrinogen level is considered an important atherosclerosis risk factor. Patients with type 2 diabetes frequently have increased fibrinogen levels. The aim of the present study was to examine the effect of angiotensin-converting enzyme (ACE) gene polymorphism and the effects of the diabetic environment on plasma fibrinogen in type 2 diabetes. PATIENTS AND METHODS: The study group included 125 patients with type 2 diabetes (40 men, 85 women). The average age of patients was 62 +/- 10 years. Fibrinogen concentration was determined with the thrombin coagulation test. ACE insertion/deletion (I/D) polymorphism was detected using polymerase chain reaction (PCR) assay. RESULTS: II homozygotes (n = 17) had the highest mean fibrinogen levels, ID heterozygotes (n = 75) had medium levels and DD homozygotes (n = 33) had the lowest (p = 0.054, ANOVA). II homozygotes also had significantly higher mean fibrinogen level than ID/DD carriers (4.3 +/- 1.7 vs. 3.5 +/- 1.3 g/l; p = 0.015). The indices of renal functions, i.e. albuminuria (r = 0.37; p < 0.0001) and serum creatinine (r = 0.22; p = 0.015), significantly correlated with fibrinogen levels. The correlation between albuminuria and fibrinogen was significant in the subgroups with genotypes II (r = 0.76; p = 0.001) and ID (r = 0.37, p = 0.002), whereas in the subgroup of DD homozygotes this relationship did not reach statistical significance. In the multivariate regression analysis with age, sex, BMI, creatinine, albuminuria and ACE genotype as independent variables, albuminuria was the only significant predictor of fibrinogen level (p < 0.0001). After interaction between the ACE genotype and albuminuria was included into multivariate analysis, the interaction became the only independent predictor of plasma fibrinogen level (p < 0.0001) in the model, and the model explained 25% of the plasma fibrinogen variance. CONCLUSION: ACE gene polymorphism is associated with plasma fibrinogen level in type 2 diabetes. This association is mediated by an interaction between ACE genotype and albuminuria. Diabetes patients with genotypes II or ID have increased plasma fibrinogen in the presence of albuminuria.     

The D allele of angiotensin I-converting enzyme gene insertion/deletion polymorphism is associated with the severity of atherosclerosis

BACKGROUND: Angiotensin II is produced primarily by angiotensin I-converting enzyme (ACE) within atherosclerotic lesions and ACE level in plaques correlates with the severity of vessel wall damage. Therefore, we investigated the possible association of ACE gene insertion/deletion (I/D) polymorphism and the severity of atherosclerosis, estimated on the basis of the number of coronary stenoses and critical arterial occlusions observed during coronary angiography. METHODS: The study cohort included 172 patients with angiographically confirmed premature coronary artery disease. The ACE gene I/D polymorphism was genotyped using a PCR method. RESULTS: The frequencies of DD genotype, D allele carrier-state (DD+ID genotypes) and the D allele increased with the number of stenoses in coronary vessels. D allele carriers (DD+ID genotypes) were more frequent in the subgroup of patients with stenoses in at least four coronary vessels than in other patients including subjects with one-, two- and three-vessel disease (97.4% vs. 74.4%, OR=13.05, 95% CI: 1.81-100.00, chi2=9.84, p=0.0017). Furthermore, the D allele was significantly more frequent in patients with critical arterial occlusions (>90%) than in subjects without critical stenoses (61.1% vs. 49.3%, chi2=9.84, p=0.023). CONCLUSIONS: The ACE I/D polymorphism influences individual differences in severity of coronary artery disease and the D allele promotes generation of numerous and critical atherosclerotic lesions.     

血管紧张素转化酶基因I/D多态性与维吾尔族高血压合并阻塞性睡眠呼吸暂停低通气综合征患者左心室肥厚的关系

目的探讨血管紧张素转化酶(ACE)基因插入/缺失(I/D)多态性与维吾尔族高血压合并阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者左心室肥厚(LVH)的关系。 方法选取2015年1月至2016年12月于新疆医科大学第一附属医院高血压科首诊住院,且未服用血管紧张素转换酶抑制剂/血管紧张素Ⅱ受体拮抗剂(ACEI/ARB)类降压药物的维吾尔族高血压合并OSAHS患者,共72例,行多导睡眠呼吸监测、动态血压、心脏彩超等检查,聚合酶链式反应(PCR)和琼脂糖凝胶电泳技术测定ACE基因多态性。根据左心室质量指数分为左心室肥厚组(LVH组,n＝24)和非左心室肥厚组(NLVH组,n＝48),比较两组间基因型及基因频率的差异,使用多因素Logistic回归分析左心室肥厚的影响因素。 结果高血压合并OSAHS患者LVH组ACE基因型频率分别为：II(37.50%),ID(20.83%),DD(41.67%),等位基因频率分别为：I(48.00%),D(52.00%),与NLVH组[II(47.92%),ID(37.50%),DD(14.58%),I(67.00%),D(33.00%)]比较,差异有统计学意义(χ²＝6.75,4.70;均P<0.05);对左心室肥厚影响因素进行多因素Logistic回归分析,呼吸暂停低通气指数(AHI)(OR＝6.20,95%CI：1.44～26.77;P<0.05)、DD基因型(OR＝4.61,95%CI：1.05～20.31;P<0.05)是维吾尔族高血压合并OSAHS患者发生LVH的独立危险因素。 结论ACE基因I/D多态性与维吾尔族高血压合并OSAHS患者发生LVH有关,其中DD基因型维吾尔族患者更易发生LVH。     

Interaction between angiotensin-converting enzyme genotype and glycaemic control influences lipoprotein levels in type 2 diabetes mellitus

AIMS: To evaluate the influence of the angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism on lipid levels in patients with Type 2 diabetes. PATIENTS AND METHODS: 109 patients with Type 2 diabetes were included. The patients were not on any lipid-lowering treatment. The groups with different ACE genotypes had similar ages, sex distributions, body mass indices, systolic blood pressures and indices of glycaemic control. ACE gene I/D polymorphism was determined using polymerase chain reaction. RESULTS: The mean apolipoprotein B (apoB) level was significantly higher in the group of DD homozygotes compared with the subjects with at least one insertion allele (DD: 1.21 +/- 0.25 g/l vs. ID + II: 1.04 +/- 0.27 g/l; P = 0.007). Significant correlations between glycated haemoglobin (HbA1c) and both apoB and cholesterol levels were found (r = 0.27; P < 0.01). For the apoB, this correlation was highly significant in the DD-genotype subgroup (r = 0.54; P < 0.01), and was not significant in the subgroup of patients with genotypes ID or II. In the multivariate analysis, HbA1c and the interaction of genotype DD with HbA1c were significant independent predictors of apoB (r2 = 0.17) and cholesterol levels. CONCLUSION: The present study showed that the interaction between the DD genotype of angiotensin-converting enzyme and chronic hyperglycaemia (expressed by HbA1c level) is related to higher plasma levels of atherogenic lipoproteins, such as apoB and cholesterol, in patients with Type 2 diabetes.     

Acute effects of nifedipine administration in pulmonary haemodynamics and oxygen delivery during exercise in patients with chronic obstructive pulmonary disease: implication of the angiotensin-converting enzyme gene polymorphisms

The angiotensin-converting enzyme (ACE) DD genotype is associated with exaggerated pulmonary hypertension and disturbance in tissue oxygenation during exercise in patients with chronic obstructive pulmonary disease (COPD). This study was designed to examine the acute effects of nifedipine administration in pulmonary haemodynamics and oxygen delivery during exercise in COPD patients with II, ID, and DD genotypes. Thirty-three COPD patients (II = 12, ID = 11, DD = 10) with placebo or nifedipine (10 mg) underwent right heart catheterization with exercise, and systemic and pulmonary haemodynamic variables were examined. At rest, there was no significant difference in either mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR) or oxygen delivery (DO2) among the three groups. However, the magnitude of mPAP or PVR after exercise was the DD > ID > II genotype. In contrast, the magnitude of DO2 after exercise was the II > ID > DD genotype. We also found that nifedipine administration significantly decreased mPAP after exercise in all the three groups. However, we found no significant difference in PVR or DO2 between placebo and nifedipine administration in all the three groups. Thus, a single administration of nifedipine may not have the clinical efficacy for the treatment of pulmonary hypertension and impaired oxygen delivery during exercise in COPD patients with different ACE gene polymorphisms.     

Insertion/deletion polymorphism of the angiotensin I-converting enzyme gene in patients with breast cancer and effects on prognostic factors.

The aims of the present study were to investigate the distribution of the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene in breast cancer patients and the association between ACE genotypes and clinicopathologic features, as well as their effects on prognosis. We assessed the I/D polymophism of the ACE gene by using polymerase chain reaction from peripheral blood in breast cancer and healthy age-matched women. The clinicopathologic parameters of breast cancer patients were obtained from medical records. Of the 57 patients, 31 (54.4%) had DD, 24 (42.1%) had ID, and 2 (3.5%) had II genotypes. In control subjects, 33 (63.5%) had DD, 12 (23.1%) had ID, and 7 (13.4%) had II genotypes. The ID genotype was seen more commonly in breast cancer patients (p = .03). When the combination of ID and II genotypes was used as a reference group, the DD genotype was associated with negative hormone receptor status (p = .003), tumor size (p = .054), and lymph node involvement (p = .07) but not histologic high grade and c-erb B2 overexpression. These results suggest that the DD genotype may accompany poor prognostic factors and influence the tumor course.     

中国人脑梗死ACE基因插入/缺失多态性的Meta-分析

目的：对中国人血管紧张素I转换酶（ACE）基因内含子16插入型（I）／缺失型（D）多态性与脑梗死的关联性进行Meta-分析。方法：以脑梗死组和非脑梗死对照组基因型分布的OR值为统计量。全面检索到相关文献,排除发表偏倚的影响,剔除不符合要求的文献,应用REVMAN3．1软件对各研究结果进行一致性检验和采用相应的数学模型进行数据合并。结果：相关文献未发现显著发表偏倚,数据合并结果未考虑原发病的脑梗死和继发于原发性高血压的脑梗死患者DD／（ID＋Ⅱ）OR有显著统计意义,继发于Ⅱ型糖尿病的脑梗死DD／（ID＋Ⅱ）OR无显著性。结论：中国人ACE／ID多态性中DD基因型与非糖尿病性脑梗死有关联,病例组DD基因型增多。     

蒙古族人群血管紧张素转换酶基因多态性与高血压的关系

背景有关血管紧张素转换酶基因多态性与高血压关系的研究已有报道,但在蒙古族人群中尚不十分清楚.蒙古族是高血压患病率较高的民族,因此有必要探讨蒙古族人群中血管紧张素转换酶基因多态性与高血压的关系.目的探讨蒙古族人群血管紧张素转换酶基因多态性与高血压的关系.设计采用现况调查的方法.地点和对象选择内蒙古自治区通辽市科左后旗朝鲁吐苏木作为本研究现场,所有研究对象均为在此长期居住的蒙古族居民.共获得有高血压家族史的高血压者51例、血压正常者32例和没有高血压家族史的高血压者64例、血压正常者85例.干预应用聚合酶链式反应检测血管紧张素转换酶基因的插入/缺失多态性.主要观察指标血管紧张素转换酶多态性基因型频率和I、D等位基因频率.结果血管紧张素转换酶基因的三种基因型(II,ID,DD)在4组人群间的分布差异无显著性意义(P＞0.1).在4组人群中均表现出ID基因型频率最高,其次为Ⅱ基因型,DD基因型频率最低.I,D等位基因在4组人群间的分布也差异无显著性意义(P＞0.1).在4组人群中I等位基因频率均高于D等位基因频率.结论血管紧张素转换酶基因I/D多态性与蒙古族高血压的发生无关联.     

ACE 基因 I/D 多态性与动脉血栓性脑梗死的关联性研究

目的研究血管紧张素转换酶（ACE）基因I/D多态位点与动脉血栓性脑梗死的关联性及相关机制。方法选取动脉血栓性脑梗死患者112例和年龄、性别匹配的对照组180例,采用PCR-AFLP技术对ACE基因I/D位点进行分型。 结果单因素分析提示病例组收缩压水平（138.1±19.7 mmHg）显著高于对照组（126.6±20.6 mmHg）（t=4.716,P<0.001）;病例组舒张压水平（88.9±10.1 mmHg）显著高于对照组（79.9±10.0 mmHg）（t=7.450,P<0.001）。病例组中ACE基因I/D位点D等位基因频率和DD基因型频率分布均显著高于对照组（等位基因:χ2=4.953,P=0.026; 基因型:χ2=6.303,P=0.043）。病例组和对照组中ACE基因I/D位点基因型DD携带者收缩压及舒张压水平显著高于基因型ID及II携带者。 结论ACE基因I/D位点等位基因D可能是汉族人群动脉血栓性脑梗死遗传易感基因。等位基因D可能通过升高个体血压的机制导致动脉血栓性脑梗死发生。       

Influence of oxygen administration on pulmonary haemodynamics and tissue oxygenation during exercise in COPD patients with different ACE genotypes

We previously found that the angiotensin-converting enzyme (ACE) DD genotype is associated with exaggerated pulmonary hypertension and disturbance of tissue oxygenation during exercise in chronic obstructive pulmonary disease (COPD) patients. This study was designed to compare the effect of oxygen administration on pulmonary haemodynamics and tissue oxygenation during exercise in COPD patients with different ACE genotypes. Forty-three COPD patients (II=16, ID=12, DD=15) underwent right heart catheterization, and then performed an exercise test with room air or oxygen. We measured pulmonary haemodynamic variables and indices of tissue oxygenation such as mixed venous oxygen tension (PVO2) and arterial lactate concentration, both at rest and after exercise. The magnitude of difference in mean pulmonary arterial pressure and pulmonary vascular resistance after exercise between breathing of room air and breathing of oxygen did not significantly differ among the three groups. PVO2 after exercise with room air or oxygen was significantly higher in patients with the II genotype than in those with the ID or DD genotype. In contrast, lactate concentration after exercise with room air or oxygen was significantly lower in patients with the II genotype than in those with the ID or DD genotype. Moreover, the magnitude of difference in PVO2 and lactate concentration after exercise between breathing of room air and breathing of oxygen was the II>ID>DD genotype. These findings suggest that the ability of oxygen administration to improve tissue oxygenation during exercise is associated with the ACE genotypes in COPD patients.     

Lack of association between angiotensin-converting enzyme gene polymorphism and type I aortic dissection

The relationship between angiotensin-converting enzyme (ACE) gene polymorphism and type I aortic dissection was examined in 205 unrelated hypertensives. A total of 94 patients underwent emergency repair due to type I aortic dissection, confirmed by computed tomography, and the remaining 111 were controls. Polymerase chain reaction was used to confirm that ACE gene polymorphism was due to insertion (I) or deletion (D) of a 287 base pair (bp) DNA sequence within intron 16. The genotype distribution and allele frequency of ACE I/D polymorphism between patients and controls were not statistically significant. When the frequency of at least one D allele carrier (DD or ID genotype) was compared with the II homozygous genotype, there was also no significant difference between the study groups. The findings revealed no association between ACE I/D polymorphism and aortic dissection. We conclude that I/D mutation of the ACE gene does not seem to be a risk factor for aortic dissection.     

ACE gene I/D-polymorphism and hereditary predisposition to myocardial infarction

The authors compare distribution of genotype frequencies and alleles of I/D of ACE gene polymorphism in patients with various forms of ischemic heart disease (IHD): with acute myocardial infarction (MI), stable effort angina (functional class II-III); in patients with postinfarction cardiosclerosis (PICS). A relationship was found between I/D polymorphism and acute MI. Frequency of DD genotype in MI patients was 0.57, in controls--0.21, p < 0.0001, RR = 4.9. The DD genotype may serve a marker of hereditary predisposition to MI. Genotype DD frequency in the group with acute MI was higher than that with PICS. In acute MI frequency of allele D was 0.76, in PICS--0.51, p < 0.0005. It is suggested that low frequency of genotype DD in the PICS group results from higher lethality of patients with DD genotype in the nearest rehabilitation period. Patients with repeated MI have a significantly higher frequency of genotype DD and complications after MI. Thus, there is a relationship between insertion-deletion polymorphism of ACE gene and myocardial infarction. Deletion DD genotype raises the risk to develop MI and probability of life-threatening complications and repeated MI.     

Association study of the I/D polymorphism and plasma angiotensin-converting enzyme (ACE) as risk factors for stent restenosis

The ID (insertion/deletion) polymorphism of the ACE (angiotensin-converting enzyme) gene controls plasma ACE levels. Both have been correlated with ISR (in-stent restenosis) in preliminary analyses, but not confirmed in larger studies. In the present study, baseline and 6-month quantitative coronary analysis were performed in 897 patients who had stent implantation and the ID polymorphism genotyped. Plasma ACE levels were measured in 848 patients (95%). Restenosis rates among genotypes were 31.2% DD, 25.5% ID and 28.8% II (not significant). Plasma ACE levels were significantly higher in restenotic patients compared with patients without restenosis (30.7+/-18.6 units/l compared with 22.8+/-12.8 units/l; P=0.0001) and a strong independent predictor of ISR [OR (odds ratio)=3.70; 95% CI (confidence interval), 2.40-5.71; P<0.0001], except in diabetics. In the subgroup of diabetics and patients with AMI (acute myocardial infarction), the DD genotypes actually had a lower risk of ISR than the II genotypes (diabetics, OR=0.16; 95% CI, 0.04-0.69; P=0.014; and patients with AMI, OR=0.21; 95% CI, 0.061-0.749; P=0.016). After exclusion of diabetics and patients with AMI, ISR rates for genotypes in 632 patients were 31.7% DD, 24.3% ID and 17.6% II (P=0.02; DD compared with non-DD OR=1.57; 95% CI, 1.09-2.25). The association between the D allele and ISR observed in selected populations does not hold with a larger sample size. Other than sample size, clinical variables can modulate the association between ID polymorphism and ISR. Plasma ACE level is a risk factor for ISR, independently of the ID genotype.