Association between menarche and increased bronchial hyper-responsiveness during puberty in female children and adolescents

PurposeBronchial hyper-responsiveness (BHR) is a key feature of asthma. The degree of BHR in children may be altered by several factors. We evaluated the prevalence of BHR according to age and gender in pediatric and adolescent population and analyzed the associated factors for gender differences. MethodsAmong the 2,067 subjects, methacholine challenge tests were performed in 1,820 children from one elementary and one middle school in Seoul, Korea. A total of 1,725 subjects between 6 and 14 years old were included in the analysis. The prevalence of BHR, defined as a provocative concentration that induced a 20% reduction of FEV1 (PC20) that was less than 8mg/ml, was evaluated according to age and gender. Gender differences associated with BHR prevalence at each age were calculated and multiple logistic regression analyses were performed to identify factors associated with BHR by gender. ResultsThe prevalence of BHR (PC(20)8mg/ml) for each gender decreased with age (P<0.001). Although the prevalence of BHR linearly decreased in males with age, females showed an increase after 11 years of age. BHR in males was associated with a younger age (aOR, 0.797; 95%CI, 0.678-0.925), a higher blood eosinophil counts (%) (aOR, 1.160; 95%CI, 1.047-1.284), atopy (aOR, 2.091; 95%CI, 1.003-4.359), and a lower FEV1/FVC ratio (aOR, 0.947; 95%CI, 0.901-0.995), and FEF25-75% (aOR, 0.980; 95%CI, 0.961-0.999). In females, BHR was significantly associated with a younger age (aOR, 0.845; 95%CI, 0.747-0.957), lower FEV1 (%) (aOR, 0.961; 95%CI, 0.938-0.984), and menarche (aOR, 3.674; 95%CI, 1.226-11.012). ConclusionBHR declined with age in the Korean pediatric population. A younger age and reduced lung function were common factors related to BHR in both genders. Additionally, atopy was related to BHR in males, whereas sexual maturation was related to BHR in females. These findings have important clinical implications for evaluating of childhood BHR and asthma related to gender. Pediatr Pulmonol. 2016;51:1040-1047. (c) 2016 Wiley Periodicals, Inc.