Author(s)

C. H. Martinez, Y. H. Chen, P. M. Westgate, L. X. Liu, S. Murray, J. L. Curtis, B. J. Make, E. A. Kazerooni, D. A. Lynch, N. Marchetti, G. R. Washko, F. J. Martinez, M. K. Han, COPDGene Investigators

ISBN

0040-6376

Publication year

2012

Periodical

Thorax

Periodical Number

5

Volume

67

Pages

399-406

Author Address

Han, MK Univ Michigan Hlth Syst, Div Pulm & Crit Care Med, Taubman Ctr 3916, Box 5360,1500 E Med Ctr Dr, Ann Arbor, MI 48109 USA Univ Michigan Hlth Syst, Div Pulm & Crit Care Med, Taubman Ctr 3916, Ann Arbor, MI 48109 USA Peking Univ, Hosp 3, Resp Dept, Beijing 100871, Peoples R China Univ Michigan, Sch Publ Hlth, Dept Biostat, Ann Arbor, MI 48109 USA VA Ann Arbor Healthcare Syst, Med Serv, Ann Arbor, MI USA Natl Jewish Hlth, Dept Med, Denver, CO USA Univ Michigan Hlth Syst, Dept Radiol, Ann Arbor, MI 48109 USA Natl Jewish Hlth, Div Radiol, Denver, CO USA Temple Univ, Philadelphia, PA 19122 USA Brigham & Womens Hosp, Pulm & Crit Care Div, Boston, MA 02115 USA

Full version

Background The value of quantitative CT (QCT) to identify chronic obstructive pulmonary disease (COPD) phenotypes is increasingly appreciated. The authors hypothesised that QCT-defined emphysema and airway abnormalities relate to St George’s Respiratory Questionnaire (SGRQ) and Body-Mass Index, Airflow Obstruction, Dyspnea and Exercise Capacity Index (BODE).
Methods 1200 COPDGene subjects meeting Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria for COPD with QCT analysis were included. Total lung emphysema was measured using the density mask technique with a -950 Hounsfield unit threshold. An automated programme measured mean wall thickness (WT), wall area percentage (WA%) and 10 mm lumenal perimeter (pi10) in six segmental bronchi. Separate multivariate analyses examined the relative influence of airway measures and emphysema on SGRQ and BODE.
Results In separate models predicting SGRQ score, a 1 unit SD increase in each airway measure predicted higher SGRQ scores (for WT, 1.90 points higher, p=0.002; for WA%, 1.52 points higher, p=0.02; for pi10, 2.83 points higher p<0.001). The comparable increase in SGRQ for a 1 unit SD increase in emphysema percentage in these models was relatively weaker, significant only in the pi10 model (for emphysema percentage, 1.45 points higher, p=0.01). In separate models predicting BODE, a 1 unit SD increase in each airway measure predicted higher BODE scores (for WT, 1.07-fold increase, p<0.001; for WA%, 1.20-fold increase, p<0.001; for pi10, 1.16-fold increase, p<0.001). In these models, emphysema more strongly influenced BODE (range 1.24-1.26-fold increase, p<0.001). Conclusion Emphysema and airway disease both relate to clinically important parameters. The relative influence of airway disease is greater for SGRQ; the relative influence of emphysema is greater for BODE.