Clin Exp Pediatr.  2021 May;64(5):229-238. 10.3345/cep.2020.01585.

Sex-based differences in factors associated with bronchial hyperresponsiveness in adolescents with childhood asthma

• Kim YH
• Jang YY
• Jeong J
• Chung HL

• KMID: 2515445
• DOI: http://doi.org/10.3345/cep.2020.01585

Abstract

Background
Bronchial hyperresponsiveness (BHR), an important physiological feature of asthma, is a prognostic marker of childhood asthma. Purpose: We aimed to investigate the factors associated with BHR in adolescents with childhood asthma.
Methods
Two hundred and fifteen adolescents (≥13 years of age; 149 males, 66 females) who were diagnosed with asthma during childhood were enrolled, underwent methacholine challenge tests, and were divided into the BHR group (<25 mg/mL of provocation concentration causing a 20% fall in forced expiratory volume in 1 second [FEV₁] [PC₂₀], n=113) or non-BHR group (≥25 mg/mL of PC₂₀, n=102). We examined longitudinal changes in BHR and the risk factors for its persistence in the 108 adolescents for whom baseline data, including methacholine PC₂₀ at age 6 years, were available. Multivariate logistic regression analyses were performed to assess the factors associated with BHR in adolescents.
Results
Mold sensitization (adjusted odds ratio [aOR], 5.569; P=0.005) and increased blood eosinophil count (aOR, 1.002; P=0.026) were independently associated with BHR in boys but not girls. The odds of BHR decreased by 32% with each 1-year increase in age in boys (aOR, 0.683; P=0.010) but not girls. A reduced FEV₁/forced vital capacity ratio (<90%) was independently related with BHR in female patients only (aOR, 7.500; P=0.007). BHR decreased with age throughout childhood. A low methacholine PC₂₀ at age 6 years was independently associated with persistent BHR throughout childhood in male and female patients, whereas early mold sensitization was a risk factor for persistent BHR in male patients only (aOR, 7.718; P=0.028).
Conclusion
Our study revealed sex-specific differences in the factors associated with BHR in adolescents with childhood asthma. Our findings suggest the risk factors that might affect asthma transition from childhood to adolescence and adulthood.

Keyword

Adolescence; Asthma; Bronchial hyperresponsiveness; Mold; Sex