Type 1 diabetes and celiac disease in adults: glycemic control and diabetic complications.

The prevalence of celiac disease (CD) in patients with type 1 diabetes mellitus (T1DM) is 4.5 %. Objective of the study is to investigate (1) the course of glycemic control at CD diagnosis and after the initiation of a gluten-free diet (GFD) in T1DM patients; (2) the prevalence of diabetic complications in T1DM patients with adult onset of CD. In 20 hospitals in the Netherlands, we identified T1DM patients diagnosed with CD at adult age. We retrospectively collected glycated hemoglobin (HbA1c) levels before CD diagnosis, at CD diagnosis, and the most recent HbA1c levels as well as the presence of nephropathy and retinopathy. The control group consisted of patients with T1DM and negative CD serology matched for age, gender, T1DM duration, and HbA1c levels. Thirty-one patients were eligible with a median duration of T1DM and CD of 27 years (IQR 14-37) and 3 years (IQR 1-8), respectively. The matched control group consisted of 46 patients. HbA1c levels at the moment of CD diagnosis were 7.5 % (IQR 7.1-8) [58 mmol/mol] and at the most recent visit 7.4 % (IQR 6.9-7.9, P = 0.15) [57 mmol/mol] indicating no difference. Prevalence of retinopathy was lower in T1DM + CD group compared with controls, (38.7 vs 67.4 %, P < 0.05), whereas no difference in the prevalence of nephropathy was found between the groups (P = 0.09). In conclusion, T1DM + CD patients have less retinopathy compared to T1DM patients without CD. A GFD possibly favorable affects the development of vascular complications in T1DM patients.