Association of COVID-19 with hepatic metabolic dysfunction

Table 1 Metabolic alterations in coronavirus disease 2019 with implications

Metabolite alteration	Implications/association
Increased branched chain amino-acids	Insulin resistance, reactive oxygen species production, and pro-inflammatory responses
Decreased tryptophan; Increased kynurenine	Increased kynurenine tryptophan ratio indicates inflammatory response
Increased glutamic acid; Decreased glutamine	Lower glutamine level is associated with insulin resistance and an increased risk of diabetes
Decrease arginine; Increased ornithine	Attempt to suppress virus-specific CD8+ T cell. Delayed interferon response or metabolic syndrome tend to increase arginine/ornithine ratio, causing tissues damage
Increased spermidine and spermine	Help structural assembling and genome replication
Increased serum triglycerides and VLDL; Decreased total cholesterol, HDL and LDL; Upregulation of fatty acid synthesis	Viral replication, inflammation, atherogenic risk, hepatic steatosis
Increased ketone bodies and 2-hydroxybutyric acid	Altered energy metabolism and oxidative stress
Decreased glycerophospholipid; Increased lysophospholipids	Indicates inflammation and tissue damage
increased levels of pyruvate, pyruvate kinase and lactate dehydrogenase	Indicates enhanced glucose metabolism. Increased glycolysis promotes replication of SARS-CoV-2 and cytokine storm
Increased methionine sulfoxide levels; Decreased glutathione levels	Indicative of increased oxidative stress

HDL: High-density lipoprotein; LDL: Low-density lipoprotein; SARS-CoV-2: Severe acute respiratory syndrome coronavirus 2; VLDL: Very-low-density lipoprotein.