Archief Roodbont

Introduction

Best Evidence Reference

Humphrey LL, Fu R, Buckley DI, Freeman M, Helfand M. Periodontal disease and coronary heart disease incidence: a systematic review and meta-analysis. J Gen Intern Med. 2008;23:2079-2086.

Abstract

This study was selected from Medscape Best Evidence, which uses the McMaster Online Rating of Evidence System. Of a possible top score of 7, this study was ranked as 5 for newsworthiness and 7 for relevance by clinicians who used this system.

Brief Summary

Previous research has found that periodontal disease can increase the risk for cardiovascular risk factors. The current systematic review and meta-analysis examine the association between periodontal disease and coronary heart disease (CHD). A summary of its findings as well as recommendations in regard to how physicians may promote better oral and cardiovascular health are described below.

Background

Dental and periodontal disease is very common, but this significant public health problem receives little attention from physicians. Using data from the 1999-2002 National Health and Nutrition Examination Survey (NHANES), researchers demonstrated that approximately 90% of adults had caries in their adult teeth.^[1] The average number of retained natural teeth was 24 (of a possible 28) among adults, and 8% of adults were edentulous. The rate of edentulism grew by 6% among older adults between the 1988-1994 and 1999-2002 study periods. Another study described the risk factors for edentulism, and older age was the most prominent.^[2] Tooth loss was not related to biological sex, and rates of tooth loss were lowest among Mexican Americans and highest among black, non-Hispanic adults. Poverty is also associated with a disproportionate burden of periodontal disease. Adults with low income and less than a high school education are approximately twice as likely to have periodontal disease compared with more affluent adults with higher educational attainment.^[3]

Physicians should be concerned about the high rates of caries, tooth loss, and periodontal disease because these oral conditions are associated with significant negative health outcomes. In one analysis that adjusted for traditional risk factors, the prevalence of the metabolic syndrome was 2.31 times higher among patients with severe periodontal disease compared with adults without periodontal disease.^[4] Moreover, the prevalence of metabolic syndrome increased gradually with the severity of periodontal disease, with a 12% increase in the risk for metabolic syndrome per 10% increase in the measurement of gingival bleeding.

One of the significant ways that periodontal disease may promote metabolic syndrome and subsequent cardiovascular disease is an increase in the degree of intravascular inflammation. Periodontal disease has been associated with increases in the levels of inflammatory markers, including an increase in serum C-reactive protein (CRP) levels of over 40% and an increase in plasma fibrinogen levels.^[5] However, this same study failed to demonstrate a significant relationship between periodontal disease and serum lipid values.

Summary of Current Trial

These associations between periodontal disease and cardiovascular risk factors are not as critical as whether periodontal disease contributes to outcomes important to patients themselves, particularly heart attack. The current systematic review and meta-analysis describe the relationship between periodontal disease and CHD. Researchers examined the MEDLINE database between 1966 and March 2008, as well as other review materials, to find pertinent research related to periodontal disease and the risk for CHD. Included research was prospective and focused on patients without a prior history of CHD. Studies that focused on the broader outcome of cardiovascular disease could also be included.

Of 143 abstracts, 7 studies with a total of 345,000 subjects were included in the final review. The duration of follow-up ranged between 5 years and 21 years. The quality of the included research was good in 3 studies and fair in the other 4.

The definition and ascertainment of periodontal disease differed between studies but generally used accepted criteria. In 2 studies, patient self-report was used to define periodontal disease, but these participants had to either cite a specific history of periodontal disease or quantify tooth loss.

Six studies examined the association between periodontitis and CHD, and half of these studies demonstrated a significant increase in the risk for CHD associated with periodontitis. When the results of these studies were combined in a meta-analysis, periodontal disease increased the risk for incident CHD by a risk ratio of 1.24.

Tooth loss was also associated with an increased risk for CHD. Compared with participants having 25-32 teeth, subjects with 0-10 teeth experienced a risk ratio of 1.34 for all CHD and cardiovascular events.

There was significant heterogeneity in the included research. The studies that used dental examination to define periodontal disease and had a longer follow-up period demonstrated a stronger relationship between periodontal disease and the risk for CHD. Women experienced a slightly higher risk for CHD associated with periodontal disease compared with men, but this difference was not statistically significant.

The collective research was limited by a lack of uniformity in the definition for periodontal disease, but any such bias would be more likely to result in underreporting the relationship between oral disease and CHD. Not all research accounted for other cardiovascular risk factors as confounders in the outcome of CHD. However, some higher-quality research did perform appropriate analyses, and this research consistently demonstrated that periodontal disease was an independent risk factor for CHD.

Commentary

The current review and meta-analysis are consistent with previous summaries of the cardiovascular risk associated with periodontal disease. A meta-analysis of 8 prospective and 1 retrospective study found a summary relative risk of 1.19 for cardiovascular events associated with periodontal disease.^[6] The negative effect of periodontal diagnosis on cardiovascular outcomes was most pronounced among adults at age 65 or younger (relative risk, 1.44). Although periodontal disease was independently linked with a higher risk for fatal cardiac events, it was even more strongly associated with a higher risk for stroke.

A prospective cohort study of 9760 subjects published in BMJ also demonstrated a 25% increase in the risk for CHD associated with periodontal disease.^[7] Moreover, even poor oral hygiene without periodontal disease, which was defined by the degree of dental debris and calculus, also increased the risk for CHD, and both periodontal disease and poor oral hygiene increased the risk for overall mortality. These findings suggest a possible continuum between the degree of poor oral health and the risk for cardiovascular disease.

The collective scientific evidence offers a clear mandate to physicians: The rate of poor oral health is high, and this problem results in severe consequences for patients. Physicians should save time during office visits to remind patients of good oral health habits and regular follow-up with dentists. This alone may help prevent cardiovascular outcomes in a significant number of patients.

Antibiotics, Periodontal Disease, and Cardiovascular Disease. However, could physicians do even more to ameliorate the risk for cardiovascular disease among patients with periodontal disease? One of the principal mechanisms by which periodontal disease may promote cardiovascular disease is transient bacteremia, which, in turn, increases intravascular inflammation and atherosclerosis. Antibiotics may be able to curb this process.

However, antibiotics have a poor track record in the prevention of cardiovascular disease. Most of the research into this subject has involved secondary prevention among patients with known CHD, and this group is at inherently higher risk compared with adults without CHD. In one trial of 4372 patients with heart disease randomized to receive clarithromycin or placebo for 2 weeks, the antibiotic actually increased the risk for mortality by 27% at 2.6 years.^[8] A recent update of this study cohort found that the hazard ratio for death continued to be higher in the clarithromycin group at 6 years (hazard ratio, 1.21).^[9] This research included a meta-analysis of all research into the use of antibiotics for patients with CHD. In a total of 17 trials involving 25,271 patients, the relative risk for death for those taking antibiotics compared with placebo was 1.10, which was statistically significant. Another systematic review suggested that whereas antibiotics appeared to be effective in smaller trials in the secondary prevention of cardiovascular disease, larger trials of a variety of antibiotics failed to confirm these results.^[10] Overall, there is no evidence to recommend the routine use of antibiotics to prevent cardiovascular disease.

The overall failure of antibiotics to prevent cardiovascular events, and the possibility that they might actually increase the risk for mortality, directs physicians back to the concept of primary prevention of periodontal disease. However, they are certainly not alone in this effort. Dental health professionals should champion this cause and educate patients with regard to the consequences of poor oral health. In addition, given the disproportionate burden of periodontal disease among the poor, health policy planners should prioritize dental hygiene programs for these communities.

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