Liraglutide and Βeta-Cell Function in Young Adults With Long-Standing Type 1 Diabetes and Residual C-Peptide: A Blinded, Randomized Controlled Trial

Liraglutide did not preserve stimulated C-peptide in adults with long-standing type 1 diabetes and residual C-peptide over 52 weeks. Exploratory analyses suggested a steeper C-peptide decline with liraglutide than with placebo, alongside increasing insulin requirements.

Journal article — Randomized, blinded, placebo-controlled trial. Population: Adults with long-standing type 1 diabetes (duration at least 5 years) and detectable fasting C-peptide. Sample size: 18 adults. Follow-up: 52 weeks (follow-up to week 65). Interventions: Liraglutide.

Liraglutide did not improve stimulated C-peptide compared with placebo at week 52. In exploratory post hoc longitudinal analyses including the post-treatment period (weeks 0-65), stimulated C-peptide declined more steeply in the liraglutide group than in the placebo group. This was accompanied by increasing insulin requirements over time.

For researchers working on liraglutide, this paper provides randomized, blinded, placebo-controlled evidence about its effect on residual beta-cell function in adults with long-standing type 1 diabetes. It does not establish a beta-cell-preserving effect; the primary endpoint was negative and exploratory analyses suggested a steeper C-peptide decline with liraglutide than with placebo.

Key findings

• In 18 adults with long-standing type 1 diabetes and residual C-peptide, liraglutide did not improve stimulated C-peptide compared with placebo at week 52.
• In exploratory post hoc analyses over weeks 0-65, stimulated C-peptide declined more steeply in the liraglutide group than in the placebo group.
• The steeper decline in the liraglutide group was accompanied by increasing insulin requirements over time.

Limitations

• Small sample size (n=18) limits precision and generalizability.
• The steeper C-peptide decline was seen in exploratory post hoc longitudinal analyses, not the prespecified primary analysis.
• The inclusion criterion of detectable fasting C-peptide means results may not generalize to people without residual beta-cell function.
• Treatment duration was 52 weeks plus follow-up to week 65, so longer-term effects were not assessed.

The record

• Journal: Diabetes, obesity & metabolism
• Published: 2026-08-13
• PMID: 42595732 — DOI: 10.1111/dom.71204
• Funding: Svenska Sällskapet för Medicinsk Forskning; Göran Gustafssons Stiftelse för Naturvetenskaplig och Medicinsk Forskning; Regionala Forskningsrådet Uppsala/Örebro
• Author countries: Sweden

Peptide profiles: Liraglutide.

All indexed evidence: Liraglutide trials & papers.

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