February 23, 2021
What impact does obesity have on IBD disease activity and outcomes?
Obese patients with Crohn’s disease face a more complicated disease course, and may be candidates for both close monitoring and early therapy.
Greuter T, Porchet F, Braga-Neto MB, et al. Impact of obesity on disease activity and disease outcome in inflammatory bowel disease: Results from the Swiss inflammatory bowel disease cohort. United Eur Gastroenterol J. 2020;8(10):1196–07; https://doi.org/10.1177/2050640620954556
Swiss and American researchers retrospectively studied data from 325 IBD patients with obesity and 1,725 IBD patients with normal weight. The patients had enrolled in a prospective Swiss IBD cohort between 2006 and 2018. Obesity was defined as a body mass index (BMI) of 30 kg per m2 or higher, while normal weight was defined as a BMI of 18.5–24.9 kg/m2.
IBD patients with obesity were older at the time of diagnosis than IBD patients with a normal weight (mean 31 and 25 years for Crohn’s disease (CD) patients with or without obesity, respectively, and 34 and 29 years for ulcerative colitis (UC) patients with or without obesity; p<0.001 for both). UC patients with obesity were more likely to be male (60.3% vs. 47.2%; p=0.006) and CD patients with obesity were less likely than their counterparts with normal weight to receive corticosteroids (39.7% vs. 48.6%; p=0.023).
Average Crohn’s Disease Activity Index (CDAI) scores were significantly higher among CD patients with obesity than CD patients with normal weight (CDAI: 33 vs. 20 for obese and normal weight, respectively; p=0.001). CD patients with obesity also had higher mean C-reactive protein levels (5 vs. 3 mg per liter; p<0.001) and fecal calprotectin (FC) levels were below 100 micrograms per gram in 25.6% and 46.4% of CD patients with or without obesity, respectively (p=0.015).
Multivariate analyses revealed that obesity reduced the likelihood of disease remission in CD patients (Odds Ratio: 0.61; 95% Confidence Interval, 0.402–0.926; p=0.020) and CD patients with obesity had an increased risk of disease complications, including fistula, strictures, surgery and hospitalization (Hazard Ratio: 1.197; 95% CI, 1.046–1.370; p=0.009).
There was no association between obesity and disease progression or treatment failure with CD or UC, and obesity had no impact on disease activity scores or likelihood of remission among UC patients.
Study Design: Retrospective cohort analysis
Funding: Swiss National Science Foundation
Allocation: Not applicable
Level of Evidence: 2b