Fig. 1

Untargeted lipidomic profiling in AD patients with severe OSA. A Volcano plots of the FC (x-axis) and p value (y-axis) for each detected lipid in the comparison of severe OSA vs. nonsevere OSA subjects. Red dots represent significantly downregulated (FC <0.80) molecules, and blue dots represent significantly upregulated (FC> 1.25) molecules in severe OSA patients. The results were adjusted for confounding factors (age, sex and BMI). The p value threshold defining statistical significance was <0.05. B Top 20 significant lipids in the classification of the study groups (severe OSA vs. nonsevere OSA) based on random forest. C Significant correlations between PSG parameters of OSA severity and the differentially expressed lipids. The colour scale illustrates the degree of correlation and ranges from red to blue, indicating negative and positive correlations, respectively. Unknown features are presented as exact mass @ retention time. Definition of abbreviations: AHI apnoea-hypopnea index, LysoPC lysophosphatidylcholine, PG phosphatidylglycerol, FC fold change, OSA obstructive sleep apnoea, PC phosphatidylcholine, PE phosphatidylethanolamine, OxTG oxidized triglyceride, CT90 time with oxygen saturation <90%. For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article