INS and prediabetes syndrome: In light of the significant pathophysiological role of myocardial insulin resistance, the primary aim of this study was to determine whether sex-related differences exist in insulin-stimulated myocardial glucose metabolic rate (MRGlu) using dynamic myocardial PET with 18F-Fluorodeoxyglucose (18F-FDG) combined with euglycemic-hyperinsulinemic clamp, in individuals with normal glucose tolerance, prediabetes and type 2 diabetes without history of heart disease.