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 ± 2.9 mL/min/mm Hg, 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 ± 23 mL, 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.