肾素-血管紧张素系统基因多态性与冠心病合并慢性心力衰竭严重程度的关系

目的检测部分中国南方汉族人群冠心病合并慢性心力衰竭患者的ACE及AGT基因多态性分布情况,以探讨肾素-血管紧张素系统（1／AS）基因多态性对冠心病合并慢性心力衰竭严重程度的影响。方法应用聚合酶链反应及限制性片断长度多态性技术,对210例冠心病合并慢性心力衰竭患者的ACE基因插入／缺失（I/D）及AGT基因M235T多态性进行检测,采用彩色多普勒检测患者的左室舒张末内径（LVDD）及左室射血分数（LVEF）。结果不同ACE基因型患者其LVDD及LVEF均存在差异,LVDD（DD）〉LVDD（ID）〉LVDD（II）（P〈0．05）,LVEF（DD）〈IXEF（ID）〈LVEF（II）（P〈0．05）,不同AGT基因型亚组间LVDD及LVEF差别均无统计学意义（P〉0．05）。结论ACE基因I／D多态性与中国南方部分汉族人群冠心病合并慢性心力衰竭的严重程度相关,DD型ACE基因的冠心病患者发生心力衰竭后病情较其他基因型者更加严重。AGT基因M235T多态性似与冠心病合并慢性心力衰竭的严重程度无关。     

Neutral endopeptidase and angiotensin I converting enzyme insertion/deletion gene polymorphism in humans

Neutral endopeptidase (NEP) hydrolyses angiotensins (Ang) I and II and generates angiotensin-(1-7) [Ang-(1-7)]. In humans, the insertion/deletion (I/D) angiotensin-I converting enzyme (ACE) gene polymorphism determined plasma ACE levels by 40%. In rats, a similar polymorphism determines ACE levels which are inversely associated to NEP activity. The objective of this study is to evaluate the relationship between ACE expression and plasma NEP activity in normotensive subjects and in hypertensive patients. In total, 58 consecutive patients with hypertension, evaluated in our Hypertension Clinic, were compared according to their ACE I/D genotypes with 54 control subjects in terms of both plasma ACE activity and NEP activities. Plasma ACE activity was elevated 51 and 70% in both DD ACE groups (normotensives and hypertensives) compared with their respective ID and II ACE groups (P<0.001). A significant effect of the ACE polymorphism and of the hypertensive status on ACE activity was observed (P<0.001). In normotensive DD ACE subjects, NEP activity was 0.30+/-0.02 U/ml, whereas in the normotensive II ACE and in the normotensive ID ACE subjects NEP activity was increased 65 and 48%, respectively (P<0.001). In the hypertensive DD ACE patients, NEP activity was 0.47+/-0.03 U/mg. An effect of the I/D ACE genotypes on NEP activity (P<0.04) and an interaction effect between the I/D ACE genotype and the hypertensive status were also observed (P<0.001). These results are consistent with a normal and inverse relationship between the ACE polymorphism and NEP activity in normotensive humans (as is also observed in rats). This normal relationship is not observed in hypertensive patients.     

血管紧张素转换酶基因多态性与不同性别慢性心力衰竭患者发病的相关性研究

目的探讨我国南方汉族人群中,血管紧张素转换酶(ACE)基因多态性与不同性别慢性心力衰竭(CHF)发病的关系。方法应用聚合酶链反应技术测定82例男性和48例女性CHF患者(试验组),以及89名男性和41名女性健康者(对照组)的ACE基因插入/缺失(I/D)多态性,并进行统计学比较。结果共检测出3种ACE基因型,分别为II型、ID型和DD型。试验组患者DD基因型及D等位基因均高于同性别对照组;与非DD型者相比,男性DD型者发生CHF的相对风险率为1.918;女性DD型者发生CHF的相对风险率为2.727。结论ACE基因I/D多态性与中国南方汉族人群不同性别CHF的发生均相关,D等位基因可能是该地区CHF发病的遗传危险因素。与男性相比,DD基因型女性罹患CHF的可能性更大。     

Association of angiotensin-converting enzyme DD genotype with 24-h blood pressure abnormalities in normoalbuminuric children and adolescents with Type 1 diabetes.

AIMS: To assess the distribution of the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene in children and adolescents with Type 1 diabetes and to evaluate the association between ACE genotype and blood pressure (BP). METHODS: ACE genotypes were assessed in 124 normoalbuminuric, clinically normotensive Type 1 diabetic children and adolescents and 120 non-diabetic controls using polymerase chain reaction. Twenty-four-hour ambulatory BP monitoring was undertaken in all patients. RESULTS: ACE genotypes distributed in patients as follows: 34 (27%) DD, 57 (46%) ID, 33 (27%) II. The distribution was similar in the control group: DD in 28% (33), ID in 45% (54), and II in 27% (33). Patients with DD genotype had higher mean 24-h diastolic BP (73.8 +/- 6.2 vs. 70.2 +/- 5.0 and 69.7 +/- 6.3 mmHg; P = 0.005) and lower diurnal variation in BP (11.8 +/- 4.6 vs. 14.2 +/- 4.2 and 14.8 +/- 4.3%; P = 0.011) compared with ID and II groups. Four patients in the DD group proved to be non-dipper compared with one in the ID and none in the II group (P = 0.026). Twenty-four-hour diastolic blood pressure was independently predictive for AER as dependent variable in the DD genotype patient group (r(2) = 0.12, P = 0.03). CONCLUSIONS: Children and adolescents with Type 1 diabetes do not differ from the non-diabetic population regarding the I/D polymorphism of the ACE gene. ACE gene polymorphism is associated with BP abnormalities in normotensive and normoalbuminuric children and adolescents with Type 1 diabetes.     

Association between angiotensin-converting enzyme gene polymorphisms and regression of left ventricular hypertrophy in patients treated with angiotensin-converting enzyme inhibitors.

PURPOSE: An insertion/deletion (ID) polymorphism of the angiotensin-converting enzyme (ACE) gene is associated with left ventricular hypertrophy. The present study examined polymorphisms of the ACE gene in patients with essential hypertension and left ventricular hypertrophy who were participants in a long-term trial of therapy with an ACE inhibitor. PATIENTS AND METHODS: ACE inhibitor therapy was administered for >2 years to 54 patients with hypertension who had moderate or severe left ventricular hypertrophy. Cardiac dimensions were monitored by echocardiography before the initiation of therapy and after 1 and 2 years of treatment. Serum ACE activity and plasma concentrations of brain natriuretic peptide, a marker for left ventricular hypertrophy, were also monitored. RESULTS: Eighteen patients had the II genotype for the angiotensin-converting enzyme gene, 19 had the ID genotype, and 17 had the DD genotype. Baseline (mean +/- SD) serum ACE activity was significantly greater (P <0.05) in the DD (18 +/- 7 IU/L) group than in the II (7 +/- 4 IU/L) or ID (12 +/- 6 IU/L) groups. ACE inhibitor therapy was effective in controlling blood pressure, and it reduced posterior and septal wall thickness, left ventricular mass index, and plasma brain natriuretic peptide concentration in all three groups. Despite similar blood pressure reductions, after 2 years, mean (+/- SD) regression in posterior wall thickness was significantly less (P <0.05) in the DD group (-9% +/- 5%) than in the ID (-21% +/- 7%) and II (-21% +/- 9%) groups. Similar results were seen for the reductions in brain natriuretic peptide levels. The magnitudes of regression of septal wall thickness and left ventricular mass index during therapy were less in the DD group than the II group (P <0.05). CONCLUSION: Hypertensive patients with the DD genotype are less likely to have regression of left ventricular hypertrophy when treated with ACE inhibitors than are patients with other ACE genotypes.     

Angiotensin-converting enzyme gene polymorphism and vascular manifestations in Korean patients with SLE

Systemic lupus erythematosus (SLE) is an inflammatory multisystem disease of unknown etiology with immunologic aberrations. Many studies have shown that genetic and environmental factors are implicated in the development of SLE. Angiotensin-converting enzyme (ACE) affects various immune phenomena through the renin-angiotensin and kallikrein-kininogen systems by creating angiotensin II and inactivating bradykinin. We investigated the correlation between insertion/ deletion polymorphism of the ACE gene and the clinical manifestations of SLE, especially vascular involvement and lupus nephritis. Two-hundred and eleven Korean patients fulfilling the ACR criteria and 114 healthy subjects were enrolled. The ACE genotype was determined by polymerase chain reaction using genomic DNA from peripheral blood. The nephritis patients were classified by the WHO classification. In addition, the activity and chronicity index were used to assess the severity of renal involvement. We evaluated vascular involvement by the presence or absence of hypertension, Raynaud's phenomenon, livedo reticularis, antineutrophil cytoplasmic antibody and the SLICC/ACR Damage Index. The gene frequency of ACE gene polymorphism was as follows: II 39 vs 34%, ID 41 vs 50%, DD 20 vs 16% in SLE patients and controls, respectively. There was no difference in genotype frequency between both groups. There were no significant differences between the distribution of ACE gene genotypes and lupus nephritis and its related parameters, including WHO classification, activity index, chronicity index, renal dysfunction and amount of 24 h urinary protein. The ACE genotypes and alleles did not affect the presence of vascular manifestations evaluated, but the frequency of DD genotype was significantly low in SLE patients with Raynaud's phenomenon compared to those without Raynaud's phenomenon (P = 0.002 for ACE ID vs DD and II, OR 2.7, 95% CI 1.43-5.09; P=0.023 for ACE DD vs ID and II, OR 0.33, 95% CI 0.12-0.89). Also skewing from DD to II genotype was noted in patients with anti-Sm antibody compared to those without anti-Sm antibody (P = 0.025 for ACE DD vs ID and II, OR 0.21, 95% CI 0.05-0.93). The onset age of serositis was older in patients with the ID genotype than the others (ID= 34.5+/-10.8, II + DD = 25.6+/-10.2, P= 0.002). Also the onset age of malar rash was older in patients with II genotype than the others (II=26.7+/-8.4, ID+DD=21.3+/-9.0; P=0.021). The patients with I allele showed a significantly higher frequency of serositis (P = 0.022). Taken together, the I/D polymorphisms of ACE gene did not affect susceptibility of SLE, lupus nephritis and the vascular manifestations, including Raynaud's phenomenon, in Korean SLE patients, although the DD genotype was negatively associated with Raynaud's phenomenon among SLE patients. However, it would be valuable to evaluate the role of other genes potentially related to vascular events, such as endothelin, nitric oxide or angiotensin II receptor as well as ACE gene.     

Hypertensive left ventricular remodeling and ACE-gene polymorphism.

OBJECTIVE: To evaluate the relationship between ACE-gene polymorphism and left ventricular geometry in never treated hypertensives. METHODS: We enrolled 200 hypertensive outpatients that underwent clinical and ambulatory blood pressure measurements, echocardiographic evaluation and analysis for insertion (I)/deletion (D) polymorphism by PCR. Patients with normal or increased (> 125 g/m2 in males and > 110 g/m2 in females) left ventricular mass were considered to have concentric remodeling or concentric left ventricular hypertrophy if their relative wall thickness was > or = 0.45. RESULTS: The left ventricular mass index values (g/m2) were 136 +/- 30 in DD genotype, 124 +/- 26 in ID genotype, and 116 +/- 20 in II genotype (DD vs. ID P < 0.005; DD vs. II P < 0.05), and were unrelated to blood pressure. Ninety-six patients presented left ventricular hypertrophy (48.0%): 51 with concentric and 45 with eccentric hypertrophy. The eccentric left ventricular hypertrophy was detected in 32 (36.8%) DD patients, in ten (10.5%) ID patients (P < 0.05), and in three (16.6%) II patients. The relative septal thickness was 0.43 +/- 0.09 in DD genotype, 0.45 +/- 0.08 in ID genotype, and 0.43 +/- 0.10 in II genotype. In DD and ID genotypes, the relative posterior wall thickness (0.37 +/- 0.07 vs. 0.41 +/- 0.07; P < 0.0001) and the end-diastolic left ventricular internal dimension (52.8 +/- 3.3 mm vs. 48.3 +/- 2.8 mm; P < 0.0001) were statistically different. CONCLUSIONS: The DD genotype of the ACE-gene is associated with an increased left ventricular mass and with a significantly higher prevalence of eccentric left ventricular hypertrophy, when compared to ID genotype.     

Angiotensin-converting enzyme gene polymorphism influences degree of left ventricular hypertrophy and its regression in patients undergoing operation for aortic stenosis.

Insertion (I)/deletion (D) polymorphism of the angiotensin-converting enzyme (ACE) gene has been associated with increased left ventricular hypertrophy (LVH) in patients with cardiomyopathy and congestive heart failure. Patients with aortic stenosis (AS) have varying degrees of LVH at a given valve area. The aim of this study was to examine the relation between ACE gene polymorphism and the degree of LVH in patients undergoing operation for AS. Eighty-two patients who underwent operation for AS with a stentless valve were followed prospectively with echocardiographic assessments of left ventricular mass index (LVMI). ACE gene polymorphism was determined by polymerase chain reaction. The genotype (DD, ID, and II) frequency was the same as in healthy controls. The pressure difference across the aortic valve did not differ between genotypes. Patients with the DD genotype of the ACE gene had a higher LVMI (197 +/- 47 g/m2) preoperatively than those with ID (175 +/- 41 g/m2) or II (155 +/- 43 g/m2) genotypes (p = 0.01). LVMI decreased significantly in DD (p <0.001) and ID (p <0.001) genotypes but not in the II genotype during follow-up (mean 15 months). There was a significant difference in regression of LVMI over time between genotypes (p = 0.0056), with no significant difference between genotypes at follow-up. The DD genotype of the ACE gene is associated with increased preoperative LVH in patients treated surgically for AS. The DD genotype appears to be an important factor which increases hypertrophic myocardial reactivity to pressure overload.     

Serum angiotensin I-converting enzyme is reduced in Crohn's disease and ulcerative colitis irrespective of genotype

OBJECTIVES: Crohn's disease (CD) is recognized to be a vascular endothelial-associated disease. Angiotensin I-converting enzyme (ACE) exists mainly in endothelial cells. There are some reports on serum ACE levels in patients with CD, but the ACE level is still controversial. Recently, genetic control of serum ACE levels by ACE gene polymorphisms (classified as II, ID, and DD) has been suggested. Although we must consider such polymorphisms to elucidate ACE levels in patients with CD, there is no report about this. METHODS: We studied 341 healthy controls (male/female = 178/162), 39 patients with CD (31/8), 43 patients with ulcerative colitis (UC) (22/21) and 19 patients with infectious enterocolitis (8/11). The polymorphism in intron 16 of the ACE gene was examined by PCR. Serum ACE levels were measured by the method of Kasahara. RESULTS: Serum ACE levels in patients with CD and UC were significantly lower than in healthy controls, irrespective of the genotype of ACE (genotype II: CD 7.0+/-2.5 [mean +/- SD], UC 7.1+/-3.3, controls 11.8+/-2.9, genotype ID: CD 9.7+/-4.1, UC 11.4+/-4.6, controls 15.2+/-3.6, genotype DD: CD 13.9+/-5.8, UC 10.7+/-3.6, controls 19.3+/-3.9 IU/L, controls vs CD, UC; p < 0.01, 0.05). However, there was no significant difference in serum ACE levels between CD and UC. CONCLUSIONS: Considering ACE gene polymorphism, serum ACE levels in patients with inflammatory bowel disease are lower than in controls. Serum ACE levels reflect a part of the pathogenesis of inflammatory bowel disease.     

I/D gene polymorphism of the angiotensin-converting enzyme and left ventricular hypertrophy. Response to converting enzyme inhibitors

BACKGROUND: The present study was designed to assess whether the angiotensin-converting enzyme (ACE) gene I/D polymorphism influence the ACE inhibitors effect on the regression of left ventricular hypertrophy. METHODS: Sixty hypertensive subjects never treated by antihypertensive drugs, aged 46 +/- 11 years, were included in the study. Follow-up with ACE inhibitor treatment was 60 +/- 26 months. Genotypes for ACE I/D polymorphism (DD, ID or II) were determined by PCR. The left ventricular mass index (LVMI) was assessed by two-dimensional directed M-mode echocardiography. RESULTS: ACE genotype distribution was in agreement with the Hardy-Weinberg equilibrium: 21 patients had the DD genotype, 29 were ID, and 10 were II. At baseline, age, systolic arterial pressure and LVMI didn't differ on the basis of genotype. Body mass index was significantly higher in II than in ID and DD groups. Regression of LVMI with ACE inhibitor treatment was similar in the 3 genotypes (-8.9%, -0.6%, -12.1% in DD, ID and II groups respectively). In addition, decrease of systolic arterial pressure was identical in 3 groups. CONCLUSION: ACE gene I/D polymorphism seems not to influence regression of left ventricular hypertrophy by ACE inhibitors in essential hypertension.     

Relationship between polymorphism of the angiotensin-converting enzyme gene and the response to angiotensin-converting enzyme inhibition in hypertensive patients.

The aim of this study was to investigate the relationship between polymorphism of the anglotensin-converting enzyme (ACE) gene and the blood pressure response to ACE inhibition in a hypertensive cohort. Imidapril (5-10 mg/day) or benazepril (10-20 mg/day) was administered for 6 weeks to 517 essential hypertensives. ACE gene polymorphism was examined by the polymerase chain reaction (PCR) method and the patients were classified as having the 190-bp deletion homozygous (DD) genotype, the 490-bp insertion homozygous (II) genotype, or the 490-bp insertion, 190-bp deletion heterozygous (ID) genotype. The achieved change in systolic and diastolic blood pressure (SBP and DBP) was analyzed for association with genotypes at the ACE gene locus. The DD genotype was observed in 132 patients (25.5%), the ID genotype in 255 patients (49.3%), and the II genotype in 130 patients (25.2%). The SBP reductions in the patients with the DD genotype, II genotype, and ID genotype were -14.5 +/- 12.7 mmHg, -14.3 +/- 13.1 mmHg and -14.0 +/- 12.2 mmHg, respectively (p = 0.94). The DBP reductions in the patients with the DD genotype, II genotype, and ID genotype were -8.7 +/- 7.4 mmHg, -8.7 +/- 7.7 mmHg and -8.5 +/- 6.7 mmHg, respectively (p = 0.96). There was no significant association between the ACE gene polymorphisms and the response to ACE inhibition. These results suggest that ACE genotype does not predict the blood pressure-lowering response to antihypertensive treatment with ACE inhibition.     

Beta-adrenergic receptor blockade and the angiotensin-converting enzyme deletion polymorphism in patients with chronic heart failure

BACKGROUND: Beta-adrenergic receptor blockade is an established treatment of chronic heart failure (HF). Previous studies have suggested a potential pharmacogenetic interaction between beta-blocker therapy and the angiotensin-converting enzyme (ACE) I/D polymorphism in patients with HF. AIMS: We designed this study to analyze changes in myocardial function of HF patients in response to beta-blocker therapy as a function of the ACE I/D polymorphism. METHODS AND RESULTS: We studied 199 consecutive patients with chronic HF not treated with beta-blockers. Before initiation of beta-blockers and 3 months after the maximal tolerated dose was reached, patients underwent echocardiography, radionuclide angiography, and a cardiopulmonary exercise test. We extracted genomic DNA from white blood cells and determined the ACE I/D polymorphism. Thirty-five (18%) patients had the II genotype, 86 (43%) the ID genotype and 78 (39%) the DD genotype. A significant and similar improvement in left ventricular ejection fraction (LVEF) was observed in II (from 0.30+/-0.10 to 0.41+/-0.13; P<0.0001), ID (from 0.29+/-0.11 to 0.39+/-0.13; P<0.0001) and DD patients (from 0.31+/-0.11 to 0.40+/-0.13; P<0.0001). Peak Vo(2) before and after beta-blockade was similar among the three groups. The proportion of responders to beta-blockers (patients without cardiac events during titration who had an increase in LVEF >5% after beta-blockers) was similar among the three groups (II: 65.9%%, ID: 60.6%%, DD: 65.9%; P=NS). During a median follow-up of 933 days, there was no evidence for any effect of ACE I/D polymorphism on cardiac survival. CONCLUSIONS: We observed no evidence of pharmacogenetic interaction between the ACE I/D polymorphism and the effects of beta-blockade on LVEF and other prognostic parameters in patients with chronic HF. Our results support the initiation of beta-blockers in HF patients with the II or the ID genotype as well as in those with the DD genotype.     

The ACE gene polymorphism and cough threshold for capsaicin after cilazapril usage

Persistent dry cough is an occasional but clinically important adverse reaction to angiotensin I-converting enzyme (ACE) inhibitors (ACEI). Its reported incidence is variable, and why cough occurs in only certain individuals has been unclear. An insertion/deletion (I/D) polymorphism of the ACE gene is associated with serum ACE activity. We have previously shown that susceptibility to cough induced by ACEI is associated with this polymorphism such that patients with genotype II are more susceptible to cough than patients with other genotypes. In order to confirm and extend our previous observation, we conducted a randomized, placebo-controlled, double-blind, cross-over study in 10 healthy volunteers with genotype II and 10 with genotype DD. The cough threshold was determined by the concentration of inhaled capsaicin causing two or more coughs. After the usage of an ACEI, cilazapril, for 4 weeks, changes in the cough threshold in subjects with genotype II [before: 6.6+/-3.7 nM (mean+/-SD); after: 5.0+/-4.6 nM] significantly differed from those in subjects with genotype DD (before: 9.0+/-9.4 nM; after: 9.3+/-9.1 nM). Skin responses to intradermal bradykinin, which is a substrate of ACE and tussigenic, were significantly increased in subjects with genotype II (before: 1.6+/-0.6 vs. after: 2.6+/-0.5 cm2, P<0.05) but not in subjects with genotype DD (before: 1.4+/-0.5 vs. after: 1.6+/-0.6 cm2, n.s.) after usage of cilazapril. By contrast, skin responses to intradermal substance P did not change in subjects with either genotype. These findings provide further evidence of a link between ACEI-induced cough and I/D polymorphism of the ACE gene and suggest that ACEIs induce cough by modulating the tissue level of bradykinin.     

DD angiotensin-converting enzyme gene polymorphism is associated with endothelial dysfunction in normal humans.

A polymorphism within the angiotensin-converting enzyme (ACE) gene may increase the risk of myocardial infarction in individuals previously thought to be at low cardiovascular risk. The mechanism through which it exerts this effect is unknown but may be due to increased angiotensin II-induced nitric oxide (NO) breakdown and/or reduced bradykinin-mediated NO release. We investigated whether endothelial function was different between different ACE genotypes. We performed a cross-sectional study comparing the endothelial function of the 3 genotypes (II: n=25; ID: n=31; DD: n=12). Mean+/-SD ages of the subjects were 24+/-4 (II), 25+/-6 (ID), and 25+/-6 (DD) years. We assessed the impact of the genotypes on endothelial function and found that the DD genotype was associated with a significant blunting in endothelial-dependent vasodilatation (forearm blood flow data are presented as mean+/-SD ratio of blood flow in response to 3 incrementally increasing doses of each vasoactive agent in the test arm to blood flow in the control arm; the comparison is between DD versus ID versus II; the P value is an expression of an overall difference by ANOVA, and the 95% CIs are of a pairwise comparison between genotypes): acetylcholine, 2.88+/-1.45 versus 3.81+/-1.93 versus 4.23+/-2.37 (P=0.002; 95% CI [II versus ID], -0.19 to 0.91; 95% CI [II versus DD], 0.36 to 1.80; 95% CI [ID versus DD], 0.02 to 1.42). There was also a significant difference with the endothelial-independent vasodilator sodium nitroprusside, with values of 2.11+/-1.00 versus 2.55+/-1.36 versus 2.75+/-1.18 (P<0.05; 95% CI [II versus ID], -0.15 to 0.51; 95% CI [II versus DD], 0.03 to 0.89; 95% CI [ID versus DD], -0.13 to 0.71), but not with verapamil. There was no effect of the ACE genotype on endothelial-dependent or -independent vasoconstrictors NG-monomethyl-L-arginine or norepinephrine. Investigating the effects of cigarette smoking on each genotype demonstrated that for II and DD genotypes, acetylcholine responses were further blunted if subjects smoked. These data demonstrate that the DD ACE genotype in a young population is associated with a blunting of stimulated endothelial NO and donated NO responses but not to non-NO vasodilators or vasoconstrictors.     

The insertion/deletion polymorphism of the angiotensin-converting enzyme gene determines coronary vascular tone and nitric oxide activity

OBJECTIVES: We investigated whether the insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme (ACE) gene modulates vasomotor tone and endothelial function. BACKGROUND: The deletion allele of the ACE I/D polymorphism has been associated with increased incidence of cardiovascular pathology. The risk is synergistically increased in patients who also possess the C allele at position 1,166 of the angiotensin type I (AT1) receptor gene. METHODS: In 177 patients with coronary atherosclerosis or its risk factors, we investigated endothelial function with intracoronary acetylcholine (ACH), endothelium-independent smooth muscle function with sodium nitroprusside (SNP) and basal nitric oxide activity with L-NG monomethyl arginine. RESULTS: Compared with ACE II genotype, patients with the ACE DD genotype had lower coronary microvascular and epicardial responses with SNP (coronary blood flow increase 196 +/- 26% vs. 121 +/- 11%, p = 0.003, and diameter increase 21.9 +/- 2% vs. 17 +/- 1%, p = 0.03, ACE II vs. DD, respectively). L-NG monomethyl arginine induced greater constriction in patients with the ACE DD compared with ACE II genotype (coronary blood flow -10 +/- 4% vs. 11 +/- 5%, p = 0.003, ACE DD vs. II and diameter constriction -6.3 +/- 1.2% vs. -1.9 +/- 1.2%, p = 0.01, respectively, in patients with atherosclerosis). No difference in ACH-mediated vasomotion was detected between the three ACE genotypes. The AT1 receptor polymorphism did not influence responses to either SNP or ACH. CONCLUSIONS: Patients possessing the D allele of the ACE gene have increased vascular smooth muscle tone. The enhanced tone appears to be counterbalanced by an increase in basal nitric oxide activity in patients with atherosclerosis.     

Angiotensin-converting enzyme I/D polymorphism and macrovascular disease in systemic sclerosis

OBJECTIVE: Systemic sclerosis (SSc) is characterized by microvascular and macrovascular alterations. The D allele of the ACE I/D polymorphism is known to be associated with an increased incidence of atherosclerosis and has been recently proposed as associated with increased risk of SSc. This study evaluates the relationship between intima-media thickness (IMT), ankle-brachial pressure measurements (ABPI) and ACE I/D polymorphism in SSc patients. METHODS: According to the presence of ACE D allele (analysed by PCR), 53 SSc patients (47 females and 6 males; median age was 60.4 +/- 10.68 yrs; range 40-75 yrs) were divided in carriers of the D allele (DD + ID) (n = 46) and carriers of the I allele (II) (n = 7). In these patients, IMT and ABPI [calculated as the posterior tibial artery pressure (mmHg) divided by the brachial pressure] were obtained. Forty-three healthy controls (40 women and 13 men; median age 56.3 +/- 10.23; range 40-70 yrs) of the same ethnicity were recruited. RESULTS: SSc patients had IMT significantly higher than controls (0.85 +/- 0.03 vs 0. 68 +/- 0.01; P < 0.03). No significant differences (P > 0.3) in ABPI values between patients (1.018 +/- 0.10) and controls (1.091 +/- 0.11) were found. SSc patients with ACE DD and ID genotype showed an IMT significantly greater (0.89 +/- 0.03) than those carrying the II genotype (0.61 +/- 0.01) (P < 0.04). ABPI was not different among ACE gene genotypes. CONCLUSION: Our findings confirm an increased prevalence of macrovascular disease in SSc patients and show that IMT is greater in patients carrying the ACE DD and ID genotype in comparison with II homozygotes. This suggests that, in SSc, the presence of ACE D allele may predispose to an involvement of the macrovascular system.     

Effects of angiotensin-converting enzyme gene polymorphism on the left-ventricular function and mass in patients with acromegaly

In this study we have investigated the contribution of the ACE genotype to the development of left-ventricular hypertrophy (LVH) and systolic and diastolic dysfunctions in acromegalic patients. The study group consisted of 30 acromegalic patients (21 women and 9 men, age: 37.9 +/- 10.8 years, disease duration: 9.0 +/- 6.9 years). The distribution of the DD, ID and II genotypes was 40.0 (n = 12), 46.6 (n = 14) and 13.3% (n = 4), respectively, being similar to frequencies observed in a healthy population. Plasma ACE levels were 55.0 +/- 12.0 (45-84), 28.7 +/- 15.7 (8-58) and 24.5 +/- 12.0 (16-33) U/I in patients with the DD, ID and II genotype, respectively. The mean serum ACE activity in the DD genotype was significantly higher than in the heterozygous group (p < 0.0001). Serum ACE activity showed a significant negative association with the mean growth hormone level (r = -0.52, p = 0.007). The LV early diastolic flow velocity/LV presystolic flow velocity (E/A) ratios were 1.2 +/- 0.4 for the DD genotype, 1.3 +/- 0.3 for the ID genotype and 0.7 +/- 0.1 for the II genotype. The E/A ratio was considerably lower in acromegalic patients with the II genotype compared to the other genotypes (p = 0.03). The LV mass index (LVMI) values were 131.5 +/- 4.2 g/m2 for the DD genotype, 141.7 +/- 50.3 g/m2 for the ID genotype and 159.6 +/- 48.2 g/m2 for the II genotype. However, there was no significant difference in LVMI among allelic groups. All other indices of systolic and diastolic function were not statistically different in the acromegalic patients. The present data fail to support a role of ACE gene polymorphism in determining LVH in acromegalic patients. However, the I allele may prove as a useful marker predicting the development of diastolic dysfunction in acromegalic patients.     

Correlation of angiotensin converting enzyme gene polymorphism with perioperative myocardial protection under extracorporeal circulation

ObjectiveTo observe the expression of angiotensin converting enzyme (ACE), angiotensin II (Ang II), cardiac troponin (cTn I), creatine kinase isozymes (CK-MB) and muscle red protein(Myo) after cardiopulmonary bypass (CPB), and to investigate the association of polymorphisms in angiotensin converting enzyme genes and myocardial injury.MethodsSixty-three patients suffered from rheumatic mitral stenosis and scheduled for mitral valve replacement with CPB, were randomly divided into three groups according polymorphisms in angiotensin converting enzyme genes: type II, type ID, type DD (each=21). Blood samples were withdrawn from artery before operation (T1), at the beginning of CPB (T2), 30 min after CPB (T3), (T4) at the end of CPB (T5), 2 h after CPB (T6), 6 h after CPB (T7) to measure the expression of ACE, Ang II, cTn I, CK-MB, Myo.ResultsThe level of ACE during and after CPB were significantly higher than those before CPB (P<0.05). As extension of CPB time, the expression of ACE was increased. The level of cTn I, CK-MB, Myo after CPB were significantly higher than those before CPB(P<0.05). The level of cTn I, CK-MB and Myo were highest at T7, T6 and T5 and T7, respectively. The level of ACE, Ang II cTn I in patients with DD genotype was significantly higher than the ID and II genotype (P< 0.05). Besides, the level of ACE, Ang II in patients with ID genotype was significantly higher than the II (P< 0.05).ConclusionsThere is certain correlation between CPB perioperative midterm ACE and cTn I, Myo, CK-MB. ACE DD genotype is a susceptibility gene of the CPB perioperative myocardial injury.     

Association of left ventricular systolic performance and cavity size with angiotensin-converting enzyme genotype in idiopathic dilated cardiomyopathy

The insertion-deletion (ID) polymorphism of the angiotensin-converting enzyme (ACE) gene is a marker linked to differences in plasma and cardiac ACE activity as well as to an increased mortality in patients with idiopathic heart failure. We examined the possibility that ACE gene ID variants are associated with differences in left ventricular (LV) systolic performance or internal LV dimensions in a high-risk cohort of patients with idiopathic dilated cardiomyopathy (IDC). The ACE genotype was determined in 171 patients selected with IDC in New York Heart Association functional class II to III heart failure and with a LV ejection fraction of < or = 40%. Left ventricular performance and dimensions were assessed using echocardiography (n = 161) and radionuclide ventriculography (n = 169). The frequency of ACE gene ID alleles was not different in the study versus non-age-matched (n = 171; odds ratio 0.94) and age-matched (n = 106, odds ratio 0.88) control groups. Ejection fraction was found to be worse in patients with the DD genotype (echocardiography, DD = 23.5 +/- 0.70, ID + II = 26.8 +/- 0.8, p = 0.009; ventriculography, DD = 21.7 +/- 0.9, ID + II = 25.3 +/- 0.8, p = 0.003). LV end-systolic and end-diastolic diameters were increased in patients with the DD genotype. Multifactor regression analysis showed the ACE genotype to be an independent predictor of both ejection fraction (echocardiography, p <0.02; ventriculography, p <0.03) and end-diastolic diameter (p <0.02). In conclusion, the results of this study indicate that the DD genotype of the ACE gene is independently associated with both a reduced LV systolic performance and an increased LV cavity size in patients with IDC.