Evaluation of Stress and Salivary Neuropeptides in Periodontal Health and Disease

Background: Neuropeptides have been identified as pivotal regulators of periodontal inflammation. The primary objective of this study is to investigate the salivary and serum levels of substance P (SP), vasoactive intestinal peptide (VIP), and cortisol, aiming to elucidate their relationship with periodontal health and disease. In addition, it aims to explore the potential associations between these biomarkers, stress factors, and clinical periodontal parameters. Materials and Methods: A total of 90 individuals were recruited as a part of this study and categorized into Group I: healthy periodontium, Group II: nonsmokers with periodontitis, and Group III: smokers with periodontitis. The clinical parameters evaluated were gingival index, plaque index, probing pocket depth, and clinical attachment loss. Perceived Stress Scale (PSS) was evaluated by validated questionnaires. Serum and salivary expression of SP, VIP, and cortisol levels were estimated all the groups. Neuropeptides were estimated with enzyme-linked immunosorbent assay procedure, and the cortisol was estimated using electrochemiluminescent method. Results: Salivary SP and salivary and serum VIP levels were comparatively high in the generalized periodontitis with smokers (Group III) than in the generalized periodontitis (Group II) and healthy periodontium (Group I) groups, and the difference was statistically significant ( P = 0.001). Salivary cortisol levels and PSS scores were comparatively high in the generalized periodontitis with smokers (Group III) than in the generalized periodontitis (Group II) and healthy periodontium (Group I) groups, and the difference was statistically significant. Conclusion: Neuropeptides SP and VIP are modulated in periodontal disease. Smoking and stress may influence neurogenic inflammation in periodontitis by enhancing the local peptidergic innervation within the periodontium.