Gastric antral injections of botulinum toxin delay gastric emptying but do not reduce body weight.

Background & Aims: Gastric injections of botulinum toxin A (BTA) have been reported to delay gastric emptying, increase satiation, and reduce body weight, but there are few data from randomized, placebo-controlled studies.

Methods: We enrolled 60 obese participants in a 24-week, double-blind, randomized, placebo-controlled, concealed allocation trial to compare the effects of gastric antral injections of BTA (100, 300, or 500 U) and saline placebo. The study was conducted at an outpatient clinical research unit. Participants were given one set of injections of BTA or placebo into the gastric antral muscularis propria by using endoscopic ultrasound guidance. Gastric emptying of solids was measured by scintigraphy; we also measured body weight, satiation (maximum tolerated volume in a caloric liquid drink test), calorie intake (by food frequency questionnaire), gastrointestinal symptoms, and psychological aspects of eating behavior (by rating scale).

Results: Compared with baseline values, 2 weeks after injections, the mean half-time for gastric emptying of solids increased by 0.8, 14, 24, and 14 minutes among subjects given placebo, 100, 300, or 500 U BTA, respectively (P = .24 overall, P = .04 for the group given 300 U vs placebo); 16 weeks after the injections, mean body weights were reduced by 2.2, 0.2, 2.3, and 3.0 kg in these groups, respectively. There were no statistically significant differences in mean body weight change, satiation volume, caloric intake, gastrointestinal symptoms, or psychological aspects of eating behavior among groups.

Conclusions: Gastric antral injections of BTA may delay gastric emptying at a dose of 300 U but do not cause early satiety, altered eating behaviors, or loss of body weight. Clinicaltrials.gov identifier: NCT00976443.