Plasma selenium over time and cognitive decline in the elderly

BACKGROUND: Because brain oxidative stress is a cause of cognitive impairment, selenium, which is an antioxidant, may protect against cognitive decline. The aim of the study was to examine whether declining selenium levels over time are associated with cognitive decline in a cohort of community-dwelling French elderly. METHODS: During 1991-1993, 1389 subjects (age 60-71 years) were recruited into a 9-year longitudinal study with 6 waves of follow-up. Cognitive functions were evaluated by neuropsychologic tests. To take into account the entire set of cognitive measurements and the within-subject correlations between measures, we analyzed mixed linear and logistic models to study associations between selenium change and cognitive decline. RESULTS: After controlling for potential confounders, cognitive decline was associated with decreases of plasma selenium over time. Among subjects who had a decrease in their plasma selenium levels, the greater the decrease in plasma selenium, the higher the probability of cognitive decline. Among subjects who had an increase in their plasma selenium levels, cognitive decline was greater in subjects with the smallest selenium increase. There was no association between short-term (2-year) selenium change and cognitive changes. CONCLUSION: Selenium status decreases with age and may contribute to declines in neuropsychologic functions among aging people.     

Causes and consequences of cognitive decline in the very elderly; the 'Leiden 85-plus Study'

In view of the absolute and relative increase in the number of oldest old, it is important to identify the causes and consequences of disease in this group. One of the areas of focus in the 'Leiden 85-plus Study', a population-based prospective study amongst 85-year-olds in the Dutch town of Leiden, is therefore to study the causes and consequences of cognitive decline in the very elderly. Cognitive impairment is the main threat to independence in the oldest old; 85-year-old people with impaired cognitive function (prevalence: 35%) have a ten times greater risk of being limited in their activities of daily life. If this cognitive impairment could be prevented, a large proportion of the independence limitations in the general population could be prevented (population attributable risk: 70%). Limitations in cognitive functioning are strongly associated with the incidence of cardiovascular disease, as well as with a lower average HDL-cholesterol concentration and signs of inflammation. Vascular factors appear to be closely related to development of cognitive impairment in very elderly. Therefore, future therapeutic research will have to demonstrate to what extent influencing the cardiovascular risk factors can lead to the prevention of cognitive decline in the very elderly.     

Coffee consumption is inversely associated with cognitive decline in elderly European men: the FINE Study

OBJECTIVE: To investigate whether coffee consumption is associated with 10-year cognitive decline in elderly men, as results of previous studies obtained hitherto have been controversial and prospective information on this association has been lacking. DESIGN, SUBJECTS AND SETTING: Six hundred and seventy six healthy men born between 1900 and 1920 from Finland, Italy and the Netherlands participated in a 10-year prospective cohort study. Cognitive functioning was assessed using the Mini-Mental State Examination (0-30 points, with a higher score indicating better cognitive performance). Coffee consumption was estimated in cups per day. A mixed longitudinal model was used to investigate the association between baseline coffee consumption and 10-year cognitive decline. Multiple adjustments were made. RESULTS: Men who consumed coffee had a 10-year cognitive decline of 1.2 points (4%). Non-consumers had an additional decline of 1.4 points (P<0.001). An inverse and J-shaped association was observed between the number of cups of coffee consumed and cognitive decline, with the least cognitive decline for three cups of coffee per day (0.6 points). This decline was 4.3 times smaller than the decline of non-consumers (P<0.001). CONCLUSIONS: Findings suggest that consuming coffee reduces cognitive decline in elderly men. An inverse and J-shaped association may exist between the number of cups of coffee consumed and cognitive decline, with the least cognitive decline for men consuming three cups of coffee per day.     

Total homocysteine and cognitive decline in a community-based sample of elderly subjects: the Rotterdam Study.

Homocysteine has been associated with an increased risk of cardiovascular disease. Cardiovascular diseases have been related to cognitive decline. The authors investigated the association of homocysteine with concurrent cognitive impairment and subsequent cognitive decline in a random sample of 702 community-dwelling respondents aged 55 years or over to the prospective Rotterdam Study in 1990-1994. Multiple logistic regression was used to calculate odds ratios and 95 percent confidence intervals for the association between total homocysteine levels and cognitive impairment (Mini-Mental State Examination (MMSE) score <26) and cognitive decline (drop in MMSE score of >1 point/year). Mean duration of follow-up was 2.7 years. After adjustment for age, sex, and education, there was no relation between total homocysteine and cognitive impairment (highest vs. lowest tertile: odds ratio (OR) = 1.30, 95% confidence interval (CI): 0.50, 3.38) or cognitive decline (middle vs. lowest tertile: OR = 1.14, 95% CI: 0.67, 1.93; highest vs. lowest tertile: OR = 0.91, 95% CI: 0.52, 1.58). Subjects who were lost to follow-up due to death or nonresponse had slightly higher age-adjusted homocysteine levels and lower MMSE scores at baseline. Sensitivity analyses showed that selective loss to follow-up was not a likely explanation for the absence of an association in the participants. Although a relation between homocysteine and reduced cognitive function is biologically plausible, this study suggests no such association in a community-based sample of the elderly.     

Methodological issues in the study of cognitive decline

In recent years, epidemiologists have given increased attention to cognition, especially to the dementing illnesses that occur in old age. Central to this study is the measurement of change in cognition as opposed to cognition measured at a single point in time. This article addresses conceptual and methodological issues in the study of changes in cognitive function, including: 1) difficulties encountered with the use of single measurements of cognition and the importance of measuring changes in cognition; 2) sources of measurement variation and its potential effects; 3) the importance of careful modeling of age and education; 4) considerations in categorizing outcomes or combining the results of cognitive tests; and 5) the benefits of using multiple-outcome statistical models.     

Prospective study of ready-to-eat breakfast cereal consumption and cognitive decline among elderly men and women

Objective  

To examine associations between frequency of ready-to-eat-cereal (RTEC) consumption and cognitive function among elderly men and women of the Cache County Study on Memory Health and Aging in Utah.     

Rapid cognitive decline: searching for a definition and predictive factors among elderly with Alzheimer's disease

The pattern and rate of cognitive decline in AD patients is far from uniform. In clinical practice, certain patients present episodes of rapid cognitive loss, whereas others deteriorate more progressively. At present time, there is little known about rapid decline in cognitive function in patients with AD, and moreover among older population. The main objective of this review was to elaborate a proposal of definition of rapid cognitive decline in order to facilitate its applicability into ordinary medical practice and to be relevant for clinical-decision making in old patients with AD. After the literature review, our results from longitudinal prospective studies and our clinical practice experience, we propose the following definition of rapid cognitive decline: a four-point or greater loss on the MMSE within six months and the loss of at least one point on the MMSE during the following six months. After ELSA cohort's results, 11% of an AD population of 312 patients were rapid cognitive decliners, complying with our proposed definition. They represent a non-negligible proportion of the population afflicted by AD.     

Brittle diabetes in the elderly

Severely unstable, or brittle, diabetes can be disruptive to patients, carers and diabetes care teams. The peak age-group for brittle diabetes is 15-30, but there are reports of its occurrence in much older patients. To explore the characteristics and cause of brittle instability perceived by diabetologists in elderly patients we circulated a questionnaire to all UK hospital diabetic clinics for adults. 130 (56%) of 231 replied. Reports were obtained on 55 patients fulfilling our criteria for 'elderly brittle diabetes'--namely, age > or =60 years, on insulin treatment, and experiencing life-disrupting glycaemic instability of any kind associated with frequent or long admissions to hospital. Further information was obtained by a research nurse who visited the relevant clinics. The mean age of patients was 74 years (range 60-89) and 71% were female. The brittleness was classed as mixed glycaemic instability in 22 (44%), recurrent ketoacidosis in 16 (29%) and recurrent hypoglycaemia in 15 (27%). In 2 cases there was insufficient information for classification. The diabetes care team judged the brittleness to have multiple origins in two-thirds of the cases: problems with memory or behaviour were rare, and in only 4 cases was deliberate manipulation of therapy considered a possibility. 84% of the patients were living independently. In younger patients the principal manifestation of brittle diabetes is recurrent ketoacidosis. The present survey, though possibly subject to ascertainment bias, indicates that the patterns of instability and their causation may be different in elderly patients. With the growing use of insulin in the elderly, brittle diabetes is likely to be encountered increasingly often in this age-group.     

Pathological correlates of cognitive decline in Alzheimer's disease

Although Alzheimer's disease (AD) has been investigated for more than 100 years, it was not until the 60s that quantitative measures of the disease progression and severity in relation to function and neuropathology were made by Blessed and his colleagues. With the increasing understanding of the pathological changes of AD that take place, there is growing interest in identifying which pathological marker most reliably predicts the dementia and the cognitive profile. Markers of pathology that have been investigated include senile plaques, neurofibrillary tangles, synaptic loss, and neurochemical changes. Many clinical measures have been evaluated as well including Clinical Dementia Rating, Mini Mental State Examination, and Functional Assessment Staging as ways of both predicting the presence of pathological changes of AD as well as correlating with the specific measures of pathology. Accumulation of neuropathology appears to correlate with functional, global, and cognitive decline as people progress through AD. This review will summarize evidence of which neuropathological change correlates robustly with cognitive decline and which cognitive index predicts pathological changes in AD. In general, tangles and synaptic loss are better correlates of cognitive decline and correlate better.     

Pulse wave velocity is associated with 1-year cognitive decline in the elderly older than 80 years: the PARTAGE study

ObjectivesStudies have shown the importance of vascular risk factors in the pathogenesis and evolution of cognitive disorders and dementia especially among the very elderly. The aim of the present longitudinal 1-year cohort analysis was to evaluate the influence of arterial stiffness on cognitive decline in institutionalized subjects older than 80 years.DesignLongitudinal study.SettingNursing homes in France and Italy.ParticipantsA total of 873 subjects (79% women), aged 87 ± 5 years were included in this longitudinal analysis from the PARTAGE cohort.MeasurementsAll completed the Mini-Mental Status Examination (MMSE) on the 2 visits over 1 year and underwent a measurement of carotid-femoral pulse wave velocity (PWV), an indicator of aortic stiffness. Clinical and 3-day self-measurements of blood pressure (BP) and activities of daily living (ADL) were evaluated at baseline visit.ResultsAccording to PWV tertiles and after adjustment for baseline MMSE, mean BP (MBP), age, education level, and ADL, Δ MMSE was –1.42 ± 3.60 in the first tertile, –1.78 ± 4.08 in the second tertile, and –2.20 ± 3.98 in the third tertile (P < .03). Similar analyses with self-measured MBP failed to show any association between BP on MMSE decline.ConclusionThis 1-year longitudinal study in institutionalized patients older than 80 years shows that the higher the aortic stiffness, the more pronounced the decline in cognitive function. These results point out the interest of measuring PWV, a simple noninvasive and validated method for arterial stiffness assessment, to detect high-risk patients for cognitive decline.     

Socio-demographic differentials in the functional decline among the elderly in Brazil

There is a positive reversion in the expectations regarding the health condition of the elderly population, possibly due to the progresses in medical technology; behavioural changes; development of special programmes for the elderly; improvements in the socio-economic status; decrease of infectious diseases. This study aims analyzing differentials in the prevalence rates of mobility disability among elderly people in Brazil. The data used were from 'The 1998 and 2003 National Household Survey (PNAD)', conducted by the Brazilian Institute of Geographic and Statistics (IBGE). The two samples were nationally representative, including approximately 30 thousand individuals aged 60 years or more respectively. "Difficulty to walk more than 100 meters" was the variable selected as the indicator of disability. Socio-demographic status measures were sex, age group, region of residence and family income per capita. Comparison of the PNAD results of 1998 and 2003 showed that over that period in Brazil the elderly disability rates decreased among all socio-demographic groups considered. Public policies directed to the elderly must focus on reducing mobility disability.     

全球烟草控制进展

从1970年开始,世界卫生组织(WHO)一直在努力为控制全球烟草泛滥做出积极努力。1999年第52届世界卫生大会通过了制定《烟草控制框架公约》(以下简称公约)的决定,经过两次工作组会议和6次政府间谈判机构会议的艰苦谈判,于2003年5月21日,第56届世界卫生大会一致通过了该《公约》。     

Nutrition and cognitive impairment in the elderly

As the number of older people is growing rapidly worldwide and the fact that elderly people are also apparently living longer, dementia, the most common cause of cognitive impairment is getting to be a greater public health problem. Nutrition plays a role in the ageing process, but there is still a lack of knowledge about nutrition-related risk factors in cognitive impairment. Research in this area has been intensive during the last decade, and results indicate that subclinical deficiency in essential nutrients (antioxidants such as vitamins C, E and beta-carotene, vitamin B(12), vitamin B(6), folate) and nutrition-related disorders, as hypercholesterolaemia, hypertriacylglycerolaemia, hypertension, and diabetes could be some of the nutrition-related risk factors, which can be present for a long time before cognitive impairment becomes evident. Large-scale clinical trials in high-risk populations are needed to determine whether lowering blood homocysteine levels reduces the risk of cognitive impairment and may delay the clinical onset of dementia and perhaps of Alzheimer's disease. A curative treatment of cognitive impairment, especially Alzheimer's disease, is currently impossible. Actual drug therapy, if started early enough, may slow down the progression of the disease. Longitudinal studies are required in order to establish the possible link of nutrient intake--nutritional status with cognitive impairment, and if it is possible, in fact, to inhibit or delay the onset of dementia.     

Socioeconomic differences in cognitive decline and the role of biomedical factors

PURPOSE: This study examines the association between socioeconomic status and cognitive decline in a community-based cohort of well-functioning older adults and seeks to determine whether this link could be explained by biomedical factors. METHODS: Data are from 2574 men and women aged 70 to 79 years from Pittsburgh, PA, and Memphis, TN, participating in the Health, Aging and Body Composition study (Health ABC). Three indicators of socioeconomic status were used: education, income, and ownership of financial assets. Cognitive decline over 4 years was defined as a decrease of five points or more in the Modified Mini-Mental State Examination (3MS) score. Biomedical factors measured at baseline, included heart disease, cerebrovascular disease, diabetes, hypertension, poor pulmonary function, and high serum levels of inflammatory markers. RESULTS: Adjusted odds ratios were significantly higher in those with low education, low income, and few assets. Odds ratios ranged from 1.51 to 2.16 in the lowest socioeconomic groups. Additional adjustment for biomedical factors reduced the odds ratios of cognitive decline by an average of 2% for education, 5% for income, and 8% for the number of assets. CONCLUSIONS: Low socioeconomic status predicts a decline in cognitive function in older adults and this relationship is not mediated by biomedical factors.