Celiac Disease Asymptomatic in Adult Patients with Type 1 Diabetes

celiac disease diabetes wpAmong individuals with type 1 diabetes (T1D), adults are more likely to test positive for asymptomatic celiac disease (CD) than children.

  • Rose Reeb, endorcrinologyadvisor.com 1

Individuals with T1D are at increased risk for CD but many individuals go undiagnosed, as CD frequently presents without symptoms. The effects of a gluten-free diet in individuals with T1D and asymptomatic CD has not yet been determined.

The Study

To examine this, 2387 individuals with T1D aged 8 to 45 years (45.6% aged ≤18 years) were screened for asymptomatic CD.

  • A total of 51 individuals who were found to have asymptomatic CD were randomly assigned to either a gluten-free or gluten-containing diet for 1 year.
  • Asymptomatic CD was defined as having a tissue transglutaminase immunoglobulin A (TTG-IgA) level ≥30 CU and was further confirmed by a gastroenterologic biopsy with a Marsh score of ≥2.
  • Dietary adherence was evaluated through TTG-IgA testing and quantification of dietary gluten intake every 3 months.
  • Hemoglobin A1c (HbA1c) was measured at baseline and every 6 months during the dietary study, and all participants used continuous glucose monitoring during the study period.


  • Individuals aged ≤18 years were significantly more likely to have previously been screened for CD (P <.0001).
  • Individuals aged >18 years had higher CD-seropositivity rates than younger patients (6.8% vs 4.7%; P =.035).
  • A significant increase in HbA1c was observed in the gluten-free diet group at 12 months (+0.30%; 95% CI, 0.40-0.57; P =.028) compared with baseline, although no significant difference in HbA1c change was observed between groups.
  • There were also no changes in the percentage of time spent in hypoglycemic, euglycemic, or hyperglycemic ranges observed over the 12-month period, but in the gluten-free diet group, postprandial glycemia was higher at both the 2-hour (+1.6 mmol/L; 95% CI, 0.7-2.6; P =.0015) and 4-hour (+1.5 mmol/L; 95% CI, 0.4-2.7; P =.0014) time points relative to premeal levels, whereas glucose levels did not significantly change and returned to premeal levels at the 4-hour time point in the gluten-containing diet group.


“…diabetes clinicians should be aware of CD as an important autoimmune comorbidity of type 1 diabetes that is frequently asymptomatic. In addition, clinical vigilance is warranted during dietary transition, as [treatment with a gluten-free diet] may impact short-term glycemic variability.”

Future studies

Should include a larger sample size and evaluate the long-term effects of a gluten-free diet in individuals with asymptomatic CD and T1D, given potentially higher risks for microvascular and skeletal complications with CD.

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Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference: Mahmud FH, Clarke ABM, Joachim KC, et al. Screening and treatment outcomes in adults and children with type 1 diabetes and asymptomatic celiac disease: the CD-DIET study [published online April 28, 2020]. Diabetes Care. doi:10.2337/dc19-1944