Salivary mitofusin levels in periodontal disease: a cross-sectional case-control study

Background: Mitofusin (Mfn) is a mitochondrial fusion protein. It has two isoforms (Mfn1 and 2) and is critical in intracellular energy production, calcium transfer, and phospholipid metabolism. Based on previous evidence linking mitochondrial function with the pathophysiology of periodontal inflammation, we hypothesized that salivary Mfn1 and Mfn2 levels may differ across periodontal health, gingivitis, and periodontitis, and that these levels correlate with markers of inflammatory and oxidative stress. Although previous studies have suggested that Mfn2 plays a role in inflammatory and oxidative pathways, clinical evidence regarding its role in periodontal disease is lacking. The null hypothesis of this study was that salivary Mfn levels are not significantly altered with periodontal conditions and are not correlated with inflammation or oxidative stress markers in saliva. Methods: A total of 81 participants were included in this cross-sectional case-control study, with 27 individuals per group. Periodontally healthy patients, patients with gingivitis, and patients with stage 3 or stage 4 grade C periodontitis were recruited for the study. Mfn-1 and Mfn-2 levels were measured. To identify their correlation with inflammatory mechanisms, interleukin-1β levels, total oxidative status (TOS), and total antioxidant status (TAS) were determined using enzyme-linked immunosorbent assay and colorimetric measurements. The oxidative stress index (OSİ) was calculated. Results: Salivary Mfn1 levels were significantly higher in patients with periodontitis compared to healthy controls (36.54 ± 13.15 ng/mL, 24.67 ± 8.69 ng/mL, p < 0.001). No significant difference was observed between the groups in terms of Mfn2 levels (p > 0.05). While significant differences were found between Group P and Group H in TAS and OSI values (p < 0.05), TOS values ​​did not show any significant difference between the groups (p > 0.05). A positive correlation was found between Mfn1 and Mfn2 and IL-1β levels (p < 0.05). Mfn1 and Mfn2 did not have any significant correlation with TAS, TOS, or OSI values (p > 0.05). Conclusions: Elevated Mfn1 levels in the saliva of patients with periodontitis suggested that mitochondrial function was disrupted in severe periodontitis. Mitofusin levels showed no significant correlation with oxidative stress markers in this study. Trial registration: This study was registered in ClinicalTrials.gov under the number NCT06510608 on July 18, 2024. © The Author(s) 2025.