Understanding the Link Between Type 1 Diabetes and Celiac Disease in Children

Celiac.com 05/29/2025 - Children with type 1 diabetes (T1D) face a higher risk of developing celiac disease (CD) compared to the general population. Diagnosing celiac disease in these children can be challenging because symptoms are often mild or absent, and standard screening tests may not always provide clear answers. A recent study from Switzerland aimed to determine the best way to identify which children with T1D should undergo further testing—such as an intestinal biopsy—to confirm celiac disease. The research focused on antibody levels in the blood, which can signal the presence of celiac disease, and explored whether combining different antibody tests could improve accuracy.

Why This Study Matters

Celiac disease is an autoimmune disorder where the ingestion of gluten damages the small intestine. Since both T1D and CD involve immune system dysfunction, children with diabetes are more likely to develop celiac disease. However, diagnosing CD in these children is complicated because:

• Many have no obvious symptoms.
• Blood test results can fluctuate over time.
• There is no universally agreed-upon threshold for when a biopsy (the gold standard for CD diagnosis) should be performed.

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This study sought to clarify when doctors should recommend a biopsy by analyzing antibody levels in children with T1D over time.

How the Study Was Conducted

Researchers examined medical records from 588 children and adolescents with T1D, tracking them from diabetes diagnosis until age 18. Over this period, they collected nearly 3,000 measurements of an important celiac disease antibody called TGA-IgA (anti-transglutaminase 2 IgA). They also recorded other antibody levels, including IgG antibodies against deamidated gliadin peptides (GLA-IgG), which are sometimes used in celiac disease testing.

Among the participants:

• 34 children (5.8%) were eventually diagnosed with celiac disease.
• Half had noticeable symptoms at diagnosis, while the other half were detected through screening.
• Two-thirds of CD cases were diagnosed within two years of T1D diagnosis.

Key Findings

1. The Best Antibody Cutoff for Biopsy Referral

The study found that a TGA-IgA level around 6.1 times the upper limit of normal was the most reliable indicator for recommending a biopsy. At this level:

• The test correctly identified 90.3% of true celiac cases (high sensitivity).
• It also minimized unnecessary biopsies in children without CD (80.4% accuracy).

2. Combining Antibody Tests Improves Accuracy

While TGA-IgA alone was useful, adding GLA-IgG (another celiac-related antibody) improved diagnostic precision. The combined approach increased the test’s overall reliability, making it better at distinguishing between children who truly had CD and those who did not.

3. Timing of Celiac Disease Diagnosis Matters

• Early CD diagnosis (within 2 years of T1D): Most children who developed CD soon after their diabetes diagnosis already had high TGA-IgA levels at the time of their T1D diagnosis.
• Late CD diagnosis (after 2 years): These children showed a slower, more gradual rise in TGA-IgA levels over time.

This suggests that early antibody testing in children newly diagnosed with T1D could help identify those at highest risk for celiac disease.

What This Means for Children with Type 1 Diabetes and Celiac Disease

For families managing T1D, this study offers important insights:

• Earlier Detection: Since many children develop CD soon after T1D diagnosis, screening at diabetes onset—and monitoring antibody levels—could lead to earlier detection and treatment.
• Fewer Unnecessary Biopsies: The proposed TGA-IgA cutoff (6.1x normal) helps doctors decide which children truly need a biopsy, reducing invasive procedures for those unlikely to have CD.
• Better Testing Strategies: Combining TGA-IgA with GLA-IgG improves accuracy, meaning fewer missed cases and fewer false alarms.

Why This Is Important for Celiac Disease Management

For children with both T1D and celiac disease, early diagnosis is crucial because:

• Untreated CD can worsen blood sugar control in diabetes.
• A gluten-free diet (the only treatment for CD) helps prevent long-term complications like nutrient deficiencies and growth delays.
• Many children with T1D and CD have no obvious symptoms, so relying on antibody testing is essential for timely diagnosis.

Conclusion

This study provides valuable guidance for doctors screening children with type 1 diabetes for celiac disease. By using a TGA-IgA threshold of 6.1 times the upper limit of normal, along with additional antibody testing, physicians can more accurately determine which children should undergo a biopsy. Early and precise detection means children with CD can start a gluten-free diet sooner, improving their overall health and diabetes management.

For families, these findings reinforce the importance of regular celiac screening in children with T1D—especially in the first few years after diabetes diagnosis—to catch the disease early, even before symptoms appear.

Read more at: academic.oup.com