title: Determinants of forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC in chronic spinal cord injury.
abstract: OBJECTIVE
  To assess factors that influence pulmonary function, because respiratory system dysfunction is common in chronic spinal cord injury (SCI).
  
  
  METHODS
  Cross-sectional cohort study.
  
  
  METHODS
  Veterans Affairs Boston SCI service and the community.
  
  
  METHODS
  Between 1994 and 2003, 339 white men with chronic SCI completed a respiratory questionnaire and underwent spirometry.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Forced expiratory volume in 1 second (FEV(1)), forced vital capacity (FVC), and FEV(1)/FVC.
  
  
  RESULTS
  Adjusting for SCI level and completeness, FEV(1) (-21.0 mL/y; 95% confidence interval [CI], -26.3 to -15.7 mL/y) and FVC (-17.2 mL/y; 95% CI, -23.7 to -10.8 mL/y) declined with age. Lifetime cigarette use was also associated with a decrease in FEV(1) (-3.8 mL/pack-year; 95% CI, -6.5 to -1.1 mL/pack-year), and persistent wheeze and elevated body mass index were associated with a lower FEV(1)/FVC. A greater maximal inspiratory pressure (MIP) was associated with a greater FEV(1) and FVC. FEV(1) significantly decreased with injury duration (-6.1 mL/y; 95% CI, -11.7 to -0.6 mL/y), with the greatest decrement in the most neurologically impaired. The most neurologically impaired also had a greater FEV(1)/FVC, and their FEV(1) 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, FEV(1), FVC, and FEV(1)/FVC may be less sensitive to factors associated with change in airway size and not reliably detect the severity of airflow obstruction.
authors.affiliation: Research Service, VA Boston Healthcare System, West Roxbury, MA 02132, USA.
authors.forename: Nitin B
authors.initials: NB
authors.lastname: Jain
authors.forename: Robert
authors.initials: R
authors.lastname: Brown
authors.forename: Carlos G
authors.initials: CG
authors.lastname: Tun
authors.forename: David
authors.initials: D
authors.lastname: Gagnon
authors.forename: Eric
authors.initials: E
authors.lastname: Garshick
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000150:complications; D015992:Body Mass Index; D002908:Chronic Disease; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D012132:Respiratory Muscles / Q000503:physiopathology; D012907:Smoking / Q000009:adverse effects; D013119:Spinal Cord Injuries / Q000150:complications / Q000503:physiopathology*; D013898:Thoracic Injuries / Q000150:complications; D014797:Vital Capacity