Middle-aged adults with symptoms of poor heart health are more likely to develop dementia, a study has found.
It has long been known that poor heart health can reduce blood flow to the brain, resulting in memory loss and confusion.
But University College London researchers found that warning signs of dementia could be detected up to 25 years before diagnosis, just by checking the patient’s heart health.
The researchers also suggested that dementia, which affects more than 980,000 people in the UK, could be prevented or delayed by improving cardiovascular risk factors including high blood pressure and cholesterol.
Lead author Professor Eric Bruner at UCL said: “Poor heart health in middle age puts people at risk of dementia later in life. He added: “The damage to the brain seen in people with dementia accumulates slowly over decades before symptoms appear. Controlling common risk factors for heart disease, stroke and dementia in middle age, such as high blood pressure, may slow or even stop the progression of dementia as well as cardiovascular disease.”
This study, published in Heart of Europe magazine And with funding from the British Heart Foundation, they found that middle-aged people with higher levels of a protein called cardiac troponin in their blood were more likely to develop dementia later in life.
This protein is released into the bloodstream when the heart muscle is damaged – for example, doctors look for very high levels of troponin in people who suspect a heart attack.
If there are higher-than-normal levels of this protein among people without symptoms, it could indicate ongoing, undiagnosed damage to the heart. It can have a knock-on effect in other parts of the body, affect the health of blood vessels and blood flow to the brain, and lead to dementia.
For the study, researchers looked at decades of data on just under 6,000 people who worked for the civil service.
All subjects aged 45 to 69 years had a test to check their troponin levels – none had dementia or heart disease at the time of the test.
They were then tracked for an average of 25 years, and tested at six different time periods to assess their memory and thinking skills.
During the study period, 695 people were diagnosed with dementia.
The researchers compared each person with dementia to four people without dementia and found that those with dementia had “consistently” higher levels of troponin in their blood.
This was evident in blood tests between 7 and 25 years before dementia was diagnosed, they said.
They found that people with the highest troponin levels at the start of the study were 38 percent more likely to develop dementia and have a faster decline in cognitive function than those with the lowest levels.
According to cognitive tests, their mental abilities at the age of 80 were equal to those of people almost a year and a half older. At the age of 90, their mental abilities were equal to those of people two years older.
“Our preliminary results suggest that troponin can be an important component of a risk score for predicting the likelihood of future dementia,” said Professor Brunner.
The researchers also looked at MRI scans of the 641 study participants and found that those with the highest troponin levels at the start of the study tended to have a smaller hippocampus — an area of the brain important for memory 15 years later.
They also tended to have less gray matter in their brains – the outer layer of the brain that is important for processing information.
To help reduce the risk of dementia later in life, experts suggest that people should focus on maintaining heart health throughout their lives.
This can be done by being active, managing blood pressure and cholesterol levels, and maintaining a healthy weight.
Professor Brian Williams, Chief Scientific and Medical Director of the British Heart Foundation, said: “This study is an important reminder that the health of our heart and brain are inseparable. The results show that middle age is a critical time and damage at this stage creates a pathway to decline in heart and brain health.
“Our advice is to focus on heart health throughout life to give our brains the best chance for aging. That means controlling blood pressure, managing cholesterol levels, staying active, maintaining a healthy weight and not smoking.”
