Association of Salivary HIF-1α Level With Epithelial and Mesenchymal Markers in Smokers and Nonsmokers With Periodontitis: A Case-Control Study.

Objectives: This case-control study aimed to investigate the relationship between the hypoxia-related biomarker hypoxia-inducible factor-1α (HIF-1α) and the epithelial-mesenchymal transition (EMT)-associated markers E-cadherin (E-CAD) and N-cadherin (N-CAD) in saliva among smokers and nonsmokers with and without periodontitis and to assess their association with clinical periodontal parameters. Methods: A case-control study was conducted, including 88 participants equally allocated into four groups ( Results: Salivary E-CAD and N-CAD levels were significantly higher in the periodontitis groups than in the healthy groups ( Conclusions: Salivary E-CAD and N-CAD were significantly altered in periodontitis and demonstrated greater potential than HIF-1α for reflecting periodontal disease status. The absence of significant differences in salivary HIF-1α levels among the study groups may indicate limited ability to reflect localized periodontal hypoxic changes. HIF-1α also showed limited and inconsistent associations with EMT-related biomarkers, with a significant positive correlation observed only between HIF-1α and N-CAD in the periodontitis group. Smoking was associated with alterations in biomarker profiles, particularly E-CAD levels. Overall, salivary EMT-related biomarkers may serve as promising noninvasive indicators of periodontal disease, although further validation is required.