Abstract
Posture-induced changes in vital capacity are associated with COPD outcomes independent of airflow obstruction in SPIROMICS
European respiratory journal, Vol.58(Suppl. 65), p.PA1860
09/05/2021
DOI: 10.1183/13993003.congress-2021.pa1860
Abstract
Rationale: Vital capacity (VC) measured by spirometry in the recumbent position is smaller than that measured in upright position. This difference is also evident when comparing CT-derived volumes with spirometry (∆VC).
Objective: Examine the relationship between ∆VC, airflow obstruction & clinical outcomes in COPD.
Methods: We derived recumbent VC from volumetric analysis of CT scans (VCCT) at full inspiration (TLC) & expiration (RV), and measured upright VC by non-forced (slow) spirometry (SVC). Both measures were obtained following inhaled bronchodilators. We explored the relationship between ∆VC (SVC-VCCT) and features of COPD in SPIROMICS cohort using regression modeling with adjustment for age, sex, height, BMI, hip-to-waist ratio, smoking status, SVC & FEV1.
Results: VCCT was consistently smaller than SVC and the magnitude of the difference (∆VC) was proportionally larger with increasing severity of airflow obstruction (FEV1) (regression coefficient (ß) [95%CI]=-0.28 [-0.31,-0.24]; p<0.001). However, even after adjustment for FEV1 & SVC, ∆VC was associated with worse respiratory symptoms (CAT ß=0.59 [0.15,1.02]; SGRQ ß=1.14 [0.11,2.17] and SF12 ß=-0.87 [-1.53, -0.22]; all p<0.020) and higher rate of severe exacerbations (0.15 [0.03,0.30]; P=0.012). ∆VC was also associated with higher air trapping (PRMfSAD ß=6.2 [5.6, 6.7]; p<0.01) but not emphysema (PRMEMPH).
Conclusions: The posture-associated difference in vital capacity is independently associated with severity of COPD in terms of airflow obstruction, symptoms and health status. We believe this reflects difficulty counteracting the posture-related decrease in TLC due to diaphragmatic weakness with COPD.
Details
- Title: Subtitle
- Posture-induced changes in vital capacity are associated with COPD outcomes independent of airflow obstruction in SPIROMICS
- Creators
- Mehrdad Arjomandi - San Francisco VA Medical CenterJianhong Chen - University of California, San FranciscoIgor Barjaktarevic - University of California, Los AngelesR. Graham Barr - NewYork–Presbyterian HospitalEugene R. Bleecker - University of ArizonaRussell P. Bowler - National Jewish HealthRussell G. Buhr - University of California, Los AngelesAlejandro P. Comellas - University of IowaDavid Couper - University of North Carolina at Chapel HillJeffrey L. Curtis - VA Ann Arbor Healthcare SystemMark T. Dransfield - University of Alabama at BirminghamM Bradly DrummondSpyridon Fortis - University of IowaMeiLan K. Han - University of Michigan–Ann ArborNadia N. HanselEric A. Hoffman - University of IowaRichard E. Kanner - University of UtahJerry A. Krishnan - University of Illinois at ChicagoWassim W. Labaki - University of Michigan–Ann ArborStephen C. Lazarus - University of California, San FranciscoFernando J. Martinez - Cornell UniversityVictor E. Ortega - Wake Forest UniversityRobert Paine - University of UtahStephen P. Peters - Wake Forest UniversityJoyce D. Schroeder - University of UtahStephen I. Rennard - AstraZenecaPrescott G. Woodruff - University of California, San FranciscoDonald P. Tashkin - University of California, Los AngelesChristopher B. Cooper - University of California, Los Angeles
- Resource Type
- Abstract
- Publication Details
- European respiratory journal, Vol.58(Suppl. 65), p.PA1860
- Publisher
- European Respiratory Society
- DOI
- 10.1183/13993003.congress-2021.pa1860
- ISSN
- 0903-1936
- eISSN
- 1399-3003
- Language
- English
- Date published
- 09/05/2021
- Academic Unit
- ICTS; Roy J. Carver Department of Biomedical Engineering; Internal Medicine; Radiology; Pulmonary, Critical Care, and Occupational Medicine
- Record Identifier
- 9984528109202771
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