Body mass index greater than 35 is associated with severe Clostridium difficile infection

Background: Obesity has been implicated in the acquisition of Clostridium difficile infections (CDI), however, no study has investigated whether there is a correlation between body mass index (BMI) and CDI severity. Aim: To determine whether obesity, as measured by BMI correlates with severe hospital-onset or community-onset CDI. Methods: Patients admitted with CDI at a tertiary-care center from January 2013 to June 2015 were identified. The cohort was stratified by onset of disease using the National Healthcare Safety Network criteria, and by severity using the 2013 American College of Gastroenterology guidelines. Multivariate logistic regression was used to determine independent predictors of severe CDI. Results: A total of 196 met the inclusion criteria, of which 57.1% (112) met criteria for severe disease. Overall, BMI >35 kg/m² was 1.7-fold more likely to be associated with severe CDI compared to a BMI 20–35 kg/m² (P < 0.005), and was an independent predictor of severe CDI (P = 0.038). In patients with community-onset-CDI and hospital-onset-CDI, a BMI >35 kg/m² was associated with a 1.96-fold and 1.48 greater rate of severe CDI compared to a BMI 20–35 kg/m² (P = 0.004 and 0.048), and was an independent predictor of severe CDI in these cohorts (P = 0.039 and 0.027) respectively. Conclusion: This study has identified an association between body mass index and Clostridium difficile infection severity. A BMI>35 kg/m² is an independent risk factor for severe community-onset and hospital-onset Clostridium difficile infections.