Bariatric surgery helps improve outcomes in IBD

Bariatric surgery (BS), particularly sleeve gastrectomy, contributes to the improvement of disease-specific outcomes in patients with inflammatory bowel disease (IBD) and obesity, reports a study.

“Sleeve gastrectomy but not Roux-en-Y gastric bypass is associated with improved disease-specific outcomes in patients with IBD and morbid obesity,” according to the authors led by Dr Aakash Desai from the Division of Gastroenterology and Hepatology, MetroHealth Medical Center, Case Western Reserve University in Cleveland, Ohio, US.

Desai and colleagues compared IBD patients with morbid obesity who underwent BS with those who did not undergo BS in this retrospective, propensity-score matched cohort study using TriNetX, a multi-institutional database.

The 2-year risk of a composite of disease-related complications, including intravenous steroid use of IBD-related surgery, served as the primary endpoint. The authors reported the risk as adjusted odds ratios (aORs) with 95 percent confidence intervals (CI).

A total of 482 patients (3.4 percent) with IBD and morbid obesity underwent BS (mean age 46.9 years, mean BMI 42.1 kg/m²), of whom 60 percent had Crohn’s disease. After propensity-score matching, those who underwent BS showed a reduced risk of a composite of IBD-related complications (aOR, 0.31, 95 percent CI, 0.17‒0.56) compared with controls. [J Clin Gastroenterol 2024;58:447-453]

Moreover, patients who underwent sleeve gastrectomy had a lower risk of a composite of IBD-related complications (aOR, 0.45, 95 percent CI, 0.31‒0.66). Of note, no difference was observed in the primary endpoint (aOR, 0.77, 95 percent CI, 0.45‒1.31) between the BS cohort with Roux-en-Y gastric bypass and the control cohort.

“Sleeve gastrectomy may be the preferred BS in patients with IBD,” Desai said.

Mechanisms

Several explanations on how BS can improve disease activity in IBD are found in the literature. For instance, some studies report that undergoing BS contributes to a reduction in the low chronic pro-inflammatory state associated with obesity, as shown by decreases in C-reactive protein, TNF-α, and IL-6. [Nat Rev Gastroenterol Hepatol 2017;14:110-121; Inflamm Bowel Dis 2020;26:1089-1097]

The benefits of BS may also be attributed to a decrease in adipose tissue hypertrophy and ectopic fat around the bowel, which is believed to be responsible for the regulation of intestinal inflammation in Crohn’s disease. [Nutrition 2012;28:113-117; Br J Surg 1992;79:955-958]

“This may affect the need for rescue therapy with intravenous steroids, failure/escalation of therapy, and risk of surgery,” the authors said.

In addition, previous studies have observed the beneficial effects of BS via changes in the microbiome. This appears to be the case regardless of changes in BMI. [Nature Medicine 2017;23:859-868; Obesity Surg 2017;27:1345-1357]

“Our study has several notable strengths, including the largest sample size of patients with IBD undergoing BS, and a diverse cohort from healthcare organizations across the US, allowing for generalizability when interpreting the results,” Desai said.

“We utilized a population-based prospectively maintained database which allowed for propensity-score matching to reduce confounding variables despite the retrospective nature of the study.”