Liraglutide Didn't Improve Blood Sugar Control in Type 1 Diabetes But Did Reduce Weight and Insulin Needs
Adding liraglutide to insulin in overweight adults with type 1 diabetes did not significantly lower HbA1c, but it reduced body weight by 6.8 kg, decreased insulin doses, and cut hypoglycemic events by 18%.
Quick Facts
What This Study Found
The primary endpoint was not met: HbA1c change did not significantly differ between groups (-0.5% with liraglutide vs -0.3% with placebo; between-group difference -0.2%, p=0.18). However, several clinically meaningful secondary benefits emerged:
- Body weight: -6.8 kg difference favoring liraglutide (p=0.015)
- Bolus insulin: -5.8 IU difference (p=0.023)
- Hypoglycemic events: 18% reduction (incident rate ratio 0.82, p<0.001)
- Heart rate: +7.5 bpm increase with liraglutide (p=0.002)
- Gastrointestinal side effects: nausea 58% vs 10%, dyspepsia 22% vs 2%
Gastric emptying was initially delayed at 3 weeks but normalized by 24 weeks.
Key Numbers
How They Did This
Randomized, double-blind, placebo-controlled trial at Steno Diabetes Center, Denmark. 100 patients with type 1 diabetes (HbA1c >8%, BMI >25 kg/m²) were randomized 1:1 to liraglutide or placebo added to existing insulin. Liraglutide was escalated from 0.6 mg to 1.8 mg daily over 2+ weeks. Treatment lasted 24 weeks. Analysis used mixed models for efficacy in the modified ITT population.
Why This Research Matters
Many people with type 1 diabetes are overweight and struggle with blood sugar control despite insulin. While liraglutide didn't improve HbA1c, the significant weight loss, insulin dose reduction, and fewer hypos are clinically meaningful. These findings help define where GLP-1 drugs might and might not help in type 1 diabetes — and set the stage for trials of newer GLP-1 drugs like semaglutide in this population.
The Bigger Picture
GLP-1 agonists are not approved for type 1 diabetes, but off-label use is growing among overweight patients who need help with weight and insulin requirements. This trial — one of the first rigorous RCTs in this space — shows the benefits are real but the primary goal of better blood sugar control was missed. Later studies with semaglutide and tirzepatide in type 1 diabetes have continued exploring this question.
What This Study Doesn't Tell Us
The sample size of 100 patients may have been insufficient to detect a modest HbA1c difference. The trial was only 24 weeks long. The high rate of GI side effects (58% nausea) may have affected adherence and could limit real-world applicability. The study was funded by Novo Nordisk, liraglutide's manufacturer. Only overweight patients with poor control were included, limiting generalizability.
Questions This Raises
- ?Would a longer trial or higher-potency GLP-1 agonist like semaglutide show significant HbA1c improvement in type 1 diabetes?
- ?Is the 6.8 kg weight loss alone sufficient reason to prescribe GLP-1 agonists off-label in overweight type 1 diabetes patients?
- ?Could the 18% reduction in hypoglycemic events translate to improved quality of life and safety in real-world practice?
Trust & Context
- Key Stat:
- -6.8 kg weight loss vs placebo While liraglutide missed its primary HbA1c target in type 1 diabetes, the significant weight loss and 18% fewer hypos highlight secondary benefits
- Evidence Grade:
- This is a well-designed randomized, double-blind, placebo-controlled trial published in The Lancet Diabetes & Endocrinology. It provides strong evidence, though the primary endpoint was not met and the sample size was relatively small.
- Study Age:
- Published in 2016, this was one of the first RCTs testing a GLP-1 agonist in type 1 diabetes. The findings remain relevant as newer GLP-1 drugs are being tested in this population.
- Original Title:
- Efficacy and safety of liraglutide for overweight adult patients with type 1 diabetes and insufficient glycaemic control (Lira-1): a randomised, double-blind, placebo-controlled trial.
- Published In:
- The lancet. Diabetes & endocrinology, 4(3), 221-232 (2016)
- Authors:
- Dejgaard, Thomas Fremming(2), Frandsen, Christian Seerup(2), Hansen, Tanja Stenbæk, Almdal, Thomas, Urhammer, Søren, Pedersen-Bjergaard, Ulrik, Jensen, Tonny, Jensen, Andreas Kryger, Holst, Jens Juul, Tarnow, Lise, Knop, Filip Krag, Madsbad, Sten, Andersen, Henrik Ullits
- Database ID:
- RPEP-02912
Evidence Hierarchy
Frequently Asked Questions
Can people with type 1 diabetes use GLP-1 drugs like liraglutide?
GLP-1 drugs are not approved for type 1 diabetes, but some doctors prescribe them off-label for overweight patients who need help with weight management. This trial shows liraglutide reduces weight and insulin needs in this group, but doesn't improve blood sugar control as measured by HbA1c.
Why didn't liraglutide improve blood sugar in type 1 diabetes if it works in type 2?
In type 2 diabetes, GLP-1 drugs boost the body's own insulin production and reduce glucose-raising glucagon — effects that depend on having some remaining pancreatic function. In type 1 diabetes, the pancreas makes little to no insulin, so GLP-1 drugs can't stimulate what isn't there. Their benefits are primarily through weight loss, appetite suppression, and slowed gastric emptying.
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Cite This Study
https://rethinkpeptides.com/research/RPEP-02912APA
Dejgaard, Thomas Fremming; Frandsen, Christian Seerup; Hansen, Tanja Stenbæk; Almdal, Thomas; Urhammer, Søren; Pedersen-Bjergaard, Ulrik; Jensen, Tonny; Jensen, Andreas Kryger; Holst, Jens Juul; Tarnow, Lise; Knop, Filip Krag; Madsbad, Sten; Andersen, Henrik Ullits. (2016). Efficacy and safety of liraglutide for overweight adult patients with type 1 diabetes and insufficient glycaemic control (Lira-1): a randomised, double-blind, placebo-controlled trial.. The lancet. Diabetes & endocrinology, 4(3), 221-232. https://doi.org/10.1016/S2213-8587(15)00436-2
MLA
Dejgaard, Thomas Fremming, et al. "Efficacy and safety of liraglutide for overweight adult patients with type 1 diabetes and insufficient glycaemic control (Lira-1): a randomised, double-blind, placebo-controlled trial.." The lancet. Diabetes & endocrinology, 2016. https://doi.org/10.1016/S2213-8587(15)00436-2
RethinkPeptides
RethinkPeptides Research Database. "Efficacy and safety of liraglutide for overweight adult pati..." RPEP-02912. Retrieved from https://rethinkpeptides.com/research/dejgaard-2016-efficacy-and-safety-of
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Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.