LEP and Obesity: Indeed, leptin has been proposed as a possible causative link between obesity and osteoarthritis (Vuolteenaho et al., 2014; Martel-Pelletier et al., 2016), while TNF-α and ILs-6 and−8 have been implicated in structural joint abnormalities (Dumond et al., 2003), nociceptive pathways (Lübbeke et al., 2013), and in the development and progression of chronic pain (Dina et al., 2008; Wang et al., 2008).