Long-term research has shown that a routine bone density scan may also detect calcified plaque build-up in the abdominal aorta, indicating if someone is more likely to develop dementia.
Late-life dementia is becoming more frequent in adults over the age of 80. A simple and common scan might identify those who are more likely to have the condition later in life, according to a recent long-term study.
When brain cells are harmed by a number of illnesses, some of which involve constriction of the blood channels to the brain, late-life dementia begins to develop.
Researchers at Edith Cowan University (ECU) have found an important connection between vascular health and dementia in old age. The abdominal aorta, the biggest artery in the body and the conduit for oxygenated blood from the heart to the abdominal organs and lower limbs, may develop plaques that can calcify. These plaques are what cause the connection.
This calcium buildup, referred to as “abdominal aortic calcification” or AAC, can be very helpful in predicting the risk of cardiovascular diseases including heart attack and stroke. But now, experts have discovered it to be a reliable predictor of dementia in old age.
The international team, which was led by ECU’s Nutrition and Health Innovation Institute and Centre for Precision Health, included academics from Harvard Medical School, the University of Western Australia, Sir Charles Gairdner Hospital, the Marcus Institute for Aging Research, Hebrew SeniorLife, and the University of Minnesota. They looked at 968 women’s AAC results from the late 1990s and then monitored their health over more than 15 years.
They discovered that independent of any cardiovascular or genetic variables, one in two older women had medium to high levels of AAC and were twice as likely to be hospitalized or pass away from late-life dementia.
AAC could detect dementia risk earlier in people’s lives, which could be crucial in preventing the illness, according to Professor Simon Laws, head of the Centre for Precision Health.
“There’s an adage in dementia research that what’s good for your heart is good for your brain,” he said.
“This study reaffirms this link and further adds to our understanding of late-onset dementia risk and potential preventative strategies. What’s come to light is the importance of modifying risk factors such as diet and physical activity in preventing dementia: you need to intervene early and hopefully this study allows for the earliest possible change and the greatest impact.”
He continues, “AAC is important as it was able to identify dementia risk in people who don’t have the major genetic risk factor present in 50% of people who develop Alzheimer’s disease, which is the most common form of dementia.”
A simple test
Conveniently, AAC can be easily detected using lateral spine scans from bone density machines. These machines are common, with some 600,000 bone density tests performed each year in Australia to screen for osteoporosis.
ECU Associate Professor and National Heart Foundation Future Leader Fellow Joshua Lewis said an additional scan capturing lateral spine images can be performed when people undergo standard bone density tests.
“It’s generally very quick and easy to capture these scans and they are less invasive, cheaper, and minuscule in radiation exposure compared to X-rays or CT scans,” Professor Lewis said.
“We know the causes of AAC go beyond traditional cardiovascular risk factors and many of these causes overlap with late-life dementia risk factors. At ECU we’re also working with the computer science team to automate the AAC assessments, which will make the process a lot quicker and easier rather than needing a trained imaging expert to read the scans. It means these scans may be a cheap, rapid, and safe way to screen a large number of susceptible older Australians for higher late-life dementia risk.”
Professor Lewis said incorporating dementia risk into discussions surrounding cardiovascular health could see people make necessary lifestyle changes. “I think the next step is telling people about their AAC and late-life dementia risk to see if this can motivate healthy diet and lifestyle behavior changes.”
Heart Foundation chief medical adviser, Professor Garry Jennings AO, welcomed the research.
“Vascular dementia is an increasingly common disability in older people,” Professor Jennings said.
“It is often associated with heart disease or risk factors such as hypertension earlier in life. Josh’s study is an excellent example of benefits arising from the Heart Foundation’s Future Leadership funding program.”
Reference: “Abdominal aortic calcification on lateral spine images captured during bone density testing and late-life dementia risk in older women: A prospective cohort study” by Tenielle Porter, Marc Sim, Richard L. Prince, John T. Schousboe, Catherine Bondonno, Wai H. Lim, Kun Zhu, Douglas P. Kiel, Jonathan M. Hodgson, Simon M. Laws and Joshua R. Lewis, 26 June 2022, The Lancet Regional Health – Western Pacific.