Oral hygiene linked to CVD

AHA Scientific Sessions 2011

ORLANDO, Fla. — Professional dental screening and cleaning may reduce the risks for stroke and myocardial infarction, researchers said here.

Zu-Yin Chen, MD, a cardiology fellow at Veterans General Hospital, Taipei, Taiwan, and colleagues investigated whether preventive dental care reduces risks for cardiovascular disease.

“Because oral health has been previously associated with increased risk for heart disease, we wanted to see if tooth scaling could help decrease risk,” Chen said in an interview. “Many studies have shown that tooth scaling could improve inflammation markers — a cause for plaque in vessels and risk for stroke and heart disease — but we didn’t know if that translated to less risk for stroke and heart attack.”

Chen and colleagues evaluated records from 51,108 adults without previous history of stroke or MI who had received full or partial mouth scaling at least once from the Taiwan National Health insurance. They also matched 51,512 control patients using age, sex and comorbidities with no history of stroke or MI who had never received a mouth scaling.

After 7 years, patients who received mouth scalings had a lower incidence of acute MI (0.44% vs. 0.55%; P=.013) and stroke (2.27% vs. 2.57%; P=.002), as compared with the control group. Patients with tooth scaling also had significantly higher acute MI-free (P=.027) and stroke-free (P=.04) survival rates. Cox proportional hazard regression analysis highlighted tooth scaling as the independent factor associated with lower risk for developing future MI (HR=0.76; 95% CI, 0.6-0.96) and stroke (HR=0.87; 95% CI, 0.78-0.96).

Additionally, the researchers discovered a relationship between frequency of tooth scaling and CV risk reduction. For MI, often and occasional tooth scaling was associated with a HR of 0.76 (95% CI, 0.6-0.96) whereas no tooth scaling was associated with a HR of 0.87 (95% CI, 0.71-1.07). Likewise, for stroke, often and occasional tooth scaling was associated with a HR of 0.87 (95% CI, 0.78-0.96) and no tooth scaling was associated with a HR of 0.91 (95% CI, 0.83-1).

“Oral health is important. We should take care of our teeth as well as other parts of our bodies,” Chen said. “However, we should never forget other important risk factors, such as smoking, cholesterol and obesity.”

Relationship with type of periodontal disease

In another study presented here, Anders Holmlund, DDS, PhD, of the Centre for Research and Development of the County Council of Gavleborg, Sweden, and colleagues conducted a study to explore the link between markers of periodontal disease and MI, stroke and heart failure. The study included 7,999 patients referred to a clinic for periodontal treatment between 1976 and 2008. All received a full mouth dental examination, including X-ray. The researchers compared various points of oral health, such as number of remaining teeth, periodontal severity index, number of deepened periodontal pockets and bleeding on probing, on risks for fatal or nonfatal MI, HF and stroke.

During a mean follow-up of more than 13 years, the researchers identified 414 cases of fatal or nonfatal MI, 204 cases of HF and 438 cases of stroke.

Analyses adjusted for age, sex, smoking and education level revealed a significant association between MI and number of remaining teeth (HR=1.69; 95% CI, 1.02-2.81) and number of deepened periodontal pockets (HR=1.53; 95% CI, 1.03-2.27). Patients with fewer than 21 teeth had a 69% increased risk for MI compared with those with the most teeth, according to the study. Further, the risk for congestive HF was 2.5 times higher among patients with the fewest teeth compared with those with the most teeth. A greater number of deepened periodontal pockets, suggesting infection of the gum around the base of the tooth, was associated with a 53% increased risk for MI compared with those with the fewest deepened pockets. Risk for stroke was also 2.1 times higher among patients with the highest incidence of gum bleeding compared with those with the lowest incidence.

“Although it is a bit too early to draw any final conclusions regarding the clinical application [of these findings], it seems that the number of teeth has the potential to be an easily obtained risk indicator for future CVD,” Holmlund told Endocrine Today. – by Melissa Foster

For more information:

• Chen Z. #17704.
• Holmlund A. #10576. Both presented at: American Heart Association Scientific Sessions 2011; Nov. 12-16, 2011; Orlando, Fla.

Disclosure: Drs. Chen and Holmlund report no relevant financial disclosures.

The association between tooth scaling or dental cleaning and CVD is intriguing from an epidemiology perspective. It's an association, which means that we don't know yet the direction of causation. For instance, is this due to having poor health habits, such as smoking and other poor behaviors? Right now, this is unclear, and these data were not able to address that question, so we need further work in this area.

- Donna Arnett, PhD
President-Elect of the American Heart Association
Epidemiologist, School of Public Health
University of Alabama at Birmingham

Disclosure: Dr. Arnett reports no relevant financial disclosures.

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