Insulin resistance in cirrhosis: evidence for a post-receptor defect

Receptor and post-receptor abnormalities of insulin action and their possible role in the insulin resistance of cirrhosis were examined in eight biopsy-proven cirrhotic subjects and eight age-weight matched healthy volunteers. To this end, oral glucose tolerance tests (OGTT), insulin dose response curves and insulin binding to circulating monocytes were determined for each subject. The dose-response curves for the cirrhotic subjects were significantly shifted to the right compared to the control subjects, indicating the presence of insulin insensitivity (ED50 223 +/- 30 versus 64 +/- 8 mU/l respectively; P less than 0.001). The magnitude of the right shift of the insulin-dose response curves correlated significantly (P less than 0.001) with the OGTT 2 h insulin levels (r = 0.74) and the insulin areas under the OGTT curves (r = 0.86). In contrast, insulin responsiveness was marginally elevated in the cirrhotic group (maximal glucose disposal 680 +/- 47 versus 574 +/- 21 ml/m2/min; P less than 0.05). Insulin binding to circulating monocytes was normal in the cirrhotic subjects. It is concluded that the insulin resistance of cirrhosis is due to a post-receptor defect in insulin action which reduces insulin sensitivity but not insulin responsiveness.