AID use and weight changes
Sarah Koning, Pim Dekker, Erwin Birnie, Tim van den Heuvel, Javier Castañeda, Koen van Beers, Henk Veeze, Ohad Cohen, Henk-Jan Aanstoot
What is the impact of an advanced hybrid closed-loop system on weight control among people with type 1 diabetes? Diabetes Obes Metab. 2025 Dec 28. Online ahead of print.
Advanced hybrid closed-loop (aHCL) insulin delivery systems substantially improve glycaemic outcomes and quality of life for people with type 1 diabetes (T1D). However, weight gain remains a growing concern in this population, with around half of people with T1D already overweight or obese and at increased cardiovascular risk. Previous studies on weight change after aHCL initiation have reported conflicting results, often relying on group averages that may obscure clinically meaningful individual differences. This study aimed to better understand the impact of aHCL initiation on weight by distinguishing individuals who gained weight from those who maintained or lost weight, and by identifying clinical and system-derived factors associated with weight gain in routine care.
This retrospective cohort study included 496 people with T1D who initiated the Medtronic MiniMed™ 780G system in routine care. Weight outcomes before and after aHCL initiation were analysed separately for youth (≤20 years, BMI z-scores) and adults (>20 years, BMI). Clinical data and system metrics were used to identify predictors of post-initiation weight gain.
KEY FINDINGS
- After aHCL initiation, two thirds of participants aged ≤20 years and just over half of adults aged >20 years experienced weight gain.
- Weight gain was common among those already overweight at baseline, affecting 60% of overweight youth and 55% of overweight adults.
- Higher baseline HbA1c was associated with greater odds of weight gain in both age groups.
- In adults, lower baseline time in range was associated with a higher likelihood of weight gain.
- Larger reductions in HbA1c after aHCL initiation were associated with increased odds of weight gain in both youth and adults.
- Increases in total daily insulin dose per kilogram were strongly associated with weight gain across age groups.
- Use of optimal system settings was low and was not associated with weight outcomes.
Weight gain after aHCL initiation is common and affects a substantial subgroup of people with T1D, particularly those with higher baseline HbA1c or pre-existing overweight. These findings underscore the need to combine aHCL initiation with targeted lifestyle counselling and follow-up to support healthy weight alongside improved glycaemic outcomes.
CONCLUDING THE AUTHORS STATE
"Stratified analyses revealed a sizeable high-risk subgroup, particularly individuals already overweight. Lifestyle counselling should accompany aHCL initiation to maximize glycaemic benefits while minimizing weight-related risk." -
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