Alteration of salivary LPO, MDA, LDH, glutathione, GPx, SOD and vitamins in oral submucous fibrosis: A three-level meta-analysis study

This study aims to investigate the alteration of salivary biomarker profiling in the development of oral submucous fibrosis (OSMF) and to explore the influence of saliva in the diagnosis of OSMF. A systematic search of published articles using the PRISMA guidelines was conducted to identify relevant studies on OSMF and saliva. All eligible studies, including case-control, cross-sectional studies, cohort, and pilot studies, contained the evaluation of salivary biomarker profiling in patients with OSMF. Salivary biomarker data from 28 selected articles were categorized into nine groups, and their mean values were determined. A three-step meta-analysis was performed by grouping salivary biomarker profiling into more heterogeneous categories based on OSMF classification, considering functional, histological, and clinical grading. The salivary biomarker profiling analysis revealed significant alterations in all markers, indicating their efficacy in OSMF diagnosis. Subgroup analyses highlighted significant associations in oxidative stress and protein with increased mean values, particularly emphasizing lipid peroxidase (LPO), malondialdehyde (MDA), and lactate dehydrogenase (LDH). Conversely, decreased mean values were observed in glutathione, glutathione peroxidase (GPx), superoxide dismutase (SOD), and vitamins. Notably, OSMF grading analysis demonstrated a significant difference in weighted effect sizes for histological grading, particularly in stage IV. The study underscores the alteration of specific salivary biomarkers, particularly those associated with LPO, MDA, LDH, glutathione, GPx, SOD, and vitamins, in diagnosing and grading OSMF.