Urine metabolomics and asthma in children and young adults.

<bold>Aim:</bold> The objective of this study was to evaluate potential biomarkers linked to asthma and its phenotypes in children and young adults. <bold>Methods:</bold> Non-targeted screening (NTS) using high-resolution mass spectrometry was performed on 608 urine samples from 4-year-olds and 845 samples from 24-year-olds collected in the Swedish birth cohort BAMSE. From the measured features, 260 metabolites were annotated using in-house compound libraries. Asthma was divided into allergic and non-allergic asthma based on presence of IgE to common allergens. Metabolites exhibiting significant variations (>1.5 or <0.67 in median peak area) and nominal p-value <0.05 in non-parametric tests were further analyzed. <bold>Results:</bold> Overall, no metabolites were associated with significant differences between participants with or without asthma at 4 or 24 years. However, 16 metabolites at 4 years and 23 metabolites at 24 years were associated with allergic- or non-allergic asthma phenotypes, whereof five metabolites were identical in both age groups. At 24 years of age, the subjects with non-allergic asthma (n=66) had higher abundance of 21 metabolites compared to both the group with allergic asthma (n=196) and the groups without asthma (n=570). Only one metabolite had differing abundance in subjects with allergic asthma. <bold>Conclusion:</bold> NTS using high-resolution mass spectrometry enabled identification of urine metabolites associated with in particular non-allergic asthma. <fig><object-id>erj;64/suppl_68/PA4050/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>