Gum disease is the most common cause of tooth loss, and gum disease-related inflammation is believed to play a role in the narrowing of arteries, the researchers said.
Positive effects of brushing and flossing
"While we can't yet advise patients to look after their teeth to lower their cardiovascular risk, the positive effects of brushing and flossing are well established. The potential for additional positive effects on cardiovascular health would be a bonus," said study lead author Dr Ola Vedin, a cardiologist at Uppsala University Hospital and Uppsala Clinical Research Centre in Sweden.
The study included more than 15,000 heart disease patients in 39 countries. They were assessed for tooth loss and followed for an average of 3.7 years.
Those with the fewest teeth were older, smokers, female, less active and more likely to have diabetes, high blood pressure, more body fat and a lower level of education, the study found.
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During the follow-up, more than 1,500 major events either cardiovascular death, heart attack or stroke occurred, as well as 705 cardiovascular deaths, 1,120 deaths from any cause, and 301 strokes.
After adjusting for certain factors, the researchers concluded that every increased level of tooth loss was associated with a 6 percent increased risk of major cardiovascular events, and a roughly 15 percent higher risk of cardiovascular death, death from any cause and stroke.
Compared to patients with all their teeth, those with no teeth had a 27 percent higher risk of major cardiovascular events. The researchers also found toothlessness was associated with an 85 percent higher risk of cardiovascular death, 81 percent higher risk of death from any cause, and a 67 percent higher risk of stroke.
Gradual risk increase
The study only found a link, not a cause-and-effect relationship, between dental health and heart health. It was published in the European Journal of Preventive Cardiology.
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"The risk increase was gradual, with the highest risk in those with no remaining teeth," Vedin said in a journal news release.
"For example the risks of cardiovascular death and all-cause death were almost double to those with all teeth remaining. Heart disease and gum disease share many risk factors such as smoking and diabetes but we adjusted for these in our analysis and found a seemingly independent relationship between the two conditions," Vedin explained.
Among study participants, around 16 percent had no teeth, and roughly 40 percent were missing half of their teeth, Vedin noted.
"This was an observational study so we cannot conclude that gum disease directly causes adverse events in heart patients. But tooth loss could be an easy and inexpensive way to identify patients at higher risk who need more intense prevention efforts," Vedin said.
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