Periodontal infection and subclinical atherosclerosis: the role of high-density lipoprotein as a modifying factor.

BACKGROUND Periodontitis is suggested to enhance the process of vascular inflammation leading to atherosclerosis. The purpose was to study the relation between periodontal infection and subclinical atherosclerosis, and whether this relation is dependent on high-density lipoprotein (HDL) cholesterol levels. METHODS A secondary analysis of the data of a diabetic study, confined to 60 dentate subjects who underwent clinical examinations in 1990-1992 and in 1996-1998, was carried out. Ultrasonographic measurements of carotid, aortic and femoral atherosclerosis were performed in 2000. RESULTS No consistent association was found between the presence of periodontal pockets and subclinical atherosclerosis in the total population, but a fairly strong association was found among subjects with a low HDL level, whereas in subjects with a high HDL level, an opposing and less consistent association was found. Product terms indicating a possible modification by HDL were statistically significant (at p=0.05 level) for total plaques with all cut-off values, for plaques in carotid arteries with cut-off values 1.2-1.4 and for intima-media thickness with cut-off values of 1.1-1.2, but not for aorta plaques. CONCLUSIONS HDL levels or factors closely associated with HDL levels appear to modify the association between periodontal infection and certain parameters of subclinical atherosclerosis.