Is tTG IgA useful for Blutzucker?

tTG IgA (anti-tissue transglutaminase IgA) is primarily a diagnostic marker for celiac disease, not for blood glucose. However, there is a well-established link: celiac disease is more common in type 1 diabetes (prevalence ~5–10 %), and untreated celiac can impair glycemic control due to malabsorption and inflammation. Clinical guidelines (e.g., ISPAD) recommend screening for celiac at type 1 diabetes diagnosis. For non-diabetic individuals or for assessing general blood sugar (e.g., insulin resistance, HbA1c), tTG IgA is not useful. Caveat: positive results need gastroenterology follow-up; false positives occur (e.g., IgA deficiency). Evidence: human-moderate (association celiac/T1D, but not a direct glucose marker).