Does a Gluten-Free Diet Affect BMI and Glycosylated Hemoglobin in Children and Adolescents with Type 1 Diabetes and Asymptomatic Celiac Disease? A Meta-Analysis and Systematic Review

Background: Children diagnosed with type 1 diabetes mellitus (T1DM) are more prone to having celiac disease (CD) than the normal population. Moreover, patients with this dual diagnosis who are also on a diabetic and gluten-free diet (GFD) risk faltering growth and uncontrolled blood glucose levels. This review aims to assess the efficacy and effectiveness of managing patients with T1DM screened for CD with GFD to prevent complications associated with these chronic pathologies in childhood and adulthood. Materials and Methods: We abided by the PRISMA guidelines in this meta-analysis and used multiple databases and search engines. We included case–control studies. The primary outcomes were changes in the standard deviation score, body mass index (SDS BMI), and glycosylated hemoglobin (HA1C) after being on a GFD for at least twelve months. Results: The pooled data from the six studies included showed that there was neither a statistically significant difference in the mean SDS BMI (−0.28 (95% CI −0.75, 0.42)) (p = 0.24) nor in the mean of HA1C (mean −0.07 (95% CI −0.44, 0.30)) (p = 0.36) for the same group. HDL cholesterol improved significantly in patients on a strict GFD (p < 0.01). Conclusions: In children with T1DM and asymptomatic CD, being on a GFD had no significant effect on BMI or HA1C. However, it can have a protective effect on the other complications found in both chronic pathologies.