Korean J Asthma Allergy Clin Immunol.  2010 Mar;30(1):21-29.

Etiologic Factors for Methacholine Upper Airway Hyperresponsiveness and Upper Airway Obstruction

Abstract

BACKGROUND
Many patients with asthma-like symptoms show upper airway hyperresponsiveness (UHR). However, few investigators have studied the etiologies of UHR.
OBJECTIVE
To investigate the etiologies of UHR. Method: During methacholine bronchoprovocation tests, acceptable inspiratory flow volume curves were obtained. UHR was defined as methacholine concentration causing a 25% fall in maximal mid-inspiratory flow (PC(25)MIF(50)) <25 mg/mL and upper airway obstruction (UAO) as maximal mid-expiratory/inspiratory flow ratio >1.0. RESULT: The PC(25)MIF(50) was significantly related to bronchial hyperresponsiveness index (r=0.68, P<0.001), blood eosinophil counts (r=-0.31, P<0.01) and serum total IgE level (r=-0.24, P<0.05). More than half of the patients with UHR/UAO had concurrent allergic rhinitis and the abnormality in paranasal sinus X-rays. Sixty-six (64.1%) of the 103 patients with UHR or UAO were female. The prevalence of smoking, blood eosinophilia, increased IgE levels and positive skin tests was significantly lower in women than in men. Women were significantly older than men (P<0.01) and had a higher prevalence of UAO (P<0.05).
CONCLUSION
UHR or UAO seems to be most closely associated with allergy and bronchial hyperresponsiveness. However, women had a higher prevalence of UAO which may be related to non-allergic factors such as a smaller airway caliber.

MeSH Terms

Airway Obstruction
Eosinophilia
Eosinophils
Female
Humans
Hypersensitivity
Immunoglobulin E
Male
Methacholine Chloride
Prevalence
Research Personnel
Rhinitis
Rhinitis, Allergic, Perennial
Skin Tests
Smoke
Smoking
Immunoglobulin E
Methacholine Chloride
Smoke