Forearm glucose uptake in cirrhosis and its relationship to glucose tolerance.

1. Oral glucose-tolerance tests (100 g) were carried out in six patients with stable well-compensated cryptogenic cirrhosis and in 12 control subjects. 2. In confirmation of previous studies, patients with cirrhosis had high post-glucose serum insulin levels and were glucose intolerant (mean incremental glucose area 954 +/- 186 compared with 482 +/- 35 mmol 3 h-1 l-1 in controls; P < 0.05). 3. Forearm arteriovenous differences of glucose and forearm blood flow were measured to estimate the proportion of the glucose load metabolized in peripheral tissues. Values in cirrhotic patients and control subjects (5614 +/- 1630 compared with 5344 +/- 672 mumol of glucose min-1 l-1 of forearm in 3 h) were similar despite higher glucose levels and sustained high insulin levels in the cirrhotic patients. 4. Peak lactate concentrations after glucose were of similar magnitude in the two groups (0.66 +/- 0.12 compared with 0.62 +/- 0.75 mmol/l) but in the patients with cirrhosis the peak occurred later and was more sustained. 5. The glucose intolerance of cirrhosis is primarily due to impaired hepatic retention of the glucose load. Insulin resistance in peripheral tissues may also be important since the higher insulin concentrations found in cirrhotic patients failed to enhance peripheral glucose uptake.