The Obesity Paradox in Emergency General Surgery Patients

Abstract

Operative management of emergency general surgery (EGS) diagnoses involves a range of procedures which can carry high morbidity and mortality. Little is known about the impact of obesity on patient outcomes. The aim of this study was to examine the association between body mass index (BMI) >30 kg/m2 and mortality for EGS patients. We hypothesized that obese patients would have increased mortality rates. A regional integrated health system EGS registry derived from The American Association for the Surgery of Trauma EGS ICD-9 codes was analyzed from January 2013 to October 2015. Patients were stratified into BMI categories based on WHO classifications. The primary outcome was 30-day mortality. Longer-term mortality with linkage to the Social Security Death Index was also examined. Univariate and multivariable analyses were performed. A total of 60 604 encounters were identified and 7183 (11.9%) underwent operative intervention. Patient characteristics include 53% women, mean age 58.2 ± 18.7 years, 64.2% >BMI 30 kg/m2, 30.2% with chronic obstructive pulmonary disease, 19% with congestive heart failure, and 31.1% with diabetes. The most common procedure was laparoscopic cholecystectomy (36.4%). Overall, 90-day mortality was 10.9%. In multivariable analysis, all classes of obesity were protective against mortality compared to normal BMI. Underweight patients had increased risk of inpatient (OR = 1.9, CI = 1.7-2.3), 30-day (OR = 1.9, CI = 1.7-2.1), 90-day (OR = 1.8, CI 1.6-2.0), 1-year (OR = 1.8, CI = 1.7-2.0), and 3-year mortality (OR = 1.7, CI = 1.6-1.9). When stratified by BMI, underweight EGS patients have the highest odds of death. Paradoxically, obesity appears protective against death, even when controlling for potentially confounding factors. Increased rates of nonoperative management in the obese population may impact these findings.

The impact of obesity on outcomes in patients undergoing emergency cholecystectomy for acute cholecystitis

“…37 Interestingly, recent studies suggest obesity is protective against mortality in emergency abdominal operations. 38,39 Maloney et al found that when stratified by weight, overweight and obese emergency surgical patients had a decreased risk of mortality compared to normal weight emergency surgery patients and underweight individuals had the highest risk of overall mortality. 38 Similar findings were reported by Benjamin et al, which found that only underweight and morbidly obese patients experienced greater postoperative complications.…”

“…38,39 Maloney et al found that when stratified by weight, overweight and obese emergency surgical patients had a decreased risk of mortality compared to normal weight emergency surgery patients and underweight individuals had the highest risk of overall mortality. 38 Similar findings were reported by Benjamin et al, which found that only underweight and morbidly obese patients experienced greater postoperative complications. 39 It has been theorized that adipose tissue plays an immunomodulatory role in the sequestration and neutralization of endotoxins thus offering protection against mortality in obese patients undergoing emergency general surgery.…”

“…Evaluating these outcomes more closely in the obese population is important as obesity was previously identified as a risk factor for conversion to open surgery in those undergoing emergency LC 37 . Interestingly, recent studies suggest obesity is protective against mortality in emergency abdominal operations 38,39 . Maloney et al .…”

Impacts of Metabolic Disorders on short- and long-term mortality after coronary artery surgery in the elderly

“…Moreover, higher BMI is associated with higher rates of thromboembolism, wound infections and blood loss perioperatively, so as to increase the in-hospital duration and the death rate after cardiac surgeries [10][11][12] . However, further in-depth studies show opposite results [13][14][15] . Overweight and obesity bene t the short-term or long-term survival after CABG [16,17] .…”

Impacts of metabolic disorders on short- and long-term mortality after coronary artery surgery in the elderly

“…Moreover, higher BMI is associated with higher rates of thromboembolism, wound infections and blood loss perioperatively, so as to increase the in-hospital duration and the death rate after cardiac surgeries [ 14 – 16 ]. However, further in-depth studies showed the opposite results [ 17 – 19 ]. Researchers have found the beneficial impact of overweight and obesity on the prognosis of CABG [ 20 , 21 ], which is called the “obesity paradox”.…”