A method is disclosed for measuring the properties of protein and lipoprotein elements in a sample. The method includes the of placing a small volume of a sample into a NMR instrument tuned to measure a particular nucleus, applying a series of radiofrequency pulses with intermittent delays in order to measure spin-spin and/or spin-lattice relaxation time constants from the time-domain decay of the signal, without the use of chemical shifts and without converting data into the frequency domain by Fourier transform or other means, at least partially suppressing the water signal prior to the beginning of a sequence used to record relaxation time constants in the time domain, optionally utilizing relaxation contrast agents or other chemical additives to perturb the solvent water or other elements of the sample, analyzing the exponentially decaying NMR signal in the time domain using multi-exponential analysis, and comparing differences in the relaxation time constants for lipoprotein- or protein-specific elements within a single human subject, or between subjects, to assess normal and abnormal metabolism reflective of increased disease risk or active disease.