INS and metabolic dysfunction-associated steatotic liver disease: The KEGG enrichment bubble plot on day 28 showed that nitrite concentration resulted in a large enrichment of differential metabolites in plasma in specific metabolic pathways, such as the pentose phosphate pathway, the HlF-1 signaling pathway, non-alcoholic fatty liver disease, carbon metabolism, the biosynthesis of unsaturated fatty acids, galactose metabolism, the insulin signaling pathway, the FoxO signaling pathway, insulin secretion, and other specific metabolic pathways.