APLN and peripheral neuropathy: Several studies have shown that apelin can improve insulin resistance (IR), inhibit arterial atherosclerosis (AS), and improve peripheral vascular perfusion and vascular function in the diabetic foot.[12–17] Increasing evidence has also confirmed that apelin is a promising new therapeutic target in diabetes.[18] Furthermore, apelin is widely present in neuronal cell bodies and fibers throughout the nerve axis.[15] However, studies investigating apelin and peripheral neuropathy are limited.