RESUMO
OBJECTIVE: The aim of this study was to determine whether there are differences in salivary oxidative stress between patients with diabetes mellitus type 2 (DM2) and healthy non-diabetic patients, and whether this oxidative stress is associated with the presence of periodontal disease in diabetic patients. MATERIAL AND METHODS: This observational study included 70 patients divided into three groups according to metabolic control levels: 19 non-diabetic patients (control group); 24 patients with good metabolic control (HbA1c<7%), and 27 patients DM2 with poor metabolic control (HbA1c>7%). The following oxidative stress parameters were measured in all subjects: glutathione peroxidase (GPx), glutathione reductase (GRd), reduced glutathione (GSH) and oxidized glutathione (GSSG). Periodontal health was determined by means of the community periodontal index (CPI) recommended by the WHO. RESULTS: The diabetic group with good metabolic control showed a significant increase in GPx and GRd activity in comparison with the control group (P<.001). The activity of the enzymes measured was significantly less in patients with poor metabolic control in comparison with the control group and well-controlled diabetic groups (P<.001). Both diabetic groups showed higher GSSG/GSH quotients and CPI in comparison with the control group, and both parameters were significantly higher in diabetic patients with poor metabolic control in comparison with well-controlled diabetic patients. CONCLUSIONS: Poor metabolic control in DM2 patients is associated with higher levels of salivary oxidative stress and worse periodontal health.
