Prevalence of celiac disease in Iranian patients with type 1 diabetes: A systematic review and meta-analysis

Patients with type 1 diabetes mellitus (T1DM) are at high risk for celiac disease (CD) due to the common genetic background and interaction between environmental and immunological factors. The purpose of this systematic review and meta-analysis was to estimate the prevalence of CD among Iranian patients with type 1 diabetes. The search for articles was conducted using the following keywords: "celiac disease," "celiac," "coeliac disease," "diabetes," "Iran," and all other possible combinations of these terms. The following databases were searched from inception to June 2019: Scientific Information Database (SID), MagIran, Web of Science, PubMed, and Scopus. Meta-analysis was performed using the random-effects models, and the heterogeneity of results across the studies was assessed using the Cochran's Q test and quantified by the I2 statistic. Data analysis was performed by Stata version 14. A total of 14 papers were included in the meta-analysis, involving 2030 Iranian patients with T1DM. The pooled prevalence of CD in patients with T1DM was 5% (95% CI 3-7). The prevalence of CD in Tehran (4%; 95% CI 1-6) was lower than in other provinces of the country (6%; 95% CI 4-8). Meta-regression analysis showed that, with increasing sample size, the prevalence of  CD was significantly reduced (p = 0.018).Given the adverse effects of CD , such as osteoporosis and malignancy (especially lymphoma), patients with T1DM must be screened for CD .