Unraveling the Impact of BMI on Surgical Outcomes in the Elderly

Obesity is presenting a significant challenge to surgical outcomes in elderly patients, underscoring the immediate need for a deeper understanding of its influence on postoperative recovery.

The same BMI measures that categorize patients into differing risk levels also link to distinct recovery trajectories. Observational cohorts suggest that some elderly surgical populations with overweight have lower 30-day mortality compared with normal BMI peers, but findings are heterogeneous and may be influenced by confounding and surgical context. This concept is supported by findings suggesting survival benefits for overweight older adults.

Higher BMI reveals not only potential survival associations but also nuanced recovery differences in elderly surgical patients. The obesity paradox, as highlighted in a systematic review, has reported associations of higher BMI with lower short-term mortality; however, these associations may reflect residual and collider confounding and do not establish causality.

These studies point toward a nuanced understanding of obesity's dual role in surgical risk and recovery. Overweight (BMI 25–29.9 kg/m²) has been associated with lower short-term mortality in some cohorts, whereas obesity (BMI ≥30 kg/m²) is linked to higher perioperative complication rates (e.g., wound infection, cardiovascular events).

Such findings may be informing how clinicians prepare patients with higher BMI for surgery, including prehabilitation emphasis and OSA screening within ERAS pathways. Tailoring surgical strategies to address comorbid conditions is vital, promoting better postoperative trajectories.

For patients with high BMI, anesthesia presents unique challenges that can impact postoperative outcomes, with anesthesia society guidance emphasizing thorough airway evaluation, dosing by lean/ideal body weight, and screening for obstructive sleep apnea.

Advances in preoperative assessment techniques now allow tailored strategies that could improve surgical outcomes, such as incorporating frailty indices, STOP-Bang screening for obstructive sleep apnea, and cardiopulmonary exercise testing.

Taken together, evidence suggests overweight status may relate to lower short-term mortality, whereas obesity raises complication risk—underscoring the importance of tailored assessment, anesthesia planning, and comorbidity management. The next step is to integrate these insights into evolving surgical protocols to enhance patient safety. Current ERAS and ASA perioperative guidance address obesity broadly, but specific recommendations for geriatric patients remain limited. Future research should refine and adapt these frameworks to better serve older adults, aiming for improved surgical care for obese elderly patients.

Key Takeaways:

• BMI shapes outcomes in older surgical patients: some cohorts show lower short-term mortality with overweight, but obesity increases complication risk—supporting tailored perioperative strategies.
• Evidence on the obesity paradox remains associative and potentially confounded, warranting cautious interpretation and individualized care planning.
• Preoperative assessment advancements (frailty indices, STOP-Bang, CPET) offer opportunities to tailor surgical care and improve safety for older adults with higher BMI.