Summary: People suffering from cardiometabolic disorders such as stroke, diabetes or a heart attack, either as separate disorders or as a combination of the disorders, are at increased risk of developing dementia, whether or not they have a genetic predisposition to neurodegeneration.
Source: University of Exeter
Several conditions that affect the heart are linked to a higher risk of dementia than high genetic risk, according to a large new study.
The study, led by Oxford University and the University of Exeter, is among the largest ever to examine the link between multiple heart-related conditions and dementia, and one of the few to address the complex issue of multiple health conditions.
Published in The Lancet Healthy Longevity, The paper examined data from more than 200,000 people aged 60 or over and of European descent in the UK Biobank. The international research team identified those who had been diagnosed with the cardiometabolic diseases diabetes, stroke or heart attack, or a combination of the three, and those who later developed dementia.
Within this study population, the researchers found that the more of these three conditions a person had, the higher their risk of dementia. People who had all three conditions were three times more likely to develop dementia than those at high genetic risk.
dr Xin You Tai, lead author and PhD student at Oxford University, said: “Dementia is a major global problem and projections suggest that by 2050, 135 million people worldwide will suffer from this devastating disease.
“We found that such heart disease is associated with dementia risk to a greater extent than genetic risk. Regardless of what genetic risk you were born with, you can potentially make a big impact in reducing the risk of dementia by taking care of your heart and metabolism throughout your life.”
The team, which included the Universities of Glasgow and Michigan, found that nearly 20,000 of the UK biobank participants they studied had been diagnosed with one of the three conditions. Just over 2,000 had two conditions and 122 had all three.
Professor David Llewellyn, senior author, Professor of Clinical Epidemiology and Clinical Health at the University of Exeter, said: “Many studies look at the risk of a single condition in relation to dementia, but health is more complex. We know that many patients do indeed have a range of medical conditions.
“Our study tells us that it’s especially important for people diagnosed with diabetes, stroke or heart attack to take care of their health and make sure they’re getting the right treatment to prevent further problems and reduce their risk of dementia.”
The team divided the 200,000 participants into three genetic risk categories, from high to low, based on a comprehensive risk assessment that reflects several genetic risk traits relevant to individuals of European descent.
They also had brain imaging data from over 12,000 participants and found widespread damage throughout the brain in people with more than one cardiometabolic disease. In contrast, high genetic risk was only associated with deterioration in specific parts of the brain.
dr Kenneth M. Langa, study co-author, Professor of Medicine at the University of Michigan and Veteran Affairs Ann Arbor Healthcare System, said, “Our research shows that protecting the heart throughout life is likely to have significant benefits for the brain as well. To protect your heart, you can exercise regularly, eat healthily and do everything you can to keep your blood pressure, blood sugar and cholesterol levels within the guidelines.”
dr Sara Imarisio, Head of Research at Alzheimer’s Research UK, said: “The evidence is clear that what’s good for your heart is also good for your head. A person’s risk of developing dementia is a complex mix of age, genes and lifestyle aspects. “
In this study, the researchers looked at data from a population aged 60 and over, including whether they had certain heart conditions, information about their genetics and how this affected their risk of developing dementia.
They found that people with multiple heart conditions were even more likely to develop dementia than people who were genetically at risk for Alzheimer’s disease.
“These results underscore once again the importance of treating the causes of poor heart health, not only for their own sake, but also for the added benefit in terms of reducing the number of dementia cases. From the generosity of our supporters, who have enabled us to fund this work, to the selflessness of the volunteers who have made this possible, we want to thank you, without you such research could not take place.
“If anyone is concerned about their heart or brain health, please speak to your doctor.”
The article is entitled Cardiometabolic multimorbidity, genetic risk, and dementia: a prospective cohort study.
Financing: The study is funded by the Wellcome Trust, Alzheimer’s Research UK, the Alan Turing Institute, the Engineering and Physical Sciences Research Council, the National Institute for Health Research Applied Research Collaboration South West Peninsula, the National Health and Medical Research Council and the JP Moulton Foundation , and the National Institutes on Aging/National Institutes of Health.
About this news from cardiometabolic health and dementia research
Author: Louise Vennels
Source: University of Exeter
Contact: Louise Vennells – University of Exeter
Picture: The image is in the public domain
Original research: Open access.
“Cardiometabolic multimorbidity, genetic risk, and dementia: a prospective cohort study” by Xin You Tai et al. Lancet Healthy Longevity
Cardiometabolic multimorbidity, genetic risk and dementia: a prospective cohort study
Individual cardiometabolic disorders and genetic factors are associated with an increased risk of dementia; However, the relationship between dementia and cardiometabolic multimorbidity is unclear. We investigated whether cardiometabolic multimorbidity increases the risk of dementia independently of genetic risk and examined the associated structural changes in the brain.
We examined the health and genetic data of 203,038 British biobank participants of European descent aged 60 years or older without dementia at baseline (2006-10) and followed them up to 31 March 2021 in England and Scotland and 28 March 2021 in England and Scotland February 2018. in Wales and brain structure data in a nested imaging subsample of 12,236 participants. A cardiometabolic multimorbidity index consisting of stroke, diabetes and myocardial infarction (one point each) and a polygenic risk score for dementia (with low, intermediate and high risk groups) were calculated for each participant. The key outcome measures were incidents of all-cause dementia and brain structure metrics.
The risk of dementia associated with high cardiometabolic multimorbidity was three times higher than that with high genetic risk (hazard ratio [HR] 5.55, 95% CI 3.39-9.08, p<0.0001 and 1.68, 1.53-1.84, p<0.0001, respectively). Participants with both high genetic risk and a cardiometabolic multimorbidity index of two or more had an increased risk of developing dementia compared to them (HR 5.74, 95% CI 4.26-7.74, p<0, 0001). with low genetic risk and without cardiometabolic diseases. Crucially, we found no interaction between cardiometabolic multimorbidity and polygenic risk (p=0.18). Cardiometabolic multimorbidity was independently associated with more extensive, widespread structural brain changes, including reduced hippocampal volume (F2, 12 110= 10 * 70; p<0 0001) and total gray matter volume (F2, 12 236= 55.65; p<0 0001).
Cardiometabolic multimorbidity was more independently associated with dementia risk and extensive brain imaging differences than genetic risk. Targeting cardiometabolic multimorbidity could help reduce dementia risk independent of genetic risk.
Wellcome Trust, Alzheimer’s Research UK, Alan Turing Institute/Engineering and Physical Sciences Research Council, National Institute for Health Research Applied Research Collaboration South West Peninsula, National Health and Medical Research Council, JP Moulton Foundation and National Institute on Aging/National Institutes of Health .