Meta-analysis of the effect of the gluten-free diet on the lipid profile of patients with celiac disease

INTRODUCTION: Celiac disease (CD) is an autoimmune disorder that affects the digestive system. Treatment for CD relies on a gluten-free diet, and previous studies have suggested alterations in the lipid profile. However, the literature shows no consensus regarding the specific lipid fraction affected, the magnitude of the change, or whether lipid parameters tend to increase or decrease. The aim of this study was to evaluate the effect of a gluten-free diet on HDL, LDL, total cholesterol, and triglyceride levels in patients with celiac disease reported in the scientific literature. METHODS: A literature review was conducted in four databases including studies published in English, Spanish, and Portuguese. Inclusion and exclusion criteria were applied. Heterogeneity was assessed using the I² statistic, publication bias was evaluated with Egger's test, and meta-analyses were performed to estimate mean differences in lipid profile parameters using a random-effects model with the REML estimation method. RESULTS: Fifteen studies were included, most of them conducted in Italian populations, comprising a total of 1,820 patients with CD, of whom 706 were pediatric. In pediatric patients, the meta-analysis showed no significant change in total cholesterol (6.2 mg/dL; 95% CI - 7.1 to 19.6), a significant decrease in triglycerides (- 14.2 mg/dL; 95% CI - 22.6 to - 5.8), and an increase in HDL cholesterol (11.4 mg/dL; 95% CI 8.5 to 14.2). In contrast, among adults, there was a significant increase in total cholesterol (12.4 mg/dL; 95% CI 5.1 to 19.7), triglycerides (5.9 mg/dL; 95% CI 0.5 to 11.2), and HDL cholesterol (6.1 mg/dL; 95% CI 3.9 to 8.3). CONCLUSION: The findings of this study indicate that patients with celiac disease experience significant changes in lipid profile following adherence to a gluten-free diet, with a differential pattern between pediatric and adult populations.