Elevation of Trimethylamine-N-Oxide in Chronic Kidney Disease: Contribution of Decreased Glomerular Filtration Rate.

International audience(1) Background: Gut microbiota-dependent Trimethylamine-N-oxide (TMAO) has been 5 reported to be strongly linked to renal function and to increased cardiovascular events in the 6 general population and in Chronic Kidney Disease (CKD) patients. Considering the lack of data 7 assessing renal handling of TMAO, we conducted this study to explore renal excretion and 8 mechanisms of accumulation of TMAO during CKD. (2) Methods: We prospectively measured 9 glomerular filtration rate (mGFR) with gold standard methods and plasma concentrations of 10 trimethylamine (TMA), TMAO, choline, betaine and carnitine by LC-MS/MS in 124 controls, CKD 11 and hemodialysis (HD) patients. Renal clearance of each metabolite was assessed in a subgroup of 12 32 patients. (3) Results: Plasma TMAO was inversely correlated with mGFR (r 2 =0.388, p