Background: Overweight and obesity prevalence has risen substantially in the last years. MicroRNAs (miRNAs) are factors that regulate gene expression through binding to a complementary sequence of mRNA.
Objective: To determine the association between the expression of miRNAs with the overweight and obesity in children.
Methods: We carried out a systematic review in Medline (Ovid), EMBASE, LILACS, and CENTRAL. We included clinical trials, cohort studies, cases and controls, and cross-section studies. We excluded quasi-experimental, prognostic studies, animal experiments, in silico studies, and studies using the adult population.
Results: We included seven studies (684 children). Three hundred sixty-one children have obesity/overweight, and 323 had normal weight, and 40.64% (278) were boys. The classification of obesity was inconsistent between the studies with several classifications used. A total of 65 miRNAs were reported to be associated with obesity and overweight, at least two references reported miR-122, miR-122-5p, miR-15b, miR15b-5p, miR191-5p, miR-222, miR-222-3p, miR 486, miR-486-3p, miR-486-5p. Blood samples were the most common samples used to measure the miRNAs, and the approaches to select the miRNAs were diverse, with four articles performing high-throughput techniques (sequencing and microarrays) before the validation of the miRNAs associated with obesity. Pathway analysis of the repeated miRNAs showed that they were involved in the regulation of metabolic and signaling pathways, including fatty acid metabolism.
Conclusion: miRNAs have potential as biomarkers of the development of pathologies such as obesity. We found a heterogeneous group of these molecules associated with obesity in children. We consider the miR-15b-5p, miR-486-5p, and hsa-miR-122-5p as good candidates for obesity biomarkers.