[Malnutrition and deficiency of insulin secretion in alcoholic cirrhosis. Study by the assay of urinary C-peptide].

In order to evaluate the relationship between nutritional status and insulin secretion in cirrhosis, the following parameters of caloric (tricipital skin fold, prealbumin) and proteic (arm muscle size, transferrin, 24 h-urinary creatinine excretion) nutritional status were compared in 20 alcoholic cirrhotics and 10 normal subjects. Insulin secretion was evaluated in both groups by insulin and C-peptide response to an intravenous glucose tolerance test and by 24 h urinary excretion of C-peptide. When compared to normals, cirrhotics have lower values for all nutritional status parameters and individually for at least three of those in 14 (70 p. 100) patients. In cirrhotics there is a significant decrease of the 4-min poststimulative response of insulin and C-peptide, contrasting with higher basal and late poststimulative values than in normals. This contrast could be explained by a reduced metabolic clearance rate of insulin (consistent with insulin resistance) and of C-peptide (the urinary clearance of which is 2.5 times lower in cirrhotics than in normals). The 24-h urinary excretion of C-peptide, probably weakly dependent of this reduced clearance, is 50 p. 100 lower in cirrhotics: 12.9 +/- 1.6 nM/24 h than in normals: 26.0 +/- 2.4 nM/24 h (p less than 0.001). In cirrhotics there is a significant linear correlation between 24 h urinary C-peptide excretion and all the nutritional status parameters but one (prealbumin). These results indicate that in cirrhosis: 1) urinary C-peptide excretion rate is a good index of insulin secretion; 2) urinary C-peptide indicates a marked deficit in insulin secretion.(ABSTRACT TRUNCATED AT 250 WORDS)