Gluten-free diet adherence suboptimal in individuals with celiac disease–IBD overlap

Adherence to gluten-free diet (GFD) in individuals with celiac disease and inflammatory bowel disease (IBD) appears to be low, according to a study.

Out of the 36 people with celiac disease and IBD included in the study, only one followed a strict GFD over 6.5 years of follow-up, lead author Dr Jonathan Montrose of Indiana University School of Medicine, Indianapolis, Indiana, US, reported at the Crohn's & Colitis Congress (CCC).

Then again, 83 percent of these people depended on themselves to learn about GFD, and only 17 percent received advice from a celiac dietician, Montrose added.

In light of the findings, Montrose emphasized that there should be celiac disease centres at tertiary hospitals to provide people with celiac disease–IBD overlap with adequate clinical guidance and to spur greater GFD adherence.

This is especially important, as 1.6 percent of individuals with celiac disease also have IBD, and both are autoimmune diseases of the bowel that share similar clinical symptoms, he said. [Am J Gastroenterol 2022;117:1471-1481]

Treatment escalation

All 36 participants (mean age at the time of celiac disease diagnosis 34.8 years, 36 percent men, 94 percent White, 44 percent had pancolitis) initiated GFD at a mean of 0.7 years from the initial diagnosis of celiac disease (diagnosis of celiac disease postdated that of IBD by 3.6 years). GFD adherence was assessed at three time points: at baseline, at 3.7 years, and at 5.2 years. By the second and third assessment, all but one had skip out on GFD. [CCC 2023, abstract P087]

During the 10.1-year follow-up since the diagnosis of IBD, at least 50 percent of the participants with celiac disease and IBD needed escalation of IBD treatment to biologics and/or steroid rescue, Montrose noted.

The IBD medications consisted of 5-aminosalicyates (5-ASA; 53 percent), oral steroids (50 percent), antitumour necrosis factor (anti-TNF; 50 percent), anti-integrins (33 percent), azathioprine (28 percent), anti-interleukin (IL) 12/23 (22 percent), topical ASA (11 percent), methotrexate (14 percent), and topical steroids (6 percent).

The mean time to medication initiation after GFD initiation were as follows: –67 weeks for oral 5-ASA, –39 weeks for anti-TNF, –14 weeks for azathioprine, –2 weeks for topical 5-ASA, 82 weeks for oral steroids, 124 weeks for anti-integrins, and 137 weeks for anti-IL 12/23.

Serum levels of the tissue transglutaminase (tTG) IgA antibody consistently dropped over 192 weeks from the diagnosis of CeD, from a mean of 45 at the first assessment to a mean of 4 at the last assessment.

“We need to further substantiate these findings with exclusive IBD and celiac control groups,” Montrose said.