Beta2-adrenergic receptor polymorphisms affect airway responsiveness to salbutamol in asthmatics.

We examined the beta2-adrenergic receptor (beta2AR) polymorphisms (Arg16-->Gly, Gln27-->Glu) and clinical status for 117 asthmatics. Airway responsiveness to methacholine and beta2-agonists was evaluated with Astograph. The atopic factors, pulmonary function test, and airway responsiveness to methacholine did not differ significantly among the different beta2AR genotypes. Asthmatics homozygous for Gly16 showed significantly lower airway responsiveness to inhaled salbutamol than those heterozygous for Arg/Gly16 or homozygous for Arg16. Asthmatics heterozygous for Gln/Glu27 had significantly later asthma onsets than those homozygous for Gln27. These results suggest that beta2AR polymorphisms play an important role in the airway responsiveness to inhaled beta2-agonist and the initial asthma onset.