Intragastric injection of botulinum toxin. A real alternative for obesity treatment? A systematic review

Background: Obesity is a prevalent disease in our environment, which comorbidities suppose a great challenge to public health. Intragastric injection of botulinum toxin has been used as treatment for obesity, both in humans and animals. It acts by inhibiting gastric emptying and inducing early satiety, consequently reducing intake and finally achieving weight loss. Materials and methods: A bibliographic search in PubMed, Scopus and EMBASE databases between 2000 and 2016 was carried out. Articles regarding the physiological basis of the treatment with intragastric injection of botulinum toxin in human were included, as well as interventional studies, randomised or not. Results: A total of 105 articles were found and 10 were chosen according to our inclusion criteria. Of those, only 4 were randomised and 8 lasted between 8 and 24 weeks. In four of the studies, one randomised, a statistically significant weight loss was found which varied between 3.5 and 11.8 kg. Most of the studies found slowing of gastric emptying. None of them notified any significant side-effects. Conclusion: Intragastric injection of botulinum toxin could be useful and safe in the treatment of obesity but better designed, placebo-controlled, long term and with an adequate sample size studies are needed.