Evidence for altered hepatic gluconeogenesis in patients with cirrhosis using in vivo 31-phosphorus magnetic resonance spectroscopy

Background and aims-Alterations in gluconeogenesis in the diseased liver ca n be assessed non-invasively using magnetic resonance spectroscopy by measu ring changes in phosphomonoester resonance which contains information regar ding several metabolites, including the phosphorylated intermediates of the gluconeogenic pathway. Methods-P-31 magnetic resonance spectroscopy was used to determine changes in phosphomonoesters following bolus infusions of 2.8 mmol/kg L-alanine in five patients with functionally compensated cirrhosis and in five patients with functionally decompensated cirrhosis. Results-Compared with six healthy volunteers, baseline phosphomonoester val ues were elevated by 35% (p <0.05) in the compensated cirrhosis group and b y 57% (p <0.01) in the decompensated cirrhosis group. Following alanine inf usion, phosphomonoesters in healthy volunteers increased by 46% from baseli ne values (p <0.01), in patients with compensated cirrhosis by 27% (p <0.02 ) but those with decompensated cirrhosis showed no increase from baseline. There was a reduction in the percentage of inorganic phosphate signal in al l subjects. Conclusions-By analysing changes in phosphomonoester and inorganic phosphat e resonances it is possible to discern clear metabolic differences between healthy volunteers and patients with cirrhosis of varying severity using ma gnetic resonance spectroscopy. Those patients with functionally decompensat ed cirrhosis have higher percentage baseline phosphomonoester values but th e absence of phosphomonoester elevation following L-alanine infusion sugges ts that they are unable to mount a significant metabolic response with a pr ogluconeogenic stimulus.