Pulmonary function changes in Navy divers during their professional careers

Introduction: In divers, conflicting results regarding the development of small airway disease and “large lungs” have been reported. Purpose: To analyze the changes in pulmonary function over time, the development of “large lungs” and to see whether the pulmonary function deviates from subjects with “non-large lungs.” Methods: It is a longitudinal cohort study from 1983 till 2013 in professional navy divers, in which lung functions tests were performed annually. Results: In 1,260 navy divers, 8,149 pulmonary function tests were analyzed. e forced expiratory volume (FEV1) did not change except initially in those with abnormally low lung function (baseline value <lower-limit-of-normal for the general population (LLN). In that group, FEV1 increased by 35 (SE 7) ml/year. For the entire cohort, the inspiratory vital capacity (iVC) increased by 73 ml/year (SE 25). In the <LLN cohort, it increased by an additional 40 ml/year (SE 18). For the entire cohort, the FEV1/iVC annual drop was 0.37% (SE 0.9), but in the <LLN cohort it increased by 0.25%/year (SE 0.04). For the entire cohort, the forced expiratory ow at 75% of expir- ation (FEF75) annual drop was 23 ml/s/year (SE 7), in contrast in the <LLN cohort it increased by an addi- tional 45 ml/second/year (SE 7). Of the Navy divers, 6.3% showed “large lungs,” but changes over time were not di erent from above except for an additional 0.2% (SE 0.1%) decline in FEV1/iVC. Conclusion: In professional navy divers, long-term pulmonary function changes (FEV1 and FEV1 /iVC and FEF75) are not di erent from those in the non-diving population. e iVC increases probably due to training e ect. Pulmonary function changes in Navy divers during their professional careers.