Study objectives: To study the flow-volume loop for
evidence of variable extrathoracic airflow obstruction in Persian Gulf
Design: Retrospective case-control,
Setting: The pulmonary division
of an academic health-care center.
convenience sample of the Persian Gulf Registry.
Measurements and interventions: (1) Midvital capacity ratio
(ratio of maximum forced midexpiratory to maximum forced midinspiratory
flow). This ratio is the criterion standard for the diagnosis of
variable extrathoracic airflow obstruction. (2) Evaluation of the
anatomy and function of the extrathoracic airway by fiberoptic
bronchoscopy. (3) Further investigation into the airway abnormality by
histologic evaluation of tracheal biopsy samples in Gulf War veterans
Results: Midvital capacity was >1.0 in 32
of 37 Gulf War veterans compared with only 11 of 38 control subjects.
The mean (± SD) value was 1.37 ± 0.4 among Gulf War veterans
and 0.88 ± 0.3 among control subjects (p = 0.0000005). FVC and its
ratio to FEV1 were normal in all these subjects.
Bronchoscopy showed inflamed larynx and trachea in all (n = 17) Gulf
War veterans. Histologic study showed chronic inflammation of the
trachea in everyone (n = 12) who had an adequate biopsy sample.
Conclusion: Physicians should be made aware of the presence
of chronic inflammation of the upper airways and inspiratory airflow
limitation in a number of Gulf War veterans.
ratio = ratio of maximum forced expiratory to maximum forced
inspiratory flow at midvital capacity; PFT = pulmonary function
tests; VA = Veterans Affairs; VC = vital capacity