Maintaining the gluten-free diet: The key to improve glycemic metrics in youths with type 1 diabetes and celiac disease

[Display omitted] •Currently there are no studies analyzing glucose control metrics with real-time CGM (rt-CGM) systems in youths with type 1 diabetes (T1D) and celiac disease (CD).•This study compared 86 children and adolescents with T1D and CD using rt-CGM, with 167 matched people with T1D only. Among the first group, 29% were not completely maintaining gluten free diet (GFD).•People with T1D and CD presented similar glucose metrics compared to ones with T1D only. Subjects not strictly maintaining GFD presented higher glycosylated hemoglobin, higher hyperglycemia rates, and less time in range compared to subjects with T1D only. Gluten-free diets (GFD) were considered as high glycemic index and/or high content of saturated fats; this could affect keeping good metabolic control in individuals with both type 1 diabetes (T1D) and celiac disease (CD). Our objective was to analyze time in range and other continuous glucose monitoring (CGM) metrics with real-time CGM systems, in youths with T1D and CD, compared to those with T1D only. An observational case-control study, comparing youths aged 8–18 years with T1D and CD, with people with T1D only was performed. The degree of maintaining GFD was assessed through anti-tissue transglutaminase antibodies and dietary interview, and maintaining Mediterranean diet through the KIDMED questionnaire. 86 youths with T1D and CD, 167 controls with T1D only, were included in the study and the two groups reported similar real-time CGM metrics. Among the first group, 29 % were not completely maintaining GFD and compared to people with T1D only they showed higher hyperglycemia rates (% time above range: 38.72 ± 20.94 vs 34.34 ± 20.94; P = 0.039). Individuals with T1D and CD who maintain GFD presented similar glucose metrics compared to youths with T1D only. Individuals not strictly maintaining GFD presented higher hyperglycemia rates.