The Impact of Increased Body Mass Index on the Clinical Course of Crohn's Disease

Background & Aims: Tumor necrosis factor-α production in adipose tissue is well documented. Crohn's disease (CD) patients with increased adipose tissue may have more severe disease. This study evaluated overweight patients with CD to determine if their clinical course differs from those with a normal or low body mass index (BMI). Methods: Patients at the Hospital of the University of Pennsylvania from 1997 to 2002 were included. Data were collected from outpatient records and standardized interviews. Overweight was defined as a BMI of 25 kg/m2 or higher. The primary outcome was time to first surgery. Secondary outcomes included age at diagnosis, number of surgeries, and escalation of therapy. Patients with a BMI of 25 kg/m2 or higher at diagnosis were compared with patients with a BMI of less than 25 kg/m2 using statistical analyses. Survival analysis compared time to first surgery. Results: A total of 148 patients were included. Forty-eight (32.4%) had a BMI of 25 kg/m2 or higher at diagnosis. Patients with a BMI of 25 kg/m2 or higher were older at diagnosis; 35 years vs 22.5 years for patients with a BMI of less than 25 kg/m2 (P = .0001). The number of surgeries, escalation of therapy, and disease distribution did not differ between the 2 groups. A significant difference was found for time to first surgery, 252 months vs 24 months for patients with a BMI of less than 18.5 kg/m2 vs patients with a BMI of 25 kg/m2 or higher, respectively (P = .043). Conclusions: CD patients with a BMI of 25 kg/m2 or higher at diagnosis were older at diagnosis and had a shorter time to first surgery than those with a BMI of less than 18.5 kg/m2. This suggests that overweight CD patients require earlier surgical intervention and perhaps more aggressive medical therapy.