Association Between Salivary Omentin-1 and C-reactive protein (CRP) levels with Periodontitis Severity in Male Patients with Type 2 Diabetes: A Cross-Sectional Study

Background & Objective: Type 2 diabetes mellitus (T2DM) and periodontitis share a well-established bidirectional relationship, where systemic inflammation act as a critical mechanistic link.Omentin-1, an anti-inflammatory adipokine with potential metabolic regulatory functions, and C-reactive protein (CRP), a widely recognized marker of systemic inflammation, may play opposing but interconnected roles in this association.This cross-sectional study aimed to evaluate salivary levels of Omentin-1 and CRP in T2DM patients, at varying stages of periodontitis, in comparison with healthy controls. Materials & Methods:In this cross-sectional study, 160 participants were enrolled, including 32 healthy controls and 128 T2DM patients stratified into four equal groups based on periodontitis stages I-IV.Unstimulated saliva samples were collected, and periodontal parameters-probing pocket depth, clinical attachment level (CAL), and bleeding on probing (BOP)-were recorded.Salivary levels of Omentin-1 and CRP were measured using ELISA. Results:Omentin-1 levels were significantly higher in healthy controls (210.61pg/mL) than in T2DM-periodontitis patients (P < 0.001), showing a progressive decline with advancing periodontitis stages (Stage I: 180.72;Stage II: 153.16;Stage III: 123.90; and Stage IV: 122.82 pg/mL).Conversely, CRP levels were significantly elevated in T2DM-periodontitis patients (P < 0.001), increasing with disease severity (Stage I: 120.4;Stage II: 178.0; Stage III: 289.4; and Stage IV: 501.0 pg/mL) compared to controls (45.3 pg/mL). Conclusion: SalivaryOmentin-1 levels decrease with the progression of periodontitis in T2DM patients while CRP levels increase, suggesting a potential protective role of Omentin-1 against inflammation.These biomarkers may serve as useful indicators for monitoring both periodontitis severity and metabolic dysfunction in T2DM, underscoring their clinical relevance.