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

Abstract

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. 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. 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). 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.