Findings from the United States and United Kingdom in diabetes provide new insights

Reports from the United States and United Kingdom highlight recent research in diabetes.

Study 1: Consumption of both resistant starch and beta-glucan improves postprandial plasma glucose and insulin in women.

According to recent research published in the journal Diabetes Care, "Consumption of a meal high in resistant starch or soluble fiber (beta-glucan) decreases peak insulin and glucose concentrations and areas under the curve (AUCs). The objective was to determine whether the effects of soluble fiber and resistant starch on glycemic variables are additive."

"Ten normal-weight (43.5 years of age, BMI 22.0 kg/m(2)) and 10 overweight women (43.3 years of age, BMI 30.4 kg/m(2)) consumed 10 tolerance meals in a Latin square design. Meals (1 g carbohydrate/kg body wt) were glucose a ne or muffins made with different levels of soluble fiber (0.26, 0.68, or 2.3 g beta-glucan/100 g muffin) and three levels of resistant starch (0.71, 2.57, or 5.06 g/100 g muffin)," wrote K.M. Behall and colleagues, Beltsville Human Nutrition Research Center.

The results indicated, "Overweight subjects had plasma insulin concentrations higher than those of normal-weight subjects but maintained similar plasma glucose levels. Compared with low beta-glucan-low resistant starch muffins, glucose and insulin AUC decreased when beta-glucan (17 and 33%, respectively) or resistant starch (24 and 38%, respectively) content was increased.

"The greatest AUC reduction occurred after meals containing both high beta-glucanhigh resistant starch (33 and 59% lower AUC for glucose and insulin, respectively). Overweight women were somewhat more insulin resistant than control women."

The authors concluded, "Soluble fiber appears to have a greater effect on postprandial insulin response while glucose reduction is greater after resistant starch from highamylose cornstarch. The reduction in glycemic response was enhanced by combining resistant starch and soluble fiber. Consumption of foods containing moderate amounts of these fibers may improve glucose metabolism in both normal and overweight women."

Behall and colleagues published their study in Diabetes Care (Consumption of both resistant starch and beta-glucan improves postprandial plasma glucose and insulin in women. Diabetes Care, 2006;29(5):976-981).

For additional information, contact K.M. Behall, USDA ARS, Beltsville Human Nutrition Research Center, BARC E, Diet & Human Performance Laboratory, Bldg 307B, Beltsville, MD 20705, USA.

Study 2: Exenatide treatments demonstrated reductions in postprandial plasma glucose excursions in type 2 diabetes.

"Exenatide is an incretin mimetic whose effect on glycemic control in patients with type 2 diabetes is currently under investigation. This study assessed the effect of injection time relative to a standardized meal on postprandial pharmacodynamics of exenatide in patients with type 2 diabetes," researchers in England report.