TNF and periodontitis: Elevated serum levels of IL-6 and TNF-α in both diabetes and obesity, with IL-6 and CRP levels predicting the future onset of type 2 diabetes. Patients with periodontitis also exhibit elevated serum levels of IL-6 and CRP, with IL-6 levels correlating with the severity of the disease. Consequently, systemic inflammation associated with periodontal disease may exacerbate diabetes.