Samples analyzed by GC-MS were derivatized using Sylon HTP kit (HMDS + TMCS + Pyridine (3 : 1 : 9), Supelco). Derivitizations of TMAO and the plasma analyte at m/z 76 also included initial reduction by titanium (III) chloride47 and further derivatized by reaction with 2,2,2-trichloroethylchloroformate48. Analyses were performed on the Agilent Technolgies 6890/5973 GC/MS in positive ion chemical ionization mode. The GC/MS analyses used a J&W Scientific (Folsom) DB-1 column (30 m, 0.25 mm inner diameter, 0.25-μm film thickness) for separations.