Determinants of forced expiratory volume in 1 second (FEV1), forced vital capacity (FVC), and FEV1/FVC in chronic spinal cord injury

Arch Phys Med Rehabil. 2006 Oct;87(10):1327-33. doi: 10.1016/j.apmr.2006.06.015.


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 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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Asthma / complications
  • Body Mass Index
  • Chronic Disease
  • Cohort Studies
  • Cross-Sectional Studies
  • Female
  • Forced Expiratory Volume
  • Humans
  • Male
  • Middle Aged
  • Respiratory Muscles / physiopathology
  • Smoking / adverse effects
  • Spinal Cord Injuries / complications
  • Spinal Cord Injuries / physiopathology*
  • Thoracic Injuries / complications
  • Vital Capacity