Fig. 4.

The combination of the levels of certain serum metabolites at admission predicts COVID-19 patients who progress from mild to severe disease in the hospital. (A) Differences in serum metabolites between COVID-19 patients with mild (n = 32) and severe (n = 47) disease at admission. (B) ROC curve based on the combination of the levels of 2-hydroxy-3-methylbutyric acid, 3-hydroxybutyric acid, cholesterol, succinic acid, L-ornithine, oleic acid and palmitelaidic acid at admission for the prediction of patients who progress from mild to severe disease in the hospital (n = 32). *, P < 0.05; **, P < 0.01; ***, P < 0.001 in the discovery cohort; #, P < 0.05; ##, P < 0.01; ###, P < 0.001 in the validation cohort.