Presence of Hypoalbuminemia Blunts the Obesity Paradox in Emergency General Surgery Outcomes

Authors:
Anahita Jalilvand, George Abboud, Holly Baselice, Jonathan Wisler, Patrick Kennedy

Body of Abstract:
Background: In patients undergoing emergency general surgery (EGS), patients with obesity demonstrate paradoxically lower mortality compared to non-obese individuals. However, malnutrition and frailty are often under-recognized in those with obesity and negatively impact surgical morbidity. Serum hypoalbuminemia can reflect malnutrition and chronic inflammation. The objective of this study was to determine how preoperative hypoalbuminemia modulates the obesity paradox in EGS patients.

Methods: We conducted a retrospective review of 366 EGS patients at a large volume tertiary academic center (2011-2015). Patients were analyzed by obesity status (obese and non-obese) and presence of admission hypoalbuminemia (albumin <3.5), generating four cohorts representing obese and non-obese patients with and without hypoalbuminemia. Demographic, socioeconomic, and laboratory data were compared between groups. Overall morbidity, systemic and surgical outcomes, hospital characteristics, and mortality data were assessed between groups. A p value <0.05 was significant. Results: The prevalence of hypoalbuminemia was similar between obese and non-obese cohorts (41% vs 43%, p = 0.60). Incidence of sepsis was comparable between obese and non-obese patients (18% vs 22%, p = 0.28) but significantly associated with hypoalbuminemia (OR 7; 95th CI: 3.8-11.7). There was no difference in the preoperative diagnosis between obese and non-obese patients (p=0.38). In the non-hypoalbuminemia cohort, obesity was associated with reduced overall morbidity (21% vs 36%, p=0.02), length of stay (LOS, 6 vs 8, p = 0.01), and trended towards decreased systemic complications (18.6% vs 30%, p = 0.07) compared to non-obese patients. For patients with hypoalbuminemia, obesity was not associated with morbidity (68% vs 66%), systemic complications (61% vs 64%), or median LOS (13 vs 12, p = 0.41). While higher 90-day mortality was associated with hypoalbuminemia (33% vs 8%, p <0.05), obesity status was not associated with a significant difference in mortality within the hypoalbuminemia cohort (27% vs 35%, p=0.28) or the control albumin cohort (4.6% vs 8%, p = 0.4). Conclusions: Hypoalbuminemia was highly prevalent in patients with and without obesity. These data suggest that malnutrition and medical frailty may be important drivers of outcome regardless of BMI. While our study demonstrates that increasing BMI may be protective for certain EGS outcomes for patients with normal albumin levels, the presence of hypoalbuminemia significantly blunts the obesity paradox.