Bariatric Surgery Complications Increase With Initial Body Mass Index

TUESDAY, July 1, 2025 (HealthDay News) — The higher a person’s body mass index (BMI), the higher their risk for complications after bariatric surgery, such as higher rates of emergency department visits and readmissions, according to a study presented at the annual meeting of the American Society for Metabolic and Bariatric Surgery (ASMBS), held from June 15 to 19 in Washington, D.C.

Nicholas Dahlgren, M.D., from University of South Carolina in Columbia, and colleagues compared the complication and readmission rates of bariatric surgical procedures between BMI classes. The analysis included 665,047 patients undergoing sleeve gastrectomy or Roux-en-Y gastric bypass from 2020 to 2023.

The researchers found that complication risk increased with each BMI category. For the lowest versus highest BMI category, the rate of complications increased by an average of 5.56 percent, and serious occurrences rose 3.21 percent. Additionally, patients with BMI ≥50 kg/m² had significantly higher mortality rates, as well as any serious or other intraoperative or perioperative complication occurrence. For those with BMI ≥50 kg/m², significantly higher rates of emergency department visits and readmissions were also seen. 

“While complication rates are generally low, this study provides granular data not previously reported that can help with preoperative counseling and to make surgery even safer and patient outcomes even better,” Richard M. Peterson, M.D., M.P.H., president-elect of the ASMBS, said in a statement.

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