The effect of periodontal therapy on neopterin and vascular cell adhesion molecule-1 levels in chronic periodontitis patients with and without acute myocardial infarction: a case-control study

Abstract The presence of neopterin in gingival crevicular fluid (GCF) is a marker for local and acute immune activation, and the presence of vascular cell adhesion molecule (VCAM-1) in GCF is accepted as a marker for chronic vascular inflammation. Objectives This study aimed to evaluate effects of periodontal treatment on GCF levels of neopterin and VCAM-1 in patients with chronic periodontitis (CP) with acute myocardial infarction (AMI) compared with systemically healthy CP patients. Material and methods Sixty subjects (20 CP patients with AMI, 20 healthy CP patients, and 20 healthy controls) were included. GCF samples were analyzed at baseline and after 3 and 6 months, and the probing pocket depth (PD), clinical attachment level (CAL), bleeding on probing, gingival (GI) and plaque (PI) indices were recorded. We determined neopterin and VCAM-1 levels (concentration and total amount) using enzyme-linked immunosorbent assay (ELISA). No significant differences were seen between the AMI+CP and CP groups for PI, GI, GCF levels of neopterin and VCAM-1 at baseline. Results The number of teeth with 5 mm≤CAL<7 mm and CAL≥7 mm were significantly increased in the AMI+CP group at baseline. There were no significant differences between the AMI+CP and CP for PI, CAL, GCF volumes, and the AMI+CP group had the highest clinical improvement in the number of teeth with 5 mm≤CAL<7 mm at the sixth month. There were significant positive correlations between clinical periodontal inflammation and the presence of neopterin and VCAM-1 in GCF prior to and following periodontal treatment, and between the GCF volume and clinical parameters. Conclusions Data suggest that the total amount and concentration of neopterin and VCAM-1 in GCF seemed to be closely associated with periodontal disease severity in CP patients with AMI. Moreover, the results of our study demonstrate that the past periodontal status is potentially correlated between groups, with similar periodontal disease severity.


Introduction
Periodontitis is a bacterially-induced, localized and chronic inflammatory disease that destroys the connective tissue and bone that support the teeth.
Periodontitis and acute myocardial infarction (AMI) are two diseases that share common risk factors 12 . In recent years, literature has paid attention to positive correlation between periodontitis and coronary heart disease, acute coronary events, including AMI 4 . In these studies, periodontitis is defined by clinical examination or radiologic criteria 6,25  and no data are currently available about GCF N and VCAM-1 levels in AMI patients with chronic periodontitis (CP). Thus, in this study, we aimed at assessing whether GCF levels of CP patients with AMI have an alteration in GCF levels of N and VCAM-1. We also assessed whether these alterations might be related to treatment of existing periodontitis in AMI patients. We hypothesized that severe CP may play a role in initiating or exacerbating MI, and that there is an increased risk of AMI among systemically healthy people affected with severe CP. To test these hypotheses, we aimed to evaluate the effects of periodontal treatment on GCF levels of neopterin and VCAM-1 in CP with AMI in comparison to systematically healthy CP patients. We also assessed whether AMI was associated with a local inflammatory response, as reflected in the levels of GCF N and VCAM-1. In addition, we tested the hypothesis that long-term exposure to severe AMI+CP in patients contributes to the development of myocardial infarction (MI), using a case-control model of MI to study the inflammatory response in GCF. To do this, we compared AMI patients with CP with those who were systemically healthy and had CP.

Clinical procedures
The periodontal examination included the assessment of plaque index (PI) 27 , gingival index (GI) 16

Statistical analysis
We performed data analysis using the SPSS statistical package program (Microsoft Corp., Chicago, IL, USA). For categorical variables, we used the chi-square test to compare two or more groups, and for metric variables, the Mann-Whitney U test for two groups, and for more than two groups, the   and GI, which, in addition, were higher in both groups when compared with the healthy control group (Table   2). An analysis was carried out to investigate the relationship between periodontal disease severity and AMI using the number of teeth with a CAL degree of 5 mm or more (Table 3). In AMI patients, there were significantly fewer individuals with mild periodontitis and significantly more individuals with severe (and moderate-to-severe) periodontitis compared with patients in the CP group. At the third and sixth months, there were no significant differences between CP and CP+AMI groups for PI and CAL (Table 4). Within each group, all clinical parameters showed statistically significant decreases at the third and sixth months.
The AMI+CP group showed statistically significant decreases in the number of teeth with 5≤CAL<7 and CAL≥7 mm after the periodontal treatment (Table 5).
AMI+CP and CP groups showed significant decreases in total amounts and concentrations of N and VCAM-1 in the GCF during the post-treatment period (Figure 1).

Groups
Time   N=Neopterin; VCAM-1=vascular cell adhesion molecule-1; T0, theraphy initiation; T3, 3 months after T0; T6, 6 months after T0. Numbers above the column show mean values and short bars show standart deviation. Significant changes compared between T0, T3 and T6 are indicated by*,**,***(p˂0.001) for AMI+CP and γ,γγ,γγγ (p˂0.001) for CP group. Different superscripts indicate statistically significant differences from baseline to 6 months between and within the groups The decreases in the AMI+CP group were greater than those in the CP group, and this difference approached statistical significance (p<0.001). During pre-and post-treatment periods, there were no statistically significant differences between the two groups regarding the concentration and total amount of N and VCAM-1. There were significant positive correlations between concentrations, the total amount of GCF N and VCAM-1 and the periodontal variables at the given time points in the AMI+CP and CP group ( Table 6).
The concentration of VCAM-1 in GCF was negatively correlated with BOP in the AMI+CP group. In a previous study, to define a threshold for periodontitis at which the risk of AMI was greatest, we compared different cutoff levels of pathologic PDs between groups 28 . PD values≥4 mm were defined as

Discussion
The effect of periodontal therapy on neopterin and vascular cell adhesion molecule-1 levels in chronic periodontitis patients with and without acute myocardial infarction: a case-control study 2018;26:e20170199 9/11 indicative of periodontal pathology 28 . The presence of>50% of sites with PDs≥4 mm showed the highest discrepancy between the groups, although this parameter lost its significance after an adjustment for known risk factors 28 . In the study mentioned, radiographs were not available, and periodontitis was defined with clinical measurements. The clinical periodontal findings of our study indicate a positive association between moderate and severe periodontitis and AMI, which was reported previously 6,28 . In studies by Beck, et al. 3 (2001) and Arbes, et al. 1 (1999) to evaluate the extent of periodontal disease, the percentage of tooth sites with different CAL levels were investigated. In this study, the association between CP and AMI varied by CAL levels, with a positive association between the number of teeth with CAL≥5 mm. We found that the number of teeth with a CAL of 5 mm or more was a significant predisposing factor for AMI in patients with CP when compared with healthy