Undiagnosed coeliac disease and risk of autoimmune disorders in subjects with Type I diabetes mellitus

AIMS/HYPOTHESIS: We tested the hypothesis that silent coeliac disease is more frequent than expected in both patients with Type I (insulin-dependent) diabetes mellitus and their first-degree relatives. We evaluated how the presence of other autoimmune disorders in diabetic patients and their first-degree relatives is related to silent, unrecognized coeliac disease. METHODS: Sera from 491 subjects with Type I diabetes, 824 relatives and 4,000 healthy control subjects were screened for anti-endomysial antibodies and all those subjects who tested positive for anti-endomysial antibodies underwent intestinal biopsy. RESULTS: We found that the prevalence of coeliac disease was 5.7 \% among the diabetic patients and 1.9 \% among the relatives, values significantly higher than those found among the control subjects (p < 0.0001; p < 0.001). The prevalence of autoimmune disorders in diabetic patients with coeliac disease was significantly higher than in subjects with Type I diabetes alone (p < 0.0001). The prevalence of autoimmune disorders in the relatives with coeliac disease was significantly higher than in those who tested negative for anti-endomysial antibodies (p = 0.01). CONCLUSION/INTERPRETATION: This report provides further confirmation of the high prevalence of undiagnosed coeliac disease among diabetic patients and their relatives. This interesting new finding is the increased presence of other autoimmune diseases in these patients, as well as in their relatives with a delayed diagnosis for coeliac disease. Patients newly diagnosed with coeliac disease showed excellent compliance with the gluten-free diet. This should encourage policymakers to consider introducing an easy-to-use screening programme for diabetic patients and their relatives into everyday clinical practice, in order to prevent coeliac-associated symptoms and the onset of additional, more serious auto-immune disorders.