# Influence of Myeloperoxidase Levels on Periodontal Disease: An Applied Clinical Study
###### Abstract  
In this trial, we evaluated the influence on plasma and salivary myeloperoxidase (MPO) levels of periodontal health, coronary heart disease (CHD), periodontitis, or both periodontitis and CHD. Clinical and periodontal parameters were collected from periodontitis patients (n = 31), CHD patients (n = 31), patients with both periodontitis and CHD (n = 31), and from healthy patients (n = 31) together with saliva and plasma samples. The median concentrations of salivary and plasma MPO were statistically higher in the CHD patients [plasma: 26.2 (18.2-34.4) ng/mg; saliva 83.2 (77.4-101.5) ng/mL, p < 0.01] and in the periodontitis plus CHD patients [plasma: 27.8 (22.5-35.7) ng/mg; saliva 85.6 (76.5-106.7) ng/mL, p < 0.001] with respect to periodontitis and control patients. Through a univariate regression analysis, c-reactive protein (CRP) and CHD (both p < 0.001) and periodontitis (p = 0.024) were statistically correlated with MPO in plasma. The multivariate regression analysis demonstrated that only CRP was statistically the predictor of MPO in plasma (p < 0.001). The multivariate regression analysis in saliva demonstrated that, regarding MPO levels the only predictors were CRP (p < 0.001) and total cholesterol (p = 0.035). The present study evidenced that subjects with CHD and periodontitis plus CHD had higher plasma and salivary levels of MPO compared to subjects with periodontitis and healthy controls. myeloperoxidase; periodontitis; cardiovascular disease; applied model +
Footnote †: journal: MedicalMyeloperoxidase (MPO) is one of the more mediators expressed within tissues during the progression of inflammation [11]. It was demonstrated that MPO, secreted by endothelial cells after exposure to pathogenic bacteria, represents a potent mediator of vascular inflammation and a vasoconstrticrator [12]. In this regard, it has been shown that several proinflammatory cytokines, including IL-1, -6, and -8, have been reported to upregulate the secretion of MPO [13]. The expression of MPO was strongly associated in the gingival tissue and endothelial cells during periodontitis [14]. More specifically, a clinical study found that, in gingival crevicular fluid, MPO increased with the progression of the periodontitis, and also that MPO was involved in the regulation of IL-1b expression in gingival tissues [15; 16]. During the last few decades, several studies have analyzed the association between periodontal disease endothelial dysfunction, and increased risk of CHD and cardiovascular disease (CVD) [17; 18]. More specifically, it has been supposed that the inflammatory mediators that are present and released during the active phase of periodontal disease such as CRP, interleukins, prostaglandandins, and metalloproteinases, can negatively influence the release of nitric oxide (NO) [19]. The altered release of NO can affect the endothelium which in turn regulates vascular tone, and, finally, dysfunction of the endothelium and enhanced risk of CVD [20; 21]. For these causes, there is growing interest to investigate some other oral mediators that can regulate and impact the subclinical endothelial dysfunctions as an early sign of augmented risk of CHD and CVD. In this regard, a correlation between high proportion of MPO, CRP, and endothelial dysfunction was recently reported [22; 23]. The production of NO at local level has been shown to be fundamental in the aetiology and progression of periodontitis. The increment and reduction of NO metabolites in saliva production in periodontal tissue against periodontal therapeutic microbiota during periodontitis have been demonstrated to be correlated endothelial dysfunction [24; 25]. Furthermore, it has been reported that MPO plays an important role in the reduction of NO synthase especially during periodontitis [26]. Based on these findings, the aims of this trial were to consider a possible association of periodontitis, CVD, or both periodontitis plus CVD on serum and salivary MPO.