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.