Hepatic extraction of insulin after carbohydrate hyperalimentation.

Peripheral venous plasma insulin and C-peptide concentrations during oral glucose tolerance tests were measured in 7 normal weight non-diabetic subjects before and after 7 days of sucrose hyperalimentation. This induced a deterioration of the glucose tolerance with higher levels of glucose, insulin and C-peptide. The C-peptide to insulin molar ratio as well as the relation between incremental areas under the plasma curves of the two peptides were used as relative measures of the hepatic insulin extraction. Both estimates of hepatic insulin extraction were unchanged by hyperalimentation, suggesting that the induced decreases in glucose tolerance and insulin receptor function are not followed by a decrease in hepatic insulin extraction as found in obese subjects with similar changes in glucose tolerance and insulin receptor function.