GLP-1 receptor agonists as an adjunct to bariatric surgery for weight loss and metabolic outcome improvement: a systematic review and meta-analysis
Yee Wen Tan, Mengge Shang, Sean Davis, Sivakumar Gananadha
Abstract
Glucagon-Like- Peptide-1 (GLP-1) receptor agonist has an emerging role in obesity management. This meta-analysis and systematic review evaluated the effectiveness of GLP-1 receptor agonists in aiding weight loss and enhancing cardiometabolic health in patients with insufficient weight loss (IWL) or weight regain (WR) after bariatric surgery. METHODS: A comprehensive literature search (PubMed, Medline, Embase, Cochrane) was conducted following PRISMA guidelines. Included studies involved adults (≥18 years) treated with GLP-1 agonists either before or after bariatric surgery. Primary outcomes assessed were weight and BMI changes; secondary outcomes included metabolic improvements and adverse effects. RESULTS : 19 studies were included in the systematic review and meta-analysis. All included study involves at least one type of GLP-1 agonist for IWL or WR after bariatric surgery with duration of intervention between 3 months to 24 months. All studies showed significant weight and BMI changes from baseline after initiation of different types of GLP-1 agonist, with effects proportionate to length of intervention. Semaglutide outperformed liraglutide in achieving ≥10% and ≥15% weight loss post-surgery. Tirzepatide, a newer GLP-1/GIP agonist, showed even greater weight loss compared to semaglutide over 6 months. A systematic review of 6 studies on the metabolic effects of GLP-1 receptor agonists (RA) post-bariatric surgery highlighted significant improvements in glycemic control, blood pressure, cholesterol levels, and liver function. Adverse effects were mostly mild gastrointestinal symptoms with no severe events reported. CONCLUSION: GLP-1 agonists have emerged as a promising alternative to revisional surgery for patients experiencing insufficient weight loss (IWL) or weight regain (WR) after bariatric surgery. Tirzepatide, the newest GLP-1 /GIP agonist, has shown superior results compared to liraglutide and semaglutide. However, more long-term randomized controlled trials are needed to confirm these findings and further assess its effectiveness. Despite this, GLP-1 agonists consistently demonstrate significant weight loss and cardiometabolic improvements when compared to placebo or lifestyle modifications, making them a valuable treatment option for post-bariatric surgery patients.