Hybrid closed-loop pumps lowered HbA1c in young people with poorly controlled type 1 diabetes

Design

Retrospective multicentre observational cohort

Population

220 children and young people ≤19 years with type 1 diabetes and HbA1c ≥69 mmol/mol

Primary outcome

Change in HbA1c after starting hybrid closed-loop therapy

Effect

82.5 → 72.8 mmol/mol at 3 months → 69.3 mmol/mol at 12 months (p<0.001)

This retrospective cohort from 13 NHS paediatric diabetes units in England included 220 children and young people aged 19 or under with type 1 diabetes for over a year and HbA1c of 69 mmol/mol (8.5%) or more, who started hybrid closed-loop insulin pump therapy.

Mean HbA1c fell from 82.5 mmol/mol (9.7%) to 72.8 mmol/mol within three months and reached 69.3 mmol/mol (8.5%) at 12 months. The largest falls were in those starting above 100 mmol/mol and those switching from multiple daily injections. Results were similar across pump systems, and diabetes-related admissions fell.

Young people with high HbA1c are often thought of as poor candidates for technology. This real-world cohort suggests they may gain the most, though most still remained above target.

• High HbA1c is not a reason to withhold hybrid closed-loop therapy from a young person.
• The greatest improvement was in those with the highest HbA1c and those moving from injections.
• Most improvement came in the first 3 months and was sustained at 12 months.
• Average HbA1c remained above target; closed-loop therapy still needs structured education and follow-up.

Why it matters

It challenges the habit of reserving diabetes technology for young people who are already doing well.

Don't overread it

This is an uncontrolled retrospective cohort; it cannot show how much of the improvement was due to the pump.

The statistics, in plain English

A fall of about 13 mmol/mol (about 1.2 percentage points) in HbA1c is clinically meaningful. Without a control group, some of the fall may reflect extra attention at pump start or regression to the mean from a high baseline.

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