# Membrane Fluidity and Oxidative Stress in Patients with Periodontitis
## 3 Results  
The frequency distribution of the gender of the participants with and without periodontitis revealed that females were higher in number in both groups, with values of 51.66% and 61.66%, respectively. The mean age of the patients with periodontitis was 44.31 \(\pm\) 10.17 years, while the mean age of the healthy subjects was 34.85 \(\pm\) 14.26 years. There was no significant difference in age between the two groups (\(p\) > 0.05; Table 1). As shown in Table 1, there were statistically significant differences in the values of the clinical parameters (PD, CAL, and BoP) between patients with periodontitis and healthy participants (\(p\) < 0.05 *). Moreover, the levels of oxidative stress markers (NO3\({}^{-}\) and \(le/Im\)) were increased in subjects with periodontitis, when compared to subjects without periodontitis. However, despite the increase, there were no statistically significant changes in the levels of the above markers, or in the MDA levels (\(p\) > 0.05; Table 1). Table 2 shows the correlation of the clinical parameters with the markers of oxidative stress in patients with periodontitis. The results showed a weak positive correlation between \(le/Im\) and PD (\(r\) = 0.268; \(p\) = 0.037 *). Moreover, the MDA level was weakly positively correlated with PD and CAL (\(r\) = 0.294; \(p\) = 0.022 *; \(r\) = 0.446; \(p\) < 0.00 *). There were no correlations between the other variables in Table 2.  
The outcomes in patients with periodontitis were re-classified on the basis of PD and CAL: Group 1 had depth \(\leq\)5 mm, while Group 2 had depth \(>\)5 mm. [PERSON]'s U-test was used to compare the BoP and oxidative stress values for both groups, as shown in Table 3. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multicolumn{1}{c}{**Periodontitis Patients**} & \multicolumn{1}{c}{**Participants without Periodontitis**} \\  & **(Mean \(\pm\) SD; \(n\) = 60)** & **(Mean \(\pm\) SD; \(n\) = 60)** & \(p\) \\ \hline Age (years) & 34.85 \(\pm\) 14.26 & 44.56 \(\pm\) 10.17 & 0.220 \\ \hline PD (mm) & 1.68 \(\pm\) 0.36 & 5.40 \(\pm\) 0.23 & \textless{}0.001 * \\ \hline CAL (mm) & 0 & 5.15 \(\pm\) 0.29 & \textless{}0.001 * \\ \hline BoP (\%) & 0 & 46.87 \(\pm\) 11.54 & \textless{}0.001 * \\ \hline NO3\({}^{-}\) (umole/mL) & 7.75 \(\pm\) 2.08 & 9.06 \(\pm\) 2.48 & 0.225 \\ \hline MDA (umole/mL) & 4.00 \(\pm\) 0.88 & 3.94 \(\pm\) 0.79 & 0.664 \\ \hline \(le/Im\) (arbitrary) & 0.44 \(\pm\) 0.24 & 0.46 \(\pm\) 0.23 & 0.666 \\ \hline \hline \end{tabular}  
* Values with \(p\) < 0.05.  
\end{table} 
Table 1: Clinical parameters and markers of oxidative stress in the 2 groups. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multicolumn{3}{c}{**Periodontitis Patients**} & \multicolumn{1}{c}{**\(r\)**} & \multicolumn{1}{c}{**\(p\)**} \\ \hline \multicolumn{1}{c}{**Variable 1**} & \multicolumn{1}{c}{**Variable 2**} & & \\ \hline NO3\({}^{-}\) & PD & 0.034 & 0.792 \\ \hline NO3\({}^{-}\) & CAL & 0.015 & 0.905 \\ \hline NO3\({}^{-}\) & BoP & 0.011 & 0.939 \\ \hline MDA & PD & 0.294 & 0.022 * \\ \hline MDA & CAL & 0.446 & 0.000 * \\ \hline MDA & BoP & 0.182 & 0.162 \\ \hline \(le/Im\) & PD & 0.268 & 0.037 * \\ \hline \(le/Im\) & CAL & 0.056 & 0.051 \\ \hline \(le/Im\) & BoP & 0.229 & 0.078 \\ \hline \hline \end{tabular}  
* Values with \(p\) < 0.05; \(r\) indicates the Pearson correlation coefficient.  
\end{table} 
Table 2: Spearman correlation between clinical parameters and markers of oxidative stress. A comparison of Group 1 and 2 showed no significant difference in the BoP of patients with periodontitis (\(p>0.05\)). However, when the PD rose, there were significant increases in the levels of NO3\({}^{-}\), MDA, and \(le/Im\) (\(p<0.05\) *; Table 3). Similarly, the classification of CAL showed increases in the levels of MDA and \(le/Im\) when the two groups were compared (\(p<0.05\) *; Table 3).