Arterial Hypertension: A Cause of Cognitive Impairment and of Vascular Dementia

Vascular Dementia and Underlying Sex Differences

Vascular dementia (VaD) is the second most common form of dementia after Alzheimer's disease (AD); where Alzheimer's accounts for 60-70% of cases of dementia and VaD accounts for 20% of all dementia cases. VaD is defined as a reduced or lack of blood flow to the brain that causes dementia. VaD is also known occasionally as vascular contributions to cognitive impairment and dementia (VCID) or multi-infarct dementia (MID). VCID is the condition arising from stroke and other vascular brain injuries that cause significant changes to memory, thinking, and behavior, and VaD is the most severe stage while MID is produced by the synergistic effects caused by multiple mini strokes in the brain irrespective of specific location or volume. There are also subtle differences in the presentation of VaD in males and females, but they are often overlooked. Since 1672 when the first case of VaD was reported until now, sex and gender differences have had little to no research done when it comes to the umbrella term of dementia in general. This review summarizes the fundamentals of VaD followed by a focus on the differences between sex and gender when an individual is diagnosed. In addition, we provide critical evidence concerning sex and gender differences with a few of the main risk factors of VaD including pre-existing health conditions and family history, gene variants, aging, hormone fluctuations, and environmental risk factors. Additionally, the pharmaceutical treatments and possible mitigation of risk factors is explored.

ABO Blood Group and Dementia Risk--A Scandinavian Record-Linkage Study

BACKGROUND

Dementia includes a group of neuro-degenerative disorders characterized by varying degrees of cognitive impairment. Recent data indicates that blood group AB is associated with impaired cognition in elderly patients. To date there are no large-scale studies that have examined the relationship between ABO blood group and dementia-related disorders in detail.

METHODS

We used data from the SCANDAT2 database that contains information on over 1.6 million blood donors from 1968 in Sweden and 1981 from Denmark. The database was linked with health outcomes data from nationwide patient and cause of death registers to investigate the relationship between blood groups and risk of different types of dementia. The incident rate ratios were estimated using log-linear Poisson regression models.

RESULTS

Among 1,598,294 donors followed over 24 million person-years of observation we ascertained 3,615 cases of Alzheimer's disease, 1,842 cases of vascular dementia, and 9,091 cases of unspecified dementia. Overall, our study showed no association between ABO blood group and risk of Alzheimer's disease, vascular dementia or unspecified dementia. This was also true when analyses were restricted to donors aged 70 years or older except for a slight, but significantly decreased risk of all dementia combined in subjects with blood group A (IRR, 0.93; 95% confidence interval [CI], 0.88-0.98), compared to those with blood group O.

CONCLUSIONS

Our results provide no evidence that ABO blood group influences the risk of dementia.

Impact of Angiotensin receptor blockers on Alzheimer disease neuropathology in a large brain autopsy series

BACKGROUND Angiotensin II may be involved in amyloid metabolism in the brain. Angiotensin receptor blockers (ARBs) may also prevent cognitive decline. OBJECTIVE To evaluate the impact of treatment with ARBs on the neuropathology of Alzheimer disease (AD) in the National Alzheimer Coordinating Center database, which includes aggregated data and brain autopsies from 29 AD centers throughout the United States. DESIGN Multiple logistic regression was used to compare the pathologic findings in hypertensive subjects taking ARBs with those taking other antihypertensive treatments as well as with hypertensive subjects who did not receive antihypertensive medications. SETTING Neuropathologic data included neuritic plaque and neurofibrillary tangle measures and vascular injury markers. PATIENTS Data were collected from participants who were self-referred or provider-referred and included those with and without cognitive disorders. Our sample included only hypertensive participants and excluded cognitively and neuropathologically normal participants (N = 890; mean age at death, 81 years [range, 39-107 years]; 43% women; 94% white). RESULTS Participants with or without AD who were treated with ARBs showed less amyloid deposition markers compared with those treated with other antihypertensive medications (lower Consortium to Establish a Registry of Alzheimer Disease score: odds ratio, 0.47, 95% CI, 0.27-0.81; Alzheimer Disease and Related Disorders Association score: odds ratio, 0.43, 95% CI, 0.21-0.91; Braak and Braak stage: odds ratio, 0.52, 95% CI, 0.31-0.85; neuritic plaques: odds ratio, 0.59, 95% CI, 0.37-0.96). They also had less AD-related pathology compared with untreated hypertensive subjects. Participants who received ARBs were more likely to have had a stroke; hence, they had more frequent pathologic evidence of large vessel infarct and hemorrhage. CONCLUSION Treatment with ARBs is associated with less AD-related pathology on autopsy evaluations. The effect of ARBs on cognitive decline in those with dementia or AD needs further investigation.

Pediatric hypertension update

PURPOSE OF REVIEW

The field of childhood hypertension has been changing rapidly since publication of the most recent consensus guidelines contained in the 2004 'Fourth Report'.

RECENT FINDINGS

Several epidemiologic studies have indicated that the prevalence of hypertension in children and adolescents is on the increase. A major factor behind this increase is the childhood obesity epidemic. There is substantial new information on the frequency of hypertensive target-organ damage in the young, including vascular, cardiac and renal effects. These data have led some authorities to recommend changes in how hypertension is evaluated and managed in the young.

SUMMARY

There has been significant new knowledge gained about many aspects of childhood hypertension over the past 5 years. Clinicians who care for children and adolescents with high blood pressure should familiarize themselves with these new data and incorporate them into their clinical decision-making.

Hypertension in children: new trends and challenges

Childhood HTN (hypertension) has become a widely investigated topic within the last decade due to its increasing prevalence. In the present review, we examine new developments and trends that have significantly contributed to aetiology, diagnosis, evaluation and management of childhood HTN. Many recent reports document an increasing prevalence of HTN, mainly essential HTN, in children worldwide. This is probably related to the increase of childhood obesity, although obesity is not the only factor. Evidence has been accumulating to suggest a rather complex interplay between obesity, uric acid level, dietary sodium intake, inflammation, inheritance and other factors, which lead to increased risk of developing HTN in childhood and adulthood. The detection and monitoring of HTN has significantly improved with the use of ABPM (ambulatory blood pressure monitoring), which allows not only for a more accurate classification and staging of HTN, but also for the calculation of more sophisticated parameters such as the AASI (ambulatory arterial stiffness index). Measurement of arterial stiffness enables assessment of arterial dysfunction, which may precede structural vascular changes evaluated by carotid intima media thickness. Sustained HTN eventually leads to end-organ damage [LVH (left ventricular hypertrophy), central nervous system], which in turn increases the risk of cardiovascular morbidity and mortality. New developments in childhood HTN, as outlined in the present review, will hopefully contribute to better screening and management of HTN in children.

Pediatric hypertension: recent trends and accomplishments, future challenges

Publication of the Fourth Report on high blood pressure (BP) in children and adolescents by the National High BP Education Program (NHBPEP) in 2004 has been followed by a remarkable increase in interest in pediatric hypertension. New data have emerged on the epidemiology of hypertension in the young, the influence of the childhood obesity epidemic on BP, how ambulatory BP monitoring (ABPM) can be used in evaluating elevated BP and the extent of hypertensive target-organ damage in the pediatric age group. Exciting new information on drug treatment of pediatric hypertension has been produced by industry-sponsored clinical trials of antihypertensive medications spurred by the FDA Modernization Act (FDAMA) and successor legislation. Despite these trends, recognition of elevated BP in children and adolescents by primary care providers remains problematic. This article will highlight these and other aspects of pediatric hypertension, hopefully providing a snapshot of where we are in early 2008, and pointing out areas where further work is needed in order to reduce the future burden of adult cardiovascular disease.

C-reactive protein, but not homocysteine, is related to cognitive dysfunction in older adults with cardiovascular disease

Cardiovascular disease (CVD) is a risk factor for cognitive impairment and dementia. Recent studies implicate homocysteine (HCY) and C-reactive protein (CRP) in this increased risk, as both are associated with cognitive dysfunction in demented and non-demented patients. However, it remains unclear whether they confer added risk in older adults with CVD. A total of 126 older CVD patients underwent blood and neuropsychological evaluation as part of a prospective examination of the neurocognitive consequences of CVD. A subset of these participants (n=37) also underwent neuroimaging to quantify the degree of white matter disease. After adjusting for demographic and medical factors, no significant relationship emerged between HCY and cognitive performance. In contrast, CRP showed significant independent relationships to test performance, including global cognitive performance, attention/psychomotor function, executive function, memory, and visuospatial abilities. Neither HCY nor CRP was related to extent of white matter disease or whole brain volume on magnetic resonance imaging. Further study is needed to identify mechanisms by which inflammatory processes impact on cognitive function and to determine whether reducing circulating levels of inflammatory markers results in improved cognition.