NAMPT and metabolic syndrome: The dysregulated adipocytes and macrophages within visceral fat component are metabolically active and may secrete or regulate various adipokines and proinflammatory cytokines, such as leptin [29], adiponectin [30], resistin [31], visfatin [32, 33], and vascular endothelial growth factor [34, 35], which may lead to low-grade systemic inflammation, insulin resistance, dyslipidemia, and/or increased synthesis of vasoactive and fibrogenic substances, eventually leading to impairment of vascular endothelial cells and kidney function [36–40].