Exercise-related hyperventilation is associated with cooling and drying of the airway mucosa. A compensatory increase in the blood perfusion of the airway (Qaw) theoretically could counteract this effect. Subjects with asthma have been shown to have a blunted endothelium-dependent vasodilation in their airway, and this could attenuate their Qaw response to exercise. We measured the Qaw response to a 5-min exercise challenge in 15 subjects with mild asthma and 10 controls. Baseline mean(±SE) Qaw was 39.6±3.5 μl.min-1.ml-1 in asthmatics and 37.7±4.1 μl.min-1.ml-1 in controls (P=NS), but asthmatics had a blunted vasodilator response to inhaled albuterol (consistent with endothelial dysfunction). Mean Qaw increased significantly in both groups after exercise, reaching a peak of 48±14% at 15 min in asthmatics and 35±10% at 60 min in controls, respectively (P=NS between the groups). In the asthmatics, mean Qaw returned to baseline level by 30 min, whereas in the non-asthmatics, mean Qaw remained high through the 90 min measurement point. Since mean arterial pressure, the driving pressure for Qaw, did not change after exercise in either group, the increase in Qaw reflected local vasodilation in the airway. Thus, brief exercise led to a transient increase in the blood perfusion of the airway without a difference between asthmatics and controls, despite the presence of a blunted endotheliumdependent vasodilation in asthmatics. This suggests that the exerciserelated increase in Qaw was not endothelium dependent.
|Original language||English (US)|
|Number of pages||8|
|Journal||Journal of Exercise Physiology Online|
|State||Published - Oct 1 2012|
- Airway blood flow
ASJC Scopus subject areas
- Physiology (medical)