Impact of physical functional capacity on quality of life in patients with interstitial lung diseases

This study aimed to investigate the physical functioning predictors for health-related quality of life (HRQL) decline in patients with idiopathic interstitial fibrosis (IPF), sarcoidosis and other interstitial lung disease (ILD). The study enrolled 52 patients with ILD and 16 healthy individuals. Participants' HRQL was assessed using the 36-item Short-Form Health Survey questionnaire. Spirometry, physical performance, and daily physical activity (PA) were monitored. Patients with IPF showed significantly lower PA compared to patients with other ILD (p = 0.002)and sarcoidosis (p = 0.01). The type of disease aetiology had no significant effect on aerobic capacity, HRQL and fatigue. Patients with ILD showed significant greater fatigue, lower physical functioning and greater physical aspects scores compared to the control group (F=6.0; p = 0.018; F=12.64; p = 0.001, respectively). A significant positive correlation was observed between 6-minute walking distance (6MWD) and the physical domain of HRQL (r = 0.35, p = 0.012) and PA and the physical aspects of HRQL (r = 0.37, p = 0.007). This study revealed that the key predictors for HRQL decline were lower lung function, lower PA and physical performance.