SESSION TITLE: Asthma - Bronchiectasis Posters
SESSION TYPE: Original Investigation Poster
PRESENTED ON: Wednesday, October 28, 2015 at 01:30 PM - 02:30 PM
PURPOSE: FEV1 is often used as a marker of disease severity in cystic fibrosis (CF). However, current literature identifies only weak associations between lung function and quality of life (QOL). Studies in COPD suggest that lung hyperinflation is more closely associated with dyspnea than is FEV1. The purpose of this study was to determine if lung hyperinflation is more closely associated with QOL and functional capacity than is FEV1 in patients with CF.
METHODS: Data was retrospectively collected from 68 adult CF patients, mean (±SD) age 29 ± 9 yr. Respiratory domain of the Cystic Fibrosis Questionnaire-Revised (CFQ-R), number of exacerbations (defined by necessity of IV antibiotics), and 6 minute walk distance (6MWD) were used as measures of QOL. Ratios of inspiratory capacity to total lung capacity (IC/TLC) and residual volume to total lung capacity (RV/TLC) were used to assess lung hyperinflation. Lung function and respiratory CFQ-R were recorded at baseline and 1-6 year follow-up. We used bivariate correlations to compare lung hyperinflation to QOL measures. Lastly, we used paired t-tests to assess differences between baseline and follow-up values.
RESULTS: Number of exacerbations over 12 months correlated significantly to baseline FEV1 (p=0.006), IC/TLC (p=0.01) and RV/TLC (p=0.001). Absolute FEV1 correlated with 6MWD (p=0.007) and respiratory CFQ-R (0.025); however, no correlation was found using % predicted FEV1. No correlation was found comparing IC/TLC and RV/TLC to 6MWD and respiratory CFQ-R. T-tests found a modest decrease in IC/TLC (p=0.048), but other measures showed no change between baseline and follow-up. Change in lung function over time did not correlate significantly with QOL measures.
CONCLUSIONS: FEV1, IC/TLC, and RV/TLC all correlate closely with number of exacerbations but not with CFQ-R or 6MWD. Lack of consistent change in lung function and CFQ-R over time is indicative of variability in individual disease progression and the multi-system nature of CF, which may explain the absence of a relationship between change in lung function over time and number of exacerbations.
CLINICAL IMPLICATIONS: That lung hyperinflation is closely related to exacerbations but not to CFQ-R or 6MWD suggests that other factors such as malnutrition, diabetes, anemia, and depression also impact QOL in CF. This underscores the importance of a multi-faceted approach to management of CF.
DISCLOSURE: The following authors have nothing to disclose: Kosal Seng, Lynn Fukushima, Pooja Patel, Arteen Pirverdian, Kamyar Afshar, Adupa Rao, Ahmet Baydur
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