IL6 and obesity due to melanocortin 4 receptor deficiency: On the other hand, there is increased prevalence of obesity among patients with OSAS, and previous evidence suggests that adipose tissue can produce proinflammatory factors, such as C-reactive protein (CRP), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-8 [13–16].