MicroRNAs in Obesity, Insulin Resistance, and Type 2 Diabetes: Mechanistic Insights and Translational Perspectives

Obesity and type 2 diabetes mellitus (T2DM) are multifactorial disorders characterized by insulin resistance, chronic low-grade inflammation, adipose tissue dysfunction, and multi-organ metabolic impairment. MicroRNAs (miRNAs) act as post-transcriptional gene regulators and play critical roles in metabolic homeostasis, the modulation of insulin signaling, adipogenesis, inflammatory pathways, and energy balance in key insulin-target tissues, including liver, skeletal muscle, and adipose tissue. This review summarizes mechanistic and translational insights into miRNA regulation in obesity, insulin resistance, and T2DM, integrating data from human studies and experimental models on miRNA sequence codes and extracellular vesicle sorting pathways. We focus on the tissue-specific and systemic roles of miRNAs, highlighting their contribution to inter-organ communication and metabolic network regulation. In addition, we emphasize their emerging roles as predictive biomarkers, modulators of treatment response, and promising targets for RNA-based interventions. Advances in sequence-specific miRNA sorting and extracellular vesicle-mediated delivery may provide avenues for therapeutic intervention. However, challenges related to delivery efficiency, tissue specificity, off-target effects, and variability in miRNA quantification remain important barriers to clinical translation. Addressing these limitations may help define the clinical utility of miRNAs as biomarkers and therapeutic targets in metabolic disorders.