Lung function trajectories and their associations with comorbidity markers.

Background: Lower lung function is linked to a higher prevalence and earlier incidence of comorbidity. However, few studies have looked at interactions of lung function trajectories with comorbidities. Methods: As a pilot project for the CADSET CRC, we included 827 individuals aged 25-40 enrolled in the population-based HUNT study in 1995-97 and also participating in follow-up surveys in 2006-08 and 2017-19. FEV1 % predicted, and comorbidity markers including BMI, waist circumference, serum cholesterol, eGFR, C-reactive protein (CRP) level, systolic blood pressure (SBP), and Hospital Anxiety and Depression Scores (HADS) were measured at each survey. Using latent-class growth analysis, we distinguished lung function trajectories groups during follow-up. Using descriptive and graphical methods, we assessed cumulative comorbidity marker change accompanying each of these trajectories. Results: Seven distinct lung function trajectories were identified (Fig.1A) and were associated with distinct differences in comorbidity markers at baseline and with change of these markers over time. Despite the rapid decline trajectory starting from a higher ppFEV1, it was already associated with a worse comorbidity profile at baseline, and was accompanied by, for example, a steeper increase in CRP and SBP over time (Fig.1). Conclusion: Lung function trajectories are associated with established comorbidity and, to some extent, their change over time.