Table 4.

Measurements by metabolomic and quantitative assays

MetabolomicQuantitative
SoluteUrinary Excretion Rate Colectomy/ControlHemodialysis/ControlUrinary Clearance Rate Relative to CreatinineFree Fraction, %Urinary Excretion Rate Colectomy/ControlHemodialysis/ControlUrinary Clearance Rate Relative to CreatinineFree Fraction, %
Urea0.832.40.5±0.175±110.863.10.6±0.1
Creatinine3.650±511.6
Indoxyl sulfate0.0852.618.7±4.62±0.70.08144.528.4±6.92±0.4
p-Cresol sulfate0.0127.47±1.22±0.40.0045.49.6±2.52±0.4
Phenylacetylglutamine0.2246.63.6±0.637±50.12103.24.1±0.7114±17
Hippurate0.5436.712±5.231±60.8187.911.6±5.333±3
  • Values are mean±SD unless otherwise stated. Metabolomic values are calculated from peak areas and quantitative values are calculated from absolute solute concentrations measured on the same samples as described in the methods. Hemodialysis/control is the ratio of average peak area or concentration in the ultrafiltrate of patients on hemodialysis relative to control patients.