Labarca Gonzalo, Bustamante Andrea, Valdivia Gonzalo, Díaz Rodrigo, Huete Álvaro, Mac Nab Paul, Mendoza Laura, Leppe Jaime, Lisboa Carmen, Saldías Fernando, Díaz Orlando
Faculty of Medicine, Universidad San Sebastián, Concepción, Concepción, Chile.
Division of Internal Medicine, Complejo Asistencial Víctor Ríos Ruiz, Los Ángeles, Chile.
BMJ Open. 2017 Aug 11;7(8):e015731. doi: 10.1136/bmjopen-2016-015731.
Clinical onset of chronic obstructive pulmonary disease (COPD) is the point at which the disease is first identifiable by physicians. It is a poorly defined stage which seems to include both mild spirometric and non-spirometric disease, and could be described as early grade COPD, for practical purposes. While dyspnoea; chronic bronchitis and CT imaging evidence of emphysema and airway disease may be present very early, the lone significance of dyspnoea, the most relevant symptom in COPD in identifying these individuals, has been scarcely assessed.The Searching Clinical COPD Onset (SOON) Study was designed primarily to detect clinical, physiological and structural differences between dyspnoeic and non-dyspnoeic individuals with early grade COPD. It is hypothesised that presence of dyspnoea in early disease may identify a subtype of individuals with reduced exercise capacity, notwithstanding of their spirometry results. In addition, dyspnoeic individuals will share worse quality of life, lower physical activity, greater lung hyperinflation greater emphysema and airway thickness and reduced peripheral muscle mass than their non-dyspnoeic counterpart.
SOON is a monocentric study, with a cross sectional design aimed at obtaining representative samples of current or ex-smoker-adults aged ≥45 and ≤80 years. Two hundred and forty participants will be enrolled into four strata, according to normal spirometry or mild spirometric obstruction and presence or not of dyspnoea modified Medical Research Council score ≥1. The primary outcome will be the difference between dyspnoeic and non-dyspnoeic individuals on the 6-min walk test performance, regardless of their spirometry results. To account for the confounding effect of heart failure on dyspnoea, stress echocardiography will be also performed. Secondary outcomes will include clinical (quality of life, physical activity), physiological (exercise testing) and structural characteristics (emphysema, airway disease and peripheral muscle mass by CT imaging).
The Institutional Ethics Committee from Pontificia Universidad Católica de Chile has approved the study protocol and signed informed consent will be obtained from all participants. The findings of the trial will be disseminated through relevant peer-reviewed journals and international conference presentations.
NCT03026439.
慢性阻塞性肺疾病（COPD）的临床发病是医生首次能够识别该疾病的阶段。这是一个定义尚不明确的阶段，似乎既包括轻度肺功能测定异常和非肺功能测定异常的疾病，实际上可将其描述为早期COPD。虽然呼吸困难、慢性支气管炎以及肺气肿和气道疾病的CT影像证据可能在很早的时候就已出现，但对于COPD中最相关的症状——呼吸困难在识别这些个体方面的单独意义，几乎未作评估。探索COPD临床发病（SOON）研究主要旨在检测早期COPD有呼吸困难和无呼吸困难个体之间的临床、生理和结构差异。据推测，尽管其肺功能测定结果如何，但早期疾病中出现呼吸困难可能识别出运动能力降低的个体亚型。此外，有呼吸困难的个体与无呼吸困难的个体相比，将具有更差的生活质量、更低的身体活动水平、更严重的肺过度充气、更严重的肺气肿和气道增厚以及更低的外周肌肉质量。
SOON是一项单中心研究，采用横断面设计，旨在获取年龄在45岁至80岁之间的当前吸烟者或既往吸烟者成年人的代表性样本。根据肺功能测定正常或轻度肺功能测定阻塞以及是否存在呼吸困难（改良医学研究委员会评分为≥1），将240名参与者分为四个层次。主要结局将是有呼吸困难和无呼吸困难个体在6分钟步行试验表现上的差异，无论其肺功能测定结果如何。为了考虑心力衰竭对呼吸困难的混杂影响，还将进行负荷超声心动图检查。次要结局将包括临床指标（生活质量、身体活动）、生理指标（运动测试）以及结构特征（通过CT影像评估肺气肿、气道疾病和外周肌肉质量）。
智利天主教大学的机构伦理委员会已批准该研究方案，将从所有参与者处获得签署的知情同意书。试验结果将通过相关的同行评审期刊和国际会议报告进行传播。
NCT03026439。
