Effects of high-fructose (90%) corn syrup on plasma glucose, insulin, and C-peptide in non-insulin-dependent diabetes mellitus and normal subjects.

Interest in sweetening agents is encouraging manufacturers and researchers to find a safe substance to maintain the life quality of diabetics. The popularity of sweetened food items has increased recently in Taiwan. The glycemic index of fructose has been reported to be 20%, much lower than most carbohydrate foods. A high-fructose corn syrup (HFCS) has come onto the market of sweetening agents and has been proposed as a low-cost substitute for fructose in dietetic management of diabetes. The aim of this study was to compare the glycemic effects of HFCS and glucose to see if there is a place for high-fructose corn syrup in diabetic management. In 8 normal and 21 non-insulin dependent diabetes mellitus (NIDDM) subjects, we performed oral tolerance tests. After an overnight fast, the subjects were given either 75g of glucose or an equivalent amount of HFCS containing 75g of carbohydrate. Blood was sampled before and at 30, 60, 90, 120 and 180 minutes after the glucose load. Blood glucose was analyzed by the glucose oxidase method using YSI 23 A (Yellow-Springs Intrument). The insulin and C-peptide were measured by RIA kits from Daiichi. The area under the curves (AUC) was calculated for plasma glucose, immunoreactive insulin (IRI) and immunoreactive C-peptide (IRCP). The results showed that the glycemic effect of HFCS was 73% of glucose. The AUC of IRI after HFCS was 56% of that of glucose. The AUC of IRCP after HFCS was 57% of that of glucose. The high glycemic index of HFCS in our study does not support the use of HFCS as a substitute for fructose.