Association of orthostatic hypotension with incident dementia, stroke, and cognitive decline

Associations Between Left Ventricular Structure, Function, and Cerebral Amyloid: The ARIC-PET Study

Background and Purpose- Cardiovascular disease is a known risk factor for cognitive decline, although the mechanisms remain unclear. We hypothesize that Aβ (β-amyloid), a core pathology of Alzheimer's disease, will be associated with subclinical cardiac structure and function echocardiogram indices. Methods- Three hundred six nondemented participants from the ARIC study (Atherosclerosis Risk in Communities Study) underwent florbetapir positron emission tomography and 2D echocardiography (echo). Cross-sectional associations between echo markers of left ventricular structure and function and global cortical Aβ (≥1.2 standardized uptake value ratio were evaluated using multivariable logistic regression with interaction terms when appropriate. Results- Participants ranged in age from 67 to 88 years, were 57% female and 42% black. Per 1 cm increase in end-diastolic left ventricular diameter, the odds of elevated florbetapir standardized uptake value ratio doubled (odds ratio, 2.04 [95% CI, 1.10-3.77]), with similar findings when excluding mild cognitive impairment (odds ratio, 2.61 [95% CI, 1.22-5.59]). Conclusions- We have demonstrated a significant association between a marker of left ventricular structure and elevated florbetapir standardized uptake value ratio, identified using positron emission tomography. Ongoing prospective work will help determine if changes in cardiac structure and function either precede, or occur simultaneously with deposition of amyloid.

Possibilities of Dementia Prevention - It is Never Too Early to Start

Dementia represents one of the greatest global challenges for health and social care in this century. More than 50 million people worldwide suffer from dementia, and this number is predicted to triple by 2050. Ageing is often associated with cognitive impairment. Therefore, prevention of cognitive impairment is an imperative. Dementia includes a heterogeneous group of disorders, the most common being Alzheimer's disease and vascular dementia. Most cardiovascular risk factors such as hypertension, diabetes mellitus, hypercholesterolemia, atrial fibrillation and smoking are not exclusive risk factors for vascular dementia but also for Alzheimer's disease. The ApoE4 allele is the single non-modifiable risk factor for Alzheimer's disease. Today we know that an important, modifiable risk factor is education. Better education means better protection against dementia. A large number of dementia cases are potentially preventable by early intervention. Early changes in the blood vessel wall can be detected by early ultrasound methods or early biomarkers. These methods allow us to detect changes before the disease becomes clinically evident. Early disease detection enables timely management, and studies have shown that careful control of vascular risk factors can postpone the onset or even reverse disease progression.

Neurovascular and Cognitive Dysfunction in Hypertension

Hypertension has emerged as a leading cause of age-related cognitive impairment. Long known to be associated with dementia caused by vascular factors, hypertension has more recently been linked also to Alzheimer disease-the major cause of dementia in older people. Thus, although midlife hypertension is a risk factor for late-life dementia, hypertension may also promote the neurodegenerative pathology underlying Alzheimer disease. The mechanistic bases of these harmful effects remain to be established. Hypertension is well known to alter in the structure and function of cerebral blood vessels, but how these cerebrovascular effects lead to cognitive impairment and promote Alzheimer disease pathology is not well understood. Furthermore, critical questions also concern whether treatment of hypertension prevents cognitive impairment, the blood pressure threshold for treatment, and the antihypertensive agents to be used. Recent advances in neurovascular biology, epidemiology, brain imaging, and biomarker development have started to provide new insights into these critical issues. In this review, we will examine the progress made to date, and, after a critical evaluation of the evidence, we will highlight questions still outstanding and seek to provide a path forward for future studies.

Orthostatic hypotension and dementia incidence: links and implications

Orthostatic hypotension (OH) is a common condition, particularly in patients with α-synucleinopathies such as Parkinson's disease, and has a significant impact on activities of daily living and quality of life. Recent data suggest an association with cognitive impairment. Herein, we review the evidence that OH increases the odds of incident mild cognitive impairment and dementia. Potential mechanisms underlying the putative relationship are discussed, including cerebral hypoperfusion, supine hypertension, white matter hyperintensities, and neurodegeneration. Finally, we highlight the challenges with respect to treatment and the negative impact on the quality of life and long-term prognosis presented by the coexistence of OH and dementia. Large population-based studies have reported that OH is associated with about a 20% increased risk of dementia in the general population, while smaller cohort studies suggest an even greater effect in patients with α-synucleinopathies (3- to 7-fold higher than controls). Ultimately, OH exposure is difficult to quantify, predominantly limited to pressure regulation during a one-time orthostatic challenge, and the causative association with dementia may turn out to be bidirectional, especially in α-synucleinopathies. Early diagnosis and treatment of OH may improve long-term prognosis.