Effect of euglycemic insulin infusion on plasma levels of branched-chain amino acids in cirrhosis.
To test the hypothesis that hyperinsulinism is responsible for reduced branched-chain amino acids in cirrhotics, plasma amino acids were sequentially determined in 8 controls and 8 matched cirrhotics during continuous i.v. insulin infusion. An artificial endocrine pancreas which infused glucose was used to sustain euglycemia. Basal plasma insulin levels were high and branched-chain amino acids were reduced in cirrhotics. Insulin infusion raised insulin levels to 3 to 4 times basal values. During the test, the decline in branched-chain amino acids was markedly higher in controls who had similar steady-state insulin levels. Not only did the level of branched-chain amino acids in controls reach the values seen in cirrhotics after 60 min, but the levels continued to fall at a significantly higher rate throughout the second hour. Glucose consumption and the ratio of glucose infused/steady-state insulin--a measure of tissue sensitivity to insulin--were markedly reduced in cirrhotics and positively correlated with the decline in branched-chain amino acids. In cirrhotics, insulin effects on carbohydrate and branched-chain amino acid metabolism were reduced. Low branched-chain amino acid levels in cirrhotics are not likely to depend only on hyperinsulinism.
D000328:Adult; D000368:Aged; D000597:Amino Acids, Branched-Chain / Q000097:blood*; D005260:Female; D005934:Glucagon / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006801:Humans; D006946:Hyperinsulinism / Q000378:metabolism; D007263:Infusions, Parenteral; D007328:Insulin / Q000494:pharmacology*; D008103:Liver Cirrhosis / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D013997:Time Factors
D000597:Amino Acids, Branched-Chain; D007328:Insulin; D005934:Glucagon; D005947:Glucose