Determinants of Forced Expiratory Volume in 1 Second (FEV1), Forced Vital Capacity (FVC), and FEV1/FVC in Chronic Spinal Cord Injury
Presented to the American Paraplegia Society, September 7−9, 2004, Las Vegas, NV.
Abstract
Jain NB, Brown R, Tun CG, Gagnon D, Garshick E. Determinants of forced expiratory volume in 1second (FEV1), forced vital capacity (FVC), and FEV1/FVC in chronic spinal cord injury.
Objective
To assess factors that influence pulmonary function, because respiratory system dysfunction is common in chronic spinal cord injury (SCI).
Design
Cross-sectional cohort study.
Setting
Veterans Affairs Boston SCI service and the community.
Participants
Between 1994 and 2003, 339 white men with chronic SCI completed a respiratory questionnaire and underwent spirometry.
Interventions
Not applicable.
Main Outcome Measures
Forced expiratory volume in 1second (FEV1), forced vital capacity (FVC), and FEV1/FVC.
Results
Adjusting for SCI level and completeness, FEV1 (–21.0mL/y; 95% confidence interval [CI], –26.3 to –15.7mL/y) and FVC (–17.2mL/y; 95% CI, –23.7 to –10.8mL/y) declined with age. Lifetime cigarette use was also associated with a decrease in FEV1 (–3.8mL/pack-year; 95% CI, –6.5 to –1.1mL/pack-year), and persistent wheeze and elevated body mass index were associated with a lower FEV1/FVC. A greater maximal inspiratory pressure (MIP) was associated with a greater FEV1 and FVC. FEV1 significantly decreased with injury duration (–6.1mL/y; 95% CI, –11.7 to –0.6mL/y), with the greatest decrement in the most neurologically impaired. The most neurologically impaired also had a greater FEV1/FVC, and their FEV1 and FVC were less affected by age and smoking.
Conclusions
Smoking, persistent wheeze, obesity, and MIP, in addition to SCI level and completeness, were significant determinants of pulmonary function. In SCI, FEV1, FVC, and FEV1/FVC may be less sensitive to factors associated with change in airway size and not reliably detect the severity of airflow obstruction.
aResearch Service, Physical Medicine and Rehabilitation Medicine Service, and Pulmonary and Critical Care Medicine Section, VA Boston Healthcare System, West Roxbury, MA
bPulmonary and Critical Care Medicine Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA
cMassachusetts Veterans Epidemiology Research and Information Center, VA Boston Healthcare System, Boston University School of Public Health, Boston, MA
dChanning Laboratory, Brigham and Women’s Hospital, Boston, MA
Reprint requests to Eric Garshick, MD, MOH, Pulmonary and Critical Care Medicine Section, VA Boston Healthcare System, 1400 VFW Pkwy, West Roxbury, MA 02132
Supported by National Institute of Child Health and Human Development, National Institutes of Health (grant no. RO1 HD42141), the Massachusetts Veterans Epidemiology Research and Information Center, Cooperative Studies Program, and Health Services Research and Development, Department of Veterans Affairs.
No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated.
ABSTRACT