Abstract P212: Plasma Metabolomics of Dietary Intake of Protein-Rich Foods and Kidney Disease Progression in Children

Introduction: There is inconsistent evidence on the efficacy of a low-protein diet for patients with chronic kidney disease (CKD) and there is a lack of objective biomarkers of dietary intake. The purpose of this study was to identify plasma metabolites associated with dietary intake of protein among children with CKD and to assess whether protein-related metabolites are associated with CKD progression. Methods: We conducted non-targeted metabolomics using plasma samples from 484 Chronic Kidney Disease in Children (CKiD) participants. Multivariable linear regression estimated the cross-sectional association between 949 known, non-drug metabolites and dietary intake of dairy, nuts and beans, red and processed meat, fish, chicken, and eggs, adjusting for demographic, clinical, and dietary covariates. Cox proportional hazards regression models assessed the prospective association between protein-related metabolites and CKD progression defined as kidney replacement therapy or 50% eGFR reduction, adjusting for demographic and clinical covariates. We used a false discovery rate <0.05 as the statistical significance threshold to account for multiple comparisons. Results: Fifty-seven unique metabolites were significantly associated with dietary protein intake (dairy: n=21; nuts and beans: n=13; red and processed meat: n=20; fish: n=2; chicken: n=3; eggs: n=0). Among them, ten metabolites were significantly associated with CKD progression (TABLE) , including one amino acid, one cofactor and vitamin, four lipids, two nucleotides, one peptide, and one xenobiotic. 1-(1-enyl-palmitoyl)-2-oleoyl-GPE (P-16:0/18:1) was positively associated with dietary intake of red and processed meat and CKD progression, and 3-ureidopropionate was inversely associated with dietary intake of red and processed meat and CKD progression. Conclusion: Untargeted plasma metabolomic profiling revealed metabolites associated with dietary intake of protein and CKD progression in a pediatric population.