Altered sphingolipid metabolism in childhood asthma and obesity

Introduction: Sphingolipids are group of lipids that are significantly associated with hyperactivity of airway and lung inflammation. Studies on sphingolipid levels showed marked differences between asthmatic and non-asthmatic children. The aim of this study was to determine whether the sphingolipid levels were altered in children with asthma and obesity.

Methods and Analysis:  A total of 327 children of 6 years and above and less than 18 years of age between August, 2017 to December 2022 were recruited from pediatric outpatient clinics at Sidra Medicine, Doha, Qatar. They were grouped into asthmatic-lean (n=84), asthmatic-overweight or -obese (n=89), overweight or obese (n=95) and lean (n=59). Sphingolipids from the blood samples were quantified using a high-performance liquid chromatography. Group comparisons on sphingolipids were performed by a one-way analysis of variance or a Kruskal-Wallis test.

Results: In overweight and obese children, ceramides (C14, C16, C18, C18:1, C20, C22, C24, C24:1) glucosyl ceramide (C24:1) and dihydroceramides (C16, C24, C24:1) were decreased for asthmatics compared to non-asthmatics whereas in lean children we observed an increasing trend in asthmatics compared to non-asthmatics. In overweight and obese children, lower levels of sphingomyelin (C12, C16:1, C18:1, C24:1) were detected in asthmatics compared to non-asthmatics. 

Conclusion: The decreased levels of sphingolipids in obese-asthmatics and elevated levels of sphingolipids in lean-asthmatics shows that altered metabolism is dependent not only on the presence of asthma but also on overweight and obesity.