Relationship between duration of disease and bronchial responsiveness in 6-8 years old children with asthma.
- Author:
Eunhee SHIM
1
;
Jinho YU
Author Information
- Publication Type:Original Article
- Keywords: Asthma duration; Bronchial hyperreactivity; FVC; PC20
- MeSH: Asthma*; Bronchial Hyperreactivity; Bronchoconstriction; Child*; Forced Expiratory Volume; Humans; Inhalation; Methacholine Chloride; Respiratory Sounds; Vital Capacity
- From:Allergy, Asthma & Respiratory Disease 2014;2(1):23-29
- CountryRepublic of Korea
- Language:English
- Abstract: PURPOSE: Bronchial hyperresponsiveness is considered as a hallmark of asthma. The duration of asthma was demonstrated to be associated with bronchial responsiveness, expressed as methacholine PC20. We investigated the relationship between duration of asthma and percentage fall in forced vital capacity (FVC) at PC20 (DeltaFVC), another index of bronchial responsiveness, which reflects excessive bronchoconstriction. METHODS: Six- to 8-year-old children with asthma underwent methacholine inhalation test. The PC20 and DeltaFVC were calculated for each individual. The subjects were classified into those with wheezing onset in the first three years of life (early-onset asthma [EA], n=63) and those with wheezing onset from three years onwards (late-onset asthma [LA], n=99). RESULTS: From the time of wheezing onset, duration of asthma ranged from 0.2 to 8.3 years. The mean duration of asthma in patients with EA was 5.6 years (standard deviation [SD], 1.2 years), compared with 2.2 years (SD, 1.3 years) in the patients with LA. Patients with EA had a significantly lower forced expiratory volume in 1 second/FVC than did those with LA (84.6%+/-5.9% vs. 86.8%+/-5.1%, P<0.05). The DeltaFVC was significantly higher in patients with EA than in those with LA (19.4%+/-5.1% vs. 17.0%+/-4.5%, P<0.01), but PC20 was not different between the two groups. In total subjects, asthma duration correlated significantly with DeltaFVC (r=0.222, P<0.01), but not with PC20. CONCLUSION: These data suggest that prolonged asthma is associated with worsened bronchial responsiveness during childhood, and such an association may be reflected primarily by DeltaFVC rather than PC20.
