Combinatie van allergie en bronchiale hyperreactiviteit risicofactor voor de progressie van astma

As asthma is considered a progressive disease, we investigated whether allergy and bronchial hyperresponsiveness are factors which predict this progression.

Design

Randomized controlled intervention study.

Method

The effect of allergy and bronchial hyperresponsiveness on the annual rate of decline in FEV₁ and the annual exacerbation rate was studied in 71 adult patients with asthma during a period of 2 years.

Results

Bronchial hyperresponsiveness was related to the FEV₁ decrease, independently of the FEV₁ level. The mean FEV₁ decrease was -94 mlyr (95 confidence limits -39 to -149 mlyr) in patients with PC₂₀ ≤ 2 mgml and -21 mlyr (34 to -76 mlyr) in patients with PC₂₀ > 2 mgml. Allergy alone was not related to the FEV₁ decrease. However, in allergic patients bronchial hyperresponsiveness was related to a more pronounced FEV₁ decrease than in nonallergic patients. Allergy alone was therefore not a risk factor, however, in combination with bronchial hyperresponsiveness it was. The combination of bronchial hyperresponsiveness and allergy also had an interacting effect on the exacerbation rate (2.4 exacerbationsyear, p = 0.07).

Conclusion

Allergy in combination with bronchial hyperresponsiveness should be considered a risk factor for developing progressive airflow obstruction in patients with asthma.