31P magnetic resonance spectroscopy of human liver in elderly patients: changes according to nutritional status and inflammatory state

Magnetic resonance spectroscopy (MRS) was used to determine the phosphorylated metabolite content in the liver of elderly patients in various nutritional states: normal, with protein deprivation, and with acute inflammatory syndrome. 31P-MRS investigations were performed at 1.5 T, and localized liver spectra were recorded using a two-dimensional chemical shift imaging sequence. Comparison to control spectra recorded on 10 healthy volunteers (age, 30.5 +/- 2.1 years) showed that the aging process does not significantly modify 31P-MRS liver spectra. Patients with protein deprivation exhibited a higher value than controls for the phosphomonoesters/nucleoside triphosphates (PME/NTP) ratio (P < .05). This increase was not due to the decrease of NTP, since the ratio of inorganic phosphate to NTP (Pi/NTP) remained constant. A decrease in the phosphodiesters to NTP (PDE/NTP) ratio (P < .04) contributed to the observed increase in the PME/PDE ratio (P < .01). In contrast, no significant difference in 31P-MRS spectra was found between elderly patients with hypoalbuminemia associated with inflammatory syndrome and the control group. We conclude that elderly patients with protein deprivation displayed changes in the level of phosphorylated metabolites in the liver that were not observed in the case of inflammatory syndrome despite lower serum albumin (Alb) concentrations.