Inhaled budesonide prevents acute mountain sickness in young Chinese men.

Background: Oral glucocorticoids can prevent acute mountain sickness (AMS). Whether inhaled budesonide (BUD) can prevent AMS remains unknown.

Objective: Our aim was to investigate the effectiveness of BUD in AMS prevention.

Methods: Eighty subjects were randomly assigned to receive budesonide (BUD, inhaled), procaterol tablet (PT), budesonide/formoterol (BUD/FM, inhaled), or placebo tablet (n = 20 in each group). Subjects were treated for 3 days before ascending from 500 m to 3700 m within 2.5 h by air. Lake Louis AMS questionnaire, blood pressure, heart rate, and oxygen saturation (SpO2) were examined at 20, 72, and 120 h after high-altitude exposure. Pulmonary function was measured at 20 h after exposure.

Results: Compared with placebo, BUD significantly reduced the incidence of AMS (70% vs. 25% at 20 h, p < 0.05; both 10% vs. 5% at 72 and 120 h, both p > 0.05) without side effects. The relative risk was 0.357, and the risk difference was 0.45. Mean SpO2 was higher in BUD, BUD/FM, and PT groups than in the placebo group at 20 h (p < 0.05). SpO2 in all 80 subjects dropped after ascent (98.1% to 88.12%, p < 0.01) and increased gradually, but it was still lower at 120 h than at baseline (92.04% vs. 98.1%, p < 0.01). Pulmonary function did not differ among the four groups at 20 h.

Conclusion: BUD can prevent AMS without side effects. The alleviation of AMS may be related to increased blood oxygen levels rather than pulmonary function.