In addition, a significant difference in serum visfatin level was found between two groups of periodontitis participants with and without obesity, with a higher level of serum visfatin found in OP group (Figure 3, MD = 4.21; 95% CI: 2.65–5.77, p < 0.00001) [28,33]. The gene discussed is NAMPT; the disease is obesity due to melanocortin 4 receptor deficiency.