Acute fructose administration improves oral glucose tolerance in adults with type 2 diabetes

OBJECTIVE - in normal adults, a small (catalytic) dose of fructose administered with glucose decreases the glycemic response to a glucose load, especially in those with the poorest glucose tolerance. We hypothesized that an acute catalytic dose of fructose would also improve glucose tolerance in individuals With type 2 diabetes. RESEARCH DESIGN AND METHODS - Five adults with type 2 diabetes underwent an oral glucose tolerance test (OGTT) on two separate occasions, at least I week apart, Each OGTT consisted of 75 g glucose with or without the addition of 7.5 g fructose (OGTT + F or OGTT - R in random order. Arterialized blood samples were collected from a heated dorsal hand vein twice before ingestion of the carbohydrate and every 15 min for 3 h afterward, RESULTS - The area under the curve (AUC) of the plasma glucose response was reduced by fructose administration in all subjects the mean AUC during the OGTT + F was 14% less than that during the OGTT - F (P < 0.05). The insulin AUC was decreased 21% with fructose administration (P = 0.2). Plasma glucagon concentrations declined similarly during OGTT- F and OGTT + F. The incremental AUC of the blood lactate response during the OGTT - F was similar to 50% of that observed during the OGTT + F (P < 0.05). Neither nonesterified fail), acid nor triglycericle concentrations differed between the two OGTTs. CONCLUSIONS - Low-close fructose improves the glycemic response to an oral glucose load in adults with type 2 diabetes, and this effect is not a result of stimulation of insulin secretion.