Pulmonary function, functional capacity and quality of life in adults with cystic fibrosis

As there are few studies on the impact of respiratory and functional status on the quality of life domains in adults with cystic fibrosis, this study aimed to evaluate the association between respiratory function, functional capacity and quality of life in these subjects.

This is a cross-sectional study, where adults with clinical and laboratorial diagnoses of CF fibrosis underwent pulmonary function tests, the six-minute walk distance test (6MWT) and responded to the Cystic Fibrosis Questionnaire-Revised (CFQ-R). Descriptive statistics was used to summarize the findings. The associations were tested by means of Pearson's or Spearman tests, and the significance level was set at 5%.

The 21 patients who completed the study presented with reduced quality of life in all CFQ-R domains, obstructive pulmonary disease and reduced 6MWT distance. The following associations were found between pulmonary function and CFQ-R domains: forced vital capacity - FVC (%) and treatment burden and digestive symptoms (r=-0.433, p<0.05; r=-0.443, p<0.05, respectively), forced expiratory volume in one second - FVC ratio - FEV1/FVC (%) and physical functioning, social and respiratory symptoms (r=0.5, p<0.05; r=0.58, p<0.01; r=0.45, p<0.05, respectively), residual volume (%) and physical functioning (r=0.49, p<0.05), airways' resistance - Raw and physical functioning and emotional functioning (r=-0.44, p<0.05; r=-0,46, p<0.05, respectively), carbon monoxide diffusing capacity (%pred) and physical functioning (r=-0,51; p<0.05).

Adults with CF have reduced quality of life, which in part is associated with the severity of their lung function.