Low attenuation area ratio (LAA%) and pectoral major parameters are in elderly patients with COPD related to pulmonary ventilation function, but there are few studies at home and abroad.

To analyze the correlation of LAA% and pectoral major parameters with impaired pulmonary ventilation function in elderly patients with COPD, and to explore the predictive value of LAA% and PMcsa in the severity of airflow restriction, in order to provide clinical basis for the early detection and diagnosis of COPD.

A total of 270 elderly patients with stable COPD who underwent chest CT and lung function examination in North Jiangsu People's Hospital affiliated to Yangzhou University from December 2019 to June 2021 were selected and divided into GOLDⅠgroup (FEV_l%pred≥80%, n=47) , GOLD Ⅱgroup (50%≤FEV_l%pred<80%, n=88) , GOLD Ⅲ group (30%≤FEV_l%pred<50%, n=84) and GOLD Ⅳ group (FEV_l%pred<30%, n=51) according to GOLD classification with their general information and CT quantitative indexes recorded. Pearson correlation analysis and multiple linear regression analysis were used to explore the relationship between LAA%, pectoralis major areas (PMcsa) and lung function. The receiver operating characteristic curve (ROC curve) was used to evaluate the predictive value of LAA% and PMcsa for FEV₁%pred<50% and FEV₁%pred<80%.

BMI and PMD in GOLDⅠgroup were higher than those in GOLD Ⅲ group and GOLD Ⅳ group (P<0.05) , and the BMI in GOLD Ⅱgroup and GOLD Ⅲ group was higher than that in GOLD Ⅳ group (P<0.05) . PMcsa, PMI, FEV₁%pred, FEV₁ and FVC in GOLD Ⅰgroup were higher than those in GOLD Ⅱ group, GOLD Ⅲ group and GOLD Ⅳ group (P<0.05) . PMcsa, PMI, FEV₁%pred, FEV₁ and FVC in GOLD Ⅱ group were higher than those in GOLD Ⅲ group and GOLD Ⅳ group (P<0.05) . PMcsa, PMI , FEV₁%pred, FEV₁ and FVC in GOLD Ⅲ group were higher than those in GOLD Ⅳ group (P<0.05) . Left lung LAA%, right lung LAA% and total lung LAA% in GOLD Ⅰ group were lower than those in GOLD Ⅱ group, GOLD Ⅲ group and GOLD Ⅳ group (P<0.05) . Left lung LAA%, right lung LAA% and total lung LAA% in GOLD Ⅱ group were lower than those in GOLDⅢ group and GOLD Ⅳ group (P<0.05) . Left lung LAA%, right lung LAA% and total lung LAA% in GOLD Ⅲ group were lower than those in GOLD Ⅳ group (P<0.05) . FEV₁%pred, FEV₁ and FVC were positively correlated with PMcsa, PMI and PMD (P<0.05) . Both FEV₁%pred and FEV₁ were negatively correlated with low attenuation area ratio (right LAA%, left LAA%, total LAA%) (P<0.05) . Multiple linear regression analysis show that gender, total LAA% and PMcsa were independent influencing factors of FEV₁%pred. The area under ROC curve of right lung LAA%, left lung LAA%, total lung LAA% and PMcsa predicting FEV₁%pred<50% in male patients were 0.832, 0.827, 0.834, 0.809, respectively. The area under ROC curve of right lung LAA%, left lung LAA%, total lung LAA% and PMcsa predicting FEV₁%pred<50% in female patientswere 0.844, 0.801, 0.845, 0.839, respectively. The area under ROC curve of right lung LAA%, Left lung LAA%, total lung LAA% and PMcsa predicting FEV₁%pred<80% in male patients were 0.830, 0.815, 0.831, 0.844, respectively. The area under ROC curve of right lung LAA%, left lung LAA%, total lung LAA% and PMcsa predicting FEV₁%pred<80% in female patients were 0.805, 0.817, 0.807, 0.846, respectively.

The low attenuation area ratio and PMcsa can assess the severity of airflow restriction in elderly patients with COPD, and can be used as an important tool for early screening and severity assessment of COPD.

老年慢性阻塞性肺疾病患者肺低衰减区比例（LAA%）及胸大肌参数与肺通气功能具有相关性，目前国内外研究较少。

分析老年慢性阻塞性肺疾病患者LAA%及胸大肌参数与肺通气功能受损的相关性，并探讨其对气流受限严重程度的预测价值，以期为临床早期发现及诊断慢性阻塞性肺疾病提供临床依据。

选择自2019年12月至2021年6月在扬州大学附属苏北人民医院完成胸部CT及肺功能检查的稳定期老年慢性阻塞性肺疾病患者270例，根据GOLD分级分为GOLDⅠ级组〔第1秒用力呼气容积占预计值百分比（FEV_l%pred）≥80%，n=47〕、GOLDⅡ级组（50%≤FEV_l%pred<80%，n=88）、GOLDⅢ级组（30%≤FEV_l%pred<50%，n=84）、GOLDⅣ级组（FEV_l%pred<30%，n=51），收集患者一般资料及CT定量指标，采用Pearson相关分析及多元线性回归分析探究LAA%、胸大肌参数与肺功能的关系。应用受试者工作特征曲线（ROC曲线）探讨LAA%及胸大肌面积（PMcsa）对FEV₁%pred<50%及FEV₁%pred<80%的预测价值。

GOLDⅠ级组体质指数（BMI）、胸大肌密度（PMD）均高于GOLDⅢ级组和GOLDⅣ级组（P<0.05），GOLDⅡ级组、GOLDⅢ组BMI高于GOLDⅣ组（P<0.05）；GOLDⅠ级组PMcsa、胸大肌指数（PMI）、FEV₁%pred、第1秒用力呼气容积（FEV₁）、用力肺活量（FVC）均高于GOLDⅡ级组、GOLD Ⅲ级组、GOLD Ⅳ级组（P<0.05），GOLDⅡ级组PMcsa、PMI、FEV₁%pred、FEV₁、FVC均高于GOLD Ⅲ级组、GOLD Ⅳ级组（P<0.05），GOLD Ⅲ级组PMcsa、PMI、FEV₁%pred、FEV₁、FVC均高于GOLD Ⅳ级组（P<0.05）；GOLD Ⅰ级组左肺LAA%、右肺LAA%、总肺LAA%低于GOLDⅡ级组、GOLD Ⅲ级组、GOLD Ⅳ级组（P<0.05），GOLD Ⅱ级组左肺LAA%、右肺LAA%、总肺LAA%低于GOLD Ⅲ级组、GOLD Ⅳ级组（P<0.05），GOLD Ⅲ级组左肺LAA%、右肺LAA%、总肺LAA%低于GOLD Ⅳ级组（P<0.05）。FEV₁%pred、FEV₁、FVC均与PMcsa、PMI、PMD呈正相关（P<0.05）。FEV₁%pred、FEV₁均与右肺LAA%、左肺LAA%、总肺LAA%呈负相关（P<0.05）。多元线性回归分析结果显示，性别、总肺LAA%、PMcsa是FEV₁%pred的影响因素（P<0.05）。男性患者右肺LAA%、左肺LAA%、总肺LAA%、PMcsa预测FEV₁%pred<50%的ROC曲线下面积（AUC）分别为0.832、0.827、0.834、0.809；女性患者右肺LAA%、左肺LAA%、总肺LAA%、PMcsa预测FEV₁%pred<50%的AUC分别为0.844、0.801、0.845、0.839；男性患者右肺LAA%、左肺LAA%、总肺LAA%、PMcsa预测FEV₁%pred<80%的AUC分别为0.830、0.815、0.831、0.844；女性患者右肺LAA%、左肺LAA%、总肺LAA%、PMcsa预测FEV₁%pred<80%的AUC分别为0.805、0.817、0.807、0.846。

LAA%及PMcsa能够评估老年慢性阻塞性肺疾病患者气流受限严重程度，可作为慢性阻塞性肺疾病早期筛查和严重程度评估的重要工具。