Altered response to oral glutamine challenge as prognostic factor for overt episodes in patients with minimal hepatic encephalopathy.
OBJECTIVE
We assessed the usefulness of oral glutamine challenge (OGC) and minimal hepatic encephalopathy in evaluating risk of overt hepatic encephalopathy in cirrhotic patients.


METHODS
Minimal hepatic encephalopathy (MHE) was inferred using neuro-psychological tests. Venous ammonia concentrations were measured pre- and post-60 min (NH(3)-60m) of a 10 g oral glutamine load. Receiver-operating-characteristic curve analysis indicated a pathological glutamine tolerance cut-off value of NH(3)-60m >128 microg/dl.


RESULTS
In healthy control subjects (n=10) ammonia concentrations remained unchanged but increased significantly in cirrhotic patients (from 70.41+/-45.2 to 127.43+/-78.6; P<0.001). In multiple logistic regression analysis, altered OGC was related to Child-Pugh (odds ratio, OR=7.69; 95% confidence interval, CI=1.72-33.3; P<0.01) and MHE (OR=5.45; 95% CI=1.17-25.4; P<0.05). In the follow-up 11 patients (15%) developed overt hepatic encephalopathy (HE). In multivariate analysis OGC (OR=14.5; 95% CI=1.26-126.3) and MHE (OR=1.56; 95% CI=1.02-21.9) were independently related with HE in the follow-up. Patients with MHE and altered OGC showed significantly higher risk of overt HE in the follow-up (60%) than patients without MHE and normal OGC (2.8%) (Log rank test=21.60; P<0.0001).


CONCLUSIONS
A pathological OGC in patients with MHE appears to be a prognostic factor for the development of overt hepatic encephalopathy, whereas a normal OGC in patients without MHE could exclude risk of overt HE.
Romero-Gómez
Manuel
M
Unit of Hepatology, Hospital Universitario de Valme, Ctra Cádiz s/n. 41014 Seville, Spain. mromerog@supercable.es
Grande
Lourdes
L
Camacho
Inés
I
Benitez
Soledad
S
Irles
José A
JA
Castro
Manuel
M
D000284:Administration, Oral; D000641:Ammonia / Q000097:blood; D005973:Glutamine / Q000008:administration & dosage*; D016481:Helicobacter Infections / Q000150:complications; D016480:Helicobacter pylori; D006501:Hepatic Encephalopathy / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D008099:Liver / Q000503:physiopathology; D008875:Middle Aged; D015999:Multivariate Analysis; D009994:Osmolar Concentration; D010313:Partial Pressure; D011379:Prognosis; D012307:Risk Factors; D012720:Severity of Illness Index
D005973:Glutamine; D000641:Ammonia