New Research Challenges BMI Guidelines: Overweight Older Adults Show Lower Post-Surgery Mortality Risk

Recent research indicates that older adults who are classified as overweight may have a lower risk of mortality within the first 30 days after major elective surgery compared to those with normal or underweight BMI levels. Published in JAMA Network Open, the study analyzed data from 414 seniors undergoing significant surgeries at a major Southern California medical center between February 2019 and January 2022. Findings revealed that individuals with a BMI between 25 and 29.9, considered overweight, experienced a remarkably low 0.8% 30-day mortality rate, whereas normal-weight patients faced an 18.8% rate, and underweight patients experienced a 15% rate. Even after adjusting for variables like age, frailty, and health conditions such as cancer, the trend persisted. This phenomenon supports the concept of the 'obesity paradox,' suggesting that in older populations, a slightly higher BMI might offer protective benefits in the short-term postoperative period.

Lead researcher Dr. Cecilia Canales from UCLA emphasized that traditional surgical guidelines, which favor a normal BMI prior to surgery, may need revision for the elderly, considering unique physiological changes with age. Dr. Catherine Sarkisian, another expert involved in the study, noted that these findings could influence preoperative assessments and risk evaluations, which are typically based on data from younger or mixed-age groups. The study underscores the importance of personalized evaluation in surgical planning for older adults and advocates for further research into the underlying biological mechanisms of this association.