The study included eighty subjects: 20 subjects with systemically and periodontally healthy (CTRL group), 20 patients with T2DM and periodontally healthy (DM-CTRL group), 20 patients with systemically healthy and CP (CP group), 20 patients with CP and T2DM (DM-CP group). Periodontitis patients received nonsurgical periodontal therapy. GCF sampling and clinical periodontal parameters were assessed at baseline and 6 weeks after periodontal therapy. Chemerin and interleukin-6 (IL-6) levels were measured by enzyme-linked immunosorbent assay, and their relative ratios were calculated.