The impact of insulin resistance on renal microcirculation in patients with MetS arises from insulin’s role as a key regulator of factors such as nitric oxide (NO), endothelin-1 (ET-1), angiotensin II (AngII), and vascular endothelial growth factor (VEGF), all of which are critical for blood vessel dilation, constriction, and formation. The gene discussed is EDN1; the disease is metabolic syndrome.