Background
Obesity is associated with the progression of inflammatory bowel disease (IBD). Visceral adiposity may be a more meaningful measure of obesity compared to traditional measures such as body mass index (BMI). This study compared visceral adiposity versus BMI as predictors of time to IBD flare in patients with Crohn’s disease and ulcerative colitis.
Methods
This was a retrospective cohort study. IBD patients were included if they had a colonoscopy and computed tomography (CT) scan within 30 days of an IBD flare.
They were followed for 6 months or until their next outbreak.
The primary exposure was the ratio of visceral adipose tissue to subcutaneous adipose tissue (VAT:SAT) obtained from computed tomography. BMI was calculated at the time of the index CT scan.
Results
A total of 100 patients with Crohn’s disease and 100 with ulcerative colitis were included. The median age was 43 (interquartile range, 31-58) years, 39% had disease duration of 10 years or more, and 14% had severe disease activity on endoscopic examination.
Overall, 23% of the cohort flared with a median time to flare of 90 (interquartile range, 67-117) days. Higher VAT:SAT was associated with shorter time to IBD flare (hazard ratio of 4.8 for VAT:SAT ≥1.0 vs. VAT:SAT ratio <1.0), while that higher BMI was not associated with shorter time to flare (hazard ratio 0.73 for BMI ≥25 kg/m 2 vs. BMI <25 kg/ m 2).
The relationship between increased VAT:SAT and shorter time to flare appeared to be stronger for Crohn’s disease than for ulcerative colitis.
Conclusions
Visceral adiposity was associated with a decreased time to IBD flare, but BMI was not. Future studies could evaluate whether interventions that decrease visceral adiposity will improve IBD disease activity.
