Figure 3.

Differences among kidney injury groups in urine metabolites related to nicotinamide adenine dinucleotide (NAD+) biosynthetic pathways. Upward and downward arrows respectively indicate a significant increase or decrease in mass spectroscopy-based area under curve (AUC) values in the acute kidney injury (AKI) group compared with the no kidney injury (NoKI, red) and chronic kidney disease (CKD, blue) groups. Grayed-out metabolites were not measured. Kyn, kynurenine; KynA, kynurenic acid; MNA, methylnicotinamide; NA, nicotinic acid; NaMN, nicotinate mononucleotide; NMN, nicotinamide mononucleotide; NR, nicotinate riboside; Quin, quinolinate; Trp, tryptophan;