Residual Beta-Cell Function in Type II Diabetes and Evaluation of the Hepatic Insulin Extraction

Summary

Insulin and C-peptide (free insulin and C-peptide in insulin-treated patients) were measured after glucose stimulation in nine Type II diabetics on chlorpropamide, eleven insulin-treated maturity-onset diabetics and in 8 normal controls. Dissociation between C-peptide and insulin response to glucose was observed in several diabetics. The relation between incremental molar areas under C-peptide and insulin curves, after glucose challenge (Δ CPR - Δ IRI / Δ CPR) were used to evaluate the hepatic insulin extraction in all but the insulin-treated diabetics.

The lower insulin requirements and better control of the short-duration insulin-treated maturity-onset diabetics in relation to the long-term ones could not be explained either by the residual insulin secretion or by the level of “insulin antibodies”. The chlorpropamide-responsive patients presented higher insulin levels after the glucose challenge and a lower hepatic insulin extraction than the non-responsive ones.

Key-Words:

Maturity-Onset Diabetics - Insulin - C-Peptide - Chlorpropamide - Hepatic Insulin Extraction