Microvascular Complications in Childhood-Onset Type 1 Diabetes and Celiac Disease: A Multicenter Longitudinal Analysis of 56,514 Patients From the German-Austrian DPV Database.

OBJECTIVE: To investigate whether celiac disease (CD) associated with type 1 diabetes increases the risk of microvascular complications. RESEARCH DESIGN AND METHODS: Patients (n = 56,514) aged >10 years with diabetes duration <20 years from 392 centers in Germany and Austria were assigned to one of three categories (n): no CD (50,933), biopsy-confirmed CD (812), or suspected CD (4,769; clinical diagnosis or positive antibodies). The confirmed and suspected groups were combined and analyzed for retinopathy or nephropathy. Cox proportional hazards regression was used to adjust for potential confounders (glycated hemoglobin [HbA1c], age at diabetes onset, sex, smoking, dyslipidemia, and hypertension). RESULTS: Kaplan-Meier analysis revealed that retinopathy and nephropathy occurred earlier in the presence versus absence of CD: retinopathy at age 26.7 years (95% CI 23.7-30.2) in 25% of patients with CD vs. age 33.7 years (33.2-34.4) in 25% without CD and microalbuminuria at age 32.8 years (29.7-42.5) vs. 42.4 years (41.4-43.3). The adjusted risk for both retinopathy (hazard ratio 1.263 [95% CI 1.078-1.481]) and nephropathy (1.359 [1.228-1.504]) was higher in patients with diabetes and CD versus those without CD. Cox regression revealed CD as an independent risk factor for microvascular complications after adjustment for confounders. CONCLUSIONS: CD is an independent risk factor for retinopathy and nephropathy in patients with type 1 diabetes. Our study therefore supports the recommendation for regular serologic testing for CD, even in the absence of clinical CD. Further prospective studies are required to investigate whether a gluten-free diet might reduce the risk of microvascular disorders in patients with diabetes and CD.