Luminal narrowing is a hallmark feature of airway remodelling in COPD, but current measures focus on airway wall remodelling. Quantification of the natural increase in cumulative cross-sectional area along the length of the human airway tree can facilitate assessment of airway narrowing.

We analysed the airway trees of 7641 subjects enrolled in the multicentre COPDGene cohort. Airway luminal tapering was assessed by estimating the slope of the change in cumulative cross-sectional area along the length of the airway tree over successive generations (T-Slope). We performed multivariable regression analyses to test the associations between T-Slope and lung function, St George's Respiratory Questionnaire score, modified Medical Research Council dyspnoea score, 6-min walk distance (6MWD), forced expiratory volume in 1 s (FEV₁) change, exacerbations and all-cause mortality after adjusting for demographics, emphysema measured as the percentage of voxels with density <–950 HU on inspiratory computed tomography scans (%CT emphysema) and total airway count.

The mean±sd T-Slope decreased with increasing COPD severity: 2.69±0.70 mm^–1 in non-smokers and 2.33±0.70, 2.11±0.65, 1.78±0.58, 1.60±0.53 and 1.57±0.52 mm^–1 in GOLD stages 0 through 4, respectively (Jonckheere–Terpstra p=0.04). On multivariable analyses, T-Slope was independently associated with FEV₁ (β=0.13 (95% CI 0.10–0.15) L; p<0.001), 6MWD (β=15.0 (95% CI 10.8–19.2) m; p<0.001), change in FEV₁ (β= –4.50 (95% CI –7.32– –1.67) mL·year^–1; p=0.001), exacerbations (incidence risk ratio 0.78 (95% CI 0.73–0.83); p<0.001) and mortality (hazard ratio 0.79 (95% CI 0.72–0.86); p<0.001).

T-Slope is a measure of airway luminal remodelling and is associated with respiratory morbidity and mortality.

管腔狭窄是 COPD 患者气道重塑的标志性特征，但目前的措施侧重于气道壁重塑。沿人体气道树长度的累积横截面积的自然增加的量化有助于评估气道狭窄。

我们分析了多中心 COPDGene 队列中 7641 名受试者的气道树。通过估计连续几代沿气道树长度的累积横截面积变化的斜率 （T 斜率） 来评估气道管腔逐渐变细。我们进行了多变量回归分析，以检验 T 斜率与肺功能、圣乔治呼吸问卷评分、改良医学研究委员会呼吸困难评分、6 分钟步行距离 （6MWD）、1 秒用力呼气容积 （FEV₁） 变化、调整人口统计学后恶化和全因死亡率、肺气肿测量为吸气计算机断层扫描中密度为 <-950 胡 的体素百分比（%CT 肺气肿）和总气道计数。

平均 ±sd T 斜率随着 COPD 严重程度的增加而降低：非吸烟者为 2.69±0.70 ^mm-1，GOLD 阶段 0 至 4 分别为 2.33±0.70、2.11±0.65、1.78±0.58、1.60±0.53 和 1.57±0.52 ^mm-1 （Jonckheere-Terpstra p=0.04）。在多变量分析中，T 斜率与 FEV₁ （β=0.13 （95% CI 0.10–0.15） L;p<0.001）、6MWD （β=15.0 （95% CI 10.8–19.2） m;p<0.001）、FEV₁ 的变化 （β= –4.50 （95% CI –7.32– –1.67） mL·year^–1;p=0.001）、恶化 （发生风险比 0.78 （95% CI 0.73–0.83）;p<0.001） 和死亡率 （风险比 0.79 （95% CI 0.72–0.86;p<0.001） 的变化独立相关。

T 斜率是衡量气道管腔重塑的指标，与呼吸系统发病率和死亡率相关。