Study objectives: To study the flow-volume loop for evidence of variable extrathoracic airflow obstruction in Persian Gulf War veterans.
Design: Retrospective case-control, single-center study.
Setting: The pulmonary division of an academic health-care center.
Subjects: A 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 only.
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.