慢性阻塞性肺疾病合并肺动脉高压患者内皮型一氧化氮合酶基因多态性分析

目的 探讨内皮型一氧化氮合酶(eNOS)基因G894T多态性与COPD合并肺动脉高压(PAH)发病的相关性及可能机制.法2005年1月至12月包头医学院第二附属医院就诊的50例COPD合并PAH患者,男31例,女19例,平均年龄(69±10)岁.康对照组50名,男29名,女21名,平均年龄(67±3)岁.两组的基因多态性特征进行研究.测一氧化氮代谢物(NOx)及内皮素含量,应用特异性PCR比较eNOS基因G894T多态性的分布差异,分析基因型与COPD合并PAH患者发病的相关性.因型、等位基因频率和组间计数资料比较采用x2检验,组问均数比较采用t检验,相关性分析采用logistic回门进行统计学分析,数据均采用均数±标准差表示.果 COPD合并PAH组的GT、TT基因型频率及T等位基因频率均高于健康对照组;GT+TT基因型组空腹血清NOx含量为(48±8)p,μmo/L,NOx与内皮素比值为0.1±0.0;GG基因型组NOx含量为(60±24)μmol/L,NOx与内皮素比值为1.3±0.4;GT+TT基因型组内皮素含量为(104±38)μg/L,明显高于GG基因型组的(50±26)μg/L;GG基因型组肺动脉压[(47±10)mm Hg,1 mm Hg=0.33 kPa]明显低于GT+TT基因型组的(57±15)mm Hg;GT+TT基因型组右心室游离壁厚度为(4.2±1.6)mm,GG基因型组为(3.4 3=0.6)mm.G基因型组与GT+TT基因型组比较其他心脏结构无差异.有患者二尖瓣血流早期与晚期充盈速度比值均＜1,而左心窒横径短轴缩短分数与射血分数均正常,存在左心室舒张功能障碍,而收缩功能正常.归分析结果显示,eNOS基因G894T多态性的T等位基因(P＜0.1,OR值为17.4,95%可信区间为4.9～72.8)、一氧化氮(P＜0.1,OR值为0.7,95%可信区间为0.5～0.9)及吸烟(P＜0.1,OR值为9.5,95%可信区间为2.4～30.8)与COPD合并PAH明显相关.论eNOS基因G894T多态性可能与COPD合并PAH的发生有关,eNOS基因町能是COPD合并PAH的候选基因.     

Endothelial dysfunction in patients with asthma: the role of polymorphisms of ACE and endothelial NOS genes.

OBJECTIVES: Polymorphisms of the angiotensin converting enzyme (ACE) and endothelial nitric oxide (eNOS) genes have been implicated in asthma pathogenesis. Angiotensin II and NO have important roles in maintaining vascular tone. In this study, the relationship between endothelial dysfunction and ACE and eNOS gene polymorphisms was investigated in patients with asthma. METHODS: This cross-sectional, controlled study was conducted at the Yedikule Chest Disease Hospital and Cardiology Center in a University Hospital. Forty-nine patients with asthma (18 male, 31 female; mean age: 33+/-12 years) and 49 age- and sex-matched healthy controls (20 male, 29 female; mean age: 30+/-8 years) were included. Pulmonary function tests and flow-mediated dilatation of the brachial artery [endothelium dependent dilatation (EDD)] were examined by high-resolution ultrasonography. The ACE and eNOS genotypes were determined by PCR. RESULTS: Asthma patients showed lower EDD (12+/-6% vs. 22+/-6%, p<0.001) as compared to controls. The EDD was correlated with both predicted value of FEV1 (r=0.31, p=0.04) and predicted value of FVC (r=0.37, p=0.013). Conversely, EDD values in patients with moderate asthma were significantly lower than those in patients with mild asthma (10.1+/-5.2% vs. 14.1+/-5.7%, p=0.017). However, the ACE and eNOS genotype distribution was not significantly different between controls and asthma groups. Furthermore, EDD was not associated with both gene polymorphism of ACE and eNOS. CONCLUSION: Patients with asthma have decreased vasodilatatory response to shear stress (EDD). Decreased EDD is correlated with the severity of asthma, but not with the distribution of ACE and eNOS genotypes.     

冠心病与血管紧张素转换酶和内皮型一氧化氮合酶基因多态性及交互作用的临床研究

目的联合对冠心病患者血管紧张素转换酶（ACE）基因多态性和内皮型一氧化氮合酶（eNOS）基因G894T多态性进行分析,探讨基因多态性与冠心病的关系和交互作用及遗传学机制在冠心病发病及预后中的临床意义。方法应用聚合酶链反应-限制性片段长度多态性（PCR—RFLP）分析技术检测236例冠心病患者及190例正常人ACE和eNOS两种基因多态性。同时测定血脂、血糖、体重指数（BMI）、左室射血分数（LVEF）和血压。结果冠心病组ACE基因DD型频率[36％（86／236）]显著高于对照组[19％（36／190）,P〈0．01],Ⅱ型频率[27％（64／236）]显著低于对照组[49％（93／190）,P〈0．05]。冠心病组DD型甘油三酯（TG）[（2．2±1．7）mmol／L]显著高于Ⅱ型TG[（1．6±0．8）mmol／L和ID型TG[（1．7±0．9）mmol／L,均P〈0．05],DD型高密度脂蛋白胆固醇[HDL—C（1．2±0．4）mmol／L]显著低于Ⅱ型HDL—C[（1．3±0．3）mmol／L,P〈0．05],DD型血糖[（6．2±1．7）mmol／L]和BMI[（25．7±2．8）kg／m^2]显著高于ID型[血糖：（5．6±1．3）mmol／L,BMI：（24．8±3．1）kg／m^2。,P〈0．05],DD型LVEF（56％±14％）显著低于Ⅱ型LVEF（62％±15％）和ID型LVEF（61％±14％）,均P〈0．05。收缩压、舒张压、总胆固醇（TC）、低密度脂蛋白胆固醇（LDL—C）、糖尿病组与非糖尿病组、急性冠状动脉综合征组与非急性冠状动脉综合征组、单支病变组与多支病变组在ACE和eNOS基因不同基因型之间差异均无统计学意义。冠心病组eNOS基因GT型频率[28％（67／236）]显著高于对照组[17％（32／190）,P〈0．01],GG型频率与对照组比较,差异无统计学意义。TG、HDL—C、血糖、BMI和LVEF在eNOS基因不同基因型之间差异均无统计学意义（均P〉0．05）。携带DD型患冠心病的概率是携带Ⅱ型的1．74倍（P〈0．01）,携带GT型患冠心病的概率是携带GG型的1．73倍（P〈0．05）。两种基因对患冠心病的交互作用显示为如同时携带Ⅱ型和GG型,患冠心病的概率是37．9％,而同时携带DD型和GT型患冠心病的概率是77．8％。结论ACE基因多态性和eNOS基因多态性与冠心病及某些危险因素显著相关,同时携带DD型和GT型两种易患基因型时,患冠心病的概率明显增加,具有显著的遗传倾向。     

Angiotensin-converting enzyme gene polymorphisms and prognosis in chronic thromboembolic pulmonary hypertension.

BACKGROUND: Angiotensin-converting enzyme (ACE) plays an important role in vascular remodeling in pulmonary hypertension, and ACE gene polymorphism is associated with exercise-induced pulmonary hypertension in Japanese patients with chronic obstructive pulmonary disease. The present study was designed to investigate if ACE-insertion (I)/deletion (D) polymorphism might be related to the susceptibility, severity, and disease outcome in chronic thromboembolic pulmonary hypertension (CTEPH). METHODS AND RESULTS: ACE-I/D genotypes were determined in 95 consecutive CTEPH patients (46 underwent surgery, 49 received medical treatment) and 97 controls. The frequencies of genotypes and alleles were not significantly different between patients and controls. Clinical characteristics were compared among ACE genotypes (II, ID, DD). ACE D allele carrier (ID plus DD) was associated with a lower 6-min walk test distance compared with D allele non-carrier (II) (330+/-102 (mean +/- SD) vs 381 +/-85 m, p=0.046). Kaplan-Meier analysis in the medically treated group showed significantly deteriorated survival for D allele carriers compared with D allele non-carriers (p=0.0389). Multivariate analysis revealed that age (p=0.013), pulmonary vascular resistance (p=0.008), and D allele carrier status (p=0.021) were independent predictors of survival. CONCLUSION: ACE D allele carrier is possibly one of the prognostic factors for medically treated CTEPH patients.     

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.     

Characterization of high-altitude pulmonary hypertension in the Kyrgyz: association with angiotensin-converting enzyme genotype

Previous studies have suggested a genetic component in susceptibility to hypoxia-induced pulmonary hypertension. We therefore estimated the prevalence of high-altitude pulmonary hypertension (HAPH) in a Kyrgyz population and whether the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene associates with HAPH. An electrocardiographic survey of 741 highlanders demonstrated electrocardiogram signs of cor pulmonale in 14% of subjects. Pulmonary artery hemodynamics measured in an independent group of 136 male highlanders with symptoms of dyspnea at altitude revealed established pulmonary hypertension (mean pulmonary artery pressure [MPAP] > or = 25 mm Hg) in 20%. However, 26% of the normal subjects demonstrated an exaggerated response (twofold or greater increase in MPAP) to inhalation of 11% oxygen, and were classified as hyperresponsive. Ten-year follow-up of this group revealed increases in the MPAP, but not in normal subjects. Comparison of ACE I/D genotypes in the catheterized group revealed a threefold higher frequency of the I/I genotype in highlanders with HAPH, compared with normal highlanders (chi2 = 11.59, p = 0.003). In addition, MPAP was higher in highlanders with the I/I genotype (26.9 +/- 4.0 mm Hg) compared with the I/D genotype (20.6 +/- 1.2 mm Hg) or the D/D genotype (18.3 +/- 0.9 mm Hg) (p < 0.05). We conclude that HAPH is associated with ACE I/D genotype among Kyrgyz highlanders and the development of HAPH in this population and may be predicted by hyperresponsiveness to acute hypoxia.     

Acute effects of sildenafil on exercise pulmonary hemodynamics and capacity in patients with COPD

BACKGROUND: We investigated in chronic obstructive pulmonary disease (COPD) patients whether a single dose of sildenafil can attenuate the exercise-induced increase in pulmonary artery pressure, thereby allowing augmentation of stroke volume (SV), and improving maximal exercise capacity. METHODS: Eighteen COPD patients (GOLD II-IV) underwent right heart catheterization at rest and submaximal exercise. Mean pulmonary artery pressure (mPpa) and cardiac output (CO) were assessed. Resting and exercise measurements were repeated 60 min after oral intake of 50mg sildenafil. Also, on different days, patients performed two maximal exercise tests (CPET) randomly, 1h after placebo and after 50mg sildenafil. RESULTS: Five COPD patients had pulmonary hypertension (PH) at rest (mPpa >25 mmHg) and six developed PH during exercise (mPpa >30 mmHg). In all patients, mPpa increased from rest to submaximal exercise (23+/-10-35+/-14 mmHg). After sildenafil mPpa at rest was 20+/-10 mmHg, in exercise mPpa was increased less to 30+/-14 mmHg (p<0.01). The reduced augmentation in mPpa was not accompanied by an increased SV and CO. In COPD patients with PH the percentage increase in mPpa to submaximal exercise was 68% before, and 51% after oral intake of sildenafil (p=0.07). In COPD without PH, these values were 46% and 41% (ns), respectively. Maximal exercise capacity and CPET characteristics were unchanged after sildenafil. CONCLUSION: Regardless of mPpa at rest, sildenafil attenuates the increase in mPpa during submaximal exercise in COPD. This attenuated increase is neither accompanied by enhanced SV and CO, nor by improved maximal exercise capacity.     

T1198C polymorphism of the angiotensinogen gene and antihypertensive response to angiotensin-converting enzyme inhibitors.

This study examined the association between T1198C polymorphism of the angiotensinogen (AGT) gene and the blood pressure response to ACE inhibitors in a Chinese hypertensive cohort. After a 2-week single-blind placebo run-in period, benazepril (10-20 mg/day) or imidapril (5-10 mg/day) was administered for 6 weeks to 509 patients with mild-to-moderate essential hypertension. Polymerase chain reaction combined with restriction enzyme digestion was used to detect the polymorphism, and the patients were classified as having the TT, TC, or CC genotype. The achieved changes in systolic and diastolic blood pressure (SBP and DBP) were analyzed to determine their association with genotypes at the AGT gene locus. In the total 509 patients, the TT genotype was observed in 44 patients (8.7%), the TC genotype in 214 patients (42.0%), and the CC genotype in 251 patients (49.3%). The SBP reductions in patients with the TT genotype, TC genotype, and CC genotype were -15.3+/-12.7 mmHg, -14.0+/-12.7 mmHg, and -14.4+/-12.4 mmHg, respectively (p=0.809). The DBP reductions in patients with the TT genotype, TC genotype, and CC genotype were -8.5+/-8.1 mmHg, -8.3+/-7.5 mmHg, and -8.9+/-6.6 mmHg, respectively (p=0.638). There were no significant differences in the changes in SBP or DBP after treatment among the three genotype groups. In conclusion, these results suggest that the AGT genotype does not predict the blood pressure-lowering response to antihypertensive treatment with ACE inhibitors in Chinese hypertensive patients.     

Polymorphism of the angiotensin converting enzyme gene and blood pressure in a Japanese general population (the Shigaraki Study).

Recent studies have described a linkage between angiotensin converting enzyme (ACE) gene polymorphism and hypertension in a large number of hypertensive sibs. Moreover, among Japanese, the DD genotype of the ACE gene has been reported to be a genetically predisposing factor for hypertension in a large general population. However, there is some controversy regarding the association between the ACE insertion/deletion (I/D) polymorphism and systemic hypertension. Therefore, we examined the influence of the ACE I/D polymorphism in a random Japanese population. The participants were 2,892 subjects (1,110 males: mean age, 58.4 +/- 15.5; 1,782 females: mean age, 56.2 +/- 15.7) who underwent medical examinations in 1999 in Shigaraki, a suburban town located in an urban area in Shiga prefecture. Among them, 2,395 subjects (917 males: mean age, 58.0 +/- 15.7; 1478 females: mean age, 56.3 +/- 15.6) who gave their informed consent for genetic analysis were enrolled in the present study. Every year since 1991, we have repeatedly performed medical examinations in Shigaraki. ACE genotypes were determined by polymerase chain reaction (PCR) methods. Logistic analysis revealed that age (p < 0.001; odds ratio = 1.091), body mass index (BMI) (p < 0.001; odds ratio = 1.211), and family history of hypertension (p < 0.001; odds ratio = 0.371) were associated with hypertension (systolic blood pressure greater than 140 mmHg and diastolic greater than 90 mmHg). There was no association between ACE polymorphism and blood pressure. There were also no significant differences in blood pressure among males or females across the three genotypes. Moreover, in an analysis of 1,484 subjects (549 males: mean age, 62.8 +/- 12.1; 935 females: mean age, 61.2 +/- 12.6) who were followed-up since 1991, there was no association between ACE polymorphism and changes in blood pressure (p = 0.3905). We conclude that ACE polymorphism does not appear to have any significant association with blood pressure, changes in blood pressure or sex in Japanese subjects, who have a more homogeneous genetic background than any other group reported to date.     

Peroxisome proliferator-activated receptor-gamma2 Pro12Ala and endothelial nitric oxide synthase-4a/b gene polymorphisms are not associated with hypertension in diabetes mellitus type 2

OBJECTIVE AND DESIGN: The Pro12Ala and the 4a/b polymorphisms of the peroxisome proliferator-activated receptor gamma (PPARgamma) and the endothelial nitric oxide-synthase (eNOS) genes, respectively, have been associated with hypertension in some but not all studies. The purpose of this study was to investigate the association between these polymorphisms and hypertension in patients with diabetes mellitus type 2 (DM2). METHODS: We determined, by polymerase chain reaction (PCR), the Pro12Ala PPARgamma2 and the eNOS 4a/b gene polymorphisms in a total of 395 patients with diabetes mellitus 2 (DM2) (225 men and 170 women) from the LIANCO (Lipid-Analytic-Cologne) study. Hypertension was defined as known or newly diagnosed hypertension according to current national guidelines. Associations were determined using chi-square statistics. The influence of genotype and other parameters on blood pressure was determined by analysis of variance (ANOVA) and multivariate analyses. RESULTS: The genotype frequencies of the Pro12Ala polymorphism were 3% AlaAla, 23% ProAla and 74% ProPro and of the eNOS 4a/b polymorphism 3% a/a, 25% b/a and 72% b/b. There were 65% patients with, and 35% without hypertension. A total of 77% of the patients with hypertension were under pharmacological treatment. The mean systolic and diastolic blood pressure (SBP, DBP) was 148 +/- 22 and 84 +/- 11 mmHg in patients with, and 131 +/- 12 and 79 +/- 8 mmHg in patients without, hypertension. There was no difference in the occurrence of hypertension among ProAla and AlaAla subjects compared with ProPro subjects (P = 0.98). There was also no difference between a-allele carriers and non-carriers of the eNOS polymorphism (P = 0.42). There were no differences between men and women in the associations. Analysis of variance did neither identify an influence on systolic or diastolic blood pressure by the presence of the Ala or the a-allele of the respective genotypes nor a significant interaction of the two. CONCLUSIONS: In DM2 the Pro12Ala and 4a/b gene polymorphisms of the PPARgamma2 and eNOS genes, respectively, are not associated with systolic or diastolic blood pressure, either in men or in women. Our results in a large cohort fail to confirm reports of recent studies suggesting an association of lower blood pressure in patients with DM2 and carriers of Pro12Ala polymorphism.     

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.     

血管紧张素转换酶基因多态性与高血压微量蛋白尿的关系

为研究血管紧张素转换酶基因插入/缺失（I/D）多态性与高血压微量蛋白尿的关系。应用聚合酶链反应方法扩增50例正常人，50例高血压伴有微量蛋白尿患者和49例高血压不伴有微量蛋白尿患者的白细胞血管紧张素转换酶基因上287bp片段，根据插入（Ⅰ）或/缺失（D）来判断其多态性，用放射免疫法测定所有对象的尿微量白蛋白。结果发现，微量蛋白尿组与健康对照组相比，其D等位基因及DD基因型显著升高。微量蛋白尿组与单纯高血压组相比，其D等位基因及DD基因型显著程式高。单纯高血压组与健康对照组相比，血管紧张素转换酶基因型和等位基因频率无显著性差异。以上提示，血压紧张素转换酶基因多态性与高血压微量蛋白尿有关联性，DD基因型可能与高血压早期肾脏损害有关。     

The DD genotype of the angiotensin converting enzyme gene is negatively associated with right ventricular hypertrophy in male patients with chronic obstructive pulmonary disease.

The renin angiotensin system plays an important role in the development of pulmonary artery remodeling and right ventricular hypertrophy in hypoxia-induced pulmonary hypertension as may occur in patients with COPD. Several polymorphisms of genes encoding for components of the renin angiotensin system such as the M235T polymorphism in the angiotensinogen gene, the 287-base-pair insertion (I)/deletion (D) polymorphism at intron 16 of the ACE gene, and the A1166C polymorphism in the angiotensin II type 1 receptor gene have been associated with an increased risk of cardiovascular diseases. With respect to the pulmonary circulation, only limited data exist on possible associations between polymorphisms of these genes and pulmonary hypertension and/or right ventricular hypertrophy. The objective of the present study was to investigate a possible relationship between polymorphisms of the renin angiotensin system and electrocardiographic evidence of right ventricular hypertrophy in patients with COPD. We therefore determined the angiotensinogen (M235T), angiotensin converting enzyme (I/D), and angiotensin II type 1 receptor (A1166C) genotypes in 87 patients with severe COPD and correlated these data with electrocardiographic parameters of right ventricular hypertrophy. Thirty-one patients (36%) of 87 patients with COPD showed electrocardiographic evidence of right ventricular hypertrophy. In the male, but not in the female, subgroup, the angiotensin-converting enzyme DD genotype was negatively associated with electrocardiographic evidence of right ventricular hypertrophy (male: chi2 = 3.8, p = 0.05; female: chi2 = 0.05, p = 0.82). We found no associations between the investigated polymorphisms in the angiotensinogen and angiotensin II type 1 receptor genes and electrocardiographic evidence of right ventricular hypertrophy.     

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.     

Sleep-related oxygen desaturation and daytime pulmonary haemodynamics in COPD patients.

It has been hypothesized that in chronic obstructive pulmonary disease (COPD), sleep-related hypoxaemia could lead to pulmonary hypertension (PH) and cor pulmonale, even in patients with only mild daytime hypoxaemia. We investigated the relationships between sleep variables and daytime pulmonary haemodynamics in 40 COPD patients with daytime arterial oxygen tension (PaO2) between 60-70 mmHg (8-9.3 kPa). Patients were considered as desaturators if they spent at least 30% of the sleep recording time with a transcutaneous O2 saturation (StcO2) less than 90%. Daytime arterial blood gases and pulmonary volumes could not discriminate desaturators "D" (n = 18) from non-desaturators "ND" (n = 22), but awake baseline StcO2, measured just prior to the onset of sleep, was lower in group D. Pulmonary artery mean pressure was significantly higher in group D (19.1 +/- 4.7 vs 16.8 +/- 1.9 mmHg, p less than 0.05) and all patients with PH (6 out of 40) belonged to group D. PH was observed in 6 of the 15 patients whose mean nocturnal StcO2 was less than 90% but in none of the 25 with a mean nocturnal StcO2 greater than 90%. The PH patients (n = 6), all desaturators, differed from the desaturators with no PH (n = 12), and from ND (n = 22) in having higher numbers of desaturation dips, longer durations of dips, and lower mean nocturnal arterial oxygen saturation (SaO2). We conclude that a causal relation between nocturnal desaturation and permanent PH is very likely. Further studies are needed to see whether oxygen therapy can prevent PH in these patients.     

Pulmonary hypertension in advanced sarcoidosis: epidemiology and clinical characteristics.

Pulmonary hypertension (PH) is a predictor of poor outcome in sarcoidosis. Little is known about the epidemiology of PH in sarcoidosis. The current authors reviewed the records of patients with sarcoidosis listed for lung transplantation in the USA between January 1995 and December 2002. PH was defined as a mean pulmonary artery pressure of >25 mmHg and severe PH as a mean pulmonary artery pressure of > or =40 mmHg. The cohort included 363 patients of whom 73.8% had PH. Neither spirometric testing nor the need for corticosteroids was associated with PH. Subjects with PH required more supplemental oxygen (2.7+/-1.8 L.min(-1) versus 1.6+/-1.4 L.min(-1)). The cardiac index was lower in individuals with PH, whereas the pulmonary capillary wedge pressure was higher. In multivariate analysis, supplemental oxygen remained an independent predictor of PH, whereas the relationship between cardiac index and PH was no longer significant. As a screening test, the need for oxygen had a sensitivity and specificity of 91.8% and 32.6%, respectively. Pulmonary hypertension is common in advanced sarcoidosis. The need for oxygen correlates with pulmonary hypertension. Since pulmonary hypertension is associated with poor outcomes and because simple clinical criteria fail to identify patients with sarcoidosis and pulmonary hypertension, more aggressive screening for this should be considered.     

Association between the angiotensin-converting enzyme gene polymorphisms and tissue oxygenation during exercise in patients with COPD

STUDY OBJECTIVES: We have recently determined that the angiotensin-converting enzyme (ACE) DD genotype might be associated with pulmonary hypertension during exercise in patients with COPD. Therefore, this study was designed to determine whether ACE gene polymorphisms adversely affect tissue oxygenation during exercise in patients with COPD. DESIGN: Cross-sectional analysis. SETTING: University hospital. PATIENTS: Thirty-nine patients (14 patients with II genotype, 12 patients with ID genotype, and 13 patients with DD genotype). INTERVENTIONS: All patients underwent right-heart catheterization and constant-load exercise testing for 5 min on an ergometer. Measurements and results: The ratio of the change in oxygen delivery (DO(2)) to the increase in oxygen consumption (O(2)) during exercise (DeltaDO(2)/DeltaO(2)) was significantly lower in patients with the DD genotype (1.5 +/- 0.2) than in those with the II genotype (1.9 +/- 0.3, p = 0.0006) and the ID genotype (1.7 +/- 0.2, p = 0.037). Mixed venous oxygen tension (PO(2)) after exercise in patients with the DD genotype (23.5 +/- 1.5 mm Hg) was also significantly lower than in patients with the II genotype (26.7 +/- 1.6 mm Hg, p = 0.0002) and the ID genotype (25.0 plus minus 2.0 mm Hg, p = 0.045). In addition, the change in plasma concentration of lactate during exercise (DeltaLactate) was significantly higher in patients with DD genotype (33.3 +/- 4.3 mmol/L) than in those with the II genotype (25.5 +/- 3.6 mmol/L, p = 0.0002) and the ID genotype (28.8 +/- 4.0 mmol/L, p = 0.029). The mean pulmonary arterial pressure after exercise was significantly correlated with DeltaDO(2)/DeltaO(2) (r = - 0.423, p = 0.0076) but not with PvO(2) after exercise and with DeltaLactate. CONCLUSIONS: The ACE DD genotype may be associated with an impairment in peripheral tissue oxygenation during exercise in patients with COPD.     

Raised circulating plasma levels of atrial natriuretic peptide in adolescent and adult patients with cystic fibrosis and pulmonary artery hypertension

Since pulmonary artery hypertension (PH) complicates advanced stages of cystic fibrosis (CF), we wondered whether plasma concentrations of h-ANP would be increased in adult patients with CF. Furthermore, if only the right ventricle is faced with an increased afterload in these patients, the increased h-ANP plasma levels should stem primarily from the right atrium. To test this hypothesis we studied 12 adult patients with CF in a clinically stable condition using right heart catheterization. Mean pressures were measured in the right atrium (Pra) and pulmonary artery (Ppa), pulmonary capillary wedge (PCWP) position, and blood were drawn from the pulmonary artery and from a peripheral vein to determine h-ANP. Plasma levels in the pulmonary artery were significantly higher than in a peripheral vein (54.3 +/- 6.0 pg/ml vs. 32.2 +/- 4.4 pg/ml; p less than 0.001). Four of the 12 patients had PH (Ppa, 25.8 +/- 2.9 mmHg) whereas 8 patients exhibited normal pulmonary artery pressures (Ppa, 15.9 +/- 0.7 mmHg). Patients with PH had higher Pra (4.2 +/- 0.4 mmHg) than patients with CF without PH (1.9 +/- 0.7 mmHg; p less than 0.05). Plasma h-ANP concentrations were significantly higher in patients with CF with PH (70 +/- 10.4 pg/ml in the pulmonary artery; 42.6 +/- 4 pg/ml in a peripheral vein) than in patients with normal pulmonary artery pressure (43 +/- 3.3 pg/ml in the pulmonary artery; p less than 0.01; 24.7 +/- 5.6 pg/ml in a peripheral vein; p less than 0.05). Although our results are derived from a small group of patients with CF, we conclude from our results that in patients with CF PH may cause increased h-ANP secretion. The right atrium seems to be a major source.     

内皮型一氧化氮合酶基因多态性与慢性阻塞性肺疾病肺动脉高压的相关性研究

慢性阻塞性肺疾病（COPD）的发生受遗传及环境因素的共同影响。不同种族及民族其临床表现、严重程度的差异,以及家族聚集性提示疾病可能存在遗传易感性。近年来人们主要研究了3个内皮型一氧化氮合酶（eNOS）基因多态性位点与COPD肺动脉高压的关系：位于第4内含子上27bp数目可变的串联重复序列（VNRT）;位于第7外显子,由894碱基G突变成T（G894T）,导致相应蛋白产物第298位的谷氨酸（Glu）被替换成天冬氨酸（Asp）;CA重复序列,现已有研究表明,eNOS基因多态性可能影响内皮NO释放水平,eNOS基因是COPD肺动脉高压的易感基因。