Leptin and urinary leukotriene E-4 and 9 alpha,11 beta-prostaglandin F-2 release after exercise challenge

Background: Leptin-related effects on inflammation and bronchial hyperresponsiveness (BHR) in the human airway have not been demonstrated.Objectives: To investigate the relationship between the levels of serum leptin and BHR and urinary leukotriene E-4 (LTE4) and 9 alpha,11 beta-prostaglandin F-2 (9 alpha,11 beta-PGF(2)) release after exercise challenge in asthmatic children.Methods: Eighty-six prepubertal children between 6 and 10 years old were enrolled and divided into 4 groups: 19 obese asthmatic children, 25 normal-weight asthmatic children, 21 obese nonasthmatic children, and 21 healthy controls. We measured serum leptin levels and urinary LTE4 and 9 alpha,11 beta-PGF(2) levels in children before and 30 minutes after the exercise challenge.Results: Serum leptin levels were significantly higher in obese asthmatic children compared with normal-weight asthmatic children. Significant increases in urinary levels of LTE4 and 9 alpha,11 beta-PGF(2) were observed in obese asthmatic children after the exercise challenge. Although smaller than in obese asthmatic children, significant increases in the urinary levels of LTE4 and 9 alpha,11 beta-PGF(2) were also observed in the normal-weight. Asthmatic children Logarithmic serum leptin values were significantly associated with the logarithmic maximum percentage change in forced expiratory volume in 1 second, the logarithmic urinary LTE4 change, and the logarithmic urinary 9 alpha,11 beta-PGF(2) change from baseline to after exercise in both obese and normal-weight asthmatic children.Conclusion: The serum levels of leptin were significantly associated with BHR and urinary LTE4 and 9 alpha,11 beta-PGF(2) release induced by exercise challenge in asthmatic children. (c) 2013 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.We thank our pediatric patients and their parents for generous donation of study samples, Mr Soon-Ho Koo for technical assistance, and Professor Young-Gwan Im and Mr Han-Sang Baek for data management. We also thank Aerocrine for their kind support of the NIOX MINO for exhaled nitric oxide measurement