Oral Systemic Link

The link between inflammation, oxidative stress and systemic disease is an important area of interest in vascular medicine. Both the New England Journal of Medicine and the Journal of the American College of Cardiology have published papers affirming that inflammation plays a key role in the development and progression of not only coronary artery disease but also of systemic atherosclerosis. Also, several inflammatory markers have been identified as risk factors in the development of heart and vascular disease. Because oral infection and periodontal disease lead to inflammation and oxidative stress, the link between oral health and cardiovascular disease is becoming increasingly clear. Several other studies have been published affirming the link between periodontal disease and vascular disease, including heart attack and stroke.

Arterial plaque development and dangers

Atherosclerosis and plaque development result from LDLs (or low-density lipoproteins, the bad cholesterol) and inflammatory cells entering the endothelial space within an artery. As plaques develop within the walls of an artery, they cause blockage. Even worse, plaque rupture leads to development of a thrombus (or blood clot) and ultimately to heart attack or, in the brain, stroke.

Arterial disease risk factors including inflammation

Physicians have known for a long time that certain risk factors are associated with arterial disease. These include high circulating levels of glucose (e.g., from diabetes), nicotine use, high cholesterol, high blood pressure, stress, chronic infections, and other factors. It appears that these factors cause damage to the endothelium, i.e., the lining of an artery, allowing the progress of plaque development.

Studies linking inflammation and vascular disease

These studies point to a link between systemic inflammation and vascular disease. In fact, several recent studies have affirmed the link.

• Inflammation plays a key role in the development and progression of not only coronary artery disease, but in systemic atherosclerosis. (New England Journal of Medicine, April 2005)
• Several inflammatory markers have been indentified as risk factors in the development of heart and vascular disease. (Journal of the American College of Cardiology, May 2008)
• Inflammation is now recognized as being pivotal in the pathogenesis of atherosclerosis. (American Heart Journal, July 2005; 150 (1) 11-18)
• A landmark study known as the Jupiter Trial, followed more than 17,000 men and women who had normal cholesterol levels and no history of heart disease, but who did have high levels of C-reactive protein (CRP), a marker for systemic inflammation. Half the group were given a statin, the potent anti-inflammatory rosuvastatin (trade-named Crestor®). The other half received a placebo. The statin group reduced their LDL level by 50 percent. They also reduced their level of CRP by 37 percent. When the study looked at the occurrence of heart attack and stroke in the two groups, they found that those taking the statin had a 54 percent lower risk of heart attack and a 48 percent lower risk of stroke.

Studies linking periodontal disease, inflammation, and vascular disease

Additional studies have focused specifically on periodontal disease as a key factor in the inflammation leading to vascular disease.

• [There is a] statistically significant correlation between the number of periodontal pathogens present in subgingival biofilm samples and the presence of coronary heart disease. (CORODONT study, Archives of Internal Medicine, 2006; 166:554-559)
• Periodontal disease with elevated bacterial exposure is associated with CHD events and early atherogenesis (CIMT), suggesting that the level of systemic bacterial exposure from periodontitis is the biologically pertinent exposure with regard to atherosclerotic risk. (Journal of Periodontology, Dec. 2007; 78(12)2289-302)
• Subjects with advanced periodontal disease exhibit endothelial dysfunction and evidence of systemic inflammation (elevated CRP levels) possibly placing them at increased risk for cardiovascular disease. (Arteriosclerosis, Thrombosis, and Vascular Biology, 2003; 23:1245)
• CRP levels are elevated three times higher in patients with combination of periodontal disease and coronary artery disease, versus subjects with either disease alone. (Clinical and Diagnostic Laboratory Immunology, March 2002, p. 425-432, Vol. 9, No. 2)
• Periodontitis results in higher systemic levels of CRP, IL-6 and neutrophils. These elevated inflammatory factors may increase inflammatory activity in atheroscelortic lesions potentially increasing the risk for cardiac or cerebrovascular events. (Periodontology, 2000; 71:1528-1534)
• A significant association was observed between tooth loss levels and carotid artery plaque prevalence. (INVEST study, Stroke, 2003; 34:2120-2125)
• Overall periodontal bacterial burden was related to carotid IMT, a marker of carotid plaque development. This relationship was specific to causative bacterial burden and the dominance of etiologic bacteria in the observed microbiological niche. This provides evidence of a direct relationship between periodontal microbiology and subclinical atherosclerosis in the carotid artery. (Circulation, 2005; 111:576-582)
• A consensus paper on the relationship between heart disease and gum disease was published concurrently in the American Journal of Cardiology and the Journal of Periodontology. The study confirmed that inflammation is a major risk factor for heart disease, and periodontal disease may increase the inflammation level throughout the body. A number of studies show that patients with periodontal disease have an increased risk for cardiovascular disease. Current evidence indicates that management of one disease may reduce the risk for the other.

The data and published studies are accumulating to substantiate that infection and periodontitis and inflammation are closely associated with coronary heart disease. Further, infection, periodontitis and inflammation are associated with atherosclerosis in the carotid artery.