Tooth loss and periodontal disease may increase the risk of ischemic stroke, according to a report in the January issue of Stroke: Journal of the American Heart Association.
Six earlier studies had examined the link between stroke and periodontal disease, tooth loss or both but had conflicting results. Harvard researchers sought to clarify the relationship by using a more uniform study population with more participants and by collecting data about whether the tooth loss and periodontal disease occurred before the stroke.
They studied 41,380 men who were mainly white dentists, veterinarians, pharmacists, optometrists, osteopathic physicians and podiatrists who were 40 to 75 years of age at the start of the 12-year study. The men completed questionnaires mailed to them every two years about their medical history, health behaviors and the occurrence of cardiovascular problems or other adverse health events.
Researchers documented 349 ischemic strokes among the subjects and found that men who had fewer than 25 teeth when they entered the study had a 57 percent higher risk of experiencing ischemic stroke than did those with 25 or more teeth.
"The association of ischemic stroke with tooth loss persisted even after we controlled for periodontal disease history, which could reflect severe periodontal disease in the extracted teeth," said lead author Dr. Kaumudi J. Joshipura of Harvard School of Dental Medicine and Harvard School of Public Health.
An unexpected and unexplained finding from the study was that the association between tooth loss and stroke risk was higher among non-smokers than among smokers. "We don’t know why nonsmokers showed a higher association," said Dr. Joshipura. "But that lends support to the argument that the association between tooth loss and stroke is not all due to smoking."
Dr. Joshipura said it is too early for physicians to try to apply the study’s findings to patients. "I would be a little cautious," she said. "We need more studies before we can say that tooth loss will definitely lead to stroke."
