Body Mass Index and Postsurgical Outcomes in Older Adults

Area of Science:

• Geriatric Medicine
• Surgical Outcomes Research
• Obesity and Health

Background:

• High body mass index (BMI) is linked to increased postoperative complications in the general population.
• Aging and frailty can alter body composition, potentially modifying the BMI-surgical outcome relationship in older adults.

Purpose of the Study:

• To investigate the association between higher BMI and all-cause mortality rates in older adults undergoing major elective surgery.
• To determine if BMI thresholds for adverse surgical outcomes differ in the aging population.

Main Methods:

• Observational cohort study of 414 adults aged 65+ undergoing major elective surgery.
• Analysis of 30-day and 1-year all-cause mortality, delirium, discharge disposition, and Clavien-Dindo complications.
• Body Mass Index (BMI) was the primary exposure, categorized as underweight, normal, overweight, and obese.

Main Results:

• Overweight patients (BMI 25.0-29.9) exhibited the lowest 30-day mortality (0.8%) compared to normal BMI (18.8%), a significant reduction (OR 0.03).
• Underweight patients (BMI <18.5) had the highest 30-day mortality rate (75.0%).
• The association of overweight BMI with reduced mortality remained significant after multivariable adjustment (OR 0.14).

Conclusions:

• In older adults undergoing major elective surgery, being overweight is associated with a lower risk of 30-day mortality.
• Current preoperative weight loss recommendations may require reevaluation for the aging surgical population, considering the potential benefits of a higher BMI.