Trimethylamine N‐Oxide (TMAO) and TNF‐α Levels in Periodontal Disease Associated With Smoking

ABSTRACTAimsTrimethylamine N‐oxide (TMAO) is a compound involved in the pathogenesis of various systemic inflammatory diseases, including cardiovascular conditions. The aim of this study was to determine differences in saliva and serum levels of TMAO between periodontitis and healthy patients according to smoking status.MethodsThe study included four systemically healthy groups: periodontally healthy non‐smokers (NS‐Control; n = 25), non‐smokers with Stage‐III‐Grade‐B periodontitis (NS‐Periodontitis; n = 25), periodontally healthy smokers (S‐Control; n = 25), and smokers with Stage‐III Grade‐C periodontitis (S‐Periodontitis; n = 25). Periodontal parameters were recorded. TMAO levels were determined in saliva and serum samples using liquid chromatography‐mass spectrometry (LC–MS/MS). TNF‐α levels were measured by the ELISA method.ResultsSalivary TNF‐α and TMAO levels were significantly elevated in the smoking periodontitis group compared to other groups (p < 0.001 and p = 0.003, respectively). Serum TMAO levels were also significantly higher in the smoking periodontitis group compared to non‐smoking controls and non‐smoking periodontitis. TMAO/SFR ratios were notably higher in the smoking periodontitis group compared to other groups, and a strong positive correlation was observed between salivary TMAO and TNF‐α levels (r = 0.892, p < 0.001).ConclusionThe data suggested that TMAO and TNF‐α are associated with inflammatory mechanisms of periodontitis in cases where periodontitis coexists with smoking.Trial RegistrationNCT06580431