Imaging Research Laboratories, Robarts Research Institute, London, Ontario, Canada.
Thorax. 2013 Aug;68(8):752-9. doi: 10.1136/thoraxjnl-2012-203108. Epub 2013 Apr 19.
The functional effects of abnormal diffusing capacity for carbon monoxide (DLCO) in ex-smokers without chronic obstructive pulmonary disease (COPD) are not well understood.
We aimed to evaluate and compare well established clinical, physiological and emerging imaging measurements in ex-smokers with normal spirometry and abnormal DLCO with a group of ex-smokers with normal spirometry and DLCO and ex-smokers with Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage I COPD.
We enrolled 38 ex-smokers and 15 subjects with stage I COPD who underwent spirometry, plethysmography, St George's Respiratory Questionnaire (SGRQ), 6 min Walk Test (6MWT), x-ray CT and hyperpolarised helium-3 ((3)He) MRI. The 6MWT distance (6MWD), SGRQ scores, (3)He MRI apparent diffusion coefficients (ADC) and CT attenuation values below -950 HU (RA950) were evaluated.
Of 38 ex-smokers without COPD, 19 subjects had abnormal DLCO with significantly worse ADC (p=0.01), 6MWD (p=0.008) and SGRQ (p=0.01) but not RA950 (p=0.53) compared with 19 ex-smokers with normal DLCO. Stage I COPD subjects showed significantly worse ADC (p=0.02), RA950 (p=0.0008) and 6MWD (p=0.005), but not SGRQ (p=0.59) compared with subjects with abnormal DLCO. There was a significant correlation for (3)He ADC with SGRQ (r=0.34, p=0.02) and 6MWD (r=-0.51, p=0.0002).
In ex-smokers with normal spirometry and CT but abnormal DLCO, there were significantly worse symptoms, 6MWD and (3)He ADC compared with ex-smokers with normal DLCO, providing evidence of the impact of mild or early stage emphysema and a better understanding of abnormal DLCO and hyperpolarised (3)He MRI in ex-smokers without COPD.
非吸烟慢性阻塞性肺疾病（COPD）患者一氧化碳弥散量（DLCO）异常的功能影响尚不清楚。
我们旨在评估和比较正常肺量计和异常 DLCO 的戒烟者以及正常肺量计和 DLCO 的戒烟者和 GOLD 阶段 I COPD 的戒烟者的既定临床、生理和新兴影像学测量值。
我们纳入了 38 名戒烟者和 15 名 I 期 COPD 患者，他们接受了肺量计、体积描记法、圣乔治呼吸问卷（SGRQ）、6 分钟步行试验（6MWT）、X 射线 CT 和极化氦-3（3）磁共振成像。评估 6MWT 距离（6MWD）、SGRQ 评分、3He MRI 表观扩散系数（ADC）和 CT 衰减值低于-950 HU（RA950）。
在 38 名无 COPD 的戒烟者中，19 名患者的 DLCO 异常，ADC（p=0.01）、6MWD（p=0.008）和 SGRQ（p=0.01）明显较差，但 RA950（p=0.53）与 19 名 DLCO 正常的戒烟者相比没有差异。I 期 COPD 患者的 ADC（p=0.02）、RA950（p=0.0008）和 6MWD（p=0.005）明显较差，但 SGRQ（p=0.59）与 DLCO 异常的患者相比没有差异。3He ADC 与 SGRQ（r=0.34，p=0.02）和 6MWD（r=-0.51，p=0.0002）呈显著相关。
在正常肺量计和 CT 但 DLCO 异常的戒烟者中，与 DLCO 正常的戒烟者相比，症状、6MWD 和 3He ADC 明显更差，为轻度或早期肺气肿的影响提供了证据，并更好地理解了无 COPD 的戒烟者的异常 DLCO 和极化 3He MRI。
