Impact of Obesity on Postoperative and Long-term Outcomes in a General Surgery Population: A Retrospective Cohort Study
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The obesity paradox has been demonstrated postoperatively in several surgical populations, but only a few studies have reported long-term survival. This study evaluates the presence of the obesity paradox in a general surgery population, reporting both postoperative and long-term survival.
This retrospective study included 10,427 patients scheduled for elective, noncardiac surgery. Patients were classified as underweight (body mass index (BMI) < 18.5 kg/m2); normal weight (BMI 18.5–24.9 kg/m2); overweight (BMI 25.0–29.9 kg/m2); obesity class I (BMI 30.0–34.9 kg/m2); obesity class II (BMI 35.0–39.9 kg/m2); and obesity class III (BMI ≥ 40.0 kg/m2). Study endpoints were 30-day postoperative and long-term mortality, including cause-specific mortality. Multivariable analyses were used to evaluate mortality risks for each BMI category.
Within 30 days after surgery, 353 (3.4 %) patients died. Overweight was the only category associated with postoperative mortality, showing improved survival [odds ratio 0.7; 95 % confidence interval (CI) 0.6–0.9]. During the long-term follow-up 4,884 (47 %) patients died. Underweight patients had the highest mortality risk [hazard ratio (HR) 1.4; 95 % CI 1.2–1.6), particularly due to high cancer-related deaths. In contrast, overweight and obese patients demonstrated improved survival (overweight: HR 0.8, 95 % CI 0.8–0.9; obesity class I: HR 0.7, 95 % CI 0.7–0.8; obesity class II: HR 0.7, 95 % CI 0.6–0.9; obesity class III: HR 0.7, 95 % CI 0.5–1.0), mainly because of a strongly reduced risk of cancer-related death.
In this surgical population the obesity paradox was validated at the long term, mainly because of decreased cancer-related deaths among obese patients.
KeywordsBody Mass Index Chronic Obstructive Pulmonary Disease Obese Patient Body Mass Index Category Baseline Body Mass Index
Dr. Valentijn is supported by an unrestricted research grant from “Lijf en Leven,” Rotterdam, The Netherlands.
Conflict of interest
The authors declare no conflicts of interest.
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