Insulin metabolism after relief of obstructive jaundice: Intravenous glucose tolerance test with portal blood sampling

Abstract

Glucose intolerance and impaired insulin secretion are often associated with obstructive jaundice. Our objective was to determine whether such abnormalities would be ameliorated after jaundice was relieved by biliary drainage. Twenty-four patients with hepatobiliary malignancy prospectively underwent intravenous glucose tolerance test with femoral and portal blood sampling, and the kinetics of insulin release were determined. Sixteen patients had obstructive jaundice (group A) that had been completely relieved by percutaneous transhepatic biliary drainage by the time of intravenous glucose tolerance testing, and eight patients exhibited no jaundice (group B). Integrated immunoreactive insulin (sigmaIRI, 10 muU min/ml; mean +/- SD) and integrated C-peptide (sigmaCPR, 10 ng min/ml) in the portal blood in group A were significantly lower than those values in group B (sigmaIRI: group A, 436.0 +/- 260.6; group B, 714.3 +/-287.2; p< 0.01; sigmaCPR; group A, 26 +/- 10.1; group B 49.5 +/- 18.8; p<0.005). The hepatic insulin extraction ratio (portal-femoral difference of sigmaIRI divided by portal sigmaIRI) in group A was significantly higher than that in group B (group A, 0.75 +/- 0.06; group B, 0.55 +/- 0.05; p<0.001), whereas the hepatic CPR extraction ratio did not differ significantly between the two groups (group A, 0.37 +/- 0.10; group B, 0.39 +/- 0.05). The impaired insulin secretion caused by obstructive jaundice is not fully reversed after percutaneous transhepatic biliary drainage. The high hepatic extraction ratio of insulin in patients who had been treated with percutaneous transhepatic biliary drainage may compensate for the impaired insulin secretion, although its mechanism is still unclear.