Utility of Lung Clearance Index Testing as a Noninvasive Marker of Deployment-related Lung Disease.

OBJECTIVE:The aim of this study was to determine utility and sensitivity of lung clearance index (LCI) testing as a marker of lung injury in symptomatic military deployers compared with healthy controls. METHODS:We tested 24 healthy controls and 28 deployers with respiratory symptoms (17 of 28 with definite and 11 of 28 with probable deployment-related lung disease). We compared mean LCI scores between deployers and controls using t tests; adjusted tests were derived from multiple regression models. RESULTS:Mean LCI scores were significantly higher (P = 0.001) in deployers [7.76, 95% confidence interval (95% CI) 7.34 to 8.17] than controls (6.95, 95% CI 6.73 to 7.17). Adjusting for body mass index (BMI), smoking, and age, there were no significant differences (P = 0.10) between mean LCI scores in deployers (7.42, 95% CI 7.13 to 7.71) and controls (7.06, 95% CI 6.74 to 7.39). CONCLUSIONS:The trend toward higher LCI scores in symptomatic deployers may be linked to underlying lung disease and/or BMI but requires further investigation in a larger population.