Effects of meals with different glycaemic index on postprandial blood glucose response in patients with Type 1 diabetes treated with continuous subcutaneous insulin infusion

OBJECTIVE: To evaluate the impact of high-glycaemic index and low-glycaemic index meals on postprandial blood glucose in patients with Type 1 diabetes treated with continuous subcutaneous insulin infusion. METHODS: Sixteen patients with Type 1 diabetes under continuous subcutaneous insulin infusion treatment, age 36±0.5 years (mean±sem), HbA(1c) 7.6±0.2% (56±1.1 mmol/mol), consumed two test meals with an identical macronutrient composition, but with a different glycaemic index: 59 vs. 90. Blood glucose was checked before the test meal and every 30 min thereafter for 180 min. The same preprandial insulin dose was administered on the two occasions. RESULTS: Blood glucose concentrations following the low-glycaemic index meal were significantly lower than those of the high-glycaemic index meal (P<0.05 to P<0.01). The blood glucose area under the curve after the low-glycaemic index meal was 20% lower than after the high-glycaemic meal (P=0.006). CONCLUSIONS: Our data show that meals with the same carbohydrate content but a different glycaemic index produce clinically significant differences in postprandial blood glucose.