TNF and metabolic syndrome: Proinflammatory cytokines including interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) are directly associated with the risk of MetS, whereas anti-inflammatory cytokines—IL-10, ghrelin, and antioxidant factors (paraoxonase 1 [PON1])—are correlated inversely with components of the cluster.18