Assessment for Predictors of Rise in Hemoglobin A1c During Extended Use of a Closed-Loop Control System

Area of Science:

• Pediatric Endocrinology
• Metabolic Diseases
• Biomedical Engineering

Background:

• Type 1 diabetes management in children requires continuous monitoring and intervention.
• Closed-loop control (CLC) systems offer advanced automated glucose regulation.
• Understanding factors influencing long-term CLC efficacy is crucial for optimizing treatment outcomes.

Purpose of the Study:

• To identify predictors of increased hemoglobin A1c (HbA1c) during long-term closed-loop control (CLC) use in children with type 1 diabetes.
• To compare characteristics of children whose HbA1c increased versus those who maintained improvement on CLC.
• To investigate potential factors such as pubertal growth and carbohydrate bolus accuracy.

Main Methods:

• A cohort of children aged 6-13 years with type 1 diabetes used a CLC system.
• Participants were categorized into an "Increased-HbA1c" group (≥0.5% rise) and a "Maintained-Improvement" group.
• Predictors including baseline HbA1c, height-for-age z-score changes, and carbohydrate bolus frequency were analyzed.

Main Results:

• The Increased-HbA1c group exhibited significantly higher pre-CLC HbA1c levels compared to the Maintained-Improvement group (8.42% vs. 7.45%, P=0.002).
• No significant differences were observed in pubertal growth indicators (Δ-height-for-age z-score) or carbohydrate bolus frequency between the groups.
• Both groups demonstrated high rates of closed-loop system utilization.

Conclusions:

• Higher baseline HbA1c is a key predictor of rising HbA1c levels during long-term CLC use in pediatric type 1 diabetes.
• Factors beyond pubertal growth and missed boluses contribute to HbA1c increases.
• Children experiencing HbA1c rises on CLC may benefit from additional support and encouragement to optimize glycemic control.