Vascular risk factors and dementia in the general population aged >85 years: prospective population-based study.

The aim of this study was to evaluate the association between dementia and common vascular risk factors including blood pressure, blood lipids, homocysteine and diabetes mellitus in a population of very old people. This study is a 9-year follow-up prospective population-based study monitoring 339 non-demented subjects aged 85 years or over in the city of Vantaa, Southern Finland. During the follow-up, those individuals with diabetes mellitus at the baseline and new incident stroke had a higher probability for developing dementia. History of hypertension or higher level of education were associated with a lower probability of dementia. It seems that the contribution of vascular risk factors to the risk of dementia may be age-dependent and their role in the very old subjects may be mediated through their influence on cerebrovascular morbidity. Thus, prevention of stroke and diabetes mellitus may reduce the risk of cognitive decline in the very old.

Neuropathologic findings of dementia with lewy bodies (DLB) in a population-based Vantaa 85+ study.

The consortium on dementia with Lewy bodies has established consensus guidelines for the neuropathologic diagnosis of dementia with Lewy bodies (DLB) including the likelihood that the neuropathologic findings associate with the clinical syndrome. Nevertheless, clinico-pathological correlations remain controversial. We applied the consensus guidelines for determining Lewy-related pathology (LRP) and evaluated the clinical presentation in the prospective, population-based Vantaa 85+ study consisting of individuals at least 85 years of age. LRP was seen in 36% of 304 subjects and categorized as follows: 3% brainstem-predominant, 14% limbic, 15% diffuse neocortical type (4% could not be categorized). The likelihood that the neuropathology predicts the DLB clinical syndrome was low in 6%, intermediate in 13%, and high in 13% of all 304 subjects. In the latter two groups, 77% were demented, 35% had at least one extrapyramidal symptom, and 15% had visual hallucinations. Surprisingly, DLB clinical features associated better with high neurofibrillary stage than with diffuse neocortical LRP. Moreover, the neurofibrillary stage, substantia nigra neuron loss, and grade of Lewy neurites in hippocampal CA2-3 region, each showed a significant association with the extent of LRP. In conclusion, the neuropathologic DLB in this very elderly population was common, but the clinical symptoms tended to associate better with severe neurofibrillary pathology than with extensive LRP.

Neurofibrillary tau pathology modulated by genetic variation of alpha-synuclein.

We analyzed whether genetic variation of alpha-synuclein modulates the extent of neuropathological changes in a population-based autopsied sample of 272 elderly Finns. None of the 11 markers was associated with the extent of neocortical beta-amyloid pathology. The intron 4 marker rs2572324 was associated with the extent of neurofibrillary pathology (p = 0.0006, permuted p = 0.004; Braak stages IV-VI vs 0-II). The same variant also showed a trend for association with neocortical Lewy-related pathology. These results suggest for the first time that variation of alpha-synuclein modulates neurofibrillary tau pathology and support the recent observations of an interaction of alpha-synuclein and tau in neurodegeneration.

Atrial fibrillation, stroke, and cognition: a longitudinal population-based study of people aged 85 and older.

BACKGROUND AND PURPOSE: The aim of this study was to investigate the association between atrial fibrillation (AF), stroke, dementia, and their correlation with brain pathology in subjects aged 85 years or older. METHODS: This is a prospective 9-year follow-up population based study in Vantaa, a town in Southern Finland; 553 subjects (92% of the total population) aged 85 years or older were clinically examined by a neurologist. The presence of AF was collected from the medical records or examined by ECG or ambulatory ECG. Neuropathological examination was conducted in more than half of the clinically examined subjects. RESULTS: AF was significantly associated with stroke at baseline; 32% of patients with AF had clinical evidence of stroke compared with 16.7% of those without such evidence (P<0.001). Dementia at baseline was significantly associated with age, clinical stroke, and the presence of apolipoprotein E epsilon4 allele, but not with sex, education, or vascular risk factors. Multiple regression analysis including neuropathological results showed that dementia was significantly associated with education (OR, 0.89; 95% CI, 0.80 to 0.98; P=0.019), the beta-amyloid load in the brain (OR, 1.26; 95% CI, 1.13 to 1.39; P<0.001) and with the vascular pathology (OR, 2.03; 95% CI, 1.14 to 3.62; P=0.016), but not with sex, age at death, apolipoprotein E epsilon4 allele, or vascular risk factors. CONCLUSIONS: AF is a significant and preventable risk factor for stroke but not for dementia in the very old. The etiology of dementia syndrome in the very old is multifactorial. Both Alzheimer disease pathology and vascular pathology, particularly multiple small infarcts, contribute to cognitive decline.

Association between blood pressure and survival over 9 years in a general population aged 85 and older.

OBJECTIVES: To investigate the association between blood pressure and mortality in people aged 85 and older. DESIGN: Population-based prospective study with 9-year follow-up. SETTING: Department of Neuroscience and Neurology and Department of Public Health and General Practice, University of Kuopio, and Department of Clinical Neurosciences, Helsinki University Hospital. PARTICIPANTS: Of all 601 people living in the city of Vantaa born before April 1, 1906, whether living at home or in institutions and alive on April 1, 1991, 521 were clinically examined and underwent blood pressure measurement. MEASUREMENTS: Blood pressure was measured using a standardized method in the right arm of the subject after resting for at least 5 minutes. Information on medical history for each participant was verified from a computerized database containing all primary care health records. Death certificates were obtained from the National Register; the collection of death certificates was complete. RESULTS: After adjusting for age, sex, functional status, and coexisting diseases (earlier-diagnosed myocardial infarction, congestive heart failure, dementia, cancer, stroke, or hypertension), low systolic blood pressure (BP) was associated with risk of death. CONCLUSION: Low systolic BP may be partially related to poor general health and poor vitality, but the very old may represent a select group of individuals, and the use of BP-lowering medications needs to be evaluated in this group.

Incidence of dementia in very elderly individuals: a clinical, neuropathological and molecular genetic study.

AIMS: To evaluate the effect of medical record use on figures for the incidence of dementia and the effect of apolipoprotein E (APOE) polymorphism on this incidence and neuropathologically defined Alzheimer's disease (AD) in very elderly individuals. METHODS: Cognitive functions were examined in a cohort of 328 (92% of the very elderly people of a town participated in this study) nondemented Finnish elderly individuals 85 years of age or more in 1991. The examination was repeated in survivors in 1994, 1996, 1999 and 2001. Medical notes and social work records were evaluated. All these individuals were genotyped for APOE. Neuropathological analysis of AD-type pathology was performed on 159 of 303 subjects who died during the follow-up. RESULTS: Age group, gender or APOE did not significantly affect the incidence of dementia, which was over 20% higher (85 vs. 69 per 1,000 person-years) if the cognitive status at death was ascertained by medical and social work records than without this evaluation. The APOE upsilon4 allele was highly significantly (p=0.002) and age almost significantly (p=0.06) associated with neuropathological AD in nondemented individuals. CONCLUSIONS: Medical records should be analyzed in studies on the incidence of dementia in very elderly individuals. APOE polymorphism does not affect the incidence of dementia in this age group. However, clinical dementia diagnosis in very elderly individuals does not necessarily correlate well with the presence of neuropathological AD which, even in this age group, is significantly associated with the APOE upsilon4 allele.

Chromosome 21 BACE2 haplotype associates with Alzheimer's disease: a two-stage study.

Genetic linkage studies have provided evidence for a late-onset Alzheimer's disease (AD) susceptibility locus on chromosome 21q. We have tested, in a two-stage association study, whether allelic or haplotype variation of the beta-amyloid cleaving enzyme-2 (BACE2) locus on chromosome 21q affects the risk of late-onset AD. In stage-1, an unselected population-based sample of Finns aged 85 years or over (n=515) was analysed. Neuropathologic examination including beta-amyloid load quantification was possible in over 50% (n=264) of these subjects. AD patients (n=100) and controls (n=48) were defined by modified neuropathological NIA-RI criteria. Positive associations were taken as a hypothesis, and tested in stage-2 using 483 AD families from the USA. Four single nucleotide polymorphisms (SNPs) of BACE2 gene were tested in stage-1. A SNP close to exon-6 was associated with neuropathologically verified AD (p=0.02) and also with beta-amyloid load in non-selected autopsied subjects after conditioning with APOE genotype (p=0.001). In haplotype analysis a specific, relatively common haplotype (H5) was found to associate with AD (p=0.004) and a second haplotype (H7) showed a weaker association with protection against AD (p=0.04). In stage-2, the SNP association was not replicated, whereas the haplotype H5 association was replicated (p=0.004) and a trend to association was found with the putative protective haplotype H7 (two-sided p=0.08). BACE2 haplotype association with AD in two independent datasets provides further evidence for an AD susceptibility locus on chromosome 21q within or close to BACE2.

Association of apolipoprotein E genotypes, blood pressure, blood lipids and ECG abnormalities in a general population aged 85+.

BACKGROUND: Several studies have linked apolipoprotein E (ApoE) epsilon4 allele with elevated cholesterol and blood pressure levels. Data on the association of APOE genotypes with blood pressure, lipids, atrial fibrillation and ECG abnormalities in individuals aged 85 years and over is sparse. METHODS: This cross sectional study consisted of all residents of the city of Vantaa (N = 601) aged 85 years or over of whom 505 participated in the study. Blood pressure was measured by using mercury sphygmomanometer. 12-Lead ECG, short ambulatory ECG, or both were taken from all study subjects to diagnose atrial fibrillation (AF). Ambulatory ECG was carried out home or in the institute. APOE genotyping was performed using a combination of the polymerase chain reaction (PCR) and solid-phase minisequencing technique. Statistical analysis was made by using Kruskall-Wallis-test (continuous data) and chi2-test (rates and proportions). RESULTS: In these very elderly individuals, APOE 4 allele was significantly associated with elevated cholesterol and low-density lipoprotein (LDL) levels. Blood pressure or cardiac arrhythmias did not differ between APOE genotypes. CONCLUSIONS: These observations suggest that the important role of APOE genotype still influences cardiovascular risk profile even among the very elderly people.