Journal of Applied Physiology, Vol 44, Issue 2 195-199, Copyright © 1978 by American Physiological Society
Effects of age on regional residual volume
R. L. Jones, T. R. Overton, D. M. Hammerlindl and B. J. Srpoule
Forty-one normal non-smokers between the ages of 20 and 80 were studied to
determine if the increased residual volume, known to occur with aging,
results from increased residual volume throughout, or only in specific
regions of the lung. The subjects were dividied into groups consisting of
20-29, 30-39, 40-49, 50-69, and 70+ yr. Measurements of regional residual
volume to regional total lung capacity ratio (RVr/TLCr) were made using
zenon-133 and a multidetector analysis system in which five zones (from top
to bottom) were analyzed in each lung. Closing volume was also measured.
The subjects were in the sitting position for all studies. The results
showed regardless of age, the RVr/TLCr was higher at the top than at the
bottom of the lung. In addition, the ratio of upper to lower RVr/TLCr was
not significantly different between any of the age groups. The results can
be explained if airways throughout the lung close at higher volumes as age
increases, or if altered emptying sequences within regions occur due to
retarded emptying of highly compliant lung regions.
