Only in two studies [16,25], visfatin levels in GCF were compared between gingivitis patients and chronic periodontitis patients, and 30 gingivitis patients and 30 chronic periodontitis patients were included in the analysis, SMD was estimated as 3.59 ng/ml (95%CI: -2.11–9.30, p = 0.217) (Table 2). This evidence concerns the gene NAMPT and periodontitis.