Prognostic Value of Altered Oral Glutamine Challenge in Patients with Minimal Hepatic Encephalopathy

Abstract

Oral glutamine challenge (OGC) has been found to be safe, and an altered response predicts elevated risk of overt hepatic encephalopathy (HE) in patients with minimal hepatic encephalopathy (MHE). We assessed the survival prognosis of patients with cirrhosis, but without current overt HE, who have an altered OGC and MHE. MHE was inferred using 3 neuropsychological tests. Venous ammonia concentrations were measured pre- and post-60 minutes of a 10 g oral glutamine load. The median follow-up was 25.2 months, by which time 22 patients had had bouts of overt HE and 18 had died from liver-related causes. The results in 126 patients with cirrhosis, indicated 25 with MHE and abnormal OGC response. Survival among patients who developed overt HE was 59% at 1 year and 38% at 3 years. In patients without HE, survival was 96% and 86% at 1 and 3 years, respectively (log-rank 50.9, P < .0001). The presence of MHE was not related to survival (log-rank 2.21, P = .23). Patients with MHE and abnormal OGC test had elevated mortality risk (log-rank 13.1, P = .0003). Multivariate analyses indicated Child-Pugh score (hazard ratio [HR] 1.46; 95% CI, 1.46-2.08), and MHE plus altered OGC response (HR 5.5; 95% CI, 1.81-16.6) were predictors of mortality, whether from liver-related or non-liver-related causes. In conclusion, a pathological OGC response in patients with MHE appears to be associated with lower survival rate and may prove useful in the selection of candidates for liver transplantation.