The Association of Plasma Levels of Mir-34A and Mir-149 with Obesity and Insulin Resistance in Obese Children and Adolescents

Context: MicroRNAs (miRNAs) are short noncoding RNAs involved in posttranscriptional regulation of gene expression that influence various cellular functions including glucose and lipid metabolism and adipocyte differentiation. Objective: The aim of this study was to evaluate the levels of miR-34a and miR-149 and their relationship with metabolic parameters in obese children and adolescents. Design: Seventy children and adolescents were enrolled in the study. Plasma levels of microRNAs were evaluated by real-time PCR using SYBR green and analyzed by ΔCt method. Plasma concentrations of visfatin and insulin were measured by ELISA method. Glucose and lipid profile were determined colorimetrically. HOMA-IR was calculated and used as an index of insulin resistance (IR). Results: miR-34a was significantly lower in subjects with insulin resistance compared to obese children with normal insulin sensitivity. There was an inverse relationship between miR-34a levels and both insulin and HOMA-IR. On the other hand, miR-149 was significantly correlated with visfatin. There was no significant difference in miR-34a and miR-149 between obese and normal weight subjects. Conclusions: miR-34a is associated with insulin and HOMA-IR and thus seems to be involved in IR. miR-149 is inversely associated with visfatin levels which could be indicative of anti-inflammatory effect of this miRNA.