HIF1A and metabolic syndrome: In summary, MetS with or without OHD enhanced the generation of oxidative stress mediated through the NFκB signaling pathway, whereas L-arginine offered a beneficial effect on lessening oxidative damages, improving angiogenesis and neurogenesis via the NRF2/HIF1α signaling pathway, as shown in a rat model of MetS with or without OHD-induced OAB.