Is coeliac disease more prevalent in young adults with coexisting Type 1 diabetes mellitus and autoimmune thyroid disease compared with those with Type 1 diabetes mellitus alone?

AIM: It is known that patients with Type 1 diabetes mellitus are more prone to develop coeliac disease and that autoimmune thyroid disease occurs more frequently in patients with coeliac disease. We therefore assessed whether coeliac disease, either known or occult, occurs more frequently in young/middle aged adults with Type 1 diabetes and coexisting autoimmune thyroid dysfunction than in adults with Type 1 diabetes alone. METHODS: The prevalence of known coeliac disease was assessed in 509 (301 males, aged 16-55 years) patients with Type 1 diabetes, 28 (5.5%) of whom had treated autoimmune thyroid disease. In a second study 38 patients with Type 1 diabetes and coexisting autoimmune thyroid disease along with 112 patients with Type 1 diabetes alone were then screened for coeliac disease using serum IgA endomysial antibodies and IgA gliadin antibodies. RESULTS: Seven of the 509 patients (1.4%) had been diagnosed with coeliac disease and two of these had later developed autoimmune thyroid disease (both hypothyroid). The subsequent screening exercise found that one of the 38 patients with both Type 1 diabetes and thyroid disease had positive endomysial antibodies on screening. However, duodenal biopsy was negative for coeliac disease. There were two patients with positive endomysial antibodies in the group of 112 patients with diabetes only. Both had duodenal biopsy but only one was consistent with coeliac disease. CONCLUSION: The prevalence of known coeliac disease in this young adult Type 1 diabetes clinic in North-west England was 7/509 (1.4%). Two of these seven patients with coeliac disease were from the group of 28 who had autoimmune thyroid disease as well. Therefore we suggest that patients with known coeliac disease and Type 1 diabetes should be screened for autoimmune thyroid disease. The second screening study then found 3/150 (2%) to have a serological marker for coeliac disease. However, patients with both Type 1 diabetes and autoimmune thyroid disease were not more likely to have occult coeliac disease compared with those with Type 1 diabetes only.