Phenotype of Spirometric Impairment in an Aging Population

Am J Respir Crit Care Med. 2016 Apr 1;193(7):727-35. doi: 10.1164/rccm.201508-1603OC.

Abstract

Rationale: The Global Lung Initiative (GLI) provides age-appropriate criteria for establishing spirometric impairment, including mild, moderate, and severe chronic obstructive pulmonary disease (COPD) and restrictive pattern, but its association with respiratory-related phenotypes has not been evaluated.

Objectives: To evaluate respiratory-related phenotypes in GLI-defined spirometric impairment.

Methods: In COPDGene (N = 10,131 patients; age range, 45-81 yr; average smoking history, 44.3 pack-years), we evaluated spirometry, dyspnea (modified Medical Research Council grade, ≥2), poor respiratory health-related quality of life (St. George's Respiratory Questionnaire total score, ≥25), poor exercise performance (6-minute-walk distance, <391 m), bronchodilator reversibility (FEV1 change, >12% and ≥200 ml), and computed tomography-diagnosed emphysema and gas trapping (>5% and >15% of lung, respectively).

Measurements and main results: GLI established normal spirometry in 5,100 patients (50.3%), mild COPD in 669 (6.6%), moderate COPD in 865 (8.5%), severe COPD in 2,522 (24.9%), and restrictive pattern in 975 (9.6%). Relative to normal spirometry, graded associations with respiratory-related phenotypes were found for mild, moderate, and severe COPD, with respective adjusted odds ratios (95% confidence intervals) as follows: dyspnea-1.31 (1.10-1.56), 2.20 (1.81-2.68), and 10.73 (8.04-14.33); poor respiratory health-related quality of life-1.49 (1.28-1.75), 2.69 (2.08-3.47), and 14.61 (10.09-21.17); poor exercise performance-1.11 (0.94-1.31), 1.58 (1.33-1.88), and 4.58 (3.42-6.12); bronchodilator reversibility-2.76 (2.24-3.40), 5.18 (4.29-6.27), and 6.21 (5.06-7.62); emphysema-4.86 (3.16-7.47), 6.41 (4.09-10.05), and 17.79 (10.79-29.32); and gas trapping-3.92 (3.12-4.93), 5.20 (3.82-7.07), and 16.28 (9.71-27.30). Restrictive pattern was also associated with multiple respiratory-related phenotypes at a level similar to moderate COPD, but it was otherwise not associated with emphysema (0.89 [0.60-1.32]) or gas trapping (1.15 [0.92-1.42]).

Conclusions: GLI-defined spirometric impairment establishes clinically meaningful respiratory disease, as validated by graded associations with respiratory-related phenotypes.

Keywords: chronic obstructive pulmonary disease; emphysema; restriction.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Aging / physiology*
  • Comorbidity
  • Dyspnea / diagnosis
  • Dyspnea / etiology*
  • Emphysema / diagnosis
  • Emphysema / diagnostic imaging
  • Emphysema / etiology*
  • Exercise Test
  • Female
  • Forced Expiratory Flow Rates
  • Forced Expiratory Volume
  • Humans
  • Lung / diagnostic imaging
  • Lung / physiopathology*
  • Male
  • Middle Aged
  • Multicenter Studies as Topic
  • Phenotype
  • Pulmonary Disease, Chronic Obstructive / classification
  • Pulmonary Disease, Chronic Obstructive / complications
  • Pulmonary Disease, Chronic Obstructive / genetics*
  • Quality of Life
  • Reference Standards
  • Severity of Illness Index
  • Smoking
  • Spirometry / standards
  • Tomography, X-Ray Computed
  • United States