Evidence check: tTG IgA in the context of Blutzucker

The tTG IgA test is a well-established serological marker for celiac disease, an autoimmune condition triggered by gluten. A positive result indicates active or untreated celiac disease. In the context of blood sugar (glycemic control), the evidence is clear: untreated celiac disease can lead to poorer glycemic control in individuals with type 1 diabetes, as intestinal damage impairs nutrient absorption and promotes inflammation. There is also some evidence of increased celiac prevalence in type 2 diabetes, but the data are weaker. Importantly, tTG IgA does not directly measure blood sugar; it is a diagnostic tool for celiac disease. A positive test requires confirmation by duodenal biopsy. If tTG IgA is negative but clinical suspicion remains, total IgA should be measured because IgA deficiency can cause false negatives. The evidence linking celiac disease to impaired blood sugar regulation is human-strong, especially for type 1 diabetes. Caveat: The test alone does not reflect current blood glucose levels. If diabetes is suspected, additional blood glucose measurements (fasting glucose, HbA1c) are necessary.