JAMA Netw Open

Higher BMI tied to lower 30-day mortality in older surgical patients

September 3, 2025

Study details: This cohort study analyzed 414 adults aged ≥65 years undergoing major elective surgery at a Southern California academic center (2019–2022). Researchers examined associations between BMI categories and postsurgical outcomes, including mortality, delirium, discharge disposition, and complications.

Results: Patients in the overweight BMI category (25.0–29.9) had the lowest 30-day mortality rate (0.8%), compared with normal weight (18.8%) and underweight (75.0%) groups. The protective effect of overweight status remained significant after adjusting for age, frailty, comorbidities, and cancer status.

Clinical impact: Moderate excess weight may confer short-term survival benefits in older surgical patients. These results challenge conventional preoperative weight loss recommendations and highlight the need to individualize surgical risk assessments based on geriatric physiology rather than standard BMI thresholds.

Source:

Canales C, et al. (2025, August 1). JAMA Netw Open. Body Mass Index and Postsurgical Outcomes in Older Adults. https://pubmed.ncbi.nlm.nih.gov/40857003/