Determinants of Exhaled Breath Condensate pH in a Large Population With Asthma
Determinants of Exhaled Breath Condensate pH in a Large Population With Asthma
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DOI：
10.1378/chest.10-0163
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发表时间：
2011-02-01
期刊：
影响因子：
9.6
通讯作者：
Gaston, Benjamin
中科院分区：
文献类型：
--
作者：
Liu, Lei;Teague, W. Gerald;Gaston, Benjamin
背景：在哮喘急性发作期间，呼出气冷凝物 (EBC) pH 值低于正常值 2 个对数级，并通过抗炎治疗恢复正常。然而，人们对 EBC pH 值的决定因素（尤其是稳定哮喘患者）知之甚少。我们假设严重哮喘患者的 EBC pH 值较低，并且存在具有特征性低值的哮喘患者亚群。方法：我们研究了参加严重哮喘研究项目的 572 名稳定受试者的 EBC pH 值与临床特征的关联。其中包括 250 名患有严重哮喘的受试者、291 名患有非严重哮喘的受试者和 31 名健康对照受试者。 结果：总体而言，在这一稳定的、接受治疗的研究受试者群体中，严重哮喘（8.02；四分位数间距 [IQR]，7.61-8.41）或非严重哮喘（7.90；IQR，7.52-8.20）的 EBC 并不低于对照受试者（7.9；IQR，7.52-8.20）。 IQR，7.40-8.20）。然而，在患有哮喘的受试者中，数据聚集在 pH 值 6.5 以下和以上。 pH < 6.5 的亚群中的受试者呼出一氧化氮 (FENO) 值分数 (FENO = 22.6 +/- 18.1 ppb) 低于 pH >= 6.5 的受试者 (39.9 +/- 40.2 ppb; P < .0001)。通过多元线性回归，低 EBC pH 值与高 BMI、高 BAL 中性粒细胞计数、低前支气管扩张剂 FEV1 比率、高过敏症状、非白人种族和胃食管反流症状相关。 结论：哮喘是一种复杂的综合征：未出现恶化但 EBC pH 值低的受试者似乎是一个独特的亚群。胸部 2011； 139(2):328-336
Background: Exhaled breath condensate (EBC) pH is 2 log orders below normal during acute asthma exacerbations and returns to normal with antiinflammatory therapy. However, the determinants of EBC pH, particularly in stable asthma, are poorly understood. We hypothesized that patients with severe asthma would have low EBC pH and that there would be an asthma subpopulation of patients with characteristically low values.Methods: We studied the association of EBC pH with clinical characteristics in 572 stable subjects enrolled in the Severe Asthma Research Program. These included 250 subjects with severe asthma, 291 with nonsevere asthma, and 31 healthy control subjects.Results: Overall, EBC in this population of stable, treated study subjects was not lower in severe asthma (8.02; interquartile range [IQR], 7.61-8.41) or nonsevere asthma (7.90; IQR, 7.52-8.20) than in control subjects (7.9; IQR, 7.40-8.20). However, in subjects with asthma the data clustered below and above pH 6.5. Subjects in the subpopulation with pH < 6.5 had lower fraction of exhaled NO (FENO) values (FENO = 22.6 +/- 18.1 parts per billion) than those with pH >= 6.5 (39.9 +/- 40.2 parts per billion; P < .0001). By multiple linear regression, low EBC pH was associated with high BMI, high BAL neutrophil counts, low prebronchodilator FEV1 ratio, high allergy symptoms, race other than white, and gastroesophageal reflux symptoms.Conclusion: Asthma is a complex syndrome: Subjects who are not experiencing an exacerbation but have low EBC pH appear to be a unique subpopulation. CHEST 2011; 139(2):328-336