Evaluation of the effects of non-surgical periodontal therapy on apelin and oxidative stress levels in individuals with periodontitis

Aim: The aim of this study was to investigate the levels of Apelin-13, Apelin-36, TAS, TOS, and OSI in GFC samples from systemically healthy individuals with different stages of periodontitis, as well as to evaluate the changes in these biochemical parameters following non-surgical periodontal therapy (NSPT). Material and Method: A total of 61 individuals diagnosed with Stage 1–2 periodontitis (G1, n=31) and Stage 3–4 periodontitis (G2, n=30) were included in the study. DOS samples were collected and clinical periodontal parameters were recorded at four time points: baseline (T0, before NSPT), 1 month (T1), 3 months (T3), and 6 months (T6) after NSPT. Results: GFC Apelin-13 levels were significantly higher in G2 compared to G1, and a decrease was observed in both groups following NSPT (p<0,01). Apelin-36 levels increased after NSPT in both groups, and baseline levels of Apelin-36 were significantly higher in G1 than in G2 (p<0,01). TAS levels were higher in G1 than in G2, with a significant time-dependent decrease in G1 and a significant increase in G2 (p<0,01). No significant differences in TOS levels were found between the groups (p>0,05). While TOS levels in G2 did not show significant changes over time (p>0,05), a significant increase was observed in G1 (p<0,01). OSI levels were significantly higher in G2 compared to G1 (p<0,01), and OSI levels showed a significant time-dependent decrease in G2 (p<0,01). Positive correlations were found between Apelin-13, TOS, OSI, and clinical periodontal parameters (p<0,01), while negative correlations were observed between Apelin-36, TAS, and clinical parameters (p<0,05). Conclusion: These findings suggest that Apelin-13 and Apelin-36 may play a role in the pathogenesis of periodontal disease. Apelin-13 may have pro-inflammatory, while Apelin-36 may exhibit anti-inflammatory effects, indicating that these biomarkers could potentially be used in the assessment of periodontal health status. Keywords: Apelin-13, Apelin-36, GCF, Non-surgical Periodontal Treatment, Oxidative Stress, Periodontitis