Effect of intragastric injection of botulinum toxin A for the treatment of obesity: A meta-analysis and meta-regression

Background Controversies persist regarding the effect of intragastric injection of botulinum toxin A for the treatment of obesity. Objective To assess the efficacy of intragastric botulinum toxin injection for the treatment of obesity. Design A systematic literature review was conducted by using the core databases. Pre-and posttreatment body weight data were extracted and analyzed by using Hedges' g. A random-effects model was applied. The methodological quality of the enrolled studies was assessed by the risk of bias table and Newcastle-Ottawa Scale. Publication bias was evaluated via the funnel plot, trim and fill method, Egger's test, and rank correlation test. Setting Meta-analysis of 8 studies. Patients A total of 115 patients (79 treated vs 36 placebo). Intervention Intragastric botulinum toxin A injection. Main Outcome Measurements Hedges' g, calculated from pre-and posttreatment body weight data and comparison of body weight changes between treatment and placebo group. Results The treatment group was associated with weight loss in a pre/post comparative approach and compared with the placebo group (Hedges' g:-0.443; 95% confidence interval,-0.845 to-0.040; P =.031; and Hedges' g:-0.521; 95% confidence interval,-0.956 to-0.085; P =.019). Wide area injection including the fundus or body rather than the antrum only was associated with weight loss. Multiple injections (>10) were associated with weight loss. However, a large amount of botulinum toxin A (500 IU) was not associated with weight loss. Sensitivity analyses showed consistent results. Meta-regression for the botulinum toxin A dose and number of injections showed consistent results. Publication bias was not detected. Conclusion In this analysis, intragastric injection of botulinum toxin A is effective for the treatment of obesity.