The etiological consideration of oxidized low-density lipoprotein in periodontitis

Epidemiologically, correlations between periodontal disease activity and CVD/serum lipid-related condition have been reported. Known mediators of these links include triglycerides, oxidized LDL (oxLDL) and inflammatory cytokines such as TNF-α supplied by adipocytes as well as oxidative degeneration products of these lipids. In this review, we focused on oxidized LDL and considered the relationship between periodontal disease and systemic conditions.

The degree of oxidation in the periodontal pocket can be evaluated by analyzing the Gingival Cervicular Fluid (GCF), which can be easily collected with paperpoint. The oxLDL/LDL ratio in GCF has been shown to be 17 times as high as that in blood, and IL-8 and IL-1β were also abundantly found in GCF. Periodontal treatment significantly lowers oxLDL levels in not only GCF but also plasma. In addition, there has been growing body of evidence that periodontal infections by periodontopathic bacteria affect arteriosclerosis. On the other hands, neutrophil extracellular traps (NETs), a form of innate immune responses, reportedly play a role as a defense mechanism in the periodontal pockets. However, the regulatory mechanism of NETs in periodontal pocket is still unknown. Recently, NETs induced by oxidized cholesterol have been reported to be involved in inflammatory damage to vascular endothelial cells.

Further understanding of the newly discovered roles of oxLDL in the defense and destruction of periodontal tissues are anticipated.