Screening for celiac disease in poorly controlled type 2 diabetes mellitus: worth it or not?

Recent studies have demonstrated that immune factors might have a role in the pathophysiology of insulin resistance and type 2 diabetes mellitus (T2DM). Inappropriate glycemic control in patients with T2DM is an important risk factor for the occurrence of diabetes complications. The prevalence of celiac disease (CD) is high in type 1 diabetes mellitus however, there are scarce data about its prevalence in T2DM. Our aim was to investigate the prevalence of celiac disease among insulin-using type 2 diabetes patients with inappropriate glycemic control.

IgA tissue transglutaminase antibodies (tTGA IgA) test was performed as a screening test. A total of 135 patients with T2DM whose control of glycemia is inappropriate (HbAlc value >7%) in spite of using insulin treatment for at least 3-months (only insulin or insulin with oral antidiabetic drugs) and 115 healthy controls were enrolled in the study. Upper gastrointestinal endoscopy with duodenal biopsy was performed to all patients with raised tTGA IgA or selective lgA deficiency.

Gender, age, body mass index (BMI) and tTGA IgA, kreatinin, calcium, LDL-cholesterol (LDL-C), total cholesterol, 25-OH vitamin D₃ levels were similar between groups. Systolic and diastolic blood pressure, waist circumference, fasting plasma glucose, postprandial plasma glucose, urea, sodium, HbA1c, LDL-C, triglyceride, vitamin B12 levels were significantly higher in DM group (p < 0.0001). BMI, high-sensitive CRP, microalbuminuria, and AST, ALT, potassium, phosphorus levels were significantly higher in the T2DM group (p < 0.05). HDL-cholesterol and parathormone levels were significantly lower in the T2DM group (p < 0.05). Two of the 135 patients with T2DM were diagnosed with CD (1.45%).

The prevalence of celiac disease among patients with type 2 diabetes, with poor glycemic control despite insulin therapy, is slightly higher than the actual CD prevalence in general population. Type 2 diabetic patients with inappropriate control of glycemia in spite of insulin treatment might be additionally tested for Celiac disease especially if they have low C-peptide levels.