FMO5 and chronic kidney disease: However, because of factors like changed protein metabolism, variations in serum protein levels, and effects of fructosamine that are non-glycemic, the correlation might not be sufficiently strong.43 Advanced glycation end products (AGEs) contribute to renal damage in CKD by promoting oxidative stress and inflammation through their interaction with receptors like RAGE, which activates NADPH oxidase and NK-κB pathways, increasing reactive oxygen species (ROS), and pro-inflammatory cytokines.