Why does high blood pressure cause dementia?

*It is only for medical professionals to read for reference.
Patients with hypertension need to pay attention.
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Alzheimer's disease (AD) is the most common type of dementia, accounting for about 60%-80% of all dementias
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The increase in its prevalence mainly occurs in low-income and middle-income countries.
There are currently about 10 million AD patients in China, and it is expected to exceed 40 million by 2050, which has risen to the fifth cause of death in China
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On October 23, 2021, at the 2nd Huashan International Forum on Cognitive and Brain Diseases and the China Neurology Forum 2021 kick-off meeting, Professor Yu Jintai from Huashan Hospital affiliated to Fudan University reported on "Precise prevention, diagnosis and treatment of Alzheimer’s disease".
A topic, and a wonderful report on the research of Chinese Alzheimer's disease biomarkers and life>
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The medical community was fortunate to have a conversation with Professor Yu Jintai and conducted an in-depth discussion on the CABLE research
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It is difficult to diagnose and identify AD at an early stage, and it is urgent to carry out relevant research on the heavy burden that AD brings to patients and families.
The basic treatment strategy is mainly "early diagnosis and early intervention"
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However, in the pre-AD stage, including pre-clinical AD and AD-derived mild cognitive dysfunction, the patient has mild clinical symptoms and almost no symptoms, which is difficult for family members and doctors to detect, but the patient still has pathological changes in the brain, which may exist for ten years.
Fifteen years or even longer
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This means that in the critical stage of AD intervention, it is possible to make effective early diagnosis and recognition clinically
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Based on this situation, Professor Yu Jintai and Professor Tan Lan's team from the Department of Neurology, Qingdao Municipal Hospital Affiliated to Qingdao University, have passed a large-scale clinical CABLE cohort study of 1546 cases over 5 years, mainly discussing the early biomarkers, diagnosis, and risk of AD Factors etc.

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Figure 1: The CABLE study is of great significance.
First of all, this is a large-scale study for us Chinese.
Second, the study also reveals the relationship between different risk factors and AD pathology and cognitive impairment
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It is worth noting that only the latest research results of the CABLE cohort revealed the relationship between different blood pressure characteristics and AD pathology and cognitive impairment, and for the first time it was found that the pathological changes of tau may be the key link in blood pressure affecting cognitive impairment
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Related research results were recently published in the international journal Alzheimer's&Dementia
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Figure 2: The research title explores the relationship between different blood pressure characteristics and AD for the first time.
The prevalence of hypertension is increasing year by year with age.
One-third of middle-aged people in China may have blood pressure problems
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Previous studies have shown that blood pressure is closely related to AD
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However, the relationship between blood pressure and cognitive impairment has not yet been fully clarified, which also poses a serious challenge for developing more precise blood pressure management programs for people with cognitive impairment
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Professor Yu Jintai said: "Hypertension and dementia have become important public health issues in today's society.
In order to explore the relationship between them, we first established a large-scale clinical study of cognitive impairment based on the established CABLE cohort.
Database and biological sample library, including participants’ daily blood pressure data, cognitive assessment data, and AD pathology-related core biomarker levels
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"Through this clinical research database and biological sample library analysis, Professor Yu Jintai’s team discussed how many The impact of a variety of different blood pressure characteristics (including diagnosis of hypertension, systolic blood pressure, diastolic blood pressure, pulse pressure difference, mean arterial pressure, and blood pressure variability) on cognitive impairment and core pathological changes in AD, and found that the relationship between them is significant Age specificity
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"The results of the study decipher the relationship between blood pressure and cognitive impairment", Professor Yu Jintai further explained, "High blood pressure in middle age significantly increases the risk of cognitive impairment, but this effect is not obvious in old age
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On the contrary, old age Periods of low blood pressure seem to be more detrimental to cognition and the brain
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High pulse pressure (systolic blood pressure-diastolic blood pressure) and high blood pressure variability significantly increase the risk of cognitive impairment in both middle-aged and elderly people
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" To give everyone a clearer understanding of the results of the study, we organize the results as follows: ①Middle-age hypertension, senile hypotension, and middle-aged/old-age high pulse pressure difference, all significantly promote the pathological process of tau, but have no effect on the pathology of Aβ, and can pass The intermediate role of tau pathology causes cognitive impairment; ②High blood pressure variability in middle/old age is closely related to cognitive impairment, but has nothing to do with tau pathology and Aβ pathology
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Figure 3: The relationship between blood pressure and AD.
Therefore, Professor Yu Jintai emphasized: "Blood pressure management for people at high risk of cognitive impairment should not only aim at lowering blood pressure, but should also consider age and various blood pressure characteristics, such as pulse pressure.
Differences and blood pressure variability
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Therefore, it is necessary to adopt individualized and comprehensive blood pressure control programs for different populations in future treatment
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"For the first time, it was discovered that tau pathological changes may be the key link in blood pressure affecting cognitive impairment.
Tau is a kind of A protein that normally exists in brain cells (neurons).
Regarding the pathological changes of tau, Science published an article revealing that the tau protein in the brain tangles of AD patients is different from that in the normal brain
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The tau protein in the brain tangles has a unique structure called phosphorylation because it carries additional phosphate molecules attached to the protein backbone, which changes the way the protein behaves in neurons
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Professor Yu Jintai said: "Further analysis shows that the pathological changes of tau protein in the core of AD may be a key link in blood pressure affecting cognitive impairment, and its effect can be as high as 30%
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This discovery is to reveal the specific effect of blood pressure on cognitive impairment.
The mechanism provides important clues
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However, it is worth noting that blood pressure variability does not seem to affect AD amyloid and tau-related pathological changes, which suggests that it may participate in cognitive impairment through other pathogenic mechanisms
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" Professor Yu Jintai It is believed that the discovery of this mechanism has implications for the prevention and treatment of AD.
In terms of prevention, tau-related pathology may become an important target for the prevention of cognitive impairment caused by blood pressure; in terms of treatment, future exploration may be able to develop The new treatment method, the early stage of AD is targeted to modify tau to treat AD, because many patients have already experienced severe memory and neurological decline when they are diagnosed with dementia
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Expert profile: Professor Yu Jintai, chief physician, doctoral supervisor, young Yangtze River scholar of the Ministry of Education, executive deputy director of the Institute of Neurology, Fudan University, Huashan Hospital, Fudan University, the leader of the subspecialty of cognitive impairment in the Department of Neurology, Huashan Hospital, Fudan University, currently serves as the behavioral medicine of the Chinese Medical Association National member of the branch, deputy leader of the Neuropsychology and Behavior Group of the Neurology Branch of the Chinese Medical Association, the deputy director of the Youth Deputy Chairman of the Neurology Branch of the Chinese Medical Association, the editor-in-chief of Brain Disorders magazine, and the deputy editor of Ann Transl Med magazine
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Presided over a number of general and major projects of the National Natural Science Foundation of China, led the formulation of Alzheimer's evidence-based prevention international guidelines, and published many academic papers in top journals such as Lancet Neurology and Alzheimers Dement
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Good at clinical diagnosis and treatment of memory decline, brain atrophy, unstable walking, various dementias, and Parkinson's syndrome
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