Characteristics Associated with Lung Function Trajectories: An Analysis of the SPIROMICS Cohort

Area of Science:

• Pulmonary Medicine
• Genetics and Genomics
• Epidemiology

Background:

• Understanding the biological basis of chronic obstructive pulmonary disease (COPD) progression, particularly rapid decline in forced expiratory volume in 1 second (FEV1), is crucial for developing targeted therapies.
• Identifying distinct COPD progression trajectories is essential for personalized treatment strategies.

Purpose of the Study:

• To define baseline characteristics of rapid decline (RD) in FEV1 (≥100 mL/year) compared to stable-to-improved (S/I) and intermediate decline (D) categories.
• To evaluate these spirometric categories as predictors of longitudinal COPD outcomes, adjusting for baseline factors.

Main Methods:

• Analysis of spirometric data from the Framingham Offspring Cohort (SPIROMICS) with ≥2 measurements over 8 years.
• Linear regression to determine FEV1 change slopes and ordinal regression to associate baseline characteristics with lung function decline categories.
• Assessment of clinical outcomes associated with identified COPD progression categories.

Main Results:

• In a cohort of heavy smokers (≥20 pack-years), 40% were S/I and 18% were RD.
• Steeper FEV1 decline was associated with better initial lung function and increased bronchodilator responsiveness.
• Rapid decline (RD) correlated with higher symptom burden, poorer quality of life, and increased mortality, but not exacerbation frequency.

Conclusions:

• Categorizing COPD progression into S/I and RD highlights bronchodilator responsiveness and smoking as key risk factors for adverse outcomes, including death.
• Further research contrasting these disease trajectories is needed to elucidate the biological underpinnings of COPD progression.