699 Role of C-Reactive Protein as a Marker for Disease Course in Obese Patients With Inflammatory Bowel Disease

Abstract

INTRODUCTION: Currently, the disease course and clinical outcomes of obese patients with inflammatory bowel disease (IBD) have been mixed. This study aims to compare biomarkers of inflammation such as erythrocyte sedimentation rate (ESR) and c-reactive protein (CRP) in both obese and non-obese African American (AA) and Caucasian populations. METHODS: We conducted a prospective observational study of consecutive Crohn's disease (CD) and ulcerative colitis (UC) patients in the outpatient setting at a tertiary referral center between 2014-2017. Body mass index (BMI), ESR, CRP, hemoglobin (Hgb) were measured at 2 consecutive visits. Obesity was defined as a BMI ≥30. The Wilcox signed rank test was used to compare continuous variables, and the Chi square test for categorical variables. A multivariate logistic regression model was created to look at change in CRP (no change, increase by half, decrease by half) from initial to follow-up visit. The regression model analysis included ethnicity, gender, BMI, type of IBD (CD versus UC), age, alcohol use, tobacco use, hypertension, kidney disease, heart disease, and treatment as covariates. RESULTS: The study included 92 subjects, 65% had CD and 30% were AA (Table 1). The average time between visits was 136 days. In the obese group, 33% were AA and 70% were female. Also, a larger portion of CD patients were obese compared to UC patients (37% and 11% respectively with P = 0.03). There was a significant decrease in the CRP in the obese group (P = 0.029) whereas non-obese individuals had an increase in CRP (Table 2). There was no significant difference in ESR and hemoglobin (Hgb) between obese and non-obese individuals. 63 patients where included in the regression model, which showed that a decrease in CRP was significantly associated with obesity (P = 0.0081) when adjusted for the above covariates. Overall, obese individuals were more likely to experience no change in CRP or a decrease in CRP while non-obese individuals were more likely to have a rise in CRP. There was no difference in clinical disease activity indices (HBI/SCCAI) between obese and non-obese patients. CONCLUSION: In our study, the obese patients were more likely to be female, have CD, and be Caucasian. While there was no difference in Hgb or ESR in obese versus non-obese, there is a difference in CRP. CRP could have importance as a sensitive marker for disease course in patients whose BMI ≥30. A larger cohort may provide further insight into this observation.