Effect of a long- and short-acting beta2-agonist on exercise-induced arterial hypoxemia.

Abstract

determine the effect of formoterol and salbutamol on the arterial oxygen saturation (SaO(2)) of highly trained nonasthmatic athletes with exercise-induced arterial hypoxemia (EIAH). Ten male athletes (age = 27.1 +/- 0.7, [OV0312]O(2max) = 65.2 +/- 2.5 mL.kg-1.min-1, SaO(2min) = 91.0 +/- 2.1%) with minimal bronchial reactivity to aerosols (i.e., negative methacholine challenge test) completed three identical exercise sessions differing only by the medication administered. Formoterol (F), a long-acting beta-2 agonist, was compared with salbutamol (S) and a placebo (P). F (12 microg), S (400 microg), or P was administered by a Turbuhaler, 10 min before exercise testing in a double-blind, randomized, three-way crossover design. Testing sessions included an incremental cycle ergometer test to exhaustion, while monitoring SaO(2) and ventilation, and a pre- and postexercise pulmonary function test. There were no significant differences between the groups in SaO(2) nadir with exercise (F = 92.0 +/- 1.0; S = 92.0 +/- 1.0; P = 91.0 +/- 0.7%). During the maximal incremental test, no differences were observed in SaO(2) or minute ventilation between the three experimental conditions. Pulmonary function tests revealed a significant increase in FEV(1) and FEV(1)/FVC after exercise in all conditions. Drug administration increased FEV(1)/FVC postexercise compared with placebo (F = 87.9 +/- 2.3, S = 87.6 +/- 1.7 > P = 85.6 +/- 2.1%; P < 0.05). An acute, inhaled, therapeutic dose of formoterol or salbutamol did not affect SaO(2) nadir or ventilation kinetics in a group of highly trained nonasthmatic athletes with EIAH.