People with celiac disease and type 1 diabetes face a higher risk of developing microvascular complications of diabetes, such as retinopathy and nephropathy (kidney disease), earlier than other people with type 1 diabetes.

56,514 children and adults, aged over 10 years of age with a diabetes duration of under 20 years, were involved in the study. The participants all had type 1 diabetes and lived in Germany or Austria. Out of the participants, 812 had celiac disease confirmed by biopsy, another 4,769 had suspected celiac disease and the remaining 50,933 had no evidence of celiac disease.

Earlier development of complications

The results showed that retinopathy occurred within 25% of type 1 diabetes patients with celiac disease by the age 26.7 years. For patients with type 1 but no celiac disease, 33.7 years was the age at which 25% of the group had developed retinopathy.

In terms of the first appearance of signs of nephropathy (kidney disease, shown by the presence of microalbuminuria (small amounts of protein in the urine), 25% of patients with celiac disease developed microalbuminuria at 32.8 years compared with 42.4 years in the group without celiac disease.

Statistical analysis showed celiac disease to be an independent risk factor for earlier development of these complications. To arrive at this finding, the researchers ensured that factors such as hemoglobin A1c levels, age at diabetes onset and evidence of high cholesterol and blood pressure, were adjusted for.

The next stage will be to determine why celiac disease confers a higher risk and what can be done to lower the risk. The researchers suggest that further studies investigate whether gluten-free diets are able to reduce the complications risk.

The research was carried out by researchers in Germany and Austria and the study is published online, ahead of print, by the Diabetes Care journal.