Journal of Diabetes | 2021
Celiac disease: A global survey
Abstract
Celiac disease (CD) is an autoimmune disorder with a strong genetic component characterized by small bowel inflammation with villous atrophy. Multiple studies over the past five decades attest to the higher prevalence of CD among youth with type 1 diabetes. The study of factors associated with CD prevalence in different countries published in the current issue of the Journal of Diabetes is based on the Better Control in Pediatric and Adolescent Diabetes: Working to Create Centers of Reference (SWEET) registry, analyzing data from 74 centers screening for CD with tissue transglutaminase (tTG-A) and/or endomysial antibody (EMA) measurement, typically with confirmatory duodenal biopsy. Among >57 000 youth with type 1 diabetes, >2600 children were found to have CD, diagnosed at a median age of 8 years and an average glycosylated hemoglobin (HbA1c) of 7.98%. As previously reported in the literature, more females than males had CD in the SWEET registry, and interestingly both younger age at diabetes diagnosis and longer duration of diabetes were associated with higher prevalence of CD, the latter suggesting that screening might appropriately be continued beyond 5 years after diagnosis, although both the American Diabetes Association and the International Society for Pediatric and Adolescent Diabetes guidelines recommend screening for CD only until 5 years after diagnosis. The Letter in the current issue of the Journal of Diabetes notes that one-third of the 33 type 1 diabetic youth found to have CD at our institution were indeed diagnosed more than 5 years after diabetes onset. Once diagnosed, CD treatment requires a strict gluten-free diet, which can be challenging in the context of otherwise complex diabetes management. CD may make glycemic control more difficult, potentially increasing both hypoglycemia and hyperglycemia, although in the SWEET study HbA1c with CD was somewhat lower than among the remainder of the population, perhaps due to the more intensive management and monitoring required. A potential adverse effect of CD on bone mineral metabolism and linear growth is suggested by the shorter height and lower weight SD scores found in the CD patients. A recent study suggests, however, that a gluten-free diet may not adversely affect young adults perception of wellness or health-related quality of life. The striking finding in the SWEET study is that CD prevalence varied more than 3-fold by region, from 1.9% in Asia and the Middle East to >6% in Australia/ New Zealand and in North America. Differences in screening approaches seem unlikely to explain this, given the prospective and standardized approach taken in the registry. Differences in diet may explain part of the variability, as the predominantly rice-based diet in Asia would have lower gluten content. Might population differences both in human leukocyte antigen (HLA) and in non-HLA gene prevalences be explanatory factors? Recent studies suggest that dysbiosis of the gut microbiome may play a role in the pathogenesis both of CD and of type 1 diabetes. Might such a role of the gut microbiome contribute to regional variations in CD prevalence? Regardless of the mechanism, it is gratifying that in the present age of molecular medicine large clinical studies such as the present report continue to add to our understanding and to suggest novel approaches to disease management.