Gluten-free diets for metabolic control of type 1 diabetes mellitus in children and adolescents: a systematic review and meta-analysis.

The aim of this review is to comprehensively assess the association between a gluten-free diet (GFD) and metabolic control of type 1 diabetes mellitus (T1DM) in children and adolescents with T1DM and with T1DM plus coeliac disease (CD). PubMed, Embase, Cochrane Library, and Web of Science were searched until June 19, 2023. Primary outcomes were hemoglobin A1c (HbA1c), insulin dose, insulin dose adjusted A1c (IDAA1c), blood glucose (B-glu) at 90 min during Mixed Meal Tolerance Test (MMTT), C-peptide area under the curve (AUC), and C-peptide. Seven studies involving 355 T1DM patients were included. Three studies involving 141 patients compared a GFD to a standard diet in children and adolescents withT1DM without CD. Additionally, two studies with 164 patients examined the same diet comparison in those with T1DM and concurrent CD. A comparison between T1DM with CD and T1DM alone, using a GFD, was conducted in two studies encompassing 50 patients. Patients withT1DM alone had similar HbA1c [pooled weighted mean difference (WMD) = -0.5, 95% confidence interval (CI): -1.0 to 0.1, P = 0.079] and IDAA1c (pooled WMD = -0.4, 95%CI: -0.9 to 0.1, P = 0.095) levels after a GFD and a standard diet. In children and adolescents withT1DM and CD, a GFD was associated with a significantly lower HbA1c compared with a standard diet (pooled WMD = -0.64, 95%CI: -1.22 to -0.05, P = 0.034). Insulin dose was significantly lower in T1DM combined with CD patients having a GFD vs a standard diet (pooled WMD = -0.34, 95%CI: -0.66 to -0.03, P = 0.032). Our study suggests that a GFD may offer significant benefits for children and adolescents with both T1DM and CD over a standard diet. While the evidence indicates improved glycemic control with a GFD, the quality of this evidence is low, highlighting the need for rigorous, randomized trials to confirm these preliminary findings. In the interim, enhancing dietary awareness and providing tailored nutritional guidance could be pivotal for optimizing glucose management in this patient population.