Combined Proteomic and Metabolomic Analysis of Cognitive Impairment in Patients With Burning Mouth Syndrome.

Burning mouth syndrome (BMS) is considered a multifactorial condition. The study aimed to investigate the association between BMS and cognitive impairment (CI), as well as the proteomic and metabolomic characteristics. A total of 42 BMS patients and 23 healthy controls were recruited from August 2022 to August 2024 to analyse the relationship between BMS, psychological factors and cognitive function. Saliva samples were collected for comprehensive proteomic and metabolomic analyses, followed by validation studies. The mini-mental state examination (MMSE) indicated a significantly higher prevalence of CI in the BMS group (50.00%) compared to the healthy control group (8.70%) (p = 0.001). Logistic regression analysis revealed that BMS incidence was negatively correlated with MMSE scores and positively correlated with depression scores (both p < 0.05). Proteomics and metabolomics identified 197 differential proteins and 208 differential metabolites in the BMS group relative to the healthy control group. Additionally, there were 407 differential proteins and 344 differential metabolites in the BMS with cognitive impairment (BC) group compared to the BMS with noncognitive impairment (BnC) group. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of combined proteomics and metabolomics data revealed the involvement of the arachidonic acid metabolic pathway and salivary secretion pathway in BMS and CI respectively. Higher levels of depression and lower cognitive function appear to be more closely associated with BMS. The pathways of arachidonic acid metabolism and salivary secretion may play significant roles in the pathogenesis of BMS and CI respectively.