TNF and diabetes mellitus: Accumulation of adipose tissue, especially visceral fat, which is the fat surrounding internal organs, is not just harmful in the way that it increases the risk of heart disease and conditions such as diabetes, but it also secretes multiple pro-inflammatory cytokines, including interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and adipokines such as leptin [23-26].