Introduction: Insulin resistance is a medical condition characterized by decreased tissue response to insulin; or a decrease in its production or quality, which translates into a consequent increase in the concentration of glucose in the blood; metabolic syndrome is a pathology mediated by insulin resistance and encompasses the coexistence of type 2 diabetes, arterial hypertension, dyslipidemia, and central obesity. Objective: To synthesize current knowledge regarding the pathophysiology of metabolic syndrome and the role of insulin resistance. Methodology: This is a narrative review of the literature that is built from original articles, systematic and narrative reviews published in Pubmed, ScienceDirect, Redalyc, and SciELO, using the descriptors and terms: metabolic syndrome, insulin resistance, cell insulin secretors. The selection was made according to the inclusion criteria: publication time of less than 10 years, English and/or Spanish language, and being freely available in its full version. Conclusions: Insulin resistance is a complex pathophysiological phenomenon that, unlike the classical and erroneous glycocentric concept, impacts on the metabolism of carbohydrates, lipids and proteins, consequently affecting all functional and structural levels of the organism, constituting the pathophysiological substrate in the development of metabolic syndrome.