Do arginine metabolites have a role in periodontitis due to smoking? A new perspective.

OBJECTIVES: Cigarette consumption is common around the world and besides its negative effects on health, and its effects on periodontitis draw attention. Arginine metabolites are involved in the pathogenesis of several systemic inflammatory diseases' including cardiovascular diseases. Our aim was to determine periodontitis and healthy individuals' arginine metabolites and IL-6 levels in saliva and serum and to evaluate those according to smoking status. MATERIALS AND METHODS: The study consisted of four groups: healthy individuals (control [C]; n = 20), smokers with healthy periodontium (S-C; n = 20), nonsmokers with Stage-III Grade-B generalized periodontitis (P; n = 20) and smokers with Stage-III Grade-C generalized periodontitis (S-P; n = 18). Periodontal parameters were measured. Analysis of methylated arginine metabolites was performed by LC-MS/MS, and IL-6 levels were determined by ELISA kits. RESULTS: In nonsmokers, salivary concentrations of asymmetric dimethylarginine (ADMA) and symmetrical dimethylarginine (SDMA) were higher in the periodontitis than control (p < 0.001, p = 0.010). Smokers with periodontitis exhibited higher ADMA (p = 0.033, p < 0.001) and arginine (p = 0.030, p = 0.001) saliva concentrations than smoking and nonsmoking controls. CONCLUSIONS: Our results demonstrated that salivary concentrations of ADMA and SDMA were associated with periodontitis. Smoking increased ADMA, SDMA and NG -monomethyl L-arginine (L-NMMA) levels in serum only in periodontitis patients.