Lung Hyperinflation Is Associated with Pulmonary Exacerbations in Adults with Cystic Fibrosis ()
Affiliation(s)
1Division of Geriatric, Hospital, Palliative and General Internal Medicine, Los Angeles, CA, USA.
2Division of Pulmonary and Critical Care Medicine, Keck School of Medicine, University of Southern California,
Los Angeles, CA, USA.
3Department of Physiology, McGill University (Emeritus), Montreal, Quebec, Canada.
ABSTRACT
Background: Forced expiratory volume 1 second (FEV1) has traditionally been used as a readily
available marker of health in adult cystic fibrosis (CF). However, due to the obstructive nature of
this disease, it is possible that lung hyperinflation could be more closely related to disease severity
than is FEV1. The purpose of this study was to determine if hyperinflation is more closely associated
with quality of life, functional status, and pulmonary exacerbations than FEV1 in patients
with CF. Methods: Sixty-eight adult patients with CF were evaluated in this retrospective study. We
used IC and functional residual capacity (FRC) and their ratios to total lung capacity (TLC) as
measures of lung hyperinflation. We used bivariate correlations and backwards regression analysis
to assess possible associations between FEV1, lung hyperinflation, and measures of disease severity
including questionnaire based quality of life, pulmonary exacerbation frequency, and mortality.
The respiratory component of the Cystic Fibrosis Questionnaire–Revised (CRQ-R-Respiratory)
was used as a measure of quality of life. Results: Both FEV1 and IC were negatively correlated
with pulmonary exacerbations over a 3 year period (p = 0.004, r2 = 0.127; p < 0.001, r2 = 0.307,
respectively), while FRC/TLC correlated positively with exacerbations (p = 0.007). Backwards regression
analysis showed that among pulmonary function variables, IC had the strongest relationship
with exacerbations over 3 years. A lower CFQ-R-Respiratory score was associated with greater
mortality (p = 0.005). However, no statistically significant relationships were found between
lung function and mortality. Conclusions: FEV1 and lung hyperinflation-as measured by IC and
FRC/TLC-are both associated with pulmonary exacerbation frequency. This suggests that chronic
dynamic hyperinflation contributes significantly to disease severity in adult cystic fibrosis.
Share and Cite:
Seng, K. , Fukushima, L. , Patel, P. , Pirverdian, A. , Rao, A. , Milic-Emili, J. and Baydur, A. (2016) Lung Hyperinflation Is Associated with Pulmonary Exacerbations in Adults with Cystic Fibrosis.
Open Journal of Respiratory Diseases,
6, 25-34. doi:
10.4236/ojrd.2016.62004.
Cited by
No relevant information.