Rationale: Airway responsiveness is a prognostic marker for asthma symptoms in later life. Objectives: To evaluate characteristics responsible for persistence of airway responsiveness in children with asthma. Methods:Atotal of 1,041 children, initially aged 5-12 years, with mild to moderate persistent asthma enrolled in the Childhood Asthma Management Program (CAMP) were studied prospectively for 8.6 ± 1.8 years with methacholine challenges yearly. Measurements and Main Results: Least squares geometric mean models were fit to determine effects of sex and age on airway responsiveness (provocative concentration producing 20% decrease in FEV1 [PC20]). Multiple linear regression analysis was performed to determine factors at baseline and over time, which were associated with PC20 at end of follow-up. A total of 7,748 methacholine challenges were analyzed. PC 20 increased with age, with boys having greater increase after age 11 years than girls (P < 0.001). The divergence coincided with the mean age for Tanner stage 2. Postpubertal girls had greater airway responsiveness, even after adjustment for FEV1 and other potential confounders. Although multivariable regression analyses noted a variety of factors that influenced airway responsivness in both sexes, a history of hay fever (β= -0.30, P = 0.005), respiratory allergy (β= -0.32, P = 0.006), or recent inhaled corticosteroid usage (β= -0.18, P = 0.02) were associated with decrements in final log PC20 only in girls. Conclusions: Airway responsiveness (PC20) is more severe in the postpubertal female with asthma than in males. Although there are factors associated with airway responsiveness in both males and females, sex-specific factors may contribute to new insights into asthma pathogenesis.
|Original language||English (US)|
|Number of pages||7|
|Journal||American journal of respiratory and critical care medicine|
|State||Published - Aug 15 2008|
ASJC Scopus subject areas
- Pulmonary and Respiratory Medicine
- Critical Care and Intensive Care Medicine