Optimal Frequency to Screen Celiac Disease amongst Patients with Type 1 Diabetes Mellitus: A Multicenter Study

•It is better that performing screening tests for CD among Type-1 diabetic mellitus. (T1DM) patients be continued at least for eight years after diagnosis of T1DM.•As the age of diagnosis of T1DM increases, the IBCD decreases.•Children with T1DM at a younger age are at risk of CD for longer years.•Most of T1DM patients may be asymptomatic at time of CD diagnosis. Celiac disease (CD) is frequent amongst patients with type 1 diabetes mellitus (T1DM). Since there is a disagreement on the optimal interval and frequency to perform screening tests for CD among diabetic patients, this study aimed to evaluate these issues amongst patients with T1DM. This retrospective cohort study was conducted in seven referral diabetic centers in different cities of Iran from January 2020 to January 2021. Data belonging to 106 patients who were affected by both T1DM and CD was collected. The time interval between CD diagnosis and diabetes (IBCD), the age of diabetes onset, and any associated diseases, symptoms, and family history of T1DM and CD were recorded and analyzed. Results show that 45% of the patients with CD were diagnosed during the first year of diabetes onset; furthermore, 18% and 16% of the patients with CD were diagnosed in the second or third year after being diagnosed with diabetes. In addition, another 18% of patients with CD were diagnosed during the fourth till the eighth year after diabetes onset. Moreover, there was a negative relationship between the age of T1DM diagnosis and IBCD. Most participants were asymptomatic at the time of CD diagnosis. Screening tests to detect CD amongst patients with T1DM should continue for at least eight years after the initial T1DM diagnosis, especially those affected at a younger age.