Potential reno-protective effects of a gluten-free diet in type 1 diabetes

Aims/hypothesis: Coeliac disease is common in type 1 diabetes. It is managed with a gluten-free diet, characterised by foods low in AGEs. We hypothesised that this diet would lead to lower plasma AGEs and be associated with reduced albuminuria. Methods: From a single paediatric clinic, we recruited 21 children with type 1 diabetes and biopsy-proven coeliac disease, and 38 individuals with diabetes alone. The groups were matched for age, sex, duration of disease and metabolic control. Participants completed a detailed clinical and dietary history. Blood samples were taken for HbA_1c, coeliac serology, thyroid function, serum IgA levels and plasma AGEs, and urine samples were obtained for estimation of the albumin/creatinine ratio (ACR). Results: All the individuals with coeliac disease were asymptomatic, with negative transglutaminase antibodies. There were no significant differences between the groups in terms of age (14 years), sex (29% male), duration of diabetes (7 years), mean HbA_1c (8.3%), lipid levels or treatment regimens. However, children with diabetes and coeliac disease had twofold lower levels of urinary ACR than with those diabetes alone (p∈=∈0.04). This was associated with lower levels of circulating AGEs (p∈=∈0.03). These associations were independent of metabolic control, diabetes management and other potentially confounding variables, such as household exposure to cigarette smoke. Conclusions/interpretation: Adherence to a gluten-free diet may provide additional benefits for individuals with coeliac disease, and potentially those with type 1 diabetes.