Dose-dependency of the glycemic response to starch-rich meals in insulin-dependent diabetic subjects: studies at constant insulinemia.

The study objective was to determine the dose-response relationship of postprandial blood glucose response areas to the amount of starch ingested in insulin-dependent diabetic (IDDM) subjects. Three test meals were served in random order with a 7-day interval to seven IDDM subjects attending the outpatient clinic at Aarhus Kommunehospital. Mixed meals of 23, 46, and 69 g parboiled white rice (raw weight) containing approximately 20, 40, and 60 g available carbohydrate were served cooked on three separate days. The patients had achieved normoglycemic blood glucose levels 2 hours before meal intake by means of an artificial pancreas (Biostator, Miles Laboratories, Elkhart, IN), which also provided constant insulin infusion during the study periods (0 to 180 minutes). A clear-cut dose-response relationship between the amount of starch ingested and postprandial peak blood glucose values (r = .96) as well as glucose response areas (r = .99) was found. Glucose response areas to meals containing 20, 40, and 60 g carbohydrate differed significantly (P < .01), attaining 291 +/- 77, 643 +/- 75, and 878 +/- 99 mmol/L x 180 minutes, respectively. Glucosuria accounted for 0.6 and 1.6 g (NS) after 20 and 40 g carbohydrate, whereas 5.0 g glucose (P < .05) was detected following 60 g carbohydrate. Similar mean serum free insulin levels (range, 102 to 150 pmol/L) during the three study periods were found.