Quantitative Comparison of Glucagon-Like Peptide-1 Receptor Agonists on Weight Loss in Adults: A Systematic Review and Model-Based Meta-Analysis

The objective of this study is to quantitatively compare the weight loss effects of glucagon-like peptide-1 receptor agonists (GLP-1RAs) in adult patients with no diabetes and type 2 diabetes (T2D). PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and Embase have been used as data sources from database inception to January 6, 2024. A total of 137 trials, encompassing 310 treatment arms, 17 GLP-1RAs, and 56,683 patients, were included in the analysis. The included trials were divided into three groups based on the characteristics of the populations: nondiabetic overweight or obesity group (NDOOG), type 2 diabetes Caucasian group (T2DCG), and type 2 diabetes Asian group (T2DAG). The effects of covariates were further evaluated, patients with a higher baseline body weight tend to have better weight loss outcomes, and patients with a higher baseline glycated hemoglobin (HbA1c) tend to achieve better blood sugar control. Five mathematical models were subjected to longitudinal analysis. In terms of Δ body weight, retatrutide (12 mg qw) was the most effective treatment (mean difference = -26.56% [95% confidence interval: -43.89% to -3.01%]). Tirzepatide (15 mg qw) demonstrated good weight loss ability in all three ΔBW models, ΔBW-NDOOG (-22.76% [-26.45% to -18.50%]), ΔBW-T2DCG (-11.09% [-12.39% to -9.44%])), and ΔBW-T2DAG (-4.97% [-5.84% to -4.12%]). In the aspect of ΔHbA1c, tirzepatide (10 mg qw) and oral orforglipron (10 mg qd) were the most effective drug, respectively. GLP-1RAs demonstrated effective weight management in both nondiabetic and T2D populations. Retatrutide achieved the most pronounced weight reduction, followed by tirzepatide. GLP-1RAs also significantly improved glycemic control for patients with T2D, with tirzepatide performing the best for glycemic control.