Obesity Paradox in patients with necrotizing soft tissue infections: A Validation Study

Author(s):
Ricardo Fonseca; Jose Aldana; Rohit Rasane; Christina X Zhang; Javier Rincon; Adrian Coleoglou Centeno; Qiao Zhang; Kelly Marie Bochicchio; Obeid Ilahi; Grant Bochicchio

Background:

The “Obesity Paradox” is well-studied and documented in chronic diseases. Recent studies have reported an association between obesity and reduced in-hospital mortality in patients with soft tissue infections. The purpose of this study was to validate those findings.

Hypothesis:

We hypothesize that obesity is associated with a protective benefit in necrotizing soft infections (NSTI).

Methods:

Patients with NSTI were identified from a prospectively maintained Acute and Critical Care Surgery (ACCS) database from 2008-2018. We then categorized patients according to their Body Mass Index (BMI) into non-obese [BMI <30], obese [BMI >=30] and morbidly-obese [BMI >=40]. Demographics, Charlson Score (CS) and outcomes were compared using Pearson’s chi-squared test (χ2), Fisher’s Exact Test and Student’s t-test. Linear regression analysis was used to determine an association between obesity and outcomes [Surgical Intensive Care Unit (SICU) admission, Length of Stay (LOS) and ventilator days].

Results:

A total of 335 patients were diagnosed with NSTI (non-obese = 149, obese = 100, morbid-obese = 86). There was no difference in demographics or CS among any groups. Obesity did not impact mortality, even when comparing non-obese against morbidly-obese (odds ratio [OR] = 1.140; 95% confidence interval [CI] = 0.41 to 3.20; P=0.94). SICU LOS was greater with increasing BMI (3.6 ± 5.7 vs 4.8 ± 7.1 vs 6.0 ± 7.7 days) when comparing non-obese, obese and morbidly-obese patients respectively. Morbidly-obese patients had a significantly longer SICU LOS than non-obese patients (P=0.012).

Conclusions:

Obesity did not provide any protective benefits to NSTI patients.  In contrast to recent reports in support of the obesity paradox, we found that morbidly-obese patients had a worse outcome. Further research is needed to validate our findings.