NMR quantification of TMAO

A computer program product for determining measures of TMAO in in vitro biosamples, comprising a non-transitory computer readable storage medium having computer readable program code embodied in the medium, the computer-readable program code that cause one or more processors to perform actions including:

• receiving an NMR spectrum for a biosample generated by an NMR spectrophotometer;
• defining a TMAO peak region in which a TMAO peak is expected to be located, the TMAO peak region being defined to between about 3.2 and 3.4 ppm;
• identifying a reference location of a reference peak that is within a reference peak region in the NMR spectrum, the reference peak region being defined based on a reference NMR spectrum generated using a reference sample;
• detecting a calibration location corresponding to a pH sensitive calibration peak within a calibration peak region in the NMR spectrum;
• identifying a TMAO peak location that is a location of a peak that is within the TMAO peak region in the NMR spectrum and that corresponds to a concentration of TMAO in the biosample, the identification being based on:
• the reference location;
• and
• the calibration location;
• detecting an amplitude of the NMR spectrum at the TMAO peak location;
• calculating a TMAO concentration metric based on the amplitude of the NMR spectrum at the TMAO peak location;
• and
• generating an electronic report that includes the TMAO concentration metric wherein the measure of TMAO is substantially linear and detects TMAO in a range of from 1-50 μM TMAO.

A computer program product for evaluating in vitro biosamples, the computer program product comprising:

• a non-transitory computer readable storage medium having computer readable program code embodied in the medium, the computer-readable program code comprising:
• computer readable program code that evaluates an NMR signal in at least one defined peak region that includes a trimethylamine-N-oxide (TMAO) peak region residing between about 3.2 and 3.4 ppm of a proton NMR spectrum of an in vitro biosample to determine a level of TMAO, wherein the computer readable program code that evaluates the TMAO peak region to determine the level of TMAO includes:
• computer readable program code that weights a region around an expected TMAO peak location with a defined function;
• computer readable program code that identifies a highest weighted data point of the weighted region as a probable actual TMAO peak location;
• and
• computer readable program code that applies a curve fitting function or functions to a curve fitting region of about 30 to about 50 data points centered about the identified probable actual TMAO peak location to determine a level of TMAO, and wherein the measurement is substantially linear and detects TMAO in the range of 1-50 μM TMAO.

An analysis system, comprising:

• at least one NMR spectrometer for acquiring an NMR spectrum for a biosample;
• and
• at least one processor in communication with the at least one NMR spectrometer, the at least one processor configured to perform actions including:
• defining a TMAO peak region in which a TMAO peak is expected to be located, the TMAO peak region being defined to between about 3.2 and 3.4 ppm;
• identifying a reference location of a reference peak that is within a reference peak region in the NMR spectrum, the reference peak region being defined based on a reference NMR spectrum generated using a reference sample;
• detecting a calibration location corresponding to a pH sensitive calibration peak within a calibration peak region in the NMR spectrum;
• identifying a TMAO peak location that is a location of a peak that is within the TMAO peak region in the NMR spectrum and that corresponds to a concentration of TMAO in the biosample, the identification being based on:
• the reference location;
• and
• the calibration location;
• detecting an amplitude of the NMR spectrum at the TMAO peak location;
• calculating a TMAO concentration metric based on the amplitude of the NMR spectrum at the TMAO peak location;
• and
• generating an electronic report that includes the TMAO concentration metric wherein the measure of TMAO is substantially linear and detects TMAO in a range of from 1-50 μM TMAO.