Am. J. Respir. Crit. Care Med., Vol 155, No. 3, 03 1997, 888-892.
Volume history effects and airway responsiveness in middle-aged and older men. The Normative Aging Study
D Sparrow, GT O'Connor, ST Weiss, D DeMolles and RH Ingram Jr
Department of Veterans Affairs Outpatient Clinic, Boston, Massachusetts, USA.
In persons with asthma, a deep inhalation (DI) to total lung capacity may
lead to bronchoconstriction. The intensity of this effect has been shown to
correlate positively with the severity of inflammatory airflow obstruction
and the level of methacholine airway responsiveness. The correlates of lung
volume history effects in the general population, however, are unknown. We
analyzed combined maximal and partial expiratory flow-volume data, pre- and
postbronchodilator spirometry data, and methacholine challenge data from 89
middle-aged and older men participating in the Normative Aging Study. The
ratio of maximal to partial expiratory flow rates (VM/VP) was significantly
correlated with methacholine airway responsiveness, even after adjustment
for age and baseline FEV1. The direction of this correlation indicated that
men with higher VM/VP ratios (i.e., greater dilator effect of a DI) tended
to have greater methacholine airway responsiveness. Subjects with a higher
VM/VP ratio also tended to have a greater response to a bronchodilator.
These results suggest that, in the general population, airway
responsiveness relates in part to airway smooth muscle tone. The
correlations suggest that this relatively simple maneuver might play a role
in future epidemiologic studies.
