The effect of glucose oral administration on hyperammonemia in cirrhotics.

In order to investigate the controverted effect of glucose on hyperammonemia the diet of eight advanced cirrhotics was supplemented hourly, between 9 a.m. and 5 p.m., with 20 g of glucose orally. Plasma insulin and arterial and median cubital venous ammonia levels were measured hourly and the results were compared to those of a control test performed in the same patients without glucose supplementation. In the control test the lunch (protein meal) induced an identical rise in arterial and venous ammonia levels (+40 +/- 3 and +36 +/- 5 microgram/100 ml, respectively). With glucose supplementation plasma insulin rose significantly and the arterial ammonia increase produced by lunch (+42 +/- 3 microgram/100 ml) did not differ from that observed in the control test; but the rise in venous ammonemia was lower (+12 +/- 4 microgram/100 ml; p less than 0.01) with a significant increase in arterio-venous ammonia difference. These results suggest that oral glucose administration increases the peripheral muscular ammonia uptake through a mechanism which remains to be elucidated but which is inefficient for arterial hyperammonemia.