Post-breakfast closed-loop glucose control is improved when accompanied with carbohydrate-matching bolus compared to...

Area of Science:

• Endocrinology
• Metabolic Diseases
• Artificial Pancreas Technology

Background:

• Type 1 diabetes management requires precise glucose control, especially after meals.
• Closed-loop systems offer automated insulin and glucagon delivery.
• Accurate insulin dosing is crucial for postprandial glycemic stability.

Purpose of the Study:

• To compare post-breakfast closed-loop glucose control using a carbohydrate-matching insulin bolus versus a weight-dependent insulin bolus.
• To evaluate the efficacy of different bolus strategies in type 1 diabetes management.

Main Methods:

• Twelve adults with type 1 diabetes participated in a crossover study.
• Participants consumed a standardized 75g carbohydrate breakfast.
• Insulin delivery was managed by a closed-loop system, comparing a full carbohydrate-matching bolus to a partial weight-dependent bolus.

Main Results:

• Both bolus strategies were safe and feasible, returning glucose to pre-prandial levels within 5 hours.
• The carbohydrate-matching bolus resulted in significantly lower 5-hour incremental glucose area under the curve (IAUC) compared to the weight-dependent bolus.
• Time spent in hyperglycemia (>10 mmol/L) was significantly reduced with the carbohydrate-matching bolus (24% vs 50%).

Conclusions:

• Post-breakfast closed-loop glucose control is feasible using a weight-dependent bolus without carbohydrate counting.
• A carbohydrate-matching insulin bolus strategy provides superior glycemic control compared to a weight-dependent bolus after breakfast in type 1 diabetes.
• Accurate carbohydrate counting remains essential for optimizing closed-loop system performance.