An Overview of Current Understanding of the Link Between Periodontal Disease and Atherosclerosis
As researchers note in today's materials, there is clear an association between periodontal disease and the progression of atherosclerosis. Atherosclerosis is universal in older humans, the growth of fatty lesions in blood vessel walls that ultimately impede circulating blood flow to a fatal degree or rupture to cause stroke and heart attack. The degree of atherosclerosis at a given age is highly variable across the human population, however. The degree to which atherogenic processes in any two individuals are driven by the same stimulus, such as increased LDL cholesterol levels or increased lipoprotein A levels or increased inflammation, can be very different. This makes it somewhat challenging to talk about how much of a problem any given atherogenic issue actually poses.
This is much the case for periodontitis and its contribution to atherosclerosis. One can demonstrate mechanisms that in principle allow periodontitis to make inflammatory diseases worse elsewhere in the body, primarily that bacteria and their inflammatory metabolites can leak into circulation via the injured gums. But it is a step from there to find good correlational data in human studies, let alone data that convincingly puts a number to the degree of risk produced by periodontitis. Still, avoiding chronic inflammation in later life is well established to be a beneficial goal for a wide range of reasons. Chronic inflammation is disruptive to tissue structure and function in many contexts, and wherever reasonable efforts can be taken to reduce sources of inflammation, the results should be worth it.
Gum disease may be linked to plaque buildup in arteries, higher risk of major CVD events
Although periodontal disease and atherosclerotic cardiovascular disease (ASCVD) share common risk factors, emerging data indicates there is an independent association between the two conditions. Potential biological mechanisms linking periodontal disease with poor cardiovascular outcomes include direct pathways such as bacteria in the blood and vascular infections, as well as indirect pathways such as chronic systemic inflammation.
Numerous studies have found that periodontal disease is associated with an increased risk of heart attack, stroke, atrial fibrillation, heart failure, peripheral artery disease, chronic kidney disease, and cardiac death. Although periodontal disease clearly contributes to chronic inflammation that is associated with ASCVD, a cause-and-effect relationship has not been confirmed. There is also no direct evidence that periodontal treatment will help prevent cardiovascular disease. However, treatments that reduce the lifetime exposure to inflammation appear to be beneficial to reducing the risk of developing ASCVD.
Direct mechanisms of the association between periodontal disease and atherosclerotic cardiovascular disease (ASCVD) are thought to be through bacteremia and vascular infection. Dental plaque in periodontal disease contains multiple bacterial strains. Periodontal pockets, with manipulation of the tissue, can result in bleeding, which allows periodontal bacteria to enter systemic circulation. Once in the bloodstream, pathogens can trigger a systemic inflammatory response. This, along with increased vascular permeability, could lead to endothelial dysfunction. Endothelial dysfunction can be a sign of early subclinical atherosclerosis.
Bacteremia from chronic periodontal infections may increase the inflammatory burden that accelerates atherogenesis. Inflammation due to direct oral microbiome actions may affect systemic inflammation of blood vessel walls through two modes: direct invasion of bacteria through the diseased and inflamed periodontal tissues into the general circulation and phagocyte-mediated bacterial translocation. The oral microbiome thereby invades vascular tissues, which may experience acute inflammation, which, in the absence of complete resolution, could lead to chronic inflammation and ASCVD.