Salivary matrix metalloproteinase‐8 in patients with and without coronary heart disease may indicate an increased susceptibility to periodontal disease

Abstract

Tissue destruction caused by periodontitis may increase the number of cytokines implicated in the pathogenesis of cardiovascular diseases. We measured the concentration of the leukocyte-derived proteolytic enzyme, salivary neutrophil collagenase-2 [matrix metalloproteinase-8 (MMP-8)], as a marker of periodontal disease and assessed its relationship to coronary heart disease (CHD). Our aim was to study whether salivary MMP-8 levels were different among patients with and without CHD. The hypothesis was that patients with heart disease might present higher salivary MMP-8 levels than cardiologically healthy controls. Saliva samples were taken from 256 patients with CHD and from 250 matched controls with known oral and general health status. The MMP-8 levels in saliva were analyzed by immunofluorometric assay, salivary albumin was assessed by enzyme-linked immunosorbent assay (ELISA) and total protein was determined using the colorimetric method. We further investigated the molecular forms and isoform distribution of salivary MMP-8 by western immunoblotting. The MMP-8 results were adjusted for the number of teeth and salivary protein concentrations. The adjusted logarithmic MMP-8 values were 0.145 +/- 0.245 microg/l in patients with CHD and 0.088 +/- 0.115 microg/l in controls (p < 0.01). The respective MMP-8 : total protein and MMP-8 : albumin ratios were also significantly higher in CHD patients than in non-CHD subjects. Elevated salivary MMP-8 levels seemed to associate with CHD, suggesting more tissue breakdown as a result of periodontitis among the patients with heart disease.