Leptin, ghrelin and calprotectin: inflammatory markers in childhood asthma?

Background: Appetite-modulating hormones ghrelin and leptin might be relevant to asthma with their pro-inflammatory effects, and calprotectin has been recognized as a promising marker of inflammation. The purpose of this study was to explore whether asthma, atopy and lung functions has a relation with serum levels of leptin, ghrelin and calprotectin as inflammatory markers in children. Methods: A cross-sectional study was performed by searching the doctor diagnosed asthma through questionnaires filled in by parents who were phoned, and children were invited to supply fasting blood samples in order to measure serum levels of leptin, ghrelin and calprotectin, and to perform skin prick test and spirometry. Participants were divided into Group 1, children with previous diagnosis of asthma, and Group 2, children without previous diagnosis of asthma. Results: One thousand and two hundred questionnaires were distributed and 589 of them were returned filled in. Out of 74 children whose parents accepted to participate in the study, 23 were in Group 1 and 51 were in Group 2. There was no statistical difference in serum levels of leptin, ghrelin, calprotectin, forced expiratory volume in one second (FEV1), forced vital capacity (FVC), peak expiratory flow (PEF), forced expiratory flow between 25 and 75% of vital capacity (FEF25-75) values, and skin prick test results between the two groups (p values are 0.39, 0.72, 0.5, 0.17, 0.5, 0.27, 0.18, and 0.81 respectively). Conclusion: In this study the inflammation in asthmatic children could not be shown by using serum leptin, ghrelin and calprotectin levels and this is possibly due to the low number of children with ever asthma and equal skin prick test positivity in both groups. This study is the first study aimed to show the relation between serum calprotectin levels and inflammation in asthma. As this study was a cross-sectional study, further prospectively designed randomized controlled studies are necessary to show the association of these markers and inflammation in asthma.