LEP and type 2 diabetes mellitus: T2DM is no longer thought of as a purely metabolic disorder of insulin resistance, hyperglycemia, and pancreatic β-cell dysfunction; indeed, T2DM is a condition of chronic, low-grade systemic inflammation, which is mainly due to visceral adiposity and ectopic lipid deposition that lead to the ongoing release of pro-inflammatory cytokines like Tumor Necrosis Alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6) as well as chemokines, acute-phase proteins, and adipokines like resistin and leptin [3,4,5].