# Influence of Myeloperoxidase Levels on Periodontal Disease: An Applied Clinical Study
## 4 Discussion  
This trial was aimed at evaluating the impact of conditions such as periodontal disease, CVD, or periodontitis plus CVD on MPO levels in serum and saliva. The present trial evidenced that the occurrence of CVD caused increased levels of MPO and hs-CRP in serum and saliva. Nevertheless, in comparison with periodontitis and healthy controls, only the group of subjects with CVD and periodontitis plus CVD had significantly elevated MPO levels in serum and saliva, endorsing the suggestion that CVD influenced the increment of MPO levels in serum and saliva. Furthermore, results of the present study show that the simultaneous presence of periodontitis in patients with CVD can determine an increased activation of MPO and therefore represent a subclinical stimulus for the purpose of an increase in CVD development. In accordance with the results of the present study, some reports have shown that high levels of MPO in serum represent real independent risk factors of CVD development and increased mortality index, possibly by inactivating NO signaling [33]. Specifically, it has also been shown that, in patients with atherosclerosis, high systemic levels of MPO are associated with significant carotid epithelial dysfunctions, underlining the fundamental inhibitory role of NO exercised by MPO [34]. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Serum MPO Levels** & \multicolumn{3}{c}{**UNVARATE**} & \multicolumn{3}{c}{**MLUTVARIATE**} \\ \hline
**Variable** & **B** & **95\% CI** & \(p\) & **B** & **95\% CI** & \(p\) \\ \hline
**CVD** & 0.442 & 0.314, 0.558 & **c.001** & 0.122 & -0.221, 0.559 & 0.578 \\ \hline
**Periodonitis** & 0.289 & 0.186, 0.274 & **0.024** & 0.231 & -0.066, 0.319 & 0.226 \\ \hline
**hs-CRP** & 0.278 & 0.028, 0.136 & **c.001** & 0.314 & 0.005, 0.189 & **c.001** \\ \hline
**Age (years)** & \(-\)0.047 & \(-\)0.287, 0.056 & 0.064 & \(-\)0.039 & \(-\)0.111, 0.315 & 0.287 \\ \hline
**Female gender** & 0.212 & \(-\)0.78, 0.549 & 0.227 & 0.219 & \(-\)0.88; 0.428 & 0.112 \\ \hline
**Education SES** & \(-\)0.114 & \(-\)0.178, 0.123 & 0.287 & \(-\)0.066 & \(-\)0.312, 0.398 & 0.312 \\ \hline
**Salivary MPO Levels** & & & & & & \\ \hline
**CVD** & 0.319 & 0.112, 0.552 & **c0.001** & \(-\)0.065 & \(-\)0.412, 0.289 & 0.451 \\ \hline
**Periodonitis** & 0.078 & \(-\)0.069, 0.328 & 0.411 & 0.007 & \(-\)0.178, 0.213 & 0.665 \\ \hline
**hs-CRP** & 0.082 & 0.027, 0.287 & **c0.001** & 0.066 & 0.021, 0.133 & **c0.001** \\ \hline
**Age (years)** & \(-\)0.051 & \(-\)0.116, 0.036 & 0.399 & 0.047 & \(-\)0.028, 0.087 & 0.741 \\ \hline
**Female gender** & 0.074 & \(-\)0.112, 0.211 & 0.398 & 0.071 & \(-\)0.065, 0.412 & 0.321 \\ \hline
**Total Cholesterol** & \(-\)0.057 & \(-\)0.151; \(-\)0.062 & **0.037** & \(-\)0.65 & \(-\)0.041, 0.314 & **0.035** \\ \hline
**Serum MPO** & 0.122 & \(-\)0.021, 0.557 & 0.057 & \(-\)0.036 & \(-\)0.369, 0.166 & 0.331 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Uni- and multivariate linear regression analysis for MPO levels in serum and saliva in all patients. Age was included as continuous variable. For periodontitis and cardiovascular disease (CVD), controls served as reference. For gender, male served as reference. Figure 3: Analysis of correlation of serum and salivary MPO levels with c-reactive protein (CRP) in all patients. Therefore, the simultaneous presence of CVD on the one hand and periodontitis on the other hand can be a real explanation for the deterioration of endothelial function due to high levels of MPO. In this regard, recent research has shown that the treatment of periodontitis has significantly reduced the systemic levels of MPO in patients with coronary disease [35]. Moreover, several reports demonstrated that increased hs-CRP levels in serum can facilitate the increment of MPO levels in serum in several diseases in humans [23; 35; 36; 37; 38].