Serum leptin and adiponectin levels correlate with mast cell activation during exercise-induced bronchospasm in asthmatic children

Background: The aim of this study was to address the correlation between leptin, adiponectin and exercise induced bronchospasm (EIB) by measuring urinary metabolites of mast cell mediators such as 9α,11β-PGF₂, LTE₄.

Methods: Seventy-two prepubertal children from the ages of 6 years to 10 years were recruited in the study. They comprised: asthmatic with EIB (n=24), asthmatic without EIB (n=21), and healthy controls (n=27). We measured exhaled nitric oxide (eNO) and serum eosinophilic cationic protein (ECP), leptin, adiponectin and cytokines. The urinary concentrations of LTE₄ and 9α,11β-PGF₂ were measured. The present study also performed pulmonary function tests: baseline, post-bronchodilator inhalation, methacholine inhalation and exercise. The area under the forced expiratory volume in one second (FEV₁)-time curve quantified the severity of EIB over a 20-minute period after exercise (AUC₂₀).

Results: The post-exercise urinary excretion of 9α,11β-PGF₂ in the asthmatics with EIB increased significantly compared with asthmatics without EIB. The post-exercise urinary excretion of LTE₄ was not significantly difference between the two groups. The maximal decreases in % FEV₁ after exercise were positively correlated with leptin levels and negatively with serum adiponectin levels in asthmatic children. Leptin presented positive associations correlated with post-exercise urinary excretion of 9α,11β-PGF_2, LTE₄ and adiponectin presented negative associations correlated with post-exercise urinary excretion of LTE₄

Conclusions: Serum concentrations of the adipocyte-derived hormones leptin and adiponectin are correlated with EIB/BHR and urinary metabolites of mast cell mediators induced by exercise challenge in asthmatic children