According to the World Health Organisation, more than 55 million individuals live with dementia worldwide, with 10 million new cases every year.
Older adults with atrial cardiopathy, which is often an undetected cause of stroke, could be at increased risk of developing dementia.
This is according to the findings of the research team at Johns Hopkins Medicine.
The researchers studied 5,078 older adults living in four US communities: Washington County, Maryland; Forsyth County, North Carolina; northwestern suburbs of Minneapolis and Jackson, Mississippi.
At the start of the study the participants did not have dementia.
The research team sought to determine whether there was a difference in the number of people who developed dementia by comparing a group that had markers of left atrial (one chamber of the heart) dysfunction, to those who did not.
Study author Michelle Johansen, MD, PhD says: “Stroke and atrial fibrillation are two medical conditions tied to atrial cardiopathy [dysfunction of the atrium, or left upper cavity of the heart.]
“We looked to see if we could find any association between the left atrium and dementia that was mediated by, or as a result of, the development of either one of these conditions.”
Johansen and her colleagues discovered that the prevalence of atrial cardiopathy among participants was 34 per cent.
The average age of participants was 75, while 59 per cent were female.
The research team focused on three markers, obtained from routine medical tests to measure the function of the left atrium.
These tests include an electrocardiogram (a record or display of an individuals heartbeat), echocardiogram (a test of the heart action using ultrasound waves to produce a visual display) and a blood marker that determines how the heat functions.
By using these three tests, the team were able to establish a definition of atrial cardiopathy and then group participants according to whether they met this definition.
Johansen says: “We found that patients who had atrial cardiopathy as we defined in our study had a higher hazard, or rate, of dementia over time versus those who did not have atrial cardiopathy.”
The team believe that this is the first time that this has been displayed.
The team also discovered that the effect was not mediated through either stroke or atrial fibrillation, despite these conditions being known to be associated with dementia.
Johansen highlights the importance of this stuffy for those who are without symptomatic cardiac disease.
Individuals with even the slightest of changes in the left atrium are at an increased risk of dementia even after controlling for other vascular risk factors.
The research team aim to understand the mechanism behind this association better with future research.
