Blood pressure reduction, cardiovascular diseases, and cognitive decline in the mini-mental state examination in a community population of normal very old people: a three-year follow-up

Hypotension with neurovascular changes and cognitive dysfunction: An epidemiological, pathobiological, and treatment review

ABSTRACT

Hypotension is a leading cause of age-related cognitive impairment. The available literature evidences that vascular factors are associated with dementia and that hypotension alters cerebral perfusion flow and can aggravate the neurodegeneration of Alzheimer's disease (AD). Despite the discovery of biomarkers and the recent progress made in neurovascular biology, epidemiology, and brain imaging, some key issues remain largely unresolved: the potential mechanisms underlying the neural deterioration observed in AD, the effect of cerebrovascular alterations on cognitive deficits, and the positive effects of hypotension treatment on cognition. Therefore, further well-designed studies are needed to unravel the potential association between hypotension and cognitive dysfunction and reveal the potential benefits of hypotension treatment for AD patients. Here, we review the current epidemiological, pathobiological, and treatment-related literature on neurovascular changes and hypotension-related cognitive dysfunction and highlight the unsettled but imminent issues that warrant future research endeavors.

Modifiable vascular risk factors for outcomes in patients with CADASIL: A literature review and meta-analysis of cross-sectional analyzes

OBJECTIVE

To investigate the association between outcomes of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and common modifiable vascular risk factors.

METHODS

Studies published between 1993 and February 2023 from PubMed, Embase, Cochrane, CNKI, and WanFang, along with their references, were systematically examined. Cross-sectional analyzes in patients with CADASIL with information on modifiable cerebrovascular risk factors and outcomes were included. Meta-analysis was conducted if at least three studies were available for each risk factor and outcome.

RESULTS

We included nine studies and 1687 samples in the analysis. The results of the meta-analysis showed that hypertension was positively associated with stroke in patients with CADASIL (OR = 2.69; 95 % CI: 2.02-3.57). Other vascular risk factors, including diabetes mellitus, dyslipidemia, hyperhomocysteinemia, smoking, alcohol drinking, and obesity, did not show stable correlations between the three outcomes (stroke, dementia, and disability).

CONCLUSIONS

Hypertension was significantly associated with stroke in patients with CADASIL. The role of other vascular risk factors in CADASIL and its outcomes: stroke, dementia, and disability, remains ambiguous.

Mendelian randomization study reveals a causal relationship between coronary artery disease and cognitive impairment

Background

Growing evidence suggests that Coronary artery disease (CAD) is associated with cognitive impairment. However, these results from observational studies was not entirely consistent, with some detecting no such association. And it is necessary to explore the causal relationship between CAD and cognitive impairment.

Objective

We aimed to explore the potential causal relationship between CAD and cognitive impairment by using bidirectional two-sample mendelian randomization (MR) analyses.

Methods

Instrument variants were extracted according to strict selection criteria. And we used publicly available summary-level GWAS data. Five different methods of MR [random-effect inverse-variance weighted (IVW), MR Egger, weighted median, weighted mode and Wald ratio] were used to explore the causal relationship between CAD and cognitive impairment.

Results

There was little evidence to support a causal effect of CAD on cognitive impairment in the forward MR analysis. In the reverse MR analyses, We detect causal effects of fluid intelligence score (IVW: β = -0.12, 95% CI of -0.18 to -0.06, P = 6.8 × 10^-5), cognitive performance (IVW: β = -0.18, 95% CI of -0.28 to -0.08, P = 5.8 × 10^-4) and dementia with lewy bodies (IVW: OR = 1.07, 95% CI of 1.04-1.10, P = 1.1 × 10^-5) on CAD.

Conclusion

This MR analysis provides evidence of a causal association between cognitive impairment and CAD. Our findings highlight the importance of screening for coronary heart disease in patients of cognitive impairment, which might provide new insight into the prevention of CAD. Moreover, our study provides clues for risk factor identification and early prediction of CAD.

Cognition and Diabetes: Examining Sex Differences Using a Longitudinal Sample of Older Adults

Objectives: This study aims to investigate sex-based differences in the diabetes status and cognition relationship using a representative sample of older Americans. Methods: Using a sample of 19,190 females and 15,580 males from the Health and Retirement Study, we conduct mixed-effects linear regression analyses to examine sex differences in the association between diabetes and cognition over a 20-year follow-up period among older adults in the United States. Main Findings: Females experience slightly steeper declines in cognition that are further exacerbated by diabetes. At age 65, females without diabetes have significantly higher cognition than males; this gap is eliminated by age 85. Among diabetics, there is no initial sex disparity, but females' cognition becomes significantly lower than males' over the following 20 years. Principal Conclusions: Relative to males, females are particularly susceptible to diabetes-related declines in cognition with increasing age.

Cognitive changes in prevalent and incident cardiovascular disease: a 12-year follow-up in the Maastricht Aging Study (MAAS)

AIMS

Cardiovascular disease (CVD) has been suggested to accelerate cognitive decline and to be a risk factor for dementia, but still little is known about the cognitive course after a first cardiovascular event. Therefore, the present study aims to investigate the cognitive trajectories in both prevalent and incident CVD over a 12-year time period in the general population.

METHODS AND RESULTS

Cognitively healthy participants (age 24-82 years, n = 1823) of a prospective cohort study were serially assessed at baseline, 6 and 12 years. Verbal memory, executive function, and information processing speed were analysed in adults with prevalent, incident, and no CVD. Random effects models were used to test the association between CVD and change in cognitive function over time. At baseline, participants with prevalent CVD showed more decline in memory and information processing speed than healthy controls. Participants with incident CVD also showed more decline in these cognitive domains, but this was only significant in the follow-up period from 6 to 12 years. Associations were more pronounced in participants aged younger than 65 years at baseline, and in sub-analyses with angina pectoris or myocardial infarction as the most prevalent CVD conditions.

CONCLUSION

Prevalent and incident CVD predict cognitive decline in middle-aged individuals. Findings for incident CVD suggest that the onset of decline is linked in time with the vascular event itself. Timely CVD management may delay the onset of decline.

White Matter Hyperintensities and Apolipoprotein E Affect the Association Between Mean Arterial Pressure and Objective and Subjective Cognitive Functioning in Older Adults

BACKGROUND

White matter hyperintensities (WMH) show a robust relationship with arterial pressure as well as objective and subjective cognitive functioning. In addition, APOE ɛ4 carriership may influence how arterial pressure affects cognitive functioning.

OBJECTIVE

To determine the role of region-specific WMH burden and APOE ɛ4 carriership on the relationship between mean arterial pressure (MAP) and cognitive function as well as subjective cognitive decline (SCD).

METHODS

The sample consisted of 87 cognitively unimpaired middle-aged to older adults aged 50-85. We measured WMH volume for the whole brain, anterior thalamic radiation (ATR), forceps minor, and superior longitudinal fasciculus (SLF). We examined whether WMH burden mediated the relationship between MAP and cognition (i.e., TMT-A score for processing speed; Stroop performance for executive function) as well as SCD (i.e., Frequency of Forgetting (FoF)), and whether APOE ɛ4 carriership moderated that mediation.

RESULTS

WMH burden within SLF mediated the effect of MAP on Stroop performance. Both whole brain and ATR WMH burden mediated the effect of MAP on FoF score. In the MAP-WMH-Stroop relationship, the mediation effect of SLF WMH and the effect of MAP on SLF WMH were significant only in APOE ɛ4 carriers. In the MAP-WMH-FoF relationship, the effect of MAP on whole brain WMH burden was significant only in ɛ4 carriers.

CONCLUSION

WMH burden and APOE genotype explain the link between blood pressure and cognitive function and may enable a more accurate assessment of the effect of high blood pressure on cognitive decline and risk for dementia.

Blood pressure in dementia, mild cognitive impairment, and subjective cognitive decline related to time of death

OBJECTIVE

It is unknown whether systolic blood pressure (SBP) drop is part of the normal aging process or due to the onset of dementia for some people. SBP drop is referring to the decrease in blood pressure often seen before death. Thus, the aim of this study was to examine whether SBP at time of diagnosis of dementia, mild cognitive impairment, or subjective cognitive decline was associated with years prior to death, and whether these associations were modified by diagnoses, age, and sex.

METHODS

Participants were 2,236 patients from the Norwegian Registry of Persons Assessed for Cognitive Symptoms (NorCog), who died during follow-up (2009-2017) for whom we had valid blood pressure measurements. Mean age at diagnosis was 77.5 years (SD 8.3), and patients were followed for an average of 3.9 years (SD 2.2, maximum 10.5 years). The patients had subjective cognitive decline (95), mild cognitive impairment (573), dementia (1,401), or no diagnoses related to cognitive deficits (167). SBP as dependent variable was regressed against years prior to death.

RESULTS

In men, SBP was 1.8 mmHg lower per year closer to death (p < .01), and this trend was linear without any acceleration. This association between years prior to death and SBP in men was not modified by age, year of diagnosis, or diagnosis. There was no such association in women.

CONCLUSION

SBP was significantly lower for those diagnosed close to death in men, but not in women. This association was not modified by either age or onset of diagnosis. Thus, the lowering of SBP is more related to closeness to death and sex than to dementia or age. The downward trend was linear all 10 years prior to death, with no acceleration closer to death.

Blood Pressure in Different Dementia Disorders, Mild Cognitive Impairment, and Subjective Cognitive Decline

The aim of the study was to investigate whether blood pressure (BP) differed among people with different dementia diagnoses, mild cognitive impairment, and subjective cognitive decline and whether BP differences were observed across age and sex. Our study population comprised clinical data from 6,236 patients (53.5% women) aged 45–97 years (Mean = 73.9, SD = 9.6) referred to dementia assessment in 42 outpatient clinics across Norway during 2009–2019. Patients with the following diagnoses were included: Subjective cognitive decline (SCD), Mild cognitive impairment (MCI), dementia due to Alzheimer’s disease (AD), Vascular dementia (VaD), mixed AD and VaD, and dementia in Parkinson’s disease/Lewy body disease (PDD/LBD). For all diagnostic groups, SBP increased with age until about 80 years, after which it trended downward, whereas DBP declined after 60 years of age for all diagnostic groups. Patients aged 65 years and younger with SCD had lower SBP compared to AD patients at the same age, but SBP increased rapidly with increasing age, resulting in a substantially higher SBP at 80 + years compared with all other diagnostic groups. No other differences in SBP or diastolic blood pressure (DBP) were found among patients with the different dementia diagnosis. Neither SBP nor DBP differed between MCI and AD groups. An interaction between age and gender was found for SBP at younger ages, as women started out with a lower pressure than men did but ended up with higher SBP.

Small vessel disease to subcortical dementia: a dynamic model, which interfaces aging, cholinergic dysregulation and the neurovascular unit

Background

Small vessels have the pivotal role for the brain’s autoregulation. The arteriosclerosis-dependent alteration of the brain perfusion is one of the major determinants in small vessel disease. Endothelium distress can potentiate the flow dysregulation and lead to subcortical vascular dementia (sVAD). sVAD increases morbidity and disability. Epidemiological studies have shown that sVAD shares with cerebrovascular disease most of the common risk factors. The molecular basis of this pathology remains controversial.

Purpose

To detect the possible mechanisms between small vessel disease and sVAD, giving a broad vision on the topic, including pathological aspects, clinical and laboratory findings, metabolic process and cholinergic dysfunction.

Methods

We searched MEDLINE using different search terms (“vascular dementia”, “subcortical vascular dementia”, “small vessel disease”, “cholinergic afferents”, etc). Publications were selected from the past 20 years. Searches were extended to Embase, Cochrane Library, and LILIACS databases. All searches were done from January 1, 1998 up to January 31, 2018.

Results

A total of 560 studies showed up, and appropriate studies were included. Associations between traditional vascular risk factors have been isolated. We remarked that SVD and white matter abnormalities are seen frequently with aging and also that vascular and endothelium changes are related with age; the changes can be accelerated by different vascular risk factors. Vascular function changes can be heavily influenced by genetic and epigenetic factors.

Conclusion

Small vessel disease and the related dementia are two pathologies that deserve attention for their relevance and impact in clinical practice. Hypertension might be a historical problem for SVD and SVAD, but low pressure might be even more dangerous; CBF regional selective decrease seems to be a critical factor for small vessel disease-related dementia. In those patients, endothelium damage is a super-imposed condition. Several issues are still debatable, and more research is needed.

Systolic blood pressure decline in very old individuals is explained by deteriorating health: Longitudinal changes from Umeå85+/GERDA

Declining systolic blood pressure (SBP) is common in very old age and is associated with adverse events, such as dementia. Knowledge of factors associated with SBP changes could explain the etiology of this decline in SBP. This study investigated longitudinal changes in socioeconomic factors, medical conditions, drug prescriptions, and assessments and their associations with SBP changes among very old followed individuals.The study was based on data from the Umeå85+/Gerontological Regional Database (GERDA) cohort study, which provided cross-sectional and longitudinal data on participants aged 85, 90, and ≥95 years from 2000 to 2015. Follow-up assessments were conducted after 5 years. The main outcome was a change in SBP. Factors associated with SBP changes were assessed using multivariate linear regression models.In the Umeå85+/GERDA study, 454 surviving individuals underwent follow-up assessment after 5 years. Of these, 297 had SBP measured at baseline and follow-up. The mean change ± standard deviation in SBP was -12 ± 25 mm Hg. SBP decline was associated independently with later investigation year (P = .009), higher baseline SBP (P < .001), baseline antidepressant prescription (P = .011), incident acute myocardial infarction during follow-up (P = .003), new diuretic prescription during follow-up (P = .044), and a decline in the Barthel Activities of Daily Living index at follow-up (P < .001).In conclusion, SBP declines among very old individuals. This decline seems to be associated with initial SBP level, investigation year, and health-related factors.

B-Vitamin Intake and Biomarker Status in Relation to Cognitive Decline in Healthy Older Adults in a 4-Year Follow-Up Study

Advancing age can be associated with an increase in cognitive dysfunction, a spectrum of disability that ranges in severity from mild cognitive impairment to dementia. Folate and the other B-vitamins involved in one-carbon metabolism are associated with cognition in ageing but the evidence is not entirely clear. The hypothesis addressed in this study was that lower dietary intake or biomarker status of folate and/or the metabolically related B-vitamins would be associated with a greater than expected rate of cognitive decline over a 4-year follow-up period in healthy older adults. Participants (aged 60-88 years; n = 155) who had been previously screened for cognitive function were reassessed four years after initial investigation using the Mini-Mental State Examination (MMSE). At the 4-year follow-up assessment when participants were aged 73.4 ± 7.1 years, mean cognitive MMSE scores had declined from 29.1 ± 1.3 at baseline to 27.5 ± 2.4 (p < 0.001), but some 27% of participants showed a greater than expected rate of cognitive decline (i.e., decrease in MMSE > 0.56 points per year). Lower vitamin B6 status, as measured using pyridoxal-5-phosphate (PLP; <43 nmol/L) was associated with a 3.5 times higher risk of accelerated cognitive decline, after adjustment for age and baseline MMSE score (OR, 3.48; 95% CI, 1.58 to 7.63; p < 0.05). Correspondingly, lower dietary intake (0.9-1.4 mg/day) of vitamin B6 was also associated with a greater rate of cognitive decline (OR, 4.22; 95% CI, 1.28-13.90; p < 0.05). No significant relationships of dietary intake or biomarker status with cognitive decline were observed for the other B-vitamins. In conclusion, lower dietary and biomarker status of vitamin B6 at baseline predicted a greater than expected rate of cognitive decline over a 4-year period in healthy older adults. Vitamin B6 may be an important protective factor in helping maintain cognitive health in ageing.

Is mid-life social participation associated with cognitive function at age 50? Results from the British National Child Development Study (NCDS)

Background

Some studies have indicated that social engagement is associated with better cognitive outcomes. This study aimed to investigate associations between life-course social engagement (civic participation) and cognitive status at age 50, adjusting for social networks and support, behavioural, health, social and socio-economic characteristics.

Methods

The vehicle for the study was the National Child Development Study (1958 Birth Cohort Study), which is a general population sample in England, Scotland and Wales (9119: 4497 men and 4622 women) participating in nationally representative, prospective birth cohort surveys. The primary outcome variable was cognitive status at age 50, measured by memory test (immediate and delayed word recall test) and executive functioning test (word fluency and letter cancelation tests). The influence of hypothesised predictor variables was analysed using linear multiple regression analysis.

Results

Cognitive ability at age 11 (β = 0.19;95% CI = 0.17 to 0.21), participation in civic activities at ages 33 (0.12; 0.02 to 0.22) and 50 (0.13; 0.07 to 0.20), frequent engagement in physical activity (sport) (β from 0.15 to 0.18), achieving higher level qualifications (β from 0.23 to 1.08), and female gender (β = 0.49;95% CI = 0.38 to 0.60) were positively, significantly and independently associated with cognitive status at age 50. Having low socio-economic status at ages 11 (β from -0.22 to -0.27) and 42 (β from -0.28 to -0.38), and manifesting worse mental well-being at age 42 (β = -0.18; 95% CI = -0.33 to -0.02) were inversely associated with cognitive status at age 50. The proportion of explained variance in the multiple regression model (18%), while modest, is impressive given the multi-faceted causal nature of cognitive status.

Conclusions

The results indicate that modest associations between adult social engagement and cognitive function at age 50 persist after adjusting for covariates which included health, socio-economic status and gender, supporting theories of neuroplasticity. In addition to the continuing emphasis on physical activity, the encouragement of civic participation, at least as early as mid-life, should be a targeted policy to potentially promote and protect cognitive function in later mid-life.

Electronic supplementary material

The online version of this article (doi:10.1186/s40359-016-0164-x) contains supplementary material, which is available to authorized users.

Hypertension and cognitive dysfunction in elderly: blood pressure management for this global burden

Arterial hypertension and stroke are strong independent risk factors for the development of cognitive impairment and dementia. Persistently elevated blood pressure (BP) is known to impair cognitive function, however onset of new cognitive decline is common following a large and multiple mini strokes. Among various forms of dementia the most prevalent include Alzheimer’s disease (AD) and vascular dementia (VaD) which often present with similar clinical symptoms and challenging diagnosis. While hypertension is the most important modifiable vascular risk factor with antihypertensive therapy reducing the risk of stroke and potentially slowing cognitive decline, optimal BP levels for maintaining an ideal age-related mental performance are yet to be established. Cognition has improved following the use of at least one representative agent of the major drug classes with further neuroprotection with renin angiotensin inhibitors and calcium channel blockers in the hypertensive elderly. However, a reduction in BP may worsen cerebral perfusion causing an increased risk of CV complications due to the J-curve phenomenon. Given the uncertainties and conflicting results from randomized trials regarding the hypertension management in the elderly, particularly octogenarians, antihypertensive approaches are primarily based on expert opinion. Herein, we summarize available data linking arterial hypertension to cognitive decline and antihypertensive approach with potential benefits in improving cognitive function in elderly hypertensive patients.

Gender Differences in Alzheimer Disease: Brain Atrophy, Histopathology Burden, and Cognition

Multiple studies suggest that females are affected by Alzheimer disease (AD) more severely and more frequently than males. Other studies have failed to confirm this and the issue remains controversial. Difficulties include differences in study methods and male versus female life expectancy. Another element of uncertainty is that the majority of studies have lacked neuropathological confirmation of the AD diagnosis. We compared clinical and pathological AD severity in 1028 deceased subjects with full neuropathological examinations. The age of dementia onset did not differ by gender but females were more likely to proceed to very severe clinical and pathological disease, with significantly higher proportions having a Mini-Mental State Examination score of 5 or less and Braak stage VI neurofibrillary degeneration. Median neuritic plaque densities were similar in females and males with AD but females had significantly greater tangle density scores. In addition, we found that AD-control brain weight differences were significantly greater for females, even after adjustment for age, disease duration, and comorbid conditions. These findings suggest that when they are affected by AD, females progress more often to severe cognitive dysfunction, due to more severe neurofibrillary degeneration, and greater loss of brain parenchyma.

Models and mechanisms of vascular dementia

Vascular dementia (VaD) is the second leading form of dementia after Alzheimer's disease (AD) plaguing the elderly population. VaD is a progressive disease caused by reduced blood flow to the brain, and it affects cognitive abilities especially executive functioning. VaD is poorly understood and lacks suitable animal models, which constrain the progress on understanding the basis of the disease and developing treatments. This review article discusses VaD, its risk factors, induced cognitive disability, various animal (rodent) models of VaD, pathology, and mechanisms of VaD and treatment options.

Examining the influence of gender, education, social class and birth cohort on MMSE tracking over time: a population-based prospective cohort study

Background

Whilst many studies have analysed predictors of longitudinal cognitive decline, few have described their impact on population distributions of cognition by age cohort. The aim of this paper was to examine whether gender, education, social class and birth cohort affect how mean population cognition changes with age.

Methods

The Medical Research Council Cognitive Function and Ageing Study (MRC CFAS) is a multi-centre population based longitudinal study of 13,004 individuals in England and Wales. Using ten years of follow-up data, mean Mini-mental State Examination (MMSE) scores were modelled by age and birth cohort adjusting for non-random drop-out. The model included terms to estimate cohort effects. Results are presented for five year age bands between 65–95 years.

Results

At a population level, women show greater change in MMSE scores with age than men. Populations with lower education level and manual work also show similar effects. More recent birth cohorts have slightly higher scores.

Conclusion

Longitudinal data can allow examination of population patterns by gender, educational level, social class and cohort. Each of these major socio-demographic factors shows some effect on whole population change in MMSE with age.

Age-related effects of blood pressure on everyday cognitive function in community-dwelling women

OBJECTIVES

Blood pressure is an indicator of vascular health that has been associated with cognition and quality of life in older age. Few studies have examined blood pressure across everyday cognitive tasks, which may have superior predictive functional utility than traditional cognitive measures. We explored blood pressure as a predictor of everyday problem solving (EPS) performance in middle-aged and older women.

METHOD

Community-dwelling women (age: 51-91) with low-normal blood pressure to mild hypertension underwent traditional and everyday cognitive testing. EPS was determined by the number of safe/effective solutions generated for real-world scenarios.

RESULTS

Analyses revealed that lower systolic blood pressure and pulse pressure were associated with worse EPS ability after controlling for age, education, and traditional cognitive abilities.

DISCUSSION

These results support that blood pressure may be an important predictor of everyday cognitive abilities in older age. Potential implications for real-world functioning are discussed.

Hypertension and cognitive function in the elderly

Alzheimer's disease is the most prevalent and common form of cognitive impairment, ie, dementia, in the elderly followed in second place by vascular dementia due to the microangiopathy associated with poorly-controlled hypertension. Besides blood pressure elevation, advancing age is the strongest risk factor for dementia. Deterioration of intellectual function and cognitive skills that leads to the elderly patient becoming more and more dependent in his, her, activities of daily living, ie, bathing, dressing, feeding self, locomotion, and personal hygiene. It has been known and demonstrated for many years that lowering of blood pressure from a previous hypertensive point can result in stroke prevention yet lowering of blood pressure does not prevent the microangiopathy that leads to white matter demyelinization which when combined with the clinical cognitive deterioration is compatible with a diagnosis of vascular dementia. It is known from many large studies, ie, SHEP, SCOPE, and HOPE, that lowering of blood pressure gradually will not and should not worsen the cognitive impairment. However, if the pressure is uncontrolled a stroke which might consequently occur would further worsen their cognitive derangement. So an attempt at slow reduction of blood pressure since cerebral autoregulation is slower as age increases is in the patient's best interest. It is also important to stress that control of blood glucose can also be seen as an attempt to prevent vascular dementia from uncontrolled hyperglycemia. Vascular dementia is not considered one of the reversible causes of dementia. Reversible causes of cognitive impairment are over medication with centrally acting drugs such as sedatives, hypnotics, antidepressants, and antipsychotics, electrolyte imbalance such as hyponatremia, azotemia, chronic liver disease, and poor controlled chronic congestive heart failure. Criteria for the clinical diagnosis of vascular dementia include cognitive decline in regards to preceding functionally higher level characterized by alterations in memory and in two or more superior cortical functions that include orientation, attention, verbal linguistic capacities, visual spacial skills, calculation, executive functioning, motor control, abstraction and judgment. Patients with disturbances of consciousness, delirium (acute confusional states), psychosis, serious aphasia, or sensory-motor alterations that preclude proper execution of neuro-psychological testing are also considered to have probably vascular dementia. Furthermore, these are ten of the other essential cerebral or systematic pathologies present that would be able to produce a dementia syndrome.

Cognitive function and risks of cardiovascular disease and hypoglycaemia in patients with type 2 diabetes: the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) trial

AIMS/HYPOTHESIS

The relationship between cognitive function, cardiovascular disease and premature death is not well established in patients with type 2 diabetes. We assessed the effects of cognitive function in 11,140 patients with type 2 diabetes who participated in the Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation (ADVANCE) trial. Furthermore, we tested whether level of cognitive function altered the beneficial effects of the BP-lowering and glycaemic-control regimens in the trial.

METHODS

Cognitive function was assessed using the Mini Mental State Examination at baseline, and defined by scores 28-30 ('normal', n = 8,689), 24-27 ('mild dysfunction', n = 2,231) and <24 ('severe dysfunction', n = 212). Risks of major cardiovascular events, death and hypoglycaemia and interactions with treatment were assessed using Cox proportional hazards analysis.

RESULTS

Relative to normal function, both mild and severe cognitive dysfunction significantly increased the multiple-adjusted risks of major cardiovascular events (HR 1.27, 95% CI 1.11-1.46 and 1.42, 95% CI 1.01-1.99; both p < 0.05), cardiovascular death (1.41, 95% CI 1.16-1.71 and 1.56, 95% CI 0.99-2.46; both p <or= 0.05) and all-cause death (1.33, 95% CI 1.16-1.54 and 1.50, 95% CI 1.06-2.12; both p < 0.03). Severe, but not mild, cognitive dysfunction increased the risk of severe hypoglycaemia (HR 2.10, 95% CI 1.14-3.87; p = 0.018). There was no evidence of heterogeneity of treatment effects on cardiovascular outcomes in subgroups defined by cognitive function at baseline.

CONCLUSIONS/INTERPRETATION

Cognitive dysfunction is an independent predictor of clinical outcomes in patients with type 2 diabetes, but does not modify the effects of BP lowering or glucose control on the risks of major cardiovascular events.

TRIAL REGISTRATION

ClinicalTrials.gov NCT00145925.

Risk factors for vascular dementia: hypotension as a key point

Physiologically, the cerebral autoregulation system allows maintenance of constant cerebral blood flow over a wide range of blood pressure. In old people, there is a progressive reshape of cerebral autoregulation from a sigmoid curve to a straight line. This implies that any abrupt change in blood pressure will result in a rapid and significant change in cerebral blood flow. Hypertension has often been observed to be a risk factor for vascular dementia (VaD) and sometimes for Alzheimer disease although not always. Indeed, high blood pressure may accelerate cerebral white matter lesions, but white matter lesions have been found to be facilitated by excessive fall in blood pressure, including orthostatic dysregulation and postprandial hypotension. Many recent studies observed among other data, that there was a correlation between systolic pressure reduction and cognitive decline in women, which was not accounted for by other factors. Baseline blood pressure level was not significantly related to cognitive decline with initial good cognition. Some researchers speculate that blood pressure reduction might be an early change of the dementing process. The most confounding factor is that low pressure by itself might be a predictor of death; nevertheless, the effect of low blood pressure on cognition is underestimated because of a survival bias. Another explanation is that clinically unrecognized vascular lesions in the brain or atherosclerosis are responsible for both cognitive decline and blood pressure reduction. We discuss the entire process, and try to define a possible mechanism that is able to explain the dynamic by which hypotension might be related to dementia.

Hypertension and cognitive function in the elderly

Alzheimer's disease is the most prevalent and common form of cognitive impairment, ie, dementia, in the elderly followed in second place by vascular dementia due to the microangiopathy associated with poorly-controlled hypertension. Besides blood pressure elevation, advancing age is the strongest risk factor for dementia. Deterioration of intellectual function and cognitive skills that leads to the elderly patient becoming more and more dependent in his, her, activities of daily living, ie, bathing, dressing, feeding self, locomotion, and personal hygiene. It has been known and demonstrated for many years that lowering of blood pressure from a previous hypertensive point can result in stroke prevention yet lowering of blood pressure does not prevent the microangiopathy that leads to white matter demyelinization which when combined with the clinical cognitive deterioration is compatible with a diagnosis of vascular dementia. It is known from many large studies, ie, SHEP, SCOPE, and HOPE, that lowering of blood pressure gradually will not and should not worsen the cognitive impairment. However, if the pressure is uncontrolled a stroke which might consequently occur would further worsen their cognitive derangement. So an attempt at slow reduction of blood pressure since cerebral autoregulation is slower as age increases is in the patient's best interest. It is also important to stress that control of blood glucose can also be seen as an attempt to prevent vascular dementia from uncontrolled hyperglycemia. Vascular dementia is not considered one of the reversible causes of dementia. Reversible causes of cognitive impairment are over medication with centrally acting drugs such as sedatives, hypnotics, antidepressants, and antipsychotics, electrolyte imbalance such as hyponatremia, azotemia, chronic liver disease, and poor controlled chronic congestive heart failure. Criteria for the clinical diagnosis of vascular dementia include cognitive decline in regards to preceding functionally higher level characterized by alterations in memory and in two or more superior cortical functions that include orientation, attention, verbal linguistic capacities, visual spacial skills, calculation, executive functioning, motor control, abstraction and judgment. Patients with disturbances of consciousness, delirium (acute confusional states), psychosis, serious aphasia, or sensory-motor alterations that preclude proper execution of neuro-psychological testing are also considered to have probably vascular dementia. Furthermore, these are ten of the other essential cerebral or systematic pathologies present that would be able to produce a dementia syndrome.

Vascular risk factors, cognitive decline, and dementia

Dementia is one of the most important neurological disorders in the elderly. Aging is associated with a large increase in the prevalence and incidence of degenerative (Alzheimer's disease) and vascular dementia, leading to a devastating loss of autonomy. In view of the increasing longevity of populations worldwide, prevention of dementia has turned into a major public health challenge. In the past decade, several vascular risk factors have been found to be associated with vascular dementia but also Alzheimer's disease. Some longitudinal studies, have found significant associations between hypertension, diabetus mellitus, and metabolic syndrome, assessed at middle age, and dementia. Studies assessing the link between hypercholesterolemia, atrial fibrillation, smoking, and dementia have given more conflicting results. Furthermore, some studies have highlighted the possible protective effect of antihypertensive therapy on cognition and some trials are evaluating the effects of statins and treatments for insulin resistance. Vascular risk factors and their treatments are a promising avenue of research for prevention of dementia, and further long-term, placebo-controlled, randomized studies, need to be performed.

Relation of Blood Pressure to Cognitive Impairment and Dementia

Over the past decade several studies have assessed the relation of blood pressure with cognitive function and dementia. While some cross-sectional studies have shown an inverse association between blood pressure levels and cognitive performance or dementia, longitudinal studies yielded controversial results. Most studies relating blood pressure levels in mid-life with late-life risk of cognitive decline or dementia reported a harmful effect of higher blood pressure levels on cognitive function. Studies assessing the effect of late-life blood pressure levels reported that low diastolic and very high systolic levels may increase the risk. Observational studies and randomized cinical trials provide limited evidence for a protective effect of antihypertensive therapy. It seems that the older the person and the more advanced the disease process, the less harmful or even inverted the effect of blood pressure elevation on dementia risk. The reason for this may be that blood pressure declines with age-related pathology, such as vessel stiffening, weight loss, and changes in the autonomic regulation of blood flow.

Asymptomatic spontaneous cerebral emboli and cognitive decline in a cohort of older people: a prospective study

BACKGROUND

Asymptomatic spontaneous cerebral emboli (SCE) are common in dementia and are associated with cognitive decline in dementia. The significance of their presence in older people is unknown.

METHOD

We included 96 participants (mean (SD) age 76.8 (6.7) years, 46% female) who were the control group in a case-control study to evaluate SCE in dementia. Cognitive functioning was assessed prospectively over 2.5 years, using the MMSE and CAMCOG.

RESULTS

The mean (SD) MMSE score was 28.7 (1.4) at baseline with an average (SD) drop of 0.79 (0.91) per year. The presence of SCE was not related to the annual drop in MMSE score, nor to the CAMCOG score at follow-up (p = 0.88 and p = 0.41, respectively). Linear regression analyses identified higher age in years (beta = 0.29, p = 0.003), history of stroke (beta = 0.31, p = 0.001) and carotid stenosis (beta = 0.28, p = 0.003) as independent predictors of cognitive decline.

CONCLUSION

We found no association between the presence of SCE and subsequent cognitive decline in older people without dementia.

Hypertension, cognitive decline, and dementia: an epidemiological perspective

Hypertension is a known risk factor for stroke, and thus for vascular dementia. However, recent large observational studies have suggested that high blood pressure may also play a role in Alzheimer's disease. The mechanisms linking hypertension to Alzheimer's disease remain to be elucidated, but white matter lesions seen on cerebral magnetic resonance imaging appear to be a good marker of this association. It is not yet clearly established whether lowering blood pressure reduces the risk of white matter lesions and dementia, so large trials dealing with this question are eagerly awaited. These future trials could confirm the hope that, by lowering blood pressure, we may have a preventive treatment for dementia. This issue is of major importance, as the number of cases of dementia is expected to rise sharply in the near future.

Blood Pressure Treatment and Cognition in the Elderly

While the health and longevity benefits of antihypertensive treatment have been established in past research, the cognitive consequences of blood pressure control in the elderly are still under debate. In this paper, the authors review the current evidence and the different ways in which cognition is measured. Since research on the cognitive consequences of blood pressure control in the elderly population is characterized by a variety of research questions, designs, and cognitive measurements, the authors conclude that a large-scale study that compares the cognitive benefits of different methods of blood pressure reduction is urgently needed.

Cerebrovascular disease, APOE epsilon4 allele and cognitive decline in a cognitively normal population

OBJECTIVES

To investigate whether cerebrovascular disease (CVD) and apolipoprotein E (APOE) epsilon4 allele were associated with cognitive decline and whether the relationship between CVD and cognitive decline varied by APOE epsilon4 status.

METHODS

A total of 809 cognitively normal community-dwelling residents aged >75 years were followed to detect subjects with cognitive decline, defined as follow-up. Mini-mental state examination (MMSE) score was >10% decease of the baseline score. Logistic and multinomial logistic models were developed to estimate odds ratio (OR) and 95% confidence interval (CI) of cognitive decline related to a history of CVD and APOE epsilon4 by taking into account major potential confounders including baseline MMSE score.

RESULTS

During the mean 3.5 years of follow-up, 190 subjects experienced cognitive decline. Multi-adjusted ORs (95% CIs) of overall cognitive decline were 2.27 (1.23-4.17) for CVD and 1.69 (1.13-2.54) for APOE epsilon4, but no interaction was detected. Multinomial logistic analysis led to the CVD-related ORs of 1.42 (0.75-2.67) for cognitive decline without progression to dementia and 3.41 (1.55-7.55) for the decline progressing to dementia; similar analysis from a separate model led to adjusted OR of 2.28 (0.88-5.87; p=0.09) for the decline progressing to Alzheimer's disease. The risk effects of CVD on cognitive decline with progression to dementias were statistically significant mainly among individuals without APOE epsilon4 allele.

CONCLUSIONS

CVD is a major risk factor for cognitive decline associated with progression to dementia and Alzheimer's disease. There appears no interaction between CVD and APOE epsilon4 on cognitive decline in very old people.

The age-dependent relation of blood pressure to cognitive function and dementia

The relation of blood pressure with cognitive function and dementia has, in recent years, received much attention from epidemiological research. Some cross-sectional studies have shown an inverse association between blood pressure and the prevalence of dementia and Alzheimer's disease, whereas longitudinal studies yield mixed results that largely depend on the age at which blood pressure is measured and the time interval between blood pressure and outcome assessments. Some studies suggest that midlife high blood pressure is a risk factor for late-life cognitive impairment and dementia, and that low diastolic pressure and very high systolic pressure in older adults may be associated with subsequent development of dementia and Alzheimer's disease. Observational studies and randomised clinical trials provide limited evidence for a protective effect of antihypertensive therapy against dementia and stroke-related cognitive decline. Atherosclerosis resulting from long-standing hypertension, and cerebral hypoperfusion secondary to severe atherosclerosis and to low blood pressure may be major biological pathways linking both high blood pressure in midlife and low blood pressure in late-life to cognitive decline and dementia.

Decline in blood pressure over time and risk of dementia: a longitudinal study from the Kungsholmen project

BACKGROUND AND PURPOSE

Low blood pressure has been related to an increased risk of dementia. We sought to verify blood pressure variations before and after a dementia diagnosis and to relate blood pressure decline to subsequent Alzheimer disease and dementia.

METHODS

A community dementia-free cohort aged > or =75 years (n=947) underwent follow-up examinations twice over a period of 6 years to detect dementia cases (Diagnostic and Statistical Manual of Mental Disorders, 3rd edition, revised [DSM-III-R] criteria, n=304). Blood pressure variation before and after dementia diagnosis was verified with linear mixed-effects models. Using the dementia-free cohort identified at first follow-up (n=719), the association between blood pressure decline from baseline to first follow-up and subsequent risk of dementia was examined.

RESULTS

Blood pressure markedly decreased over 3 years before dementia diagnosis and afterward, whereas no substantial decline was present 3 to 6 years before the diagnosis. However, among subjects with baseline systolic pressure <160 mm Hg, systolic pressure decline > or =15 mm Hg occurring 3 to 6 years before diagnosis was associated with relative risks (95% CI) of 3.1 (1.3 to 7.0) for Alzheimer disease and 3.1 (1.5 to 6.3) for dementia. There was a dose-response relationship between systolic pressure decline and dementia risk in subjects with vascular disease.

CONCLUSIONS

Blood pressure starts to decrease only 3 years before dementia diagnosis and continues to decline afterward. A greater decline in systolic pressure occurring 3 to 6 years before diagnosis is associated with an increased risk of dementia only in older people with already low blood pressure or affected by vascular disorders.

Predictors of cognitive decline and mortality of aged people over a 10-year period

BACKGROUND

The search for preventable and remediable risk conditions of cognitive decline is ongoing, but results have thus far been inconsistent. According to the hypothesis of our 10-year prospective study, the predictive values of different risk indicators change over time in a general 75+ population.

METHODS

A population-based sample of 75-, 80-, and 85-year-old individuals (n=650) underwent comprehensive clinical examinations in 1990 in Helsinki, Finland. Cognitive function was assessed by the Mini-Mental State Examination (MMSE) and/or Clinical Dementia Rating (CDR) at baseline and after 1, 5, and 10 years.

RESULTS

At baseline, a low MMSE score was associated with age, history of stroke, apolipoprotein E allele epsilon4 (APOE4), and intermittent claudication. After 1 year, cognitive decline was typical of participants suffering from vascular diseases, e.g., heart failure and intermittent claudication. Five-year decline was predicted by the presence of atrial fibrillation (RR [relative risk] 2.8), APOE4 (RR 2.4), elevated C-reactive protein (CRP) (RR 2.3), diabetes mellitus (RR 2.2), and heart failure (RR 1.8). They also tended to increase 5-year all-cause mortality. At 10 years, the decline associated with APOE4 (RR 3.3), slightly elevated serum ionized calcium (RR 3.3), and feelings of loneliness (RR 3.0).

CONCLUSIONS

Long follow-up of a general aged population explains several inconsistencies of earlier reports. In 75+ individuals, general ill health is a strong associate of cognitive deficits. The strongest predictors of both cognitive decline and mortality are age, APOE4, manifest vascular diseases, and diabetes. The role of new potential predictors, feelings of loneliness and hypercalcemia, needs clinical testing.

Left ventricular hypertrophy and blood pressure as predictors of cognitive decline in old age

BACKGROUND AND AIMS

The relationships between blood pressure (BP) and cognition are complex and are still partly unclear. The impact of history of hypertension, present BP levels, and left ventricular hypertrophy (LVH) on cognition was investigated in a 10-year follow-up study of an aged population.

METHODS

The population-based sample consisted of 75-, 80- and 85-year-old individuals at baseline (N=650). Their history of hypertension was investigated, and present BP values were recorded several times. Echocardiographic examinations were performed twice at 3-year intervals, and electrocardiography (ECG) at entry. Cognitive function was assessed by the Mini-Mental State Examination (MMSE) at baseline and at 10 years, and by the Clinical Dementia Rating (CDR) at baseline, at 1, 5 and 10 years.

RESULTS

At baseline, elderly individuals with impaired cognition or dementia had lower BP, but thicker left ventricle posterior wall (LVPW), greater cardiac mass, and more often signs of LVH in ECG than those without cognitive deficits. Echocardiographic LVH, but not BP, predicted cognitive decline in a 5-year follow-up. Patients who died demented within 5 years were characterized by low BP and thin LVPW. Baseline BP and echocardiographic variables were not significantly different between those who had and had not cognitive decline at 10 years, but declining BP tended to precede cognitive deficits.

CONCLUSIONS

Results indicate that, the closer cognitive decline, the lower the BP, and suggest that, although LVH is a risk factor of cognitive decline, it loses its predictive value in old age.

Vers une prévention de la démence ?

Many studies have shown that high blood pressure and, to a lesser extent, other vascular risk factors could be the target of interventions aiming to reduce the incidence of dementia. Two large controlled trials have demonstrated that blood pressure lowering drugs have a significant effect on the risk of dementia including Alzheimer's disease. On another hand, large epidemiological studies have shown associations between different vascular factors and dementia. Overall, these data suggest that interventions aiming to reduce the level of vascular risk factors might prevent dementia. The expected benefit of these interventions could be estimated from data provided by epidemiological studies, but large population-based controlled studies are needed to demonstrate the efficacy of preventive interventions.

A systematic review of cognitive decline in the general elderly population

BACKGROUND

The public health impact of cognitive decline and dementia is increasing as the population ages. Studies exploring therapies or risk factors for cognitive impairment require understanding of expected age-related decline.

OBJECTIVE

To establish the rate of age-related cognitive decline in the general elderly population.

DESIGN

Systematic review of studies of cognitive decline in the general elderly population. Medline, Embase and PsycINFO databases were searched using an adapted version of McMaster's aetiology, causation and harm strategies and the Cochrane Dementia and Cognitive Impairment Group strategy. Grey literature was explored and experts contacted. A second observer was involved at all stages and quality appraisal of included studies was performed. Included studies were representative, community-based, cohort studies of people aged over 60, incorporating individuals with dementia.

RESULTS

Identification of 5990 abstracts and retrieval of 163 full texts led to inclusion of 19 papers. Heterogeneity made narrative review the appropriate method of data synthesis. Some degree of cognitive impairment with increasing age was found in all studies, although the extent varied. The prevalence of cognitive impairment and the rate of decline increased with age. Studies were of variable quality.

CONCLUSIONS

Cognitive decline is almost universal in the general elderly population and increases with age. Improved communication between researchers and between clinicians to identify a core minimum data set of neuropsychological tests that could be used in different populations would support consistent study design and meta-analysis, helping to quantify the true rate of cognitive decline in the elderly and assisting diagnosis in clinical practice.

Vascular factors and cognition: toward a prevention of dementia?

High blood pressure is a known risk factor for stroke and dementia. However, very little is known about the prevention of dementia by lowering blood pressure. Perindopril pROtection aGainst REcurrent Stroke Study (PROGRESS) was designed to determine the effects of an angiotensin-converting enzyme (ACE) inhibitor-based blood pressure-lowering regimen on the risk of stroke among individuals with a prior stroke or transient ischaemic attack (TIA). One of the important aims of the study was to test the hypothesis that treatment would reduce the incidence of dementia and cognitive decline. A total of 6105 patients were randomized to active treatment or placebo. Active treatment comprised perindopril for all participants, and indapamide for those with neither a specific indication for, nor a contraindication to, a diuretic. Dementia was diagnosed according to the criteria of the Diagnostic and Statistical Manual of Mental Disorders, 4th edition. Cognitive decline was defined as a drop of 3 points or more on the Mini-Mental State Examination (MMSE) between baseline and final follow-up. During a median follow-up of 3.9 years, dementia was diagnosed in 410 patients and cognitive decline in 610. Active treatment reduced the risk of cognitive decline (risk reduction [RR] 19%; 95% confidence interval [CI], 4-32; P = 0.01] but there was no clear reduction in the risk of dementia (RR, 12%; 95% CI, -8-28; P = 0.2]). The RR for cognitive outcomes preceded by a recurrent stroke was 34% (95% CI, 3-55; P = 0.03) for dementia and 45% (95% CI, 21-61; P = <0.001) for cognitive decline. Among individuals with a history of stroke or TIA, blood pressure-lowering treatment reduced the risk of cognitive decline by about one fifth. Cognitive decline and dementia associated with recurrent stroke during follow-up were each reduced by between one third and one half. These findings provide further support for the recommendation that blood pressure lowering with perindopril and indapamide be considered for all patients with cerebrovascular disease.

Hypertension and cognitive function: pathophysiologic effects of hypertension on the brain

Accumulating evidence supports a causal role of hypertension for cognitive decline above and beyond its relationship to frank stroke. Hypertension-associated pathologic changes in the brain and its vasculature include vascular remodeling, impaired cerebral autoregulation, cerebral microbleeds, white matter lesions, unrecognized lacunar infarcts, and Alzheimer-like changes such as amyloid angiopathy and cerebral atrophy. White matter lesions and retinal vascular changes, both of which can be imaged noninvasively, may reveal the general condition of the cerebral vasculature or the presence of arteriosclerotic or hypertensive encephalopathy. These noninvasive indicators may also identify a subgroup in whom infarct prevention, particularly via blood pressure reduction, is of paramount importance. Optimal control of blood pressure on a population-wide basis, but particularly in those prone to cognitive loss, is thus a critically important but as yet elusive goal that should be fully exploited for its potential to reduce future cognitive impairment.

Association between blood pressure and cognitive function in a biracial community population of older persons

We examined whether or not blood pressure is related to cognitive function in a cross-sectional study of a biracial community of 5,816 persons aged 65 years and older. Blood pressure had a curvilinear association with cognitive performance in linear regression models adjusted for age, sex, race and education. Scores were lower by 2-5 percentiles at 100 mm Hg systolic pressure compared to scores at the mean of 140 mm Hg and lower by <1 percentile at 180 mm Hg. For diastolic pressure, scores were lower by 2-3 percentiles at 60 mm Hg and by 1-2 percentiles at 100 mm Hg compared to scores at the mean (77 mm Hg). The differences in the scores with low blood pressure were reduced with further adjustment for body mass index, self-perceived health status, depressive symptoms, alcohol use and smoking. The curvilinear associations were stronger among persons with histories of stroke, myocardial infarction and hypertension. The cross-sectional association between blood pressure and cognitive functions is small and curvilinear and more apparent in persons with cardiovascular conditions.

Hypertension and dementia

The increase in life expectancy is associated with a sharp rise in cognitive disorders, particularly after the age of 80 years. The identification and management of risk factors for these invalidating and distressing conditions must be considered a priority. The fact that antihypertensive treatment has been demonstrated to decrease that risk offers a new opportunity to reduce the prevalence of such related disorders and promote healthy aging.

[Cerebral complications of hypertension in the elderly]

PURPOSE

This review focuses on cerebral complications of hypertension, which include stroke, impairment of cognitive function, dementia, and possibly depression and anxiety. These conditions are major causes of morbidity and mortality in the elderly.

CURRENT KNOWLEDGE AND KEY POINTS

Not only elevated diastolic blood pressure, but also isolated systolic hypertension and elevated pulse pressure play an important role in the development of brain complications. Randomised placebo-controlled trials have provided evidence that reduction of hypertension decreases safely and effectively morbidity and mortality rates in the elderly. The new classes of drugs, in particular calcium-channels blockers and angiotensin-converting enzyme inhibitors, have been shown to be as effective as the originally used diuretics and beta-blockers.

FUTURE PROSPECTS AND PROJECTS

Several trials are currently in progress and should provide more information on the benefit of antihypertensive treatment in very elderly persons (Hypertension in the Very Elderly Trial, HYVET) and secondary prevention of stroke (PROGRESS). The importance of assessing new dosages of the presently used antihypertensive drugs as well as the benefit of new classes of drugs is emphasised. Further trials specifically focusing on the prevention of dementia by antihypertensive drugs are needed to confirm the results of the Syst-Eur Vascular Dementia Project. The benefit of calcium antagonists in the prevention of dementia in elderly hypertensive patients should be assessed in the Dementia Prevention in Hypertension trial (DEPHY).

Cerebral imaging changes in patients with chronic renal failure treated conservatively or in hemodialysis

BACKGROUND

Nonuremic patients with apparently normal memory and behavior, studied by means of cerebral computed tomography and found to have cerebral atrophy (CA), evidenced functional intellectual deficits when they underwent psychometric testing. The finding of CA has been repeatedly reported in limited case groups of uremic patients who also demonstrated functional intellectual deficits on the basis of the same tests. This retrospective study considered all diagnostic cerebral computed tomography scans done in our department between 1981 and 1998. Fifty-five uremic patients in conservative treatment (CT) and 111 patients in hemodialysis treatment (HT) were selected on the basis of the following two criteria: primary nephropathy as the cause of uremia and an age < or =55 years to exclude involutive brain changes occurring with age.

AIMS

The aims of the study were to determine the percent of uremic patients with CA, the characteristics of their CA (cortical or subcortical), and eventual associated morphological lesions.

RESULTS

CA was detected in 50.9% (cortical atrophy in 47.3% and subcortical atrophy in 3.6%) of the uremic patients in CT and in 77.5% of those in HT (cortical atrophy in 65.7% and subcortical atrophy in 7.7%). The average degree of CA was 0.872 in the patients in CT and 1.765 in the patients in HT. Thirty-four of the patients in the CT group and 46 in the HT group were hypertensive: these patients had a more severe degree of CA than the nonhypertensive subjects. In the CT group, the degree of CA in the hypertensive patients was 1.205 versus 0.428 for the nonhypertensive subjects. In the HT group, the degree of CA was 2.087 for the hypertensive patients versus 1.538 for the nonhypertensive patients. Of the overall population, 7.8% had ischemic lesions, 9.6% had endocranial calcifications, and 5.4% evidenced periventricular white matter hyperintensities.

CONCLUSIONS

The high percent of CA found in young uremic patients increased in subjects in HT and, even more so in hypertensive patients. Vascular calcifications, focal ischemia and leukoaraiosis, well-known expressions of a chronic state of cerebrovascular insufficiency, were also found in HT patients; hypertension alone is a recognized accelerator of vascular damage. Thus, early and severe atherosclerosis and related hypoperfusion can be considered as the paramount causes of parenchymal cerebral damage in uremia.

Hypertension in older adults

The high prevalence of hypertension in older persons (nearly one of two subjects aged 60 years and older) suggests that the recognition and treatment should be a priority for physicians. Although diastolic blood pressure is regarded as an important risk factor, it is now clear that isolated systolic hypertension and elevated pulse pressure also play an important role in the development of cerebrovascular disease, congestive heart failure, and coronary heart disease, which are the major causes of cardiovascular morbidity and mortality in the population aged older than 65 years. Controlled, randomized trials have shown that treatment of systolic as well as systolodiastolic hypertension decreases the incidence of cardiovascular and cerebrovascular complications in older adults. The question of whether treatment of hypertension should be maintained in very old persons, those older than 80 years, is still undecided.

Alzheimer's disease and vascular dementia. Some points of confluence

The lack of biologic markers for Alzheimer's disease and vascular dementia, the controversy regarding the definition of vascular dementia, and the new evidence of vascular risk factors for Alzheimer's disease suggest that the traditional differentiation between Alzheimer's disease and vascular dementia is no longer very clear. We believe that both vascular and degenerative mechanisms contribute to the development of dementia, especially in very old age. The question of whether they are two independent parallel processes or interacting pathologies needs to be clarified.

Prevalence, treatment, and control of hypertension by sociodemographic factors among the Dutch elderly

The study objective was to assess the prevalence, level of treatment, and control of hypertension in a general elderly population according to age and sociodemographic factors. We conducted a cross-sectional analysis of 7983 participants of the Rotterdam Study who were >/=55 years old and living in a district of Rotterdam. The prevalence of hypertension was based on blood pressure levels (>/=160/95 mm Hg) and the use of blood pressure-lowering medication for the indication of hypertension, type of treatment, and control of hypertension. Systolic blood pressure rises with age, whereas diastolic blood pressure declines. The prevalence of hypertension increases with age and was higher among women (39%) than among men (31%). About 80% of the hypertensives were aware of having hypertension, and 82% of the 80% were treated. For 70% of them, treatment was adequate with reference to conservative criteria. Hypertension was more prevalent among persons not living in a home for the elderly, for more-educated men, and for less-educated women. Persons without a partner and men living in a home for the elderly had a higher risk of being unaware of or of not being treated for existing hypertension. Treatment was more often successful among those living in a home for the elderly. The prevalence of hypertension was higher among older women and increased with age in both genders. A large proportion of hypertensive elderly persons were aware and were successfully treated for hypertension. The degree of awareness and control appeared to be affected by sociodemographic factors. More importantly, the majority of hypertensives did not have their hypertension well controlled. This group requires more attention by medical practitioners to reduce the burden of cardiovascular diseases in elderly persons.

A unifying hypothesis of Alzheimer's disease. III. Risk factors

Normal ageing and Alzheimer's disease (AD) have many features in common and, in many respects, both conditions only differ by quantitative criteria. A variety of genetic, medical and environmental factors modulate the ageing-related processes leading the brain into the devastation of AD. In accordance with the concept that AD is a metabolic disease, these risk factors deteriorate the homeostasis of the Ca(2+)-energy-redox triangle and disrupt the cerebral reserve capacity under metabolic stress. The major genetic risk factors (APP and presenilin mutations, Down's syndrome, apolipoprotein E4) are associated with a compromise of the homeostatic triangle. The pathophysiological processes leading to this vulnerability remain elusive at present, while mitochondrial mutations can be plausibly integrated into the metabolic scenario. The metabolic leitmotif is particularly evident with medical risk factors which are associated with an impaired cerebral perfusion, such as cerebrovascular diseases including stroke, cardiovascular diseases, hypo- and hypertension. Traumatic brain injury represents another example due to the persistent metabolic stress following the acute event. Thyroid diseases have detrimental sequela for cerebral metabolism as well. Furthermore, major depression and presumably chronic stress endanger susceptible brain areas mediated by a host of hormonal imbalances, particularly the HPA-axis dysregulation. Sociocultural and lifestyle factors like education, physical activity, diet and smoking may also modulate the individual risk affecting both reserve capacity and vulnerability. The pathophysiological relevance of trace metals, including aluminum and iron, is highly controversial; at any rate, they may adversely affect cellular defences, antioxidant competence in particular. The relative contribution of these factors, however, is as individual as the pattern of the factors. In familial AD, the genetic factors clearly drive the sequence of events. A strong interaction of fat metabolism and apoE polymorphism is suggested by intercultural epidemiological findings. In cultures, less plagued by the 'blessings' of the 'cafeteria diet-sedentary' Western lifestyle, apoE4 appears to be not a risk factor for AD. This intriguing evidence suggests that, analogous to cardiovascular diseases, apoE4 requires a hyperlipidaemic lifestyle to manifest as AD risk factor. Overall, the etiology of AD is a key paradigm for a gene-environment interaction. Copyright 2000 John Wiley & Sons, Ltd.