FEV1 response to bronchodilation in an adult urban population.

Author(s): Kainu A, Lindqvist A, Sarna S, Lundback B, Sovijarvi A

Affiliation(s): Department of Medicine, Helsinki University Central Hospital, FIN-00029 HUS, Helsinki, Finland.

Publication date & source: 2008-08, Chest., 134(2):387-93. Epub 2008 Apr 10.

Publication type: Multicenter Study; Randomized Controlled Trial; Research Support, Non-U.S. Gov't

BACKGROUND: Most studies evaluating bronchodilation in flow-volume spirometry have been conducted in patients with obstructive airways diseases, but less is known about bronchodilation responses in the general population or in healthy subjects. METHODS: We evaluated an urban population sample of 628 adults (260 men, 368 women) aged 25 to 74 years with flow-volume spirometry using inhalation of 0.4 mg of a salbutamol aerosol with a spacer device for bronchodilation. On the basis of a structured interview, a subgroup of 219 healthy, asymptomatic nonsmokers was selected. RESULTS: In the population sample, the average increase in FEV(1) from baseline after salbutamol inhalation was 77.2 mL (SD, 109.7 mL) or 2.5% (SD, 3.9%). In healthy asymptomatic nonsmokers, the mean change in FEV(1) was 62.0 mL (SD, 89.7 mL) or 1.8% (SD, 2.6%). In the whole population, the 95th percentile limit of the increase in FEV(1) was 8.5%, while it was 5.9% among healthy asymptomatic nonsmokers. The absolute change in FEV(1) correlated significantly with baseline FVC (p < 0.01). The FEV(1)/FVC ratio at baseline was the strongest influencing factor for the bronchodilation response. CONCLUSIONS: The results indicate that a significant increase in FEV(1) from baseline in a bronchodilation test is around 9% in an urban population. The level of the significant absolute increase in FEV(1) seems to depend on FVC. Low baseline FEV(1)/FVC ratio, reflecting airflow limitation, is the strongest determinant for FEV(1) response to bronchodilation.