慢性阻塞性肺疾病患者体质指数与高分辨率CT容积量化参数的相关性研究

Correlation of high-resolution CT volumetric data with body mass index in patients with chronic obstructive pulmonary disease

目的研究慢性阻塞性肺疾病(COPD)患者的体质指数(BMI)与高分辨率CT(HRCT)容积量化参数及其表型的相关性。方法 COPD患者62例,完成HRCT检查,并记录其身高及体质量。根据HRCT中是否存在肺气肿和支气管壁增厚对COPD患者进行分型,将HRCT原始数据传至Extended Brilliance Workspace^(TM)后处理工作站,自动计算出总肺体积(TLV),设定吸气末闯值低于-950 HU为肺气肿区,得出总肺气肿体积(TEV),计算肺气肿指数(EI=TEV/TLV)。运用Spearman相关分析检验HRCT容积量化参数与BMI的相关性,采用单因素方差分析比较组间差异。结果 COPD患者的HRCT表型分别为:A型42例,E型9例,M型11例。COPD患者的HRCT容积量化参数TEV和EI与BMI均呈负相关(r=-0.389,P=0.002;r=-0.424,P=0.001)。HRCT表型为A型的患者平均BMI为(23.4±3.4)kg/m^2,高于E型[(20.6±3.1)kg/m^2,P<0.05];而M型患者BMI为(21.3±2.7)kg/m^2,与A型和E型比较差异均无统计学意义。结论 COPD患者TEV和EI与BMI呈负相关,HRCT表型为A型的患者BMI较高。

Objective To explore the association of body mass index （BMI） with high-resolution CT （HRCT） volumetric data and HRCT phenotypes in patients with chronic obstructive pulmonary disease （COPD）. Methods Sixty-two consecutive COPD patients underwent HRCT and their weight and height were recorded. COPD subjects were classified into three phenotypes based on the visual HRCT findings （with or without emphysema and/or bronchial wall thickening）. With the volumetric HRCT data, the total lung volume （TLV） was calculated automatically by Extended Brilliance WorkspaceTM, the total emphysema volume （TEV） was obtained by applying density thresholds of -950 HU, and the TEV/TLV was calculated as an emphysema index （El）. The correlation between the volumetric HRCT data and BMI was assessed using Spearman correlation analysis. The three phenotypes of COPD subjects were evaluated using one way ANOVA. Results Visual HRCT findings showed that the COPD patients were classified into 3 phenotypes., phenotype A （n= 42）, phenotype E （n= 9） and phenotypeM （n=11）. BMI of COPD patients was correlated with bothTEV （r =-0.389, P=0.002） and EI （r=-0.424, P=0. 001）. COPD patients with phenotype A had a significantly higher BMI （[23.4±3.4] kg/m2） compared with those with phenotype E （[20. 6±3. 1] kg/m^2, P〈0. 05）. The BMI of patients with phenotype M（[21. 3±2. 7] kg/m^2） was not significantly different from those of phenotypes A or E. Conclusion The TEV and EI are negatively correlated with BMI in COPD patients. HRCT phenotype A compared with phenotype B and C is associated with a higher BMI in COPD patients.