Previous studies have shown that bariatric surgery is safe for people with IBD, but there have been few long-term data on whether the weight loss improves disease outcomes for that population, said lead author Aakash Desai, MD, from the division of gastroenterology and hepatology at Case Western Reserve University, Cleveland, in an interview.
Gastroenterologists are often hesitant to pursue bariatric surgery in patients with IBD because of potential complications from taking immunosuppressive medications, Dr. Desai added.
“We hope that this encourages providers caring for patients with IBD to make a referral to a weight loss specialist who can evaluate whether they would be candidates for bariatric surgery,” he said.
The findings from Dr. Desai and co-authors were published online in the Journal of Clinical Gastroenterology.
Outcomes compared with and without surgery
The prevalence of obesity in patients with IBD ranges from 15% to 40%, the authors note.
And although obesity is a risk factor for IBD disease severity and clinical outcomes, studies on its influence on disease outcomes in patients with IBD have reported conflicting results. The effect of bariatric surgery, an antiobesity intervention, on IBD outcomes also has not been well understood, the authors write.
To evaluate the effect of bariatric surgery on IBD, the researchers compared outcomes in patients living with IBD and morbid obesity who had bariatric surgery versus those in patients living with both conditions who had not had surgery. The retrospective, propensity score–matched cohort study used de-identified U.S. data on 473 patients and 473 controls from TriNetX, a diverse, population-based research network of health care organizations.
The primary endpoint was a composite of disease-related complications. The composite included a disease flare that resulted in hospitalization requiring an intravenous steroid or major IBD-related surgery within 2 years.
Researchers found that the surgery group had a lower risk (adjusted odds ratio, 0.31; 95% confidence interval, 0.17-0.56) for a composite of IBD-related complications, compared with controls.
Looking at the impact of bariatric surgery type, they found that patients who had a sleeve gastrectomy had a decreased risk (aOR, 0.45; 95% CI, 0.31-0.66) for the composite of IBD-related complications. There was no significant difference in the risk (aOR, 0.77; 95% CI, 0.45-1.31) for composite IBD-related complications between the Roux-en-Y gastric bypass group and controls.
As to why sleeve gastrectomy can improve outcomes with IBD, the authors write that “studies have shown a decrease in the low chronic pro-inflammatory state associated with obesity with reductions in C-reactive protein, TNF-α, and IL-6 following weight loss after [bariatric surgery].”
The authors add that another reason could be that the decrease from surgery in adipose tissue hypertrophy and ectopic fat around the bowel may help regulate intestinal inflammation in Crohn’s disease and “may affect the need for rescue therapy with intravenous steroids, failure/escalation of therapy, and risk of surgery.”
Study helps confirm benefits of weight loss
Ali Aminian, MD, director of the Bariatric and Metabolic Institute at the Cleveland Clinic, said this study furthers understanding because it used a large national database and helps confirm findings from smaller cohorts regarding the benefit of large weight loss for patients with IBD.
“Obesity can worsen the severity of inflammatory conditions,” he said in an interview, so it can be hard for gastroenterologists to help patients with obesity to control their IBD symptoms. Dr. Aminian has previously published research on the relationship between IBD and obesity.
“Telling the patient to eat less or exercise probably won’t help,” he said, adding that this study helps make the case for either bariatric surgery or new weight loss medications that have demonstrated significant effect.
Dr. Aminian said this study showed a dramatic benefit after bariatric surgery for IBD patients, but some questions need further study.
“Ideally, we need to have prospective clinical trials with a good control group and accurate endoscopy findings” to get a true long-term picture of the weight loss effect on IBD, he said.
Dr. Desai reports no relevant financial relationships. Co-author Farraye serves on advisory boards for Braintree, BMS, GI Reviewers, GSK, IBD Educational Group, Iterative Health, Janssen, Pfizer, and Sebela and is on the data safety monitoring board for Adiso Therapeutics. Co-author Kochhar serves on the advisory boards for Lilly Pharmaceuticals, CorEvitas Research Foundation, and GIE Medical and has stock options with Digbi Health. Aminian receives research support and speaking honoraria from Medtronic and Ethicon.
A version of this article appeared on Medscape.com.