血管紧张素原基因M235T多态性与老年脑梗死的相关性研究

目的　探讨血管紧张素原 (angiotensinogen ,AGT)基因M2 35T分子变异与脑梗死 (cerebralinfarction ,CI)之间的关系。方法　采用聚合酶链反应 (PCR)及限制性片段长度多态性分析 (RFLP)法对 75例CI、48例健康对照进行了AGT基因M2 35T多态性检测。结果　CI组AGT基因T2 35等位基因频率为 0 .78,2 35TT基因型频率为 0 .6 4,与对照组(分别为 0 .6 0 4和 0 .375 )比较差异具有显著性 (χ2 =8.82 ,P=0 .0 0 3;χ2 =8.2 7,P =0 .0 0 4)。校正了CI的几种危险因素 (血总胆固醇、血糖及年龄 )后 ,2 35TT基因型仍可使CI发生的危险性增加 (分别为OR =3.2 89,P =0 .0 36 ;OR =2 .49,P =0 .0 2 3)。结论　AGT基因 2 35TT型可能是脑梗死发病的独立危险因素。     

AGT基因M235T多态同哈萨克族高血压病的关联分析

目的探讨新疆哈萨克族血管紧张素原（angiotensinogen,AGT）基因第二外显子（M235T）多态性同高血压病（essential hypertension,EH）的关系。方法4次高血压流行病学调查采集新疆巴里坤哈萨克族EH组278例,正常血压（norm altensive,NT）组220例。测定EH患者和NT者体质量指数（BM I）、空腹血糖、血浆胆固醇、甘油三酯。用MS-PCR法（mutagen ically separated polym erase chain reaction techn ique）检测AGT基因M235T多态性。结果M235T多态性符合Hardy-W e inberg平衡。MT、TT、MM基因型分布频率在EH组及NT组分别为32.7%,62.6%,4.7%;38.2%,51.8%,10.0%。T等位基因频率分别为79.0%及70.9%。M235T基因型频率（P<0.05）及等位基因频率（P<0.01）分布在EH组及NT组均有显著性差异。T等位基因携带者OR值为非T等位基因携带者OR值的2.3倍（95%C I 1.14.6;P<0.05）。对未治疗的EH者在不同基因型间进行比较,未发现MT、MM、TT基因型间收缩压、舒张压、体质量指数、血糖、血脂水平有显著性差异。结论AGT基因M235T可能同新疆哈萨克族高血压病发病相关。     

Angiotensinogen T174M and M235T gene polymorphisms are associated with the extent of coronary atherosclerosis.

BACKGROUND: The relations of the angiotensinogen (AGT) T174M and M235T gene polymorphisms to the risk of coronary heart disease (CHD) have been investigated in only a few studies with conflicting results. RESULTS: Therefore, we analysed the relationship of the AGT gene polymorphisms to the presence and extent of CHD in 2250 male Caucasians whose coronary anatomy was defined by means of coronary angiography. The relative frequencies of the T and M alleles of the T174M and of the M235T gene variation did not significantly differ between patients without or with single-, double- or triple-vessel disease and between subjects without or with myocardial infarction (MI). In contrast the mean CHD score--defined by Gensini--was higher within MM homozygotes of the T174M gene variation than within TT genotypes; TM subjects had intermediate values. In M235T genotypes, mean CHD scores were similar in the total sample and in older individuals (> or = 62 years), whereas in younger individuals (< 62 years) a higher CHD score was found within AGT 235 T allele carriers than within MM homozygotes. In younger individuals with high apoAI plasma levels, the mean CHD score was clearly higher within TT homozygotes of the M235T gene variation than within MM genotypes; MT subjects had intermediate values. An interaction between both angiotensinogen gene polymorphisms on the extent of CHD or on the risk of non-fatal MI were not observed when the M allele of AGT T174M was combined either with the T allele or the TT genotype of M235T. CONCLUSIONS: The present study strengthens the hypothesis of an association of both angiotensinogen gene polymorphisms with the extent of coronary heart disease.     

Progression of kidney disease in type 2 diabetes – beyond blood pressure control: an observational study

Background

Essential hypertension is a common, polygenic, complex disorder resulting from interaction of several genes with each other and with environmental factors such as obesity, dietary salt intake, and alcohol consumption. Since the underlying genetic pathways remain elusive, currently most studies focus on the genes coding for proteins that regulate blood pressure as their physiological role makes them prime suspects. The present study examines how polymorphisms of the insertion/deletion (I/D) ACE and M235T AGT genes account for presence and severity of hypertension, and embeds the data in a meta-analysis of relevant studies.

Methods

The I/D polymorphisms of the ACE and M235T polymorphisms of the AGT genes were determined by RFLP (restriction fragment length polymorphism) and restriction analysis in 638 hypertensive patients and 720 normotensive local blood donors in Weisswasser, Germany. Severity of hypertension was estimated by the number of antihypertensive drugs used.

Results

No difference was observed in the allele frequencies and genotype distributions of ACE gene polymorphisms between the two groups, whereas AGT TT homozygotes were more frequent in controls (4.6% vs. 2.7%, P =.08). This became significant (p = 0.035) in women only. AGT TT genotype was associated with a 48% decrease in the risk of having hypertension (odds ratio: 0.52; 95% CI, 0.28 to 0.96), and this risk decreased more significantly in women (odds ratio: 0.28; 95% CI, 0.1 to 0.78). The meta-analysis showed a pooled odds ratio for hypertension of 1.21 (TT vs. MM, 95% CI: 1.11 to 1.32) in Caucasians. No correlation was found between severity of hypertension and a specific genotype.

Conclusion

The ACE I/D polymorphism does not contribute to the presence and severity of essential hypertension, while the AGT M235T TT genotype confers a significantly decreased risk for the development of hypertension in the population studied here. This contrasts to the findings of meta-analyses, whereby the T allele is associated with increased risk for hypertension.     

Polymorphism in the angiotensin converting enzyme but not in the angiotensinogen gene is associated with hypertension and type 2 diabetes: the Skaraborg Hypertension and diabetes project

OBJECTIVE: To study the association between polymorphisms in the angiotensin converting enzyme (ACE) gene and angiotensinogen (AGT) gene and hypertension and/or type 2 diabetes in a community population. PATIENTS AND METHODS: The insertion (I)/deletion (D) polymorphism of the ACE gene and the M235T polymorphism of the AGT gene were genotyped in 773 nondiabetic individuals with hypertension, 193 normotensive patients with type 2 diabetes, 243 patients with type 2 diabetes and hypertension, and in 820 normotensive control individuals identified in a community-based study. RESULTS: The DD genotype was associated with hypertension in individuals less than 70 years [odds ratio (OR) = 1.54, confidence interval (CI) = 1.09-2.18] and remained so when patients with type 2 diabetes were excluded from the analysis (OR = 1.45, CI = 1.01-2.09). The strongest association was with the combination of type 2 diabetes and hypertension (OR = 2.19, CI = 1.09-4.38). There was no association with type 2 diabetes without hypertension. No association was observed between the M235T variant or the 3'-microsatellite polymorphism of the AGT gene and hypertension. CONCLUSION: The D-allele of the ACE gene ID polymorphism increases susceptibility to hypertension, particularly when associated with type 2 diabetes. No association was observed between the M235T variant or 3'-microsatellite polymorphism of the AGT gene and hypertension.     

肾素-血管紧张素系统基因多态性与原发性高血压左心室肥厚关系的探讨

目的　探讨肾素 血管紧张素系统 (RAS)基因多态性与原发性高血压左心室肥厚 (EH LVH)的相关性以及在EH LVH产生中的多基因协同作用。方法　对 10 9例原发性高血压病 (EH)患者 ,采用聚合酶链反应 (PCR)以及聚合酶链反应 限制性片段长度多态性方法检测血液白细胞染色体DNA中血管紧张素转换酶 [ACE(I D) ]、血管紧张素原 [AGT(M2 35T) ]和血管紧张素Ⅱ 1型受体 [AT1 R(A116 6C) ]基因多态性 ;利用超声心动图检测左心室质量 (LVM)并计算左心室质量指数 (LVMI)。结果　ACE(I D)基因多态性D等位基因频率在EH LVH组中明显增高 (χ2 =4 .6 9,P=0 .0 30 ) ,男性EH患者中 ,ACE(I D)基因型构成比与LVH有关联 (χ2 =9.5 5 ,P =0 .0 0 8)。协同存在AGT TT型时 ,ACE(I D)基因多态性与EH LVH有关 (χ2 =6 .2 2 ,P =0 .0 4 4 ) ,且D等位基因在EH LVH明显增高 (χ2 =6 .91,P =0 .0 0 9) ,该类EH患者发生LVH的相对危险度增高 (OR :2 .5 0 ,95 %CI:1.2 5～ 5 .0 0 )。结论　ACE(I D)基因多态性D等位基因可能是LVH的独立危险因子。ACE基因多态性与AGT基因多态性之间的协同效应表明 ,同时携带AGT TT型时 ,具有ACE(I D)基因多态性D等位基因的EH患者更易发生LVH。     

Angiotensinogen gene M235T polymorphism predicts left ventricular hypertrophy in endurance athletes.

OBJECTIVES: We studied whether left ventricular mass in athletes associates with polymorphisms in genes encoding components of the renin-angiotensin system. BACKGROUND: Adaptive left ventricular hypertrophy is a feature of the athlete's heart. However, similarly training athletes develop left ventricular mass to a different extent, suggesting that genetic factors may modulate heart size. METHODS: We measured left ventricular mass by echocardiography in 50 male and 30 female elite endurance athletes aged 25 +/- 4 (mean +/- SD) years. Deoxyribonucleic acid samples were prepared for genotyping of angiotensinogen (AGT) gene M235T polymorphism, angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and angiotensin II type 1 receptor (AT1) gene A1166C polymorphism. RESULTS: The AGT gene M235T genotypes were significantly associated with left ventricular mass independently of blood pressure in both genders (p = 0.0036 for pooled data). TT homozygotes had greater mass compared with MM homozygotes in both men (147 +/- 12 g/m vs. 132 +/- 15 g/m, p = 0.032) and women (121 +/- 12 g/m vs. 101 +/- 13 g/m, p = 0.019). There was a gender difference in the relation between myocardial mass and AGT genotype, MT heterozygotes resembling MM homozygotes among women and TT homozygotes among men. The other studied gene polymorphisms were not associated with left ventricular mass. CONCLUSIONS: Angiotensinogen gene M235T polymorphism is associated with the variability in left ventricular hypertrophy induced by endurance training, with athletes homozygous for the T allele having the largest hearts. We found no association between ACE gene I/D or AT1 gene A1166C polymorphisms and left ventricular mass.     

Angiotensinogen M235T polymorphism and left ventricular indices in treated hypertensive patients with normal coronary arteries.

OBJECTIVE: Hypertension and left ventricular hypertrophy (LVH) are important causes of morbidity and mortality in the population. Angiotensinogen (AGT) M235T polymorphism has been associated with LVH, left ventricular dimensions, coronary artery disease and antihypertensive drug response in previous studies. We examined relationship between AGT M235T polymorphism and echocardiographic left ventricular indices in a Turkish population of treated hypertensive patients with normal coronary arteries. METHODS: In this cross-sectional study a Turkish population of 92 hypertensive patients treated in our outpatient clinic were enrolled. All patients had normal coronary angiographic examinations. Genotypes for AGT M235T were determined from peripheral leukocytes. Left ventricular dimensions, mass and function indices, after adjustment for clinical covariates were analyzed by multiple regression analysis according to genotypes. RESULTS: Genotype frequencies for AGT M235T were MM-24.7%, MT-52.8% and TT-22.5%. Left ventricular end-systolic (LVES) dimensions for AGT M235T MM, MT, TT genotypes were 17.9+/-4.2 mm, 19.4+/-6.2 mm, and 16.4+/-2.9 mm, respectively (p=0.08). Angiotensinogen M235T TT genotype showed a trend towards a lower LVES dimension but results were not statistically significant. Left ventricular ejection fractions for AGT M235T MM, MT, TT subgroups were 61.3+/-15.0%, 59.4+/-14.0%, and 67.8+/-8.5%, respectively (p=0.07). Angiotensinogen M235T TT genotype showed a tendency towards lower left ventricular mass index but results were not statistically significant. None of the AGT M235T genotypes predicted left ventricular dilatation, mass or function in treated hypertensive patients with normal coronary arteries. CONCLUSION: Angiotensinogen M235T polymorphism was not useful to predict left ventricular mass, function, hypertrophy or dilatation in a small population of treated Turkish hypertensive patients with normal coronary arteries.     

Meta-analysis of the association of 4 angiotensinogen polymorphisms with essential hypertension: a role beyond M235T?

Angiotensinogen (AGT) gene polymorphisms have been linked to increased risk of hypertension, but the data remain controversial. In this study we review the most commonly investigated polymorphisms at the AGT locus (other than M235T) and provide summary estimates regarding their association with essential hypertension, while addressing heterogeneity, as well as publication biases. Data on 26 818 subjects from 46 studies for the 4 most-studied AGT variants (T174M in exon 2 and 3 promoter variants: A-6G, A-20C, and G-217A) were meta-analyzed. Statistically significant associations with hypertension were identified for the T174M (odds ratio [OR]: 1.19; 95% CI: 1.07 to 1.33; P=0.002) and G-217A (OR: 1.37; 95% CI: 1.17 to 1.59; P=0.00006) polymorphisms. A dual but consistent effect was observed for the -20C allele, which was associated with a decreased risk of hypertension in populations of mixed and European ancestries (OR: 0.64; 95% CI: 0.44 to 0.92; P=0.02 and OR: 0.77; 95% CI: 0.65 to 0.91; P=0.003, respectively), but with a 24% increase in the odds of hypertension in Asian subjects (OR: 1.24; 95% CI: 1.04 to 1.48; P=0.02). No association of the A-6G variant with hypertension was detected. Current studies support the notion that single variants at the AGT might modulate the risk of hypertension but indicate caution in interpreting these results because of the putative presence of publication bias and gene-environment interactions.     

The involvement of the renin-angiotensin system gene polymorphisms in coronary heart disease

INTRODUCTION AND OBJECTIVES: Previous studies angiotensin-converting enzyme gene insertion/deletion polymorphism ACE (I/D), angiotensinogen gene polymorphism, and angiotensin II AT1 receptor polymorphism in relation to coronary heart disease controversial results. This study was designed to analyze the association between these gene polymorphisms and the first coronary event in individuals residing on Grand Canary Island, Spain. PATIENTS AND METHOD: Case-control study. Case subjects (n = 304) were recruited at the first coronary event; age-matched controls (n = 315) were randomly selected from the Grand Canary population. Participants were examined for the usual risk factors. Blood samples were obtained for biochemical analyses and DNA extraction. Genotyping was performed by PCR and restriction analysis. RESULTS: Neither ACE (I/D) nor AT1 receptor polymorphism was associated with coronary heart disease, whereas the frequency distribution of AGT M235T genotypes among patients and control subjects (TT: 29% and 19%; MT: 48% and 50%; MM: 22% and 31%, respectively) was statistically different (p = 0.003). Multiple logistic regression analysis identified the TT genotype of the angiotensinogen gene (OR = 1.9; 95% CI 1.1-3.4), diabetes (OR = 4.4; 95% CI 2.0-9.4) and hypertension (OR = 2.1; 95% CI 1.3-3.3) as risk factors predicting the coronary event. CONCLUSIONS: Our results provide no evidence of an association between ACE (I/D) or AT1 receptor polymorphism and coronary heart disease. However, homozygosity for the T allele of the angiotensinogen gene, diabetes and hypertension independently place individuals at higher risk of experiencing a coronary event on Grand Canary Island.     

Renin-angiotensin system gene polymorphisms: assessment of the risk of coronary heart disease

BACKGROUND: Renin-angiotensin system genes are candidate genes in cardiovascular system diseases. Angiotensinconverting enzyme (ACE), angiotensinogen (AGT) and angiotensin II type 1 receptor (AT1R) gene polymorphisms are considered risk factors in coronary heart disease (CHD). AIM: To evaluate the involvement of the ACE, AGT and AT1R genetic variants in predisposition to CHD as well as their association with other known risk factors. METHODS: The study included 400 male subjects (200 with CHD and 200 healthy individuals). Genotypes were determined by a polymerase chain reaction (PCR). For the AGT and AT1R genes a restriction analysis of the PCR product was performed. The allele frequency and genotype distribution were compared between groups. RESULTS: The allele and genotype frequencies of the ACE gene were similar in both groups, however, a significantly higher frequency of the DD genotype was observed in the presence of hyperlipidemia (39% vs 24% in non-hyperlipidemic subjects, p<0.01). The AGT gene polymorphism was associated with the development of CHD. The T allele was significantly more frequent in patients than in the control group (55% vs 44%, p<0.05). The heterozygous MT genotype was observed in 61% of patients compared to 40% in the controls (p<0.05). The A1166C polymorphism of the AT1R gene was also associated with CHD as well as with age at the onset of disease. The frequency of the C allele was 29% compared to 21% in the control group (p<0.01) and the frequency of the CC homozygote was almost three times higher in patients. CONCLUSIONS: There is an association between molecular variants of the angiotensinogen and angiotensin II type 1 receptor and increased risk of CHD. The DD genotype of the ACE gene polymorphism and the TT genotype of the AGT gene polymorphism were significantly more frequent in patients with hyperlipidemia. The TT genotype of the AGT gene M235T polymorphism was associated with an increased risk of CHD and myocardial infarction only in smokers.     

Angiotensinogen M235T and T174M gene polymorphisms in combination doubles the risk of mortality in heart failure

Angiotensinogen M235T and T174M polymorphisms have individually been associated with elevated levels of plasma angiotensinogen, hypertension, and left ventricular hypertrophy. In this study, heart failure patients (n=451) were genotyped for the angiotensinogen M235T and T174M polymorphisms to investigate association with survival (recorded over 4 years of follow-up) and prognostic hormone markers. Patients carrying the 235TT genotype (n=86) were 3 years younger at admission (P=0.011), and, in those with hypertension, diagnosis was made approximately 10 years earlier than other patients. Patients carrying >or=1 174M allele (n=94) were more likely to have a previous history of heart failure (P=0.044) and increased mortality during follow-up (risk ratio: 1.69, 95% CI: 1.03 to 2.79; P=0.038) compared with 174TT homozygotes (n=355), despite having a higher left ventricular ejection fraction (P=0.009). "High-risk" genotype combinations (defined a priori as 235TT and/or >or=1 174M allele; n=144; 32%) were independently predictive of mortality, conferring a 2-fold greater risk of dying during the follow-up period (odds ratio: 2.0; 95% CI: 1.3 to 3.0; P=0.001). This study suggested that angiotensinogen gene variants M235T and T174M may provide prognostic information for long-term survival in heart failure patients.     

Genetic variation in the renin-angiotensin system and autonomic nervous system function in young healthy Japanese subjects

CONTEXT: The renin-angiotensin system (RAS) interacts with the autonomic nervous system (ANS) in the regulation of blood pressure and cardiovascular function. Several genetic polymorphisms in the RAS have been identified and have been implicated as a cause of hypertension and cardiovascular disease. OBJECTIVE: The aim of the present study was to evaluate the relation between genetic polymorphisms of the RAS (M235T of AGT gene, insertion/deletion of ACE gene, A1166C of AT1R gene, and A1675G of AT2R gene) and ANS function. SUBJECTS: One hundred forty-nine young healthy Japanese males were genotyped for each RAS polymorphism. MAIN OUTCOME MEASURES: ANS function was evaluated by power spectral analysis of heart rate variability (HRV) during supine rest and in a standing position. RESULTS: In a supine position, subjects homozygous for the AGT 235T allele had a higher HRV sympathetic index than 235M allele carriers, whereas the orthostatic change in this index was relatively blunted in AGT 235TT carriers. In the analysis of gene-gene interaction, these effects of the AGT 235T homozygotes on HRV sympathetic index were more apparent in the presence of the ACE D allele. Meanwhile, the AT1R 1166C allele was significantly associated with higher HRV low-frequency power and sympathetic index in a standing position. These data suggest that the AGT M235T polymorphism is associated with sympathetic predominance at rest, and AT1R 1166C allele carriers have potentially increased sympathetic response. CONCLUSIONS: Cardiac autonomic function can be modulated by genetic variation in the RAS even in young and healthy states.     

血管紧张素原M235T基因多态性对血压影响的研究

目的：研究血管紧张素原基因（ＡＧＴ）第二外显子Ｍ２３５Ｔ等位基因的多态性与高血压之间的关系。方法： 应用多聚酶链反应（ＰＣＲ）结合限制性酶切方法对１０５例健康体检者与１０２例原发性高血压（ＥＨ）患者进行基因突变的检测。结果：（１）ＥＨ患者Ｔ２３５ 等位基因频率（０．４４５）高于对照组（０．３２３）,Ｐ＜ ０．０５。在男性ＥＨ患者与男性对照组中差别更为明显（Ｐ＜ ０．０１）;（２）在有家族史的ＥＨ 患者中,Ｍ２３５Ｔ 突变基因型（ＴＴ型）频率高于正常对照组（４２．１％ ＶＳ１８．８％ ,Ｐ＜０．０５）。结论：（１）ＡＧＴ基因的突变与ＥＨ的发病具有相关性。对男性ＥＨ影响可能更大;（２）在有家族史的高血压患者中, ＡＧＴ２３５的ＴＴ基因型与ＥＨ有关     

AGT基因型对贝那普利降压疗效的影响

目的研究原发性高血压(EH)患者的血管紧张素原(AGT)基因M235T多态性与贝那普利降压疗效的相关性。方法251例EH患者口服贝那普利10～20mg/d,进行为期6周的降压治疗。用聚合酶链反应(PCR)和限制性酶切方法检测所有患者的AGT基因M235T多态性,按MM、MT和TT三种基因型分组。治疗前后及治疗过程中对患者的收缩压(SBP)和舒张压(DBP)等进行监测,以比较不同基因型患者之间的降压疗效。结果基因型为MM、MT及TT者分别为23例(9.2%)、104例(41.4%)和124例(49.4%);在251例患者中,MM、MT及TT三组患者间治疗后SBP和DBP的降幅差异无统计学意义(P>0.05);按年龄分层进行的亚组分析显示:在≥60岁的老年亚组中,治疗后MM、MT及TT三组患者DBP的降幅分别为(14.8±4.8)mmHg,(7.9±7.7)mmHg和(9.8±6.4)mmHg(P=0.034),MM较MT和TT组的DBP降幅大。结论本研究显示,老年(≥60岁)EH患者的AGTM235T多态性与贝那普利降压疗效相关,提示特定的基因多态性可能会影响某些降压药物的疗效。     

基因芯片技术分析与冠心病的相关基因

目的评估血管紧张素原(angiotensinogen,AGT)、内皮型一氧化氮合酶(endothelial nitric oxide synthase,eNOS)和载脂蛋白E(apolipoprotein E,ApoE)多态性与冠心病的关系,并分析AGT、eNOS和ApoE基因多态性在冠心病的发生和发展中是否存在协同作用。方法选择冠心病患者133例及对照者154名,用基因芯片技术检测AGT、eNOS和ApoE基因多态性,并对比其基因型及等位基因频率。结果冠心病组AGT TT和eNOS TT基因型频率与对照组相比差异有统计学意义,分别为OR=2．63,P<0．001,OR=8．50,P< 0．05。AGT和eNOS基因多态性与冠心病相关。同时携带AGT TT和eNOS TT基因型者与冠心病密切相关(OR=1．05,P<0．01)。ApoE基因型频率及等位基因频率与对照组相比差异无统计学意义(P>0．05)。结论AGT和eNOS基因多态性可能是中国人冠心病的危险因素,基因芯片技术为研究多种易感基因与冠心病的相关性提供了一项高效、敏感的方法。     

Searching for a better assessment of the individual coronary risk profile. The role of angiotensin-converting enzyme, angiotensin II type 1 receptor and angiotensinogen gene polymorphisms.

BACKGROUND: Polymorphisms within renin angiotensin system genes have been investigated as risk factors for coronary artery disease in different populations with contradicting results. The aim of this study was to investigate the genotype distribution and the allele frequencies of ACE, AT1R and AGT gene polymorphisms as coronary artery disease factors and their synergistic effects on coronary risk in an Italian population. METHODS AND RESULTDS: In this study ACE, AT1R and AGT gene polymorphisms were investigated in 205 consecutive coronary artery disease patients and in 209 controls. These polymorphisms were analysed by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). The ACE D and AGT 235T allele, but not AT1R C allele, frequency was statistically significant in patients. An association between coronary artery disease and ACE DD, AT1R CC and AGT TT genotype, was found by univariate analysis (OR 2.06 P=0.0007, OR 2.49 P=0.009, OR 1.87 P=0. 019, respectively). At multivariate analysis ACE DD and AT1R CC genotype (OR 1.81 P=0.011, OR 2.61 P=0.011, respectively) remained associated with coronary heart disease. Subjects carrying the ACE DD genotype and AT1R C allele showed a stronger association with myocardial infarction (OR=4.02, P<0.0001). CONCLUSION: Our report indicates the increased risk of coronary artery disease in the presence of ACE DD and AT1R CC genotypes independent of other risk factors, in Italian patients. The present study stresses the relevance of screening for genetic risk factors.     

肾素-血管紧张素系统双基因多态性与高血压合并舒张性心力衰竭的关系

目的探讨中国南方部分汉族高血压患者肾素一血管紧张素系统中血管紧张素转换酶（ACE）及血管紧张素原（AGT）双基因多态性与舒张性心力衰竭发病的关系。方法应用聚合酶链反应及限制性片断长度多态性技术,对432例高血压患者的ACE基因插入／缺失（I／D）及AGTM235T多态性进行检测。将其中207例合并舒张性心力衰竭者作为病例组,其余225例心功能正常者作为对照组。结果①病例组DD基因型及D等位基因的频率均高于对照组;②病例组TT基因型及T等位基因的频率与对照组比较差异无统计学意义;③联合分析ACE与ACT基因多态性显示,两组中同时具有DD型ACE基因及TT型AGT基因的频率分别为29．0％及14．9％,前者明显高于后者。结论DD型ACE基因可能是该地区高血压患者舒张性心力衰竭发病的遗传危险因素,ACE和AGT基因在慢性心力衰竭的发生中具有协同作用。     

Relation between the angiotensinogen (AGT) M235T gene polymorphism and blood pressure in a large,homogeneous study population

The aim of this study was to assess the association of the angiotensinogen M235T polymorphism with arterial blood pressure (BP) at rest and under physical stress in a homogeneous large-scale study population. In all, 1903 men who passed routine medical examination for military flying duty were recruited. BP and heart rate were measured at rest, during, and after bicycle ergometry. Genotyping for the AGT M235T polymorphism was carried out by PCR and RFLP technique. The AGT T235 allele was associated with a significantly higher diastolic BP (n=1903; MM 81+/-8, MT 83+/-7, TT 83+/-8; P=0.003). Pulse pressure (PP) at rest differed significantly between AGT genotypes (n=1903; MM 51+/-10 mmHg, MT 49+/-10 mmHg, TT 49+/-10 mmHg; P=0.001). During physical activity, BP values showed no significant difference between genotypes. In healthy young men, the AGT T235 allele is significantly associated with elevated diastolic BP but also reduced PP at rest. During physical activity, the AGT polymorphism had no impact on blood pressure, indicating the existence of other counteracting mechanisms, which might balance the influence of this gene.