Intragastric injection of botulinum toxin A for weight loss: A systematic review and meta-analysis of randomized controlled trials.

[BACKGROUND AND AIM] Intragastric botulinum toxin A (BTA) injection is a potential treatment for weight reduction in obese patients. Current studies yielded conflicting results. We performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the efficacy of intragastric BTA injection for weight management.

[METHODS] We searched several databases to identify RCTs evaluating intragastric BTA injections for obesity. We applied random-effects models for all meta-analyses due to heterogeneity in the included studies. The mean difference (MD) and 95% confidence interval (CI) were calculated for continuous outcomes.

[RESULTS] A total of 6 RCTs including 192 subjects met the inclusion criteria and were included for the meta-analysis. Although the pooled data from six studies showed no difference in the absolute weight loss between intragastric BTA injection and control, subgroup analysis showed a significantly decreased absolute weight after a BTA injection dose ≥ 200 U (MD, -2.04 kg; 95% CI, -3.96 to -0.12) and after multiple injection regions in the stomach combined with diet control (MD, -4.44 kg; 95% CI, -6.54 to -2.33 kg) compared with the control. Regarding absolute weight loss, the impact of endoscopic ultrasound-guided injection and follow-up duration showed no difference. Intragastric BTA injection had a significant change in body mass index (MD, -1.25 kg/m ; 95% CI, -2.18 to -0.32 kg/m ) and prolonged gastric half-emptying time (MD, 11.37 min; 95% CI, -3.69 to 19.06 min).

[CONCLUSION] Intragastric BTA injection is effective for obesity treatment, and adequate doses (≥ 200 U), multiple gastric injection regions, and combined diet control are crucial. However, given the small sample size and limited power, caution should be exercised.