[Insulin secretion and hepatic extraction in juvenile non-insulin-dependent diabetes].

Beta-cell secretion is still a point of controversy. As the liver is the major site of insulin metabolism, evaluation of hepatic insulin extraction is crucial for correct measurement of beta-cell secretion. Methods for calculating the secretion and hepatic extraction of insulin indirectly from peripheral C-peptide concentration have been proposed by some investigators. To characterize the low insulin response of a group of young non-insulin-dependent diabetics we evaluated secretion and hepatic insulin extraction during an oral glucose tolerance test by peripheral IRCP determination and IRCP/IRI molar ratio. Our data show that in this population of young non-insulin-dependent diabetics, the low peripheral insulin response to an oral glucose challenge is a possible consequence of diminished beta-cell secretion, as hepatic insulin extraction is at near normal value