Identification of distinct trajectories of FEV1 progression in the ECLIPSE cohort

Background: Chronic obstructive pulmonary disease (COPD) is a heterogeneous disease differing in disease progression as measured by FEV1. Better characterization will help disease management and improve clinical trials. Aim: We investigated the heterogeneity in forced expiratory volume in one second (FEV1) over a 3-year period. and the association of endotrophin, a fragment of type VI collagen (PRO-C6) suggested to be involved in disease progression, to each trajectory Methods: A total of 2083 COPD patients were extracted from the ECLIPSE cohort (NCT00292552), with FEV1 measured at seven time points over 3 years. Latent Class Trajectory models were used to identify distinct trajectories of FEV1, corrected for age, BMI, height and smoking status. Akaike information criterion (AIC) was used to select the optimal number of classes and splines to be used. ANOVA tests were then used to identify significant differences between the latent classes at baseline in a sub-population (n=989). Results: Five distinct trajectories of FEV1 were found, characterized as being (1) rapid decliners, (2) slow decliners, (3) improvers, (4) stable, and (5) slow decliners. FEV1 (p<0.001) was found to be significantly different between the groups at baseline as was PRO-C6 (p=0.0002). Groups did not differ in age and BMI (p>0.05). Conclusion: These results indicate distinct progression profiles of FEV1 exist in COPD patients, which may be explained by baseline characteristics. Further investigation is needed to understand possible mechanisms involved. Funding: GSK (ECLIPSE; SCO104960, NCT00292552).