Pulmonary nitrogen clearance in relation to age in healthy males

Lung volumes and N 2 clearance during O 2 breathing were recorded in 80 healthy males, 24–65 years of age. Lung volume changes with age were similar to those found in other studies. Uneven distribution of inspired gas in the lungs as estimated from N 2 clearance data showed relatively small changes with age, and the range of variability of these data was larger among the older subjects. The results suggest that impaired intrapulmonary gas distribution in older subjects is not a physiological consequence of aging, but may rather be related to long-term effects of inhaled noxious agents such as tobacco smoke. Submitted on June 11, 1962