OBJECTIVEAsthma is the most common chronic respiratory disease of children. The association between asthma and bronchial hyperresponsiveness (BHR) has been well-demonstrated. The objective of the study was to investigate relationship between the bronchial responsiveness and the peripheral obstruction in stable asthmatic children.

METHODSThirty-nine children with stable asthma, 28 boys and 11 girls with a mean age of 128 (77 - 197) months, received the bronchial provocation test by the maximal expiratory flow-volume (MEFV) curve measurement. The children were divided into two groups: one with maximal mid-expiratory flow (MMEF) < 80% (n = 15) and the other with MMEF >/= 80% (n = 24). Positive rates of bronchial provocation test were compared between groups of MMEF < 80% and >/= 80% and between the children whose relief duration was 12 months (n = 13). Statistical analysis was performed by using Chi-square, rank sum test or t test (SPSS10.0), P values < 0.05 were considered significant.

RESULTSIn the 39 stable asthmatic children, 15 (38%) were detected MMEF < 80% and 28 (72%) had BHR. There was no significant difference in BHR between the children with MMEF < 80% and those with MMEF >/= 80% (P > 0.05). There was no significant difference in BHR between the children whose relief duration was 12 months (P > 0.05), either.

CONCLUSIONSThe stable asthmatic children still had peripheral obstruction and BHR, which indicated the presence of airway inflammation. There was no significant difference in BHR between the children whose relief duration was 12 months.