Quantitative Computed Tomography Measures of Emphysema and Airway Wall Thickness Are Related to Respiratory Symptoms

• Published in: American journal of respiratory and critical care medicine Vol. 181; no. 4; pp. 353 - 359
• Main Authors: Grydeland, Thomas B, Dirksen, Asger, Coxson, Harvey O, Eagan, Tomas M. L, Thorsen, Einar, Pillai, Sreekumar G, Sharma, Sanjay, Eide, Geir Egil, Gulsvik, Amund, Bakke, Per S
• Format: Journal Article
• Language: English
• Published: New York, NY Am Thoracic Soc 15.02.2010; American Thoracic Society
• Subjects: Aged; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Chronic obstructive pulmonary disease; Confidence Intervals; Cough - pathology; Cough - physiopathology; Dyspnea; Dyspnea - pathology; Dyspnea - physiopathology; Emergency and intensive respiratory care; Emphysema; Female; Humans; Intensive care medicine; Logistic Models; Lung - diagnostic imaging; Lung - pathology; Lung - physiopathology; Male; Medical sciences; Middle Aged; Odds Ratio; Pulmonary Disease, Chronic Obstructive - pathology; Pulmonary Disease, Chronic Obstructive - physiopathology; Pulmonary Emphysema - pathology; Pulmonary Emphysema - physiopathology; Questionnaires; Respiratory Sounds - physiopathology; Sex Factors; Spirometry; Tomography; Tomography, X-Ray Computed; computed tomography; Lung disease; Intensive care; Respiratory disease; Wheezing; Cough; Dyspnea; Bronchus disease; Chronic obstructive pulmonary disease; Computerized axial tomography; Obstructive pulmonary disease; Emphysema; Resuscitation
• ISSN: 1073-449X; 1535-4970; 1535-4970
• DOI: 10.1164/rccm.200907-1008OC

There is limited knowledge about the relationship between respiratory symptoms and quantitative high-resolution computed tomography measures of emphysema and airway wall thickness. To describe the ability of these measures of emphysema and airway wall thickness to predict respiratory symptoms in subjects with and without chronic obstructive pulmonary disease (COPD). We included 463 subjects with chronic obstructive pulmonary disease (COPD) (65% men) and 488 subjects without COPD (53% men). All subjects were current or ex-smokers older than 40 years. They underwent spirometry and high-resolution computed tomography examination, and completed an American Thoracic Society questionnaire on respiratory symptoms. Median (25th percentile, 75th percentile) percent low-attenuation areas less than -950 Hounsfield units (%LAA) was 7.0 (2.2, 17.8) in subjects with COPD and 0.5 (0.2, 1.3) in subjects without COPD. Mean (SD) standardized airway wall thickness (AWT) at an internal perimeter of 10 mm (AWT-Pi10) was 4.94 (0.33) mm in subjects with COPD and 4.77 (0.29) in subjects without COPD. Both %LAA and AWT-Pi10 were independently and significantly related to the level of dyspnea among subjects with COPD, even after adjustments for percent predicted FEV(1). AWT-Pi10 was significantly related to cough and wheezing in subjects with COPD, and to wheezing in subjects without COPD. Odds ratios (95% confidence intervals) for increased dyspnea in subjects with COPD and in subjects without COPD were 1.9 (1.5-2.3) and 1.9 (0.6-6.6) per 10% increase in %LAA, and 1.07 (1.01-1.14) and 1.11 (0.99-1.24) per 0.1-mm increase in AWT-Pi10, respectively. Quantitative computed tomography assessment of the lung parenchyma and airways may be used to explain the presence of respiratory symptoms beyond the information offered by spirometry.