941. The effect of body mass index on the risk of Clostridium difficile infection in persons with inflammatory bowel disease
Session: Poster Abstract Session: Clostridium difficile Infections: Epidemiology and Diagnostics
Friday, October 9, 2015
Room: Poster Hall
Background: Clostridium difficile infection (CDI) is one of the leading causes of infectious diarrhea in hospitalized patients. Shifts in the normal gut flora that occur with antibiotic exposure, hospitalization and proton-pump inhibitor use could lead to decreased gut microbiome diversity and are thought to increase risk of CDI.  Inflammatory bowel disease (IBD) and body weight are also known to impact the gut microbiome and it has been hypothesized they may be associated with increased risk of CDI.

Methods: We conducted a retrospective case-cohort study to investigate the effect of body mass index (BMI) on risk and severity of CDI in recently hospitalized adults with inflammatory bowel disease from 2001-2012. A model was constructed to control for known risk factors of CDI including age, antibiotic exposure, length of hospitalization and proton-pump inhibitor use. 

Results: There were 68 cases of CDI in the 821 subjects included in the study. CDI occurred slightly more frequently in subjects with Ulcerative Colitis (9.5%) than those with Crohn’s disease (6.8%).  Only 12% of the total population had a low BMI, but prior to controlling for known risk factors of CDI, 13.5% of the low BMI group developed CDI versus 7.5% of the normal and 7.8% of high BMI groups.  Severe CDI, which occurred in 22% of the total cases, occurred more frequently in the low BMI group (38.5%) than the normal BMI (20%) or high BMI (13.3%) groups. Recurrent CDI (28% of the total cases) occurred more frequently in the higher BMI group (40%).

Conclusion: In patients with IBD, the type of bowel disease and their BMI may play a role in risk of CDI, severity of the initial infection and risk of recurrence with standard antibiotic treatment.

Amanda Thornton, MD, Infectious Disease, Boston Medical Center, Boston, MA, Gregory Patts, MPH, Boston University, Boston, MA, Janice Weinberg, ScD, Department of Medicine, Boston University, Boston, MA and Nahid Bhadelia, MD, MA, Boston Medical Center, Boston, MA


A. Thornton, None

G. Patts, None

J. Weinberg, None

N. Bhadelia, None

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