GLP-1 Receptor Agonists.
This review article provides a comprehensive overview of glucagon-like peptide-1 (GLP-1) receptor agonists, a class of incretin-based therapies used in the management of type 2 diabetes mellitus and obesity. The authors describe the multiple mechanisms of action of these agents, including glucose-mediated insulin stimulation, slowing of gastric emptying, glucagon inhibition, favorable shifts in the intestinal microbiome, and direct hypothalamic effects that promote satiety and weight loss. The review highlights findings from large-scale randomized controlled trials demonstrating that GLP-1 receptor agonists can reduce cardiovascular risk and slow progression to renal failure in high-risk individuals and those with type 2 diabetes. It also covers dual GLP-1 and glucose-dependent insulinotropic peptide (GIP) agonists. The authors note that adverse effects are predominantly gastrointestinal and raise concerns about potential loss of muscle and bone mass. Unresolved questions include long-term treatment adherence, weight regain following discontinuation, and the clinical significance of muscle and bone changes. Emerging research is exploring additional therapeutic applications. As a narrative review, it does not present original data, which limits its direct evidentiary weight.
Why this grade: This is a narrative review article that synthesizes existing literature, including RCT data, rather than generating original clinical trial evidence itself.
Glucagon-like peptide-1 (GLP-1) receptor agonists are incretin analogues that promote glucose-mediated insulin release and are used to treat type 2 diabetes mellitus and obesity. GLP-1 receptor agonists and GLP-1 and glucose-dependent insulinotropic peptide agonists have several mechanisms of action, including reduction of gastric emptying, inhibition of glucagon secretion, beneficial changes in the intestinal microbiome, and direct effects on hypothalamic nuclei to enhance satiety (which promotes weight loss). Beyond the impressive effects of GLP-1 receptor agonists on blood glucose levels and body weight, large-scale randomized, controlled trials have shown that GLP-1 receptor agonists reduce cardiovascular risk and slow progression to renal failure in persons at high risk and those with type 2 diabetes. Adverse side effects from GLP-1 receptor agonists are mostly gastrointestinal but may also include loss of muscle and bone mass. Questions remain about long-term adherence, weight regain after discontinuation of treatment, and the functional implications of the loss of muscle and bone mass. Recent and ongoing targeted studies suggest the possibility of additional uses for GLP-1 receptor agonists.
Educational summary of published research — not medical advice. Full text is shown only where licensing permits.