A five-minute ulstrasoound scan of blood vessels in the neck could predict a person's risk of developing dementia a full decade before symptoms emerge, found a study of more than 3,000 people over 15-years, presented at the American Heart Association Scientific Sessions.
Scientists used ultrasound scanners to look at blood vessels in the necks of more than 3,000 people and monitored them over the next 15 years and found those with the most intense pulses went on to experience greater cognitive decline over the next decade than the other study participant
An international team of experts, led by University College London (UCL), measured the intensity of the pulse travelling towards the brain in 3,191 people in 2002. A more intense pulse can cause damage to the small vessels of the brain, structural changes in the brain's blood vessel network and minor bleeds known as mini-strokes. Over the next 15 years, researchers monitored participants' memory and problem-solving ability.
The report says those with the highest intensity pulse (the top quarter of participants) at the beginning of the study were about 50% more likely to show accelerated cognitive decline over the next decade compared with the rest of the participants, the study found. Researchers said this was the equivalent of about an extra one to one-and-half years of decline.
Cognitive decline is often one of the first signs of dementia, but not everyone who experiences it will go on to develop the condition. Researchers are quoted in the report as saying that the test could provide a new way to identify people who are at risk of developing dementia, leading to earlier treatments and lifestyle interventions.
Dr Scott Chiesa, from UCL, said: "Dementia is the end result of decades of damage, so by the time people get dementia it's too late to do anything. What we're trying to say is you need to get in as early as possible, identify a way to see who's actually progressing towards possibly getting dementia and target them."
However, the report says, the study, co-funded by the British Heart Foundation, does not contain data on which study participants went on to develop dementia.
Researchers next plan to use MRI scans to check if people in the study also display structural and functional changes within the brain that may explain their cognitive decline. They also want to test whether the scan improves predictive risk scores for dementia which already exist.
According to the report, Dr Carol Routledge, director of research at Alzheimer's Research UK, said it was not yet clear if the scan could improve the diagnosis of dementia. She added: "What we do know is that the blood supply in the brain is incredibly important, and that maintaining a healthy heart and blood pressure is associated with a lower risk of developing dementia."
Abstract
Introduction: Accumulating evidence suggests that vascular risk factors may contribute to the development of dementia. Increased pulse pressure (PP) is hypothesized to impair cognitive function due to its damaging effect on the fragile cerebral microcirculation, but a direct relationship between the intensity of pulse waves travelling towards the brain and subsequent impairment in cognitive function has never been investigated. Wave intensity analysis allows the measurement of both the magnitude and direction of travel of waves within the common carotid artery, and may therefore represent a novel risk factor for future cognitive decline.
Hypothesis: We hypothesized that the intensity of carotid artery forward compression waves (FCW) measured during mid- to late-life would predict future cognitive decline during 11-14 year follow-up.
Methods: Duplex Doppler ultrasound was used to calculate net FCW in the common carotid artery of 3,192 individuals aged 58-74 years taking part in the Whitehall II Study. PP was measured in the brachial artery using an automated cuff sphygmomanometer. Cognitive function – assessed using a global z-score incorporating multiple cognitive domains – was measured at baseline (2002-2004) and then repeated a further three times until 2015-2016. To address possible confounding, all statistical models were adjusted for multiple sociodemographic variables, health-related risk factors, and health-related behaviors.
Results: Increased FCW were associated with a faster rate of overall cognitive decline (β = – 0.020 [- 0.038, -0.002]; p = 0.03). Individuals with carotid FCW in the top quartile of the population distribution had a ~ 50% greater risk of experiencing accelerated cognitive decline (top 15% of decline in global cognitive score) than the rest of the cohort (Odds Ratio = 1.53 [1.17, 2.00]). Although brachial PP was positively associated with carotid artery FCW (p < 0.001), there was no relationship between PP and change in cognitive function (β = – 0.002 [- 0.018, 0.014]; p = 0.78).
Conclusions: Elevated carotid artery FCW in mid- to late-life are independently associated with a faster rate of cognitive decline. These findings support a link between cardiovascular disease and cognitive impairment in later life.
Authors
Scott T Chiesa, Stefano Masi, Martin Shipley, Elizabeth A Ellins, Alan G Fraser, Alun D Hughes, Ashraf W Khir, Julian P Halcox, Archana Singh-Manoux, Mika Kivimaki, David S Celermajer, John E Deanfield
[link url="https://www.bbc.com/news/health-46155607"]BBC News report[/link]
[link url="https://www.ahajournals.org/doi/10.1161/circ.138.suppl_1.13364"]Circulation abstract[/link]