IL6 and obesity due to melanocortin 4 receptor deficiency: Previous studies have demonstrated that the systemic level of IL-6 and TNF-α increase in obese individuals and decrease after weight loss.2,3,17 A significant relationship between serum IL-6 and BMI and WC have been reported, in the absence of a relationship with TNF-α.27 Recent studies reported both higher levels of IL-6 and TNF-α in overweight and obese individuals with periodontitis compared to non-obese counterparts.28,29 Khaodhiar, et al.30(2004) also found a significant association between obesity and IL-6 in their study of obese subjects, but not with TNF-α.