Evaluation of postprandial glycemic response in rats (Wistar) fed with different starch sources

The consumption of readily digestible starch sources, such as corn, can negatively impact endocrine disorders related to hyperglycaemia in predisposing animals. In this sense, starch sources containing slowly digestible and resistant fractions can assist glycemic control. The present study analyzed the postprandial glycemic response and blood variables of rats fed with four extruded diets containing corn, brown rice, sweet potato and pea as the main starch source. Thirty-two male Wistar rats (90 days old) were divided into groups of eight animals each. The rats received one of the experimental diets for 30 days according to a completely randomised design. The glycemia was measured on the 29th and 30th days. The glycemia measured on the 29th day was analyzed at 0, 30, 60, 120 and 240 min after oral administration of 50% glucose solution. On the 30th day, the same protocol was repeated after providing 3 g of the experimental diet for each animal to obtain the glycemic curve. After the euthanasia on the 30th day, 7 ml of blood was collected via cardiac puncture for glycated haemoglobin (HBA1c), triglycerides, cholesterol, and aspartate and alanine aminotransferases analysis. Diets with pea and sweet potato provided lower glycemic index, average and maximum glycemia, and glycemic increment in relation to the other starch sources (p < 0.05). Animals fed with the corn diet had higher serum concentrations of triglycerides and HBA1c than the other treatments (p < 0.05). Results demonstrated that pea and sweet potato are interesting starch sources for the control of metabolic disorders related to glycemia.