Preoperative GLP-1s Do Not Affect Bariatric Surgery Weight Loss

Bariatric surgery patients who used GLP-1 medications prior to their procedure experienced comparable weight loss at the one-year mark to individuals who had not been exposed to the drug class, according to a retrospective review. The study, published in the journal *Obesity Surgery*, analyzed data from 383 patients who underwent bariatric surgery between January 2022 and December 2023. Of these, 108 patients had used GLP-1 receptor agonists, such as semaglutide (Ozempic, Wegovy) or liraglutide (Victoza, Saxenda), within six months before surgery, while 275 patients had no prior GLP-1 exposure.

Researchers found that both groups achieved significant weight loss following bariatric surgery. The mean percentage of excess weight loss (%EWL) at 12 months post-surgery was 69.5% for the GLP-1 user group and 71.2% for the non-user group. This difference was not statistically significant, suggesting that preoperative GLP-1 use does not negatively impact the effectiveness of bariatric surgery in terms of weight reduction. The study controlled for several variables, including age, sex, body mass index (BMI) at the time of surgery, and type of bariatric procedure (sleeve gastrectomy or Roux-en-Y gastric bypass).

This finding challenges some clinical concerns that the potent weight-loss effects of GLP-1 agonists might lead to diminished outcomes from bariatric surgery, potentially by reducing visceral fat or altering gastrointestinal anatomy in ways that could interfere with the surgical intervention. The study's authors noted that GLP-1 medications are increasingly prescribed for weight management, and many patients are on these drugs when they consider or undergo bariatric surgery. The results provide reassurance to both clinicians and patients that continuing or initiating GLP-1 therapy before bariatric surgery is unlikely to compromise the long-term success of the procedure in achieving substantial weight loss.

Further research is recommended to explore the long-term effects beyond one year and to investigate potential differences in metabolic outcomes or complication rates between the two groups. The study's retrospective nature and the specific patient cohort are limitations, and prospective, randomized controlled trials would be beneficial to confirm these findings. However, this initial analysis offers valuable insights into the interplay between GLP-1 medications and bariatric surgery, suggesting a potentially synergistic or at least non-detrimental relationship in achieving significant weight loss.