Changes in maximum expiratory flow-volume curve configuration after treatment with inhaled corticosteroids

Abstract

The present study reports the changes in configuration of maximal flow-volume curves after eight weeks' treatment with inhaled corticosteroids in 14 asthmatic patients. The configuration was compared with that seen after bronchodilatation following inhalation of a single dose of ipratropium bromide. After inhaled corticosteroids the shape of the flow-volume curves was less bowed toward the volume axis, whereas the shape of the flow-volume curves after inhalation of ipratropium bromide showed no significant change. A significant correlation was observed between the decrease in blood eosinophil cell count and the straightening of the flow-volume curves, quantitatively expressed as shape factor and slope ratio. It is concluded that these changes in flow-volume curve configuration reflect a decrease in inhomogeneously distributed inflammatory airway narrowing.