Exercise-induced interstitial pulmonary edema at sea-level in young and old healthy humans.

We asked whether aged adults are more susceptible to exercise-induced pulmonary edema relative to younger individuals. Lung diffusing capacity for carbon monoxide (DLCO), alveolar-capillary membrane conductance (Dm) and pulmonary-capillary blood volume (Vc) were measured before and after exhaustive discontinuous incremental exercise in 10 young (YNG; 27±3 years) and 10 old (OLD; 69±5 years) males. In YNG subjects, Dm increased (11±7%, P=0.031), Vc decreased (-10±9%, P=0.01) and DLCO was unchanged (30.5±4.1 vs. 29.7±2.9mL/min/mmHg, P=0.44) pre- to post-exercise. In OLD subjects, DLCO and Dm increased (11±14%, P=0.042; 16±14%, P=0.025) but Vc was unchanged (58±23 vs. 56±23mL, P=0.570) pre- to post-exercise. Group-mean Dm/Vc was greater after vs. before exercise in the YNG and OLD subjects. However, Dm/Vc was lower post-exercise in 2 of the 10 YNG (-7±4%) and 2 of the 10 OLD subjects (-10±5%). These data suggest that exercise decreases interstitial lung fluid in most YNG and OLD subjects, with a small number exhibiting evidence for exercise-induced pulmonary edema.