Pulmonary and Critical Care Medicine Division, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston MA, USA.
Respir Med. 2010 Aug;104(8):1145-51. doi: 10.1016/j.rmed.2010.02.023. Epub 2010 Apr 10.
To assess the association of emphysema and airway disease assessed by volumetric computed tomography (CT) with exercise capacity in subjects with chronic obstructive pulmonary disease (COPD).
We studied 93 subjects with COPD (Forced Expiratory Volume in 1 s [FEV(1)] %predicted mean +/- SD 57.1 +/- 24.3%, female gender = 40) enrolled in the Lung Tissue Research Consortium. Emphysema was defined as percentage of low attenuation areas less than a threshold of -950 Hounsfield units (%LAA-950) on CT scan. The wall area percentage (WA%) of the 3rd to 6th generations of the apical bronchus of right upper lobe (RB1) were analyzed. The 6-min walk distance (6MWD) test was used as a measure of exercise capacity.
The 6MWD was inversely associated with %LAA-950 (r = -0.53, p < 0.0001) and with the WA% of 6th generation of RB1 only (r = -0.28, p = 0.009). In a multivariate regression model including CT indices of emphysema and airway disease that were adjusted for demographic and physiologic variables as well as brand of CT scanner, only the %LAA-950 remained significantly associated with exercise performance. Holding other covariates fixed, this model showed that a 10% increase of CT emphysema reduced the distance walked in 6 min 28.6 m (95% Confidence Interval = -51.2, -6.0, p = 0.01).
These results suggest that the extent of emphysema but not airway disease measured by volumetric CT contributes independently to exercise limitation in subjects with COPD.
评估通过容积 CT（CT）评估的肺气肿和气道疾病与慢性阻塞性肺疾病（COPD）患者的运动能力的相关性。
我们研究了 93 名 COPD 患者（FEV1 预测值的平均值 +/- SD 57.1 +/- 24.3%，女性 = 40），这些患者均来自肺组织研究联合会。通过 CT 扫描，将肺气肿定义为低于-950 豪斯菲尔德单位（-950 Hounsfield units，HUs）阈值的低衰减区域百分比（%LAA-950）。分析右上叶（RB1）第 3 至 6 代支气管的壁面积百分比（wall area percentage，WA%）。6 分钟步行距离（6MWD）测试用于评估运动能力。
6MWD 与 %LAA-950 呈负相关（r = -0.53，p < 0.0001），与仅 RB1 第 6 代的 WA%呈负相关（r = -0.28，p = 0.009）。在一个包含肺气肿和气道疾病 CT 指标的多变量回归模型中，这些 CT 指标通过调整人口统计学和生理学变量以及 CT 扫描仪的品牌进行了调整，只有 %LAA-950 与运动表现仍显著相关。在固定其他协变量的情况下，该模型表明 CT 肺气肿增加 10%，6 分钟步行距离减少 28.6 米（95%置信区间=-51.2，-6.0，p = 0.01）。
这些结果表明，通过容积 CT 测量的肺气肿程度而非气道疾病独立地导致 COPD 患者运动受限。
