[Aging of the lung parenchyma].

INTRODUCTION: The study of lung parenchymal function is focused on the measurement of carbon monoxide diffusing transfer (TLCO) which is a function of both membrane characteristics (Dm) and capillary lung volume (Vc) The objective of this study was to estimate the effect of age on both variables.

METHODS: At rest, 134 healthy non-smokers (18-85 year old) were investigated by a double transfer NO-CO method. Capillary pulmonary compliance was estimated by applying a continuous negative pressure (CNP: -10 mmHg) at the mouth to 24 subjects.

RESULTS: Significant decreases in VA, TLCO, TLNO, Dm and Vc in relation to age were observed (p < 0.05). CNP induced a significant increase in all variables, the increase in Vc in elderly was greater than that in younger subjects.

CONCLUSION: Alveolo capillary membrane aging induces a decrease in Dm and Vc, however the increase in the estimated capillary compliance with CNP could provide an adaptation to the decrease in Vc.