DALLAS — Obesity, as defined by body mass index (BMI), appears to be somewhat of an advantage in inflammatory bowel disease (IBD), including Crohn’s disease, according to a new study involving veterans.

The study, published ahead of print recently in the journal Digestive Diseases and Sciences, noted that both obesity and inflammatory bowel disease (IBD) are very prevalent in Western societies. While IBD — including Crohn’s and the related disease, ulcerative colitis — long have been associated with weakness, wasting of the body and malnutrition, it has been unclear how obesity, a chronic pro-inflammatory state, impacts the course of the illness.1

Researchers from the University of Texas Southwestern Medical Center sought to report the prevalence of obesity in patients with IBD in a metropolitan U.S. population and to assess the impact of obesity on disease phenotypes, treatment and surgical outcomes in those patients.

To do so, the study team reviewed the medical records of patients identified from the IBD registries of the Dallas VAMC and Parkland Health and Hospital Systems from Jan. 1, 2000, to Dec. 31, 2012.

Of 581 identified IBD patients, 32.7 % were obese, and 67.6 % were non-obese. The rate of obesity was 30.3% among the 297 Crohn’s patients and 35.2% among the 284 ulcerative colitis patients.
“Overall, obese patients were significantly less likely to receive anti-TNF treatment, undergo surgery or experience a hospitalization for their IBD than their non-obese counterparts,” according to the authors, who noted that only 55.8% of obese patients had those outcomes compared to 72.1% of the non-obese patients.

“Obesity is highly prevalent in our IBD patients, paralleling the obesity rates in the U.S. population. Clinical outcomes were significantly different in obese versus non-obese patients with IBD,” the authors concluded. “Despite the plausible mechanisms whereby obesity might exacerbate IBD, we have found that obesity (as defined by BMI) is a marker of a less severe disease course in IBD.”

1 Flores A, Burstein E, Cipher DJ, Feagins LA. Obesity in Inflammatory Bowel
Disease: A Marker of Less Severe Disease. Dig Dis Sci. 2015 Mar 24. [Epub ahead
of print] PubMed PMID: 25799938.