GLP-1 analogue-induced weight loss does not improve obesity-induced AT dysfunction

Area of Science:

• Metabolism and Endocrinology
• Adipose Tissue Biology
• Pharmacology

Background:

• Obesity-associated adipose tissue (AT) dysfunction is linked to metabolic diseases.
• Glucagon-like peptide-1 (GLP-1) analogues promote weight loss, potentially improving AT function.
• GLP-1 receptor (GLP-1R) expression in AT suggests direct treatment effects.

Purpose of the Study:

• To investigate the impact of GLP-1 analogue treatment versus calorie restriction on subcutaneous AT (SCAT) inflammatory and fibrotic markers.
• To compare the effects of Liraglutide and diet-induced weight loss on AT characteristics in Type 2 diabetes patients.

Main Methods:

• Randomized controlled trial involving 30 participants with Type 2 diabetes over 4 months.
• Interventions: Liraglutide treatment (n=22) or calorie restriction (n=8).
• Assessment of clinical parameters and repeated subcutaneous abdominal AT biopsies, including gene expression analysis.

Main Results:

• Liraglutide induced significant weight loss and reduced visceral AT (VAT), with superior fasting glucose reduction compared to diet.
• Liraglutide treatment increased AT expression of tumor necrosis factor-α (TNFA) and macrophage chemoattractant protein-1 (MCP-1), alongside elevated serum MCP-1 levels.
• Liraglutide also upregulated extracellular matrix (ECM) deposition factors, transforming growth factor-β (TGFB) and collagen type 1 alpha 1 chain (COL1A1) in AT.

Conclusions:

• Liraglutide treatment in Type 2 diabetes patients promotes AT inflammation and ECM remodeling, contrasting with calorie restriction.
• Despite benefits in weight loss and glycemic control, Liraglutide does not ameliorate obesity-related SCAT dysfunction.
• The inflammatory and fibrotic changes in AT induced by Liraglutide may have implications for lipid storage capacity and long-term metabolic health, particularly upon treatment cessation.