Does a gluten-free diet lead to better glycemic control in children with type 1 diabetes? Results from a feasibility study and recommendations for future trials

Background: Increasing evidence suggests a link between type 1 diabetes (T1D) and intake of gluten, but no controlled trials have examined whether a gluten-free diet (GFD) has positive effects on glycemic control in children with T1D. Methods: We conducted a non-randomized feasibility study. Twenty-three children with newly diagnosed T1D were included and either followed a GFD (n = 14) or a normal diet (n = 9) for 12 months. Effects of diet on glycemic control were examined by measuring insulin production (c-peptide), hemoglobine A1c (HbA1c) and insulin dose adjusted A1c (IDAA1c). Degree of adherence to the GFD and effects on quality of life were also examined. Results: Children on a GFD showed a statistically significantly lower HbA1c at six months (P = 0.042) compared with children on a normal diet and point estimate differences indicated better glycemic control in the GFD group at 6 and 12 months. Adherence to a GFD varied but was satisfactory for a majority of children. The GFD group reported poorer quality of life at inclusion and there was a non-significant difference for quality of life between groups throughout the study. Conclusions: A strict GFD can be maintained by children with newly diagnosed T1D and may have positive effects on glycemic control. Our findings should be interpreted carefully because of small samples and possible confounding. We provide recommendations for future trials and suggest using a randomized-controlled design with 30-40 participants in each arm.