Associations of pre-COPD indicators with lung function decline and their longitudinal transitions

Area of Science:

• Respiratory Medicine
• Pulmonology
• Epidemiology

Background:

• Pre-chronic obstructive pulmonary disease (COPD) indicators are linked to COPD development.
• Associations between these indicators and lung function decline in non-COPD individuals, along with their longitudinal changes, require further investigation.

Purpose of the Study:

• To investigate the association between pre-COPD indicators and lung function decline in individuals without COPD.
• To examine the longitudinal transitions of these indicators and their impact on lung function.

Main Methods:

• A prospective cohort study involving 3526 Chinese adults without COPD was conducted.
• Four pre-COPD indicators were assessed: chronic bronchitis, preserved ratio impaired spirometry (PRISm), low peak expiratory flow (PEF), and spirometric small airway dysfunction (sSAD).
• Lung function decline was measured by changes in FEV1, FVC, and FEV1/FVC, with FEV1 <80% predicted used as a proxy for PRISm.

Main Results:

• Smokers with initial chronic bronchitis showed faster declines in FEV1 and FVC.
• Consistent sSAD was linked to accelerated FEV1/FVC decline in both smokers and non-smokers.
• Incident COPD developed from sSAD in nearly half of the cases.

Conclusions:

• Initial chronic bronchitis, FEV1 <80% predicted, sSAD, and low PEF are associated with excessive lung function decline in smokers.
• Consistent chronic bronchitis and sSAD are linked to excessive lung function decline in non-smokers.
• Initial sSAD is a more significant predictor of incident COPD than chronic bronchitis, PRISm, or low PEF.