Quantitative computed tomography: emphysema and airway wall thickness by sex, age and smoking

We investigated how quantitative high-resolution computed tomography (HRCT) measures of emphysema and airway wall thickness (AWT) vary with sex, age and smoking history. We included 463 chronic obstructive pulmonary disease (COPD) cases and 431 controls. All included subjects were current or ex-smokers aged >= 40 yrs, and all underwent spirometry and HRCT examination. The HRCT images were quantitatively assessed, providing indices on lung density and airway dimensions. The median (25-75th percentile) %LAA950 (% low-attenuation area < -950 HU) was 8.9 (3-19) and 4.7 (1-16) in male and female COPD cases, respectively, and 0.71 (0.3-1.6) and 0.32 (0.1-0.8) in male and female controls, respectively. %LAA950 was higher in ex-smokers and increased with increasing age and with increasing number of pack-years. The mean So standardised AWT was 0.504 +/- 0.030 and 0.474 +/- 0.031 in male and female COPD cases, respectively, and 0.488 +/- 0.028 and 0.463 +/- 0.025 in male and female controls, respectively. AWT decreased with increasing age in cases, and increased with the degree of current smoking in all subjects. We found significant differences in quantitative HRCT measures of emphysema and AWT between varying sex, age and smoking groups of both control and COPD subjects.