Format

Send to

Choose Destination
See comment in PubMed Commons below
Am J Respir Crit Care Med. 2015 Oct 1;192(7):817-25. doi: 10.1164/rccm.201503-0463OC.

Phenotype of normal spirometry in an aging population.

Author information

1
1 Veterans Affairs Clinical Epidemiology Research Center, West Haven, Connecticut.
2
2 Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut.
3
3 Los Angeles Biomedical Research Institute, Harbor-UCLA Medical Center, Los Angeles, California.
4
4 LDS Hospital and University of Utah, Salt Lake City, Utah; and.
5
5 Division of Pulmonary and Critical Care Medicine, Duke University School of Medicine, Durham, North Carolina.

Abstract

RATIONALE:

In aging populations, the commonly used Global Initiative for Chronic Obstructive Lung Disease (GOLD) may misclassify normal spirometry as respiratory impairment (airflow obstruction and restrictive pattern), including the presumption of respiratory disease (chronic obstructive pulmonary disease [COPD]).

OBJECTIVES:

To evaluate the phenotype of normal spirometry as defined by a new approach from the Global Lung Initiative (GLI), overall and across GOLD spirometric categories.

METHODS:

Using data from COPDGene (nā€‰=ā€‰10,131; ages 45-81; smoking history, ā‰„10 pack-years), we evaluated spirometry and multiple phenotypes, including dyspnea severity (Modified Medical Research Council grade 0-4), health-related quality of life (St. George's Respiratory Questionnaire total score), 6-minute-walk distance, bronchodilator reversibility (FEV1 % change), computed tomography-measured percentage of lung with emphysema (% emphysema) and gas trapping (% gas trapping), and small airway dimensions (square root of the wall area for a standardized airway with an internal perimeter of 10 mm).

MEASUREMENTS AND MAIN RESULTS:

Among 5,100 participants with GLI-defined normal spirometry, GOLD identified respiratory impairment in 1,146 (22.5%), including a restrictive pattern in 464 (9.1%), mild COPD in 380 (7.5%), moderate COPD in 302 (5.9%), and severe COPD in none. Overall, the phenotype of GLI-defined normal spirometry included normal adjusted mean values for dyspnea grade (0.8), St. George's Respiratory Questionnaire (15.9), 6-minute-walk distance (1,424 ft [434 m]), bronchodilator reversibility (2.7%), % emphysema (0.9%), % gas trapping (10.7%), and square root of the wall area for a standardized airway with an internal perimeter of 10 mm (3.65 mm); corresponding 95% confidence intervals were similarly normal. These phenotypes remained normal for GLI-defined normal spirometry across GOLD spirometric categories.

CONCLUSIONS:

GLI-defined normal spirometry, even when classified as respiratory impairment by GOLD, included adjusted mean values in the normal range for multiple phenotypes. These results suggest that among adults with GLI-defined normal spirometry, GOLD may misclassify normal phenotypes as having respiratory impairment.

KEYWORDS:

COPD; COPDGene; emphysema; normal spirometry; phenotype

PMID:
26114439
PMCID:
PMC4613896
DOI:
10.1164/rccm.201503-0463OC
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Atypon Icon for PubMed Central
    Loading ...
    Support Center