Liraglutide Added to Insulin Pumps Cuts Blood Sugar, Weight, and Insulin Needs in Type 1 Diabetes | Research

The takeaway

Adding liraglutide to insulin pump therapy in overweight type 1 diabetes patients lowered HbA1c by 0.7% more than placebo, reduced weight by 6.3 kg, and cut insulin needs by 16% — without increasing hypoglycemia risk.

6.3 kg weight loss
Liraglutide reduced body weight by 6.3 kg more than placebo over 26 weeks in overweight type 1 diabetes patients — while also improving blood sugar and reducing insulin needs

What the researchers found

Adding liraglutide 1.8 mg daily to insulin pump therapy in overweight adults with type 1 diabetes produced three significant benefits over 26 weeks compared to placebo: HbA1c dropped by 0.5% (vs. a 0.2% increase with placebo, p<0.001), body weight decreased by 6.3 kg (p<0.001), and total insulin dose fell by 8 units/day (16% reduction, p=0.008). Time in the target glucose range (71-180 mg/dL) increased without raising the risk of hypoglycemia.

Why it matters

GLP-1 drugs are primarily used for type 2 diabetes and obesity, but some type 1 diabetes patients — especially those who are overweight with poor glucose control — may also benefit. This trial provides rigorous evidence that liraglutide can improve multiple outcomes simultaneously in these patients without the feared increase in dangerous low blood sugar episodes.

The numbers in context

HbA1c: -0.5% vs. +0.2% (p<0.001) · Weight: -6.3 kg vs. placebo (p<0.001) · Insulin: -8 units/day (-16%, p=0.008) · No increased hypoglycemia

How the study worked

26-week randomized, double-blind, placebo-controlled trial (Lira Pump trial). 44 overweight/obese adults with type 1 diabetes on insulin pump therapy (CSII) were randomized 1:1 to liraglutide 1.8 mg once daily or placebo. Primary endpoint was HbA1c change. Secondary endpoints included insulin dose, glycemic variability, body weight, and adverse events.

Who was studied

Overweight or obese adults with type 1 diabetes on insulin pump therapy with HbA1c ~8.2% at baseline

What this study cannot tell us

Small sample size (44 patients total, 22 per group). Single-center trial. 26-week duration doesn't capture long-term outcomes or sustainability. Only studied the 1.8 mg dose. Results apply specifically to overweight/obese type 1 patients on insulin pumps — may not generalize to all type 1 diabetes patients. Liraglutide is not FDA-approved for type 1 diabetes.

How to read the evidence

Rated strong because this is a well-designed randomized, double-blind, placebo-controlled trial with clear primary and secondary endpoints and statistically significant results across multiple measures.

When this study was published

Published in 2020, this trial used liraglutide (an earlier GLP-1 drug). Since then, newer agents like semaglutide have become available, but the findings remain relevant for understanding GLP-1 therapy in type 1 diabetes.

The bigger picture

While GLP-1 drugs have transformed type 2 diabetes treatment, their role in type 1 diabetes remains off-label and debated. This well-designed trial adds to growing evidence that a subset of type 1 patients — particularly those who are overweight with insulin resistance features — can meaningfully benefit from GLP-1 therapy as an add-on to insulin, not a replacement for it.

Questions still open

Would the benefits persist beyond 26 weeks, or do patients plateau or regain weight?
Could newer, more potent GLP-1 drugs like semaglutide produce even larger effects in this population?
Should liraglutide be formally studied for FDA approval in type 1 diabetes, given this and similar evidence?

Common questions

Can people with type 1 diabetes take GLP-1 drugs like liraglutide?

GLP-1 drugs are not FDA-approved for type 1 diabetes, but this trial shows they can be beneficial when added to insulin in overweight type 1 patients with poor glucose control. Some endocrinologists prescribe them off-label for this purpose. They must always be used alongside insulin — never as a replacement — because type 1 patients cannot make their own insulin.

Did liraglutide cause dangerous low blood sugar in these type 1 patients?

No. Despite reducing both HbA1c and insulin doses, liraglutide did not increase the rate of hypoglycemia compared to placebo. This was a key safety finding, since adding glucose-lowering drugs on top of insulin raises theoretical hypoglycemia concerns.

Read the original research

Liraglutide reduces hyperglycaemia and body weight in overweight, dysregulated insulin-pump-treated patients with type 1 diabetes: The Lira Pump trial-a randomized, double-blinded, placebo-controlled trial.

Diabetes, obesity & metabolism, 22(4), 492-500

View on PubMed ↗Publisher’s paper ↗

Citation

Dejgaard, Thomas F; Schmidt, Signe; Frandsen, Christian S; Vistisen, Dorte; Madsbad, Sten; Andersen, Henrik U; Nørgaard, Kirsten. (2020). Liraglutide reduces hyperglycaemia and body weight in overweight, dysregulated insulin-pump-treated patients with type 1 diabetes: The Lira Pump trial-a randomized, double-blinded, placebo-controlled trial.. Diabetes, obesity & metabolism, 22(4), 492-500. https://doi.org/10.1111/dom.13911