Celiac disease confers added risk for autoimmune thyroid disease in adults with type 1 diabetes, according to research in Diabetes Care.
In a population-based cohort study, Matthew Kurien, MD, MRCP, of the department of gastroenterology at Royal Hallamshire Hospital in Sheffield, United Kingdom, and colleagues analyzed data from Swedish National Patient Register between 1964 and 2009.
Researchers identified all patients with a diagnosis of type 1 diabetes before age 31 years (n = 42,539); small intestinal biopsy reports showing villous atrophy were used to identify type 1 diabetes patients with celiac disease between 1969 and 2008 (n = 947; 55.1% women; mean age of celiac disease diagnosis, 12 years). Researchers then selected up to five type 1 diabetes patients as controls for each patient with both type 1 diabetes and celiac disease, matched for age, sex and birth year (n = 4,584; 54.5% women). Researchers used Cox regression analysis to calculate HRs for future thyroid disease, with celiac disease as a time-dependent variable.
During a mean 13 years of follow-up, 90 patients in the group with both type 1 diabetes and celiac disease developed autoimmune thyroid disease (hypothyroid or hyperthyroid); mean age at thyroid disease diagnosis was 25 years. Overall, 10.8% of patients in the type 1 diabetes and celiac disease group were diagnosed with thyroid disease at some stage of life vs. 7.2% of patients with type 1 diabetes but no celiac disease. Patients with both type 1 diabetes and celiac disease were at an increased risk for hypothyreosis (HR = 1.66; 95% CI, 1.3-2.12) and hyperthyreosis (HR = 1.71; 95% CI, 0.95-3.11). The RR for thyroid disease in patients with both type 1 diabetes and celiac disease was 1.67 (95% CI, 1.32-2.11).
In addition, the highest risk estimates for developing thyroid disease were observed in the first calendar period of the study (between 1964-1975), which researchers attributed to poor screening for thyroid disease in those with type 1 diabetes at the time.
“Importantly, the highest risks were seen after > 10 years with [celiac disease], suggesting that long-term double autoimmunity is a risk factor for [autoimmune thyroid disease],” the researchers wrote.
Disclosure: The researchers report no relevant financial disclosures.
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