Is obesity a risk factor for Clostridium difficile infection?

Summary Background The epidemiology of Clostridium difficile infection (CDI) has become an important area of investigation, especially in light of the global increase in both hospital-acquired (HA) and community-acquired (CA) CDI. Recently, obesity was found to be associated with CDI and was suggested to represent an independent risk factor for it. Objective We undertook a case–control study to examine obesity as an exposure for both HA and CA cases in adults (age ≥ 18 years) admitted to a tertiary, university-affiliated, acute care medical facility in the northeastern United States. Methods During the period January 2012–July 2013, we examined cross-sectional BMI data on 189 cases of CDI and 189 contemporaneous age and gender-matched controls. Results We were unable to detect a statistically significant difference between the two groups; in fact, the BMI values for both groups were substantially equivalent (cases: median = 26.5 kg/m, IQR: 22.1–32.5; controls: median = 26.0, IQR: 22.7–31.0; p = 0.696). Odds ratios (and 95% confidence intervals), evaluated at BMI of 25, 30 and 35 kg/m2 , did not demonstrate statistical significance. Conclusion These data suggest that obesity, as described by BMI, may not be a risk factor for CDI in all populations.