Hypoxic Status in COPD and ARDS Patients: Impact on Lipid Signature.

In patients with respiratory diseases, a panel of markers is often used to assess disease severity and progression. Here we test whether the serum lipid signature may surge as a reliable alternative marker to monitor systemic hypoxia, a frequent unfavourable outcome in acute respiratory distress syndrome (ARDS) and chronic obstructive pulmonary diseases (COPD). We recruited 9 healthy controls, 10 COPD patients, and 10 ARDS patients. Various markers related to inflammation, redox imbalance, and iron handling were measured alongside lipid profiles obtained through untargeted lipidomic analysis. The results show that serum lipids were moderately lower in COPD patients and significantly reduced in ARDS patients compared to the controls. Six lipid classes (cholesteryl esters, coenzyme Q, phosphatidylinositol, sterols, hexosylceramides, and phosphatidylethanolamine) exhibited significant changes (ANOVA < 0.05) and correlated with the Horowitz index (P/F), suggesting their potential as markers of hypoxia severity. While conventional markers also correlated with P/F, the lipid signature was more specific and reliable. This study highlights that hypoxia in pulmonary diseases depresses circulating lipids, with certain lipid classes offering more precise predictions of hypoxia severity. Expanding this research to larger populations could support the lipid signature as a clinical tool.