Association of Salivary Levels of Heme Oxygenase-1 and Sulfiredoxin-1 with Periodontal Health in Smokers and Nonsmokers: A Cross-Sectional Analytical Study

Introduction: We aimed to determine the association between salivary levels of heme oxygenase 1 (HO-1) and sulfiredoxin-1 (SRXN-1) with periodontal health in smokers and nonsmokers. Methods: This cross-sectional study was conducted on 175 participants and was divided into five groups equally: (1) healthy controls, (2) nonsmoker gingivitis patients, (3) smoker gingivitis patients, (4) nonsmoker periodontitis patients, and (5) smoker periodontitis patients. From each participant, whole-unstimulated salivary samples were collected. The periodontal parameters, including plaque index (PI), bleeding on probing (BOP), probing pocket depth, and clinical attachment loss, were recorded. Enzyme-linked immunosorbent assays were used to measure the protein levels of salivary HO-1 and SRXN-1. Results: Salivary HO-1 and SRXN-1 levels were significantly lower in gingivitis and periodontitis patients than in healthy controls ( p < 0.001). Also, levels of SRXN-1 were significantly lower in smokers than non-smokers among gingivitis and periodontitis groups ( p < 0.001). The HO-1 and SRXN-1 had a significant ( p < 0. 001) and negative correlation with PI and BOP. Conclusion: Within the limitations of this study, salivary levels of SRXN-1 were lower in smokers with gingivitis and periodontitis.