Salivary matrix metalloproteinase-9 (MMP-9) as a biomarker of periodontitis in pregnant patients with diabetes

Background. Pregnancy and diabetes increase the risk of developing pathological conditions in the peri-odontium. Salivary biomarkers, such as matrix metalloproteinase-9 (MMP-9), as well as antioxidants can be used as diagnostic indicators in monitoring periodontitis.Objectives. The aim of the study was to assess the periodontal status of pregnant women with regard to the presence of diabetes. In addition, we aimed to assess antioxidant activity and the level of MMP-9 in saliva in order to establish the optimal noninvasive determinants of periodontitis.Material and methods.The study included 104 pregnant women: 35 patients had gestational diabetes mellitus (GDM); 30 patients had type 1 diabetes (T1D); and 39 patients did not have diabetes (the con-trol group). The physical examination included the assessment of the approximal plaque index (API), the gingival index (GI), bleeding on probing (BOP), the probing pocket depth (PPD), and clinical attachment loss (CAL). In the saliva study, MMP-9 concentration as well as the ferric reducing ability of plasma (FRAP), and the activity of superoxide dismutase (SOD), glutathione reductase (GR) and glutathione peroxidase (GPX) were measured.Results. The pregnant patients with GDM and T1D had higher GI, BOP, PPD, and CAL scores than the con-trol women (p < 0.0001, p = 0.0040, p = 0.0100, p = 0.0030, and p < 0.0001, p < 0.0009, p < 0.0001, p < 0.0001, respectively). The T1D patients had higher API scores as compared to the control women (p = 0.0010). The patients with periodontitis had higher salivary MMP-9 levels than the patients without periodontitis (p = 0.0001). The salivary antioxidant levels and activity were comparable among the study groups. The determinants of periodontitis (p < 0.0001) were MMP-9 concentration (p = 0.0008) and oral hygiene (p = 0.0001). The concentration of MMP-9 was also a useful determiner of the presence of periodontitis (p < 0.0001).Conclusions. In the pregnant women with diabetes, we observed worse gingival conditions, deeper periodontal pockets and greater attachment loss in comparison with the women from the control group. The concentration of MMP-9 in saliva is a good predictor of periodontitis and might be a useful tool for diagnosing periodontitis.