Metabolic profiling of urine by H-1-NMR spectroscopy - A critical assessment of interpreting metabolite concentrations for normal and diabetes groups

The metabolic profile of urine from a control group has been obtained by 1H-NMR spectroscopy at 400 MHz. Data have been processed both as absolute (mmol/L) and relative (mmol/mol of creatinine) concentrations. The normal values have been compared with data from type II diabetes mellitus (DM II). The average concentrations of various metabolites in urine for normal and DM II subjects are presented. Some of these values are not routinely obtained by classical urine analysis. Our data are in good agreement with some previously reported data but they are not identical. Possible explanations for the small variations are discussed in terms of NMR experimental parameters and lifestyle differences. Preliminary results indicate significant differences between the two groups for the averaged relative concentrations (mmol/mol creatinine) of valine (Val), lactate (Lac), g-aminobutyrate (GABA), pyruvate (Pyr), and alanine (Ala). However, the interval over which the individual values are spread is overlapping for all metabolites, excepting glucose. Keywords: NMR, MRS, Urine, Metabolites, Diabete