Gum disease was associated with a higher rate of strokes caused by the hardening of large arteries in the brain and with severe artery blockages that haven’t yet caused symptoms, according to a pair of studies that will be presented at the American Stroke Association (ASA) International Stroke Conference 2020, February 19 to February 21 in Los Angeles.
The studies raise the possibility that treating gum disease alongside other stroke risk factors might reduce the severity of artery plaque buildup and narrowing of brain blood vessels that can lead to a new or a recurrent stroke, the ASA says, though they do not conclusively confirm a cause and effect relationship between gum disease and artery blockage or stroke risk.
“Gum disease is a chronic bacterial infection that affects the soft and hard structures supporting the teeth and is associated with inflammation,” said Souvik Sen, MD, MS, MPH, author of both studies and professor and chair of the Department of Neurology at the University of South Carolina School of Medicine in Columbia.
“Because inflammation appears to play a major role in the development and worsening of atherosclerosis, or ‘hardening’ of blood vessels, we investigated if gum disease is associated with blockages in brain vessels and strokes caused by atherosclerosis of the brain vessels,” said Sen.
In the first study, researchers examined 265 patients with an average age of 64, 49% white and 56% male, who experienced a stroke between 2015 and 2017, analyzing whether gum disease was associated with specific types of stroke. According to the study:
- Large artery strokes due to intracranial atherosclerosis were twice as common in patients with gum disease as in those without gum disease.
- Patients with gum disease were three times as likely to have a stroke involving blood vessels in the back of the brain, which controls vision, coordination, and other vital bodily functions.
- Gum disease was more common in patients who had a stroke involving large blood vessels within the brain, yet not more common among those who had a stroke due to blockage in blood vessels outside the skull.
The second study selected 1,145 people who had not experienced a stroke from the Dental Atherosclerosis Risk in Communities Study and used two magnetic resonance images to measure blockages in arteries inside the brain. Participants had an average age of 78%, with 78% white and 55% male.
Periodontal examinations classified the presence and severity of gum disease. People who had gum disease serious enough to have resulted in tooth loss were excluded from the study. According to the study:
- Arteries in the brain were severely blocked (50% or more) in 10% of participants.
- People with gingivitis were twice as likely to have moderately severe narrowed brain arteries from plaque buildup compared to those with no gum disease.
- After adjusting for risk factors such as age, high blood pressure, and high cholesterol, people with gingivitis were 2.4 times as likely to have severely blocked brain arteries.
“It’s important for clinicians to recognize that gum disease is an important source of inflammation for their patients and to work with patients to address gum disease,” said Sen. “We are working on a current study to evaluate if treatment of gum disease can reduce its association with stroke.”