Effect of aging on lung mechanics in healthy nonsmokers.

The purpose of the present investigation was to determine the effects of aging on air flow limitation. In 22 healthy nonsmoking subjects, we constructed maximum expiratory flow-static recoil pressure curves. Analysis indicates that with aging there was a progressive increase in the critical transmural pressure. The conductance of the S segment was not dependent on age, with the exception of a significant increase in the oldest group. This is probably due to a more peripheral location of the equal pressure point secondary to a loss of lung recoil or to increased resistance, or both.