Role of obesity in postoperative inflammatory response

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: SUN 690-701-Obesity Pathophysiology
Translational
Sunday, June 16, 2013: 1:45 PM-3:45 PM
Expo Halls ABC (Moscone Center)

Poster Board SUN-695
Roja Motaghedi*1, James J Bae2, Michael A Gordon2, Jacques T Ya Deau2, Starvor G Memtsoudis2, Susanna Cunningham-Rundles3 and Spencer S Liu2
1Children's Hospital of Seatt, Seattle, WA, 2Hospital for Special Surgery, New York, NY, 3Weill Cornell Medical College, New York, NY
Background: Obesity is increasing at an alarming rate, and often leads to degenerative joint disease requiring surgery such as total hip replacement (THR). Since obesity is considered an inflammatory state, and the magnitude of postoperative inflammatory response has been associated with postoperative organ dysfunction, infection and morbidity, we examined the inflammatory response after THR in obese subjects.

Methods: After institutional approval and written informed consent were obtained, 60 male and female aged of 18 to 85 (20 subjects normal weight, 20 overweight and 20 obese) undergoing elective primary unilateral THR were enrolled in this prospective cross-sectional study. Blood samples were collected for fasting insulin, glucose, C- Reactive Protein (CRP) and cytokine levels, including IL-1b, IL-2, IL-6, IL-8 and TNF-α from subjects prior to and 24 hours after the surgery. Cytokine response was evaluated in vitro with two activators Phorbol 12-Myristate 13 Acetate (PMA), Lipopolysaccharide (LPS) and media alone using blood samples from subjects at 24 hours.  

Results: There was no death or major morbidity in any of subjects. Preoperative circulatory levels of CRP were <1.0 and rose modestly after surgery (4.6 ± 5.2).  Levels of IL-1b and IL-2 were negligible before and after surgery while low and moderate levels of TNF-α did not change within patients confirming that procedures were minimally traumatic. In contrast IL-6 and IL-8 increased significantly in all patients (p<0.001). IL-6 is a predictor of pain and IL-8 was implicated in local inflammatory response in this setting. No significant correlation was found between Body Mass Index (BMI) and postoperative circulatory cytokine levels. However, there was a significant positive correlation between the BMI and IL-1b, IL-6 and TNF-α levels (r=0.26-0.32, P<0.05), and borderline significant correlation between BMI and IL-8 after leukocyte activation with LPS suggesting that Toll-Like Receptor-4-mediated response was affected by obesity.  Insulin resistance (homeostatic model assessment) was not associated with increased cytokines after surgery.

Conclusion: Obesity, independent of insulin resistance is associated with inflammatory response and altered cytokine reactivity after THR. Since inflammatory response plays a major role in pain, healing and mortality during the postoperative period, larger studies exploring the specific impact of obesity and inflammation on surgical outcomes are warranted.

Nothing to Disclose: RM, JJB, MAG, JTY, SGM, SC, SSL

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

Sources of Research Support: This work was supported by a grant from Hospital for Special Surgery, Department of Anesthesiology and Clinical Traslational Science Center at Weill Cornell Medical College.