Cognitive impairment and mortality: a study of possible confounders

Cognitive Function, Healthy Lifestyle, and All-Cause Mortality among Chinese Older Adults: A Longitudinal Prospective Study

BACKGROUND

Both cognitive decline and unhealthy lifestyles have been linked to an elevated risk of mortality in older people. We aimed to investigate whether a healthy lifestyle might modify the association between cognitive function and all-cause mortality in Chinese older populations.

METHODS

The final analysis included 5124 individuals free of dementia, selected from the Chinese Longitudinal Healthy Longevity Survey from 2011 to 2018. Cognitive function was assessed in 2011 using the Mini-Mental State Examination (MMSE). A lifestyle score was calculated based on five lifestyle factors, including smoking, alcohol consumption, physical activity, diet, and body mass index. Cox proportional hazards models were performed to evaluate the association between baseline cognitive function and the risk of all-cause mortality, with an interaction term of cognitive function and lifestyle score being added to the models.

RESULTS

The average age of participants was 81.87 years old at baseline. During a median follow-up of 6.4 years, 1461 deaths were documented. Both higher cognitive function (HR: 0.96; 95% CI: 0.96-0.97) and a healthier lifestyle (HR: 0.92; 95% CI: 0.87-0.97) were significantly associated with a reduced risk of mortality. We found that lifestyle significantly modified the association of cognitive function with mortality (p for interaction = 0.004). The inverse relation between cognitive function and mortality was found to be more pronounced among participants with a healthier lifestyle. Of note, among the lifestyle scores component, diet showed a significant interaction with mortality (p for interaction = 0.003), and the protective HR of the all-cause mortality associated with higher MMSE scores was more prominent among participants with healthy diets compared with unhealthy diets.

CONCLUSIONS

Our study indicates that cognitive decline is associated with a higher risk of mortality, and such associations are attenuated by maintaining a healthy lifestyle, with a particular emphasis on healthy diet.

Interaction between the animal-based dietary pattern and green space on cognitive function among Chinese older adults: A prospective cohort study

Green space is associated with better cognition, while the animal-based dietary pattern can be a risk factor. We aimed to verify the associations and explore their interaction among the elderly. The China Longitudinal Healthy Longevity Survey (CLHLS) cohort including 17,827 participants was used. The average green space coverage rate was used to measure green space exposure. The animal-based diet index (ADI) was scored based on the non-quantitative frequency questionnaire of ten types of food intake (three types of animal foods and seven types of plant foods). We used the Mini-Mental State Examination (MMSE) to assess cognitive function. The Cox proportional hazard regression was applied to explore the correlations and interactions. In the models, we gradually adjusted for the potential risk factors. Compared with participants living in the area with the lowest green space, those living with the highest were associated with a 20% decrease in the risk of cognitive impairment (hazard ratio (HR): 0.80, 95% CI: 0.73, 0.89). As for ADI, the highest group was related to a 64% increase in the risk of cognitive impairment (HR: 1.64, 95% CI: 1.38, 1.95). The protective effect of the highest green space group on cognitive impairment was more evident among participants with low ADI (HR = 0.72, 95% CI: 0.62, 0.83), compared to those with high ADI. Green space was positively associated with cognition, while the animal-based dietary pattern was a cognitive disadvantage. The animal-based dietary pattern may mitigate the beneficial effects of green space on cognition.

Associations Between Cognitive Functioning and Mortality in a Population-Based Sample of Older United States Adults: Differences by Sex and Education

Objective: To determine whether cognition is associated with mortality among older US adults. Methods: We studied 5,989 National Health and Nutrition Examination Survey participants age 60+ in years 1999-2014 with mortality follow-up through 2015. Cognitive function was measured in one standard deviation decrements using the Digit Symbol Substitution Test (DSST), Animal Fluency (AnFl), and two Consortium to Establish a Registry for Alzheimer's Disease (CERAD) tests. Results: Each decrement in cognitive function was associated with increased risk of mortality overall (DSST HR: 1.36, 95% CI: 1.25, 1.48), among women only (AnFl: 1.51, 95% CI: 1.02, 2.24), and among those with less than a high school education only (AnFl HR: 1.46, 95% CI: 1.09, 1.97; CERAD-WL HR: 1.34, 95% CI: 1.07, 1.67; and CERAD-DR HR: 1.38, 95% CI: 1.05, 1.82). Discussion: Among US adults, lower cognitive functioning was associated with mortality; associations were stronger among women and those with less education.

Association of ankle-brachial index with cognitive decline in patients with lacunar infarction

Atherosclerosis is an important risk factor for cognitive decline. This study aimed to investigate the relationship of ankle-brachial pressure index (ABI) and brachial-ankle pulse wave velocity (baPWV) with cognitive function in patients with lacunar infarction. We included records of consecutive patients with their first-ever acute stroke and a diagnosis of lacunar infarction through magnetic resonance imaging (MRI) from July 1, 2011 to December 31, 2018. We excluded patients diagnosed with dementia, including strategic single-infarct dementia, before or after stroke onset. Moreover, we excluded patients with one or more microbleeds, severe white matter lesions, or severe medial temporal atrophy on MRI. For ABI, we used the lower ankle side and divided the results into ABI < 1.0 and ABI ≥ 1.0. For baPWV, we used the higher ankle side and divided the results into two groups based on the median value of the participants. We analyzed 176 patients with stroke (age 72.5 ± 11.4 years, 67 females). The median score on the Mini-Mental State Examination (MMSE) was 27. The number of patients with ABI < 1.0 was 19 (10.8%). Univariate analysis revealed that the MMSE score was associated with age, body mass index, education, chronic kidney disease, periventricular hyperintensity, and ABI < 1.0 (p < 0.10), but not baPWV. Multivariate analysis revealed that body mass index (p = 0.039) and ABI < 1.0 (p = 0.015) were independently associated with the MMSE score. For patients with lacunar infarction, a lower ABI, but not a higher PWV, was associated with cognitive decline.

Lobar microbleeds are associated with cognitive impairment in patients with lacunar infarction

Associations between cognitive decline and cerebral microbleeds (CMBs) have received increasing attention. An association between CMB distribution (deep or lobar) and cognitive decline has been reported, but these findings are controversial. We investigated the association between magnetic resonance imaging (MRI) findings, including CMBs, and cognitive function in patients with first-ever lacunar infarction. We retrospectively included consecutive patients admitted with first-ever lacunar infarction identified by MRI from July 1, 2011, to December 31, 2018. We excluded patients diagnosed with dementia, including strategic single-infarct dementia, before or after the onset of stroke. The Mini-Mental State Examination (MMSE) was performed within 3 days of admission. We searched the records of 273 patients (age 72.0 ± 11.2 years, 95 females). The median MMSE score was 27 (interquartile range 25.5–29). In a univariate analysis, the MMSE score was associated with age, body mass index (BMI), education, dyslipidemia, chronic kidney disease (CKD), periventricular hyperintensity, medial temporal atrophy, lobar CMBs, and mixed CMBs (p < 0.20). The lacunar infarction location was not associated with the MMSE score. In a multivariate analysis of these factors, lobar CMBs (p < 0.001) and mixed CMBs (p = 0.008) were independently associated with the MMSE score. Lobar CMBs were associated with cognitive impairment.

Cognitive decline and mortality among community-dwelling Chinese older people

BACKGROUND

Whether cognitive decline is related to a higher risk of death independent of the initial cognitive function is inconclusive. Evidence of the association between cognitive decline and mortality among Chinese older people is limited. We aimed to examine whether cognitive decline, assessed by the rate of decrease in the Mini-Mental State Examination (MMSE) score, was associated with mortality independent of initial cognitive function (baseline MMSE score) among Chinese older people.

METHODS

We established two successive and non-overlapping cohorts of older adults nested within the Chinese Longitudinal Healthy Longevity Survey (CLHLS), an ongoing, open, community-based cohort survey conducted every 2-3 years. Cognitive function was measured using the Chinese version of the MMSE. A total of 11,732 older adults who completed two consecutive cognitive function examinations were included and followed for 3 years. A Cox proportional hazards model was used to examine the association of cognitive decline with mortality after adjusting for sociodemographic characteristics, health behaviours, comorbidities and initial cognitive function.

RESULTS

The mean age was 82.5 years old, and 44.9% (5264/11732) of participants were men. After adjusting for baseline MMSE scores and other covariates, the rate of change in MMSE scores over 3 years was monotonically and positively associated with subsequent 3-year mortality. Compared to those with stable cognitive function, participants with rapid cognitive decline (decline faster than average, a reduction of MMSE scores > 1.62 points/year) had a 75% higher risk of death (hazard ratio = 1.75, 95% confidence interval 1.57-1.95). The association between cognitive decline and mortality was stronger among relatively younger Chinese older people (aged 65-79 years versus 80 years and over) and those with normal cognitive function at baseline (MMSE scores ≥ 24 versus < 24 points), respectively, but did not differ by cohort and sex.

CONCLUSION

Faster cognitive decline was associated with higher mortality independent of initial cognitive function, especially among those aged 65-79 years and those with normal cognitive function at baseline. The association was consistent across two successive cohorts. Our findings indicate the practical significance of monitoring cognitive change in older adults.

Understanding the relationship between cognition and death: a within cohort examination of cognitive measures and mortality

Despite several studies demonstrating an independent and inverse association between cognition and mortality, the nature of this association still remains unclear. To examine the association of cognition and mortality after accounting for sociodemographic, health and lifestyle factors and to explore both test and population characteristics influencing this relationship. In a population based cohort of 8585 men and women aged 48-92 years, who had cognitive assessments in 2006-2011 and were followed up till 2016 for mortality, we examined the relationship between individual cognitive tests as well as a global cognition score to compare their ability in predicting mortality and whether these differed by population characteristics. Risk of death was estimated using Cox proportional hazard regression models including sociodemographic, lifestyle and health variables, and self-reported comorbidities, as covariates in the models. Poor cognitive performance (bottom quartile of combined cognition score) was associated with higher risk of mortality, Hazard Ratio = 1.32 (95% Confidence Interval 1.09, 1.60); individual cognitive tests varied in their mortality associations and also performed differently in middle-age and older age groups. Poor cognitive performance is independently associated with higher mortality. This association is observed for global cognition and for specific cognitive abilities. Associations vary depending on the cognitive test (and domain) as well as population characteristics, namely age and education.

Ankle-Brachial Index: An Ubiquitous Marker of Cognitive Impairment-The EPIDEMCA Study

Epidemiological research on the implication of atherosclerosis in the development of cognitive impairment is lacking in low- and middle-income countries, where two-thirds of the individuals affected by dementia live. Individuals aged ≥65 years living in urban and rural areas of 2 countries in Central Africa were invited. Demographic, clinical, and biological data were collected, and the ankle-brachial index (ABI) was measured. Cognitive impairment was defined according to the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) criteria. Among 1662 participants (age 72.9 years, 59.3% females), the prevalence of cognitive impairment was 13.6%, which is higher in individuals with ABI ≤ 0.90 and ABI ≥ 1.40 than those with 0.90 < ABI < 1.40 (20.1% and 17% vs 12%, P = .0024). Cognitive impairment was significantly associated with the factors such as age (odds ratio [OR]: 1.09; 95% confidence interval [CI]: 1.07-1.12, P < .0001), female gender (OR: 2.36, 95% CI: 1.59-3.49, P < .0001), smoking (OR: 1.54, 95% CI: 1.06-2.23, P = .0026), and low ABI (≤0.90; OR: 1.52, 95% CI: 1.03-2.25, P = .0359). The ABI, a ubiquitous marker of atherosclerosis, provides independent and incremental information on susceptibility to present with cognitive disorders.

Disability and all-cause mortality in the older population: evidence from the English Longitudinal Study of Ageing

Despite the vast body of literature studying disability and mortality, evidence to support their association is scarce. This work investigates the role of disability in explaining all-cause mortality among individuals aged 50+ who participated in the English Longitudinal Study of Aging. The aim is to explain the gender paradox in health and mortality by analysing whether the association of disability with mortality differs between women and men. Disability was conceived following the International Classification of Functioning, Disability and Health (ICF), proposed by the WHO, that conceptualizes disability as a combination of three components: impairment, activity limitation and participation restriction. Latent variable models were used to identify domain-specific factors and general disability. The association of the latter with mortality up to 10 years after enrolment was estimated using discrete-time survival analysis. Our work confirms the validity of the ICF framework and finds that disability is strongly associated with mortality, with a time-varying effect among men, and a smaller constant effect for women. Adjusting for demographic, socioeconomic and behavioural factors attenuated the association for both sexes, but overall the effects remained high and significant. These findings confirm the existence of gender paradox by showing that, when affected by disability, women survive longer than men, although if men survive the first years they appear to become more resilient to disability. Sensitivity analyses suggested that the gender paradox cannot be solely explained by gender-specific health conditions: there must be other mechanisms acting within the pathway between disability and mortality that need to be explored.

Physical Activity as Protective Factor against Dementia: A Prospective Population-Based Study (NEDICES)

The aim of this study was to analyze whether physical activity (PA) is a protective factor for the incidence of dementia after 3 years of follow-up. The Neurological Disorders in Central Spain (NEDICES) is a prospective population-based survey of older adults (age 65 years and older) that comprised 5278 census-based participants at baseline (1994-1995). A broad questionnaire was used to assess participants' sociodemographic characteristics, health status, and lifestyle. Subsequently, a modified version of Rosow-Breslau questionnaire was applied to classify individuals' baseline PA into groups (i.e., sedentary, light, moderate, and high). Cox regression models adjusted for several covariates (age, sex, education, previous stroke, alcohol consumption, hypertension, health related variables) were carried out to estimate the association between the PA groups and risk of dementia at the 3-year follow-up (1997-1998). A total of 134 incident dementia cases were identified among 3105 individuals (56.6% female; mean age=73.15 ± 6.26) after 3 years. Hazard ratios (HRs) of the light, moderate, and high PA groups (vs. sedentary group) were 0.40 (95% confidence interval {CI} [0.26, 0.62]; p<.001), 0.32 (95% CI [0.20, 0.54]; p<.001) and 0.23 (95% CI [0.13, 0.40]; p<.001), respectively. Even after controlling for covariates and the exclusion of doubtful dementia cases, HRs remained significant. However, a supplementary analysis showed that the dose-effect hypothesis did not reach statistical significance. PA is a protective factor of incident dementia in this population-based cohort.

Arterial stiffness and cognitive function in the elderly

Cognitive decline and dementia are a major cause of disability and mortality among older adults. Cross-sectional evidence from observational studies suggests that greater arterial stiffness is associated with worse cognitive performance. These associations have been observed on measures of global cognition and across multiple domains of cognition. Epidemiologic evidence on the association between arterial stiffness and rate of cognitive decline has been less definitive, and very few studies have investigated the risk of developing dementia. This review summarizes the current research on arterial stiffness and cognition, issues around measurement, and the effect that potential intervention might have on the course of cognitive aging. The evidence on pharmacological and non-pharmacological (exercise, nutrition, etc.) interventions in older adults with arterial stiffness is promising. Yet there are no studies or trials that directly evaluate how interventions of arterial stiffness reduce or prevent cognitive impairment and risk of developing dementia. More research is needed to elucidate the causal link between arterial stiffness and cognitive decline and dementia, and to identify whether potential interventions to prevent or reduce arterial stiffness may benefit cognitive health of the elderly.

Associations between oral health and risk of dementia in a 37-year follow-up study: the prospective population study of women in Gothenburg

OBJECTIVES

To investigate the association between incident dementia and previous number of teeth measured over a long interval.

DESIGN

Retrospective analysis of a 37-year cohort study.

SETTING

Prospective Population Study of Women in Gothenburg.

PARTICIPANTS

Women with (n = 158) and without (n = 539) dementia in 2000 to 2005.

MEASUREMENTS

Tooth counts in 1968-69, 1980-81, and 1992-93. Covariates included age, education, stroke, myocardial infarction, diabetes mellitus, smoking status, blood pressure, body mass index, and cholesterol level.

RESULTS

After adjustment for age, odds ratios (ORs) for dementia in 2000-05, comparing first with fourth tooth count quartiles, were 1.81 (95% confidence interval (CI) = 1.03-3.19) for tooth counts measured in 1968, 2.25 (95% CI = 1.18-4.32) for those in 1980, and 1.99 (0.92-4.30) for those in 1992. After further adjustment for education, ORs were 1.40 (95% CI = 1.03-3.19) for 1968, 1.96 (95% CI = 0.98-3.95) for 1980, and 1.59 (95% CI = 0.71-3.53) for 1992, and after additional adjustment for vascular risk factors, ORs were 1.38 (95% CI = 0.74-2.58) for 1968, 2.09 (95% CI = 1.01-4.32) for 1980, and 1.61 (95% CI = 0.70-3.68) for 1992.

CONCLUSION

In most of the analyses, lower tooth count was not associated with dementia, although a significant association was found for one of the three examinations. Further research may benefit from more-direct measures of dental and periodontal disease.

Factors associated with self-rated oral health among community-dwelling older Japanese: A cross-sectional study

OBJECTIVES

A cross-sectional study was carried out to investigate the determinants of self-rated oral health among community-dwelling older people in Japan.

METHODS

The participants were 897 (357 men and 540 women) aged 65 years and over who participated in a comprehensive geriatric health examination, which included an oral examination, a face-to-face interview assessing cognitive function, questionnaires regarding depressive symptoms and functional capacity, and a medical examination. The oral examination measured indices of oral health status: number of present teeth, number of functional teeth, occlusal force and amount of resting saliva. Multiple logistic regression analyses were carried out to determine the factors associated with poor self-rated oral health.

RESULTS

The mean age of the participants was 73.5 ± 5.0 years. The prevalence of poor and rather poor self-rated oral health was 11.5% and 29.5%, respectively. Multiple logistic regression analyses showed that the number of present teeth (odds ratio [OR] 0.97, 95% confidence intervals [CI] 0.95-0.99), difficulty in mastication (OR 3.20, CI 2.18-4.70), presence of xerostomia (OR 1.43, CI 1.02-2.01), total score on the MoCA-J (OR 1.06, CI 1.01-1.11), and reduction in frequency of leaving the house (OR 1.64, CI 1.12-2.41) were significantly associated with poor self-rated oral health.

CONCLUSIONS

The present results suggested that self-rated oral health was a significant factor in oral health status as well as overall well-being among community-dwelling older Japanese people.

Mini-mental state examination as a predictor of mortality among older people referred to secondary mental healthcare

Background

Lower levels of cognitive function have been found to be associated with higher mortality in older people, particularly in dementia, but the association in people with other mental disorders is still inconclusive.

Methods and Findings

Data were analysed from a large mental health case register serving a geographic catchment of 1.23 million residents, and associations were investigated between cognitive function measured by the Mini-Mental State Examination (MMSE) and survival in patients aged 65 years old and over. Cox regressions were carried out, adjusting for age, gender, psychiatric diagnosis, ethnicity, marital status, and area-level socioeconomic index. A total of 6,704 subjects were involved, including 3,368 of them having a dementia diagnosis and 3,336 of them with depression or other diagnoses. Descriptive outcomes by Kaplan-Meier curves showed significant differences between those with normal and impaired cognitive function (MMSE score<25), regardless of a dementia diagnosis. As a whole, the group with lower cognitive function had an adjusted hazard ratio (HR) of 1.42 (95% CI: 1.28, 1.58) regardless of diagnosis. An HR of 1.23 (95% CI: 1.18, 1.28) per quintile increment of MMSE was also estimated after confounding control. A linear trend of MMSE in quintiles was observed for the subgroups of dementia and other non-dementia diagnoses (both p-values<0.001). However, a threshold effect of MMSE score under 20 was found for the specific diagnosis subgroups of depression.

Conclusion

Current study identified an association between cognitive impairment and increased mortality in older people using secondary mental health services regardless of a dementia diagnosis. Causal pathways between this exposure and outcome (for example, suboptimal healthcare) need further investigation.

Cognitive impairment and cancer mortality: a biological or health care explanation?

PURPOSE

To examine whether the documented association of suboptimal cognitive function with total and cardiovascular (CVD) mortality also applies to cancer mortality and probe whether the explanation for this association is biomedical or health care related.

METHODS

In a subsample of 733 participants of the EPIC-Greece cohort from Athens and surrounding area, we assessed cognitive function at age 65 or older in the period 2004-2006, using the Mini-Mental State Examination (MMSE). Incidence of cancer, mortality from cancer and CVD, and overall mortality were ascertained through active follow-up for a median of 4 years after MMSE assessment using Cox proportional hazards models.

RESULTS

A total of 86 participants died during follow-up. A 2-point decrease in MMSE score was associated with increase in overall (hazard ratio (HR) 1.26, 95 % confidence interval (CI) 1.11-1.43), CVD (HR 1.26, 95 % CI 1.02-1.56), and cancer (HR 1.32, 95 % CI 1.02-1.70) mortality. In contrast, there was no noticeable difference in cancer incidence associated with a 2-point decrease in MMSE score (HR 1.07, 95 % CI 0.79-1.45).

CONCLUSIONS

Cognitive function appears to be inversely associated not only with CVD and overall, but also with cancer mortality. Although for CVD mortality there is a biomedical explanation invoking vascular mechanisms, for cancer mortality we may need to focus on socially conditioned factors, such as compromised ability to identify early signs and suboptimal compliance to treatment. Our hypothesis-generating results need to be confirmed in larger studies, as the issue is of major importance, since cognitive decline is not uncommon among the elderly.

Executive function and mortality in homebound elderly adults

OBJECTIVES

To determine the association between executive function and mortality in homebound elderly adults.

DESIGN

Longitudinal study.

SETTING

Four home care agencies in the Boston area.

PARTICIPANTS

Homebound adults aged 60 and older with 8-year follow-up for mortality (N=1,172).

MEASUREMENTS

Cognitive domains including executive, memory, and language functions were evaluated at baseline. Executive function was measured using the Trail-Making Test Part B (TMT B), and subjects were divided into four subgroups from lowest to highest TMT B score. The second cross-group analyses were used to compare those who were alive and those who had died. Multivariate logistic regression analysis was used to determine whether there was an association between TMT B scores and mortality.

RESULTS

At baseline, 436 (37.2%) homebound elderly adults had the highest TMT B scores (≥300), which indicated the slowest performance. At 8-year follow-up, 381 (32.5%) participants had died. Participants with the highest TMT B scores were more than twice as likely to have died as those with the lowest scores (0–99) (odds ratio=2.39, 95% confidence interval=1.27–4.52, P=.003) after adjusting for confounders including medical comorbidities related to death. The other cognitive domains, including memory and language, were not associated with mortality in the same model.

CONCLUSION

Many homebound elderly adults have multiple medical conditions, and executive function may be critical in their ability to manage their medical conditions and may affect the outcome of death.

Relationship between dietary patterns and cognitive function in a community-dwelling population in Japan

The purpose of this study was to clarify the association between dietary patterns and cognitive function in a community-dwelling population in Japan. A total of 388 volunteers (60 years and older) who participated in the Iwaki Health Promotion Project 2011 were recruited. Diet was assessed with a validated, self-administered brief-type diet history questionnaire. Dietary patterns were extracted from 52 predefined food groups by principal component analysis. The Mini-Mental State Examination was also used to measure global cognitive status. Three dietary patterns were identified as follows: "Healthy," "Noodle," and "Alcohol and accompaniment." Compared with the low tertile of the "Alcohol and accompaniment" pattern, only the middle tertile was independently related to an increased risk of poor cognitive function. In conclusions, present study failed to substantiate dose-dependent associations between dietary patterns and the risk of poor cognitive function. Further studies with longitudinal observations are warranted.

Reduced prevalence of cognitive impairment in families with exceptional longevity

IMPORTANCE

Family studies of centenarians and long-lived persons have found substantial familial aggregation of survival to extreme ages; however, the extent to which such familial longevity is characterized by cognitively intact survival is not established.

OBJECTIVE

To determine whether families with exceptional longevity are protected against cognitive impairment consistent with Alzheimer disease.

DESIGN

Cross-sectional analysis.

SETTING

Multisite study in New York, Massachusetts, Pennsylvania, and Denmark.

PARTICIPANTS

A total of 1870 individuals (1510 family members and 360 spouse controls) recruited through the Long Life Family Study.

MAIN OUTCOME AND MEASURE

Prevalence of cognitive impairment based on a diagnostic algorithm validated using the National Alzheimer's Coordinating Center data set.

RESULTS

The cognitive algorithm classified 546 individuals (38.5%) as having cognitive impairment consistent with Alzheimer disease. Long Life Family Study probands had a slightly but not statistically significant reduced risk of cognitive impairment compared with spouse controls (121 of 232 for probands vs 45 of 103 for spouse controls; odds ratio = 0.7; 95% CI, 0.4-1.4), whereas Long Life Family Study sons and daughters had a clearly reduced risk of cognitive impairment (11 of 213 for sons and daughters vs 28 of 216 for spouse controls; odds ratio = 0.4; 95% CI, 0.2-0.9). Restriction to nieces and nephews in the offspring generation attenuated this effect (37 of 328 for nieces and nephews vs 28 of 216 for spouse controls; odds ratio = 0.8; 95% CI, 0.4-1.4).

CONCLUSIONS AND RELEVANCE

Rates of cognitive impairment characteristic of Alzheimer disease were relatively high. In the proband generation, rates were comparable across family members and spouse controls, whereas sons and daughters of probands had significantly lower rates than spouse controls. Results suggest a delayed onset of cognitive impairment in families with exceptional longevity, but assessment of age-specific incidence rates is required to confirm this hypothesis.

Cognitive function and number of teeth in a community-dwelling population in Japan

BACKGROUND

It has been reported that oral health is poor in elderly populations and is associated with poor cognition and dementia. The objective of this study was to examine the association between tooth loss and cognitive function in a community-dwelling population in Japan.

METHODS

We examined the association between tooth loss and cognitive function in 462 Japanese community-dwelling individuals. The Mini-Mental State Examination (MMSE) was employed to measure global cognitive status. A multiple logistic regression analysis, with both crude and adjusted conditions for confounding factors, was used to assess the relationship between poor cognition and the number of remaining teeth.

RESULTS

The overall prevalence of poor cognition (MMSE ≤ 23) in this study population was 5.6%. Subjects with poor cognition were significantly older, less educated, scored lower in intellectual activity, and had fewer remaining teeth than those with normal cognition. According to the multiple logistic regression analysis, a lower number of teeth (0-10) was found to be a significant independent risk factor (OR = 20.21, 95% confidence interval = 2.20 to 185.47) of cognitive impairment.

CONCLUSIONS

This cross-sectional study on a Japanese community-dwelling population revealed relationships between tooth loss and cognitive function. However, the interpretation of our results was hampered by a lack of data, including socioeconomic status and longitudinal observations. Future research exploring tooth loss and cognitive function is warranted.

Mini-Mental Status Examination as predictors of mortality in the elderly

OBJECTIVE

Because the number of elderly is increasing worldwide, cognitive dysfunction becomes important health care issue. This study investigated the association between cognitive dysfunction and mortality in the elderly.

METHOD

Data were analyzed from a longitudinal mortality follow-up study of 2712 Korean elderly aged 60 and over, examined in 2002 with complete data followed an average 6.03 years. Measurements included socio-demographic and clinical factors and Mini-Mental State Examination (MMSE). MMSE was categorized into groups with no, mild, or moderate cognitive dysfunction, and the subscores of MMSE domains were categorized into no dysfunction or dysfunction. The Cox proportional hazards models were conducted to examine the association between MMSE score and mortality, after adjusting for age, gender, education and other socio-demographic factors.

RESULTS

Death during follow-up occurred in 318 subjects. The mortality risk was significantly associated with the elderly with mild cognitive dysfunction [hazard ratio (HR) = 1.93] and with moderate cognitive dysfunction (HR = 2.66). 'Orientation-to-time' (HR = 1.39) and 'Attention' (HR = 1.48) domains of MMSE were independently associated with mortality.

CONCLUSION

This study showed that cognitive dysfunction independently predicted mortality in the elderly. Cognitive dysfunction should be considered part of identifying the elderly at high risk for mortality.

A Bayesian model for cluster detection

The detection of areas in which the risk of a particular disease is significantly elevated, leading to an excess of cases, is an important enterprise in spatial epidemiology. Various frequentist approaches have been suggested for the detection of "clusters" within a hypothesis testing framework. Unfortunately, these suffer from a number of drawbacks including the difficulty in specifying a p-value threshold at which to call significance, the inherent multiplicity problem, and the possibility of multiple clusters. In this paper, we suggest a Bayesian approach to detecting "areas of clustering" in which the study region is partitioned into, possibly multiple, "zones" within which the risk is either at a null, or non-null, level. Computation is carried out using Markov chain Monte Carlo, tuned to the model that we develop. The method is applied to leukemia data in upstate New York.

Cognitive function in families with exceptional survival

The authors investigated whether cognitive function may be used as an endophenotype for longevity by assessing the cognitive performance of a family-based cohort consisting of 1380 individuals from 283 families recruited for exceptional survival in field centers in Boston, New York, Pittsburgh, and Denmark. Cognitive performance was assessed in the combined offspring of the Long Life Family Study (LLFS) probands and their LLFS siblings as compared with their spouses' cognitive performance. Our results indicate that the combined offspring of the LLFS probands and their siblings achieve significantly higher scores on both digit forward and backward tasks (p = 5 10(-5) and p = 8 10(-4) respectively) as well as on a verbal fluency task (p = 0.008) when compared with their spouse controls. No differences between groups were found for the other cognitive tests assessed. We conclude that LLFS family members in the offspring generation demonstrate significantly better performance on multiple tasks requiring attention, working memory, and semantic processing when compared with individuals without a family history of exceptional survival, suggesting that cognitive performance may serve as an important endophenotype for longevity.

Prospective comparison of the prognostic utility of the Mini Mental State Examination and the Montreal Cognitive Assessment in patients with brain metastases

PURPOSE

The Mini Mental State Examination (MMSE) is the most commonly chosen cognitive screening test (CST) in clinical practice and trials, despite its poor sensitivity, likely because of its prognostic utility. The Montreal Cognitive Assessment (MoCA) is an alternative CST, is more sensitive, and is better correlated with quality of life.

METHODS

Sixty-five patients with brain metastases were prospectively accrued and completed both the MMSE and MoCA. We compared the prognostic utility of both CSTs.

RESULTS

The mean age of patients was 59.0 years; 42.0% had single brain metastases. Median MMSE and MoCA scores were 28 and 22, respectively. Median overall survival (OS) was worse for individuals with below- versus above-average MMSE scores (10.4 versus 36.3 weeks, p = 0.007). Likewise, below- versus above-average MoCA scores were prognostic (6.3 versus 50.0 weeks, p < 0.001). Median OS for MoCA scores <22, 22-26, and >26 were 6.3, 30.9, and 61.7 weeks, respectively (p < 0.001). On multivariable analysis, below-average MMSE scores were no longer prognostic (hazard ratio [HR] = 1.71 [0.90-3.26]), though below-average MoCA scores were (HR = 5.44 [2.70-10.94]). Furthermore, the MoCA demonstrated superior prognostic utility when comparing multivariable models with continuous CST scores.

CONCLUSIONS

Our results indicate that the MoCA is a superior prognostic indicator than the MMSE. Furthermore, given its superior sensitivity and better correlation with quality of life, the MoCA should be preferentially chosen in clinical practice and trials.

Comparison of ankle-brachial pressure index and pulse wave velocity as markers of cognitive function in a community-dwelling population

BACKGROUND

Vascular factors have been implicated in the development of cognitive decline and dementia. The purpose of this study is to determine the association of the Ankle Brachial pressure Index (ABI) and brachial-ankle Pulse Wave Velocity (ba-PWV) to cognitive impairment in a community-dwelling population.

METHODS

The ABI and ba-PWV were measured using the volume-plethymographic apparatus in 388 subjects aged 60 years old and over. The Mini-Mental State Examination was also employed to measure global cognitive status. The effectiveness of the ABI and ba-PWV as putative markers of cognitive impairment were determined by using a multiple logistic regression analysis after adjusting for confounding factors.

RESULTS

Subjects with poor cognition were significantly older and less well educated than those with normal cognition. According to the multiple logistic regression analysis, the lowest ABI tertile was found to be a significant independent risk factor (OR = 3.19, 95% CI = 1.30 to 7.82) of the cognitive impairment, whereas the highest brachial-ankle PWV tertile was not.

CONCLUSIONS

A low ABI was an independent risk factor for cognitive impairment in community-dwelling older populations, whereas a high ba-PWV may not be. Further research will be required to analyze ABI and PWV with greater accuracy.

Plasma beta-amyloid and duration of Alzheimer's disease in adults with Down syndrome

OBJECTIVES

To investigate the relation of plasma levels of Abeta peptides (Abeta1-40 and Abeta1-42) and apolipoprotein E (APOE) genotype to dementia status, and the duration of Alzheimer's disease (AD) in adults with Down syndrome (DS).

METHODS

Adults with DS were recruited from community settings and followed up for a mean period of 6.7 years. Plasma levels Abeta1-40 and Abeta1-42 and APOE genotype were determined at the last visit.

RESULTS

There were 83 nondemented participants and 44 participants with prevalent AD. Overall, plasma levels of Abeta1-42, Abeta1-40 and the ratio Abeta1-42/Abeta1-40 did not differ significantly between the adults with DS. Among demented participants, the mean level of Abeta1-40 was significantly lower (157.0 vs. 195.3) and the ratio of Abeta1-42/Abeta1-40 was significantly higher (0.28 vs. 0.16) in those with more than 4 years duration of dementia than in those with 4 or fewer years' duration of dementia. This pattern was generally similar in those with and without an APOE epsilon4 allele.

CONCLUSIONS

There is an association between plasma Abeta peptide levels and the duration of AD in older persons with DS. The predictive and diagnostic roles of Abeta1-42 and Abeta1-40 measurements for AD, however, remain controversial. Change in Abeta peptide levels with onset of AD and with the duration of dementia may account for a lack of difference between prevalent cases and nondemented individuals and for variation in the predictive power of Abeta peptide levels.

Profiles of functioning as predictors of mortality in old age: the advantage of a configurative approach

This study proposes the concept of functioning profile, by which one's status is summarized across essential functioning domains, and validates its efficiency in predicting mortality. The study analyzed data of two cohorts of community-dwelling Israelis aged 75 and over, nationally sampled in 1989 (N=1200) and 1999 (N=421), respectively. Eight groups with differential profiles reflected higher versus lower levels of functioning in three domains: physical (activities of daily living), cognitive (Orientation-Memory-Concentration test=OMC) and affective (depressive symptoms). The analyses predicted mortality within 4 years, adjusting for sociodemographic and health variables. Relative to the optimal profile, most functioning profiles represented groups having elevated mortality risks of considerable consistency across cohorts. Physical functioning was the most predictive component in the profiles, but its combinations with cognitive and affective functioning produced unique contributions to mortality prediction. The study suggests that the functioning profile, representing a person-centered configurative approach (i.e., one that considers the person's combined standing on key factors), is a useful concept for delineating risk groups in late life and evaluating risk factors in predicting mortality.

Cognitive decline and mortality in a community-based cohort: the Monongahela Valley Independent Elders Survey

OBJECTIVES

To compare, in a longitudinal cohort study, declines in specific cognitive domains on their ability to predict time to death, in the presence and absence of dementia, and to explore an explanatory role for vascular disease.

DESIGN

Prospective population-based epidemiological study.

SETTING

The mid-Monongahela valley of southwestern Pennsylvania from 1987 to 2002.

PARTICIPANTS

Nine hundred eighty-nine community-dwelling adults aged 65 and older enrolled in the Monongahela Valley Independent Elders Survey.

MEASUREMENTS

Biennial assessments of a range of cognitive domains for up to 12 years. Mortality was modeled as a function of decline in each domain, adjusting for vascular diseases and stratified according to age (< or =75 (younger-old) and >75 (older-old)) using Cox proportional hazards modeling.

RESULTS

Average annual declines in almost all cognitive domains were significant predictors of mortality in the cohort as a whole. However, after adjustment for dementia, only general cognition, processing speed, the language composite, and the executive function composite remained significant. Adjustment for vascular diseases did not alter the results. In the younger-old group, decline in memory (hazard ratio (HR)=21.4) and executive function (HR=25.5) remained strong predictors after adjustment for dementia and vascular disease. In the older-old group, decline in processing speed was a strong predictor of mortality before (HR=7.4) and after (HR=5.3) controlling for dementia and vascular diseases.

CONCLUSION

Decline in most cognitive domains predicted mortality across the cohort, but declines in memory and learning were not independent of dementia. Different domains predicted mortality in the younger and older subgroups.

Does cognition predict mortality in midlife? Results from the Whitehall II cohort study

The authors examined the association of 'g' (general intelligence) factor and five specific cognitive measures assessed in 1997-1999 with mortality till 2006 (mean follow-up of 8 years) in the middle-aged Whitehall II cohort study. In age- and sex-adjusted analysis, a decrease in 1 S.D. in memory (hazard ratio (HR), 1.19; 95% confidence interval (CI): 1.02, 1.39) and in Alice Heim 4-I (AH4-I) (HR, 1.16; 95% CI: 1.01, 1.35) was found to be associated with higher mortality. The association with 'g' factor, phonemic and semantic fluency did not reach significance at p<0.05. No association was found with vocabulary. Out of education, health behaviours and health measures, it was health behaviours that explained the greater part of the association between cognition and mortality, ranging from 21% for memory to 70% for semantic fluency. All the covariates taken together explained only 26% of the association with memory and between 33 and 90% for the other cognitive measures. This study suggests that 'g' type composite measure of cognition might not be enough to understand the associations between cognition and health.

Cognitive functioning predicts survival in the elderly

Prior studies of aging have identified a number of predictors of survival, including performances on some cognitive-functioning tests. However, few studies have used a multidomain test battery to identify which specific cognitive abilities predict death. The current study examined the 12 subtests of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) to see which subtests predicted death in a sample of 796 older, primary care patients. After 4 years, 98 individuals died, and 698 individuals remained alive. The individuals who died performed more poorly at baseline on 9 of the 12 RBANS subtests (p < .05) than did their peers who remained alive. In a multivariate analysis, however, only the RBANS Coding subtest independently predicted death (p < .001), along with male gender and greater initial medical comorbidity. Although the mechanism of poorer cognition and impending death remains unclear, some possibilities are discussed (e.g., brain dysfunction, poor medical compliance, impaired cellular immunity).

Neurocognitive costs and benefits of psychotropic medications in older adults

Psychotropic medications are widely used in older adults and may cause neurocognitive deficits. Older adults are at increased risk of developing adverse effects because of age-related pharmacodynamic and pharmacokinetic changes. This article provides a comprehensive review of the undesirable, and at times beneficial, effects of psychotropic medications. The review covers a wide range of medications that impair executive function, memory, and attention, as well as a much smaller group of medications that lead to improved neurocognitive function. Some of the most commonly used psychotropic medications in older adults, namely, antidepressants, sedatives, and hypnotics, are among the drugs that most consistently lead to cognitive impairments. Medications with anticholinergic properties almost invariably lead to neurocognitive dysfunction, despite symptom improvement. The neurocognitive costs and benefits of psychiatric medications should be considered in the context of disease treatment in older adults.

Elevated plasma beta-amyloid peptide Abeta(42) levels, incident dementia, and mortality in Down syndrome

BACKGROUND

Deposition of the beta-amyloid peptide Abeta(42) is thought to be an important initial step in the pathogenesis of Alzheimer disease (AD). Individuals with Down syndrome have increased levels of beta-amyloid peptides and an increased risk for AD.

OBJECTIVE

To examine the relation of plasma levels of Abeta(42) and Abeta(40) to the risk of dementia in nondemented participants and all-cause mortality in adults with Down syndrome.

DESIGN

Prospective, community-based longitudinal cohort study.

SETTING

State and voluntary service providers in New York State.

PARTICIPANTS

Adults with Down syndrome (N = 204).

MAIN OUTCOME MEASURE

Plasma Abeta(42) and Abeta(40) levels were measured at initial examination. Participants were assessed for cognitive and functional abilities, behavioral/psychiatric conditions, and health and vital status at 14- to 18-month intervals for 4 cycles of data collection.

RESULTS

Among participants who were nondemented at baseline, those in the middle and highest tertiles of plasma Abeta(42) levels were more than 2 times as likely to develop AD as those in the lowest tertile. Compared with participants without AD, participants with prevalent AD had higher levels of plasma Abeta(42) but not Abeta(40). Among all participants, those in the highest tertile of plasma Abeta(42) level at baseline were more than twice as likely to die during the study period as those in the lowest tertile, whereas there was no difference in risk of death between those in the middle and lowest tertiles of plasma Abeta(42) level.

CONCLUSION

Elevations in plasma Abeta(42) peptide levels are associated with earlier onset of AD and increased risk of death.

Mortality and Heart Rate in the Elderly: Role of Cognitive Impairment

Mortality related to heart rate (HR) increase in the elderly has not yet been well established. To ascertain the relationships among cognitive impairment (CI), mortality, and HR increase, the authors prospectively studied a random sample of elderly subjects stratified according to presence or absence of CI. Elderly subjects randomly selected in 1991 (n = 1332) were followed up for 12 years. Mortality was established in 98.1% of the subjects. When HR was stratified in quartiles (< 69, 70-75, 76-80, and > 80 bpm), mortality was linearly associated with increased HR in all (from 47.7 to 57.0; r2 = .43, p = .019) and in subjects without (from 41.7 to 51.1%; r2 = .50, p = .043) but not in those with CI (from 57.5 to 66.1; r2 = .20, p = .363). Cox regression analysis, adjusted for several variables, shows that HR doesn't predict mortality in all subjects (RR 0.69; 95% CI = 0.27-1.73) or in those with CI (RR 0.91; 95% CI = 0.81-1.02). In contrast, HR predicts mortality in subjects without CI (RR 1.10; 95% CI = 1.00-1.22). Hence, HR increase is a predictor of mortality in elderly subjects without CI. However, when considering all elderly subjects and those with CI, HR increase seems to have no effect on mortality. Thus, CI should be considered when focusing on HR increase as risk factor for mortality in the elderly.

Shorter telomeres are associated with mortality in those withAPOEϵ4 and dementia

OBJECTIVE

Reduced telomere length may be a marker of biological aging. We hypothesized that telomere length might thus relate to increased risk for dementia and mortality.

METHODS

This nested case-control study used stored leukocyte DNA from 257 individuals (mean age, 81.4 +/- 7.9 years; 64.6% female; 44.7% Hispanic, 33.5% non-Hispanic black, and 21.8% non-Hispanic white). Our assay used real-time polymerase chain reaction, with two separate reactions amplifying telomere sequence and reference single copy gene (ribosomal-protein-P0), providing a calculated telomere-to-single copy gene (T/S) ratio.

RESULTS

Mean telomere length was shorter among subjects dying during follow-up than in those surviving (0.453 +/- 0.211 vs 0.525 +/- 0.226 [+/- standard deviation]; p < 0.009). It was also shorter in those with Alzheimer's disease compared with control subjects (0.458 +/- 0.207 vs 0.516 +/- 0.229; p < 0.03). For participants with Alzheimer's disease, compared with those with the longest telomeres, the mortality odds ratio (OR) was 4.8 (95% confidence interval [CI], 1.7-13.8) in those with intermediate-length telomeres and 7.3 (95% CI, 2.4-22.0) in those with the shortest telomeres. The presence of an epsilon4 allele also increased the mortality OR, with an OR of 5.8 (95% CI, 1.3-26.4) for intermediate-length telomeres and an OR of 9.0 (95% CI, 1.9-41) for the shortest telomeres.

INTERPRETATION

Our findings suggest that leukocyte telomere length is related to both dementia and mortality and may be a marker of biological aging.

Age-related changes in cognitive domains. A population-based study

BACKGROUND AND AIMS

The aim of the present study is to describe the effects of aging on various cognitive domains (global cognitive function, executive function, motor speed) in a population sample of elderly men, and to describe how their age-related changes are influenced by education, depression, or prevalent cerebrovascular accidents (CEVD).

METHODS

A cross-sectional observational study was conducted in a cohort of 334 men, 65 to 95 years old, living in rural communities, participating in the Italian cohort of two population studies--MATISS (Malattie cardiovascolari ATerosclerotiche Istituto Superiore di Sanità) and FINE (Finland, Italy, Netherlands, Elderly). Global cognitive function was measured by the Mini-Mental State Examination (MMSE), executive function by the Stroop test, motor speed by the Purdue Pegboard test, and depression by the CES-D test. Prevalence of cerebrovascular accidents (CEVD), myocardial infarction, and diabetes were evaluated by a questionnaire and a clinical examination. Blood pressure, and total and HDL cholesterol were measured. Current smoking status was self-reported.

RESULTS

An age-associated decline in global cognitive functions, executive functions, and motor speed was observed. The decline is more apparent after the age of 85 for the MMSE, and after 75 for executive functions and motor speed. Logistic regression analysis revealed that age was independently associated with altered global cognitive functions, executive functions, and motor speed, even after adjusting for education, depression or prevalent CEVD.

CONCLUSIONS

In a cohort of community-living elderly men aged 65 to 95 years, age-associated changes in mental functions are more evident after the age of 85. These changes are independent of education, depression, or prevalent CEVD.

Arterial stiffness is an independent risk factor for cognitive impairment in the elderly: a pilot study

BACKGROUND

Loss of cognitive function is a common condition in the elderly population. Cognitive impairment is defined as the transitional stage of cognitive decline, between normal aging and early dementia. We tested whether arterial stiffness, evaluated as pulse wave velocity (PWV), is associated with cognitive impairment in older subjects, and whether PWV is increased at a comparable extent in older subjects with cortical or subcortical cerebral lesions when compared with age-matched controls referred for memory deficits.

SUBJECTS AND METHODS

Eighty-four subjects (78 +/- 5 years, 30 men and 54 women) referred for memory deficit with no history of stroke or atrial fibrillation were studied. Carotid-femoral PWV was determined non-invasively with Complior. The Mini Mental State Examination was assessed as a measure of global cognitive function. The sum of the score on the Activities of Daily Living and Instrumental Activities of Daily Living scales was used as a measure of personal independency. Based upon brain imaging, subjects were classified as referred for memory deficits with normal brain imaging, or control, with subcortical microvascular lesions or with cortical atrophy.

RESULTS

PWV, normalized for mean blood pressure, was inversely correlated with the Mini Mental State Examination (r = -0.26, P < 0.05), even after controlling for education, prevalent cardiovascular (CV) disease, CV risk factors, and medication use (beta coefficient = -0.28, P < 0.01). PWV was also inversely correlated with personal independency (r = -0.36, P < 0.01; beta coefficient = -0.38, P < 0.01, after multiple adjustment). In the presence of no significant differences in age, education, traditional CV risk factor levels, carotid plaques, or prevalence of CV disease, higher PWV values were more frequent in subjects with cortical atrophy than in patients with subcortical microvascular lesions or controls (P < 0.05).

CONCLUSIONS

PWV was associated with cognitive impairment and with a greater personal dependency, independently of major modifiable CV risk factors.

Mortality and blood pressure in elderly people with and without cognitive impairment

BACKGROUND

Controversial data are available on the association between mortality, blood pressure and cognitive impairment in the elderly.

OBJECTIVE

To verify the role of blood pressure on mortality in an elderly population with and without cognitive impairment.

METHODS

A cross-sectional survey with a 6-year mortality evaluation was conducted in a region of southern Italy in elderly subjects with and without cognitive impairment. Subjects were divided into 4 groups on the basis of systolic, diastolic, mean and pulse blood pressure values.

RESULTS

Mortality shows a linear relationship with pulse blood pressure and a U-curve shape for diastolic blood pressure. This phenomenon was more evident in subjects with cognitive impairment showing the greatest risk of mortality at the lowest and highest levels of diastolic blood pressure.

CONCLUSION

The study shows that mortality increases linearly with increasing blood pressure in the elderly. In contrast, mortality shows a U-shape curve for diastolic blood pressure; cognitively impaired patients with the lowest and highest diastolic blood pressures show the greatest relative risk of mortality.

The role of cognitive ability (intelligence) in explaining the association between socioeconomic position and health: evidence from the Whitehall II prospective cohort study

Associations among cognitive ability, socioeconomic position, and health have been interpreted to imply that cognitive ability could explain social inequalities in health. The authors test this hypothesis by examining three questions: Is cognitive ability related to health? To what extent does it explain social inequalities in health? Do measures of socioeconomic position and cognitive ability have independent associations with health? Relative indices of inequality were used to estimate associations, using data from the Whitehall II study (baseline, 1985-1988), a British prospective cohort study (4,158 men and 1,680 women). Cognitive ability was significantly related to coronary heart disease, physical functioning, and self-rated health in both sexes and additionally to mental functioning in men. It explained some of the relation between socioeconomic position and health: 17% for coronary heart disease, 33% for physical functioning, 12% for mental functioning, and 39% for self-rated health. In analysis simultaneously adjusted for all measures of socioeconomic position, cognitive ability retained an independent association only with physical functioning in women. These results suggest that, although cognitive ability is related to health, it does not explain social inequalities in health.

Usefulness of a single item in a mail survey to identify persons with possible dementia: a new strategy for finding high-risk elders

The objective of this study was to examine the characteristics of elderly persons who responded positively to a question about "severe memory problems" on a mailed health questionnaire yet were missed by the existing health risk algorithm to identify vulnerable elderly persons. A total of 324,471 respondents aged 65 and older completed a primary care health status questionnaire that gathered clinical information to quickly identify members with functional impairment, multiple chronic diseases, and higher medical care needs. The respondents were part of a large, integrated, not-for-profit managed care organization that implemented a model of care for elders using a uniform risk identification method across eight regions. Respondents with severe memory problems were compared to general respondents by morbidity, geriatric syndromes, functional impairments, service utilization, sensory impairments, sociodemographic characteristics, and activities of daily living. Of the respondents, 13,902 persons (4.3%) reported severe memory problems; the existing health risk algorithm missed 47.1% of these. When severe memory problems were included in the risk algorithm, identification increased from 11% to 13%, and risk prevalence by age groups ranged from 4.4% to 40.5%; one third had severe memory problems, a finding that was fairly consistent within age groups (28.4% to 36.5%). A question about severe memory problems should be incorporated into population risk-identification techniques. While false-negative rates are unknown, the false-positive rate of a self-report mail survey appears to be minimal. Persons reporting severe memory problems clearly have multiple comorbidities, higher prevalence of geriatric syndromes, and greater functional and sensory impairments.

Preservation of cognitive and functional ability as markers of longevity

Longevity is a complex biological process for which the phenotypes have not been established. Preservation of cognitive and physical function may be important and preservation of these functions is, in part, inherited. We investigated the relation between rate of change in cognitive and functional abilities in probands and risk of death in their siblings. Probands were classified as showing no decline, slow, medium, or rapid rate of decline, based on the slope of change in cognitive and physical/functional factors over three or more assessments. Siblings of probands who did not decline on measures of memory, visuospatial/cognitive function or ADL skills were approximately half as likely to die as siblings of probands who had the most rapid decline. The reduction in risk of death in siblings of probands who did not decline in was primarily observed among siblings of probands who were older than 75 years, suggesting that genetic influences on life span may be greater at older ages. There was no association between probands' rate of change in language, IADL skills, upper or lower extremity mobility and risk of death in siblings. The results of the present study identify phenotypes associated with preserved cognitive and functional abilities which may serve as markers for longevity.

Does intact pair status matter in the study of African American twins? The Carolina African American Twin Study of Aging

In twin research, typically both members of a pair must participate. Survivorship of members of intact pairs compared to surviving members of nonintact twin pairs may reflect differences in psychosocial and health factors, and represent a potential selection bias relative to the general population. The purpose of the present study is to examine health, cognition, and well-being among members of African American intact twin pairs compared to individuals from nonintact twin pairs. Data from the Carolina African American Twin Study of Aging (CAATSA) were used for analyses. Subjects ranged in age from 25 to 89 years of age (mean = 59.78 years, SD = 12.84 years). CAATSA implements a 3-h protocol to collect data on demographics, health, cognition, and well-being. Data from one randomly selected member of each twin pair (N = 78) was compared to data from surviving members of nonintact twin pairs (N = 52). The results indicated significant differences on 11 of the 39 measures (i.e., age, education, forced expiratory volume, mean standing and sitting systolic and diastolic blood pressures, cognitive impairment score, alpha span, digit symbol, and logical memory). In each case, members of intact twin pairs performed better than surviving members of nonintact twin pairs. After controlling demographic variables, only blood pressures differed between the groups. It appears that using only pairs in research on older African American twins may represent a selection bias in estimating origins of individual variability in cognitive functioning and health but not psychological well-being.

Mild cognitive deterioration with subcortical features: prevalence, clinical characteristics, and association with cardiovascular risk factors in community-dwelling older persons (The InCHIANTI Study)

OBJECTIVES

To identify subjects with minimal or mild nonamnestic cognitive impairment with parkinsonian stance and gait and investigate vascular correlates of this condition.

DESIGN

First wave of an epidemiological longitudinal study (InCHIANTI) on factors predicting loss of mobility in older persons.

SETTING

The Chianti geographic area (Tuscany, Italy).

PARTICIPANTS

Five hundred fifty-six subjects aged 70 to 90 with Mini-Mental State Examination (MMSE) scores greater than 23 of 30, of the 1,260 persons aged 65 and older randomly selected from the population registry of Greve in Chianti and Bagno a Ripoli, two small towns near Florence.

METHODS

Low cognitive performance (LCP) was defined as an age- and education-adjusted MMSE below the 50th percentile for the InCHIANTI population. Subcortical features were plastic rigidity on neurological examination (parkinsonism), gait disturbance (small-step gait or parkinsonian gait), and dysexecutive features. Two hundred forty-three participants had high cognitive performance, 166 had LCP without subcortical features, and 75 had LCP with subcortical features. Vascular risk factors were hypertension, atrial fibrillation or pathological findings on electrocardiogram (ECG), low serum high-density lipoprotein (HDL) or high low-density lipoprotein cholesterol, diabetes mellitus, obesity, and heavy smoking.

RESULTS

Three main vascular risk factors were significantly more prevalent in LCP with subcortical features: hypertension (P =.02), atrial fibrillation or ECG changes (P =.04), and low HDL cholesterol (P =.001). LCP with subcortical features was significantly associated with cerebrovascular risk factors (P =.001).

CONCLUSION

Gait disturbance and nonamnestic cognitive symptoms might be the consequence of subcortical vascular damage.

Cognitive impairment and mortality in older mexican americans

OBJECTIVES

To examine the extent to which cognitive status and decline in cognitive status predict mortality in older Mexican Americans.

DESIGN

Longitudinal cohort.

SETTING

Older Mexican Americans residing in five southwestern states in the United States.

PARTICIPANTS

Two thousand six hundred twenty-five persons aged 65 and older living in Texas, New Mexico, Colorado, Arizona, and California.

MEASUREMENTS

The cognitive function of participants was assessed using the Mini-Mental State Examination (MMSE) in 1993-94 and again in 1995-96. Cognitive decline was defined using two sets of criteria: a drop to 17 or less (moderate-severe cognitive impairment) on the MMSE at 2-year follow-up and a decrease of at least four points, a threshold change in scores that was used to predict mortality in this sample. Cox proportional hazards models were conducted to examine the association between the MMSE and increased risk for mortality, after controlling for sociodemographic characteristics, medical conditions, and depressive symptoms.

RESULTS

Five-year mortality risk was significantly associated with persons in the moderately-severely cognitively impaired category (hazard ratio (HR) = 2.35, P <.001). Moreover, mild cognitive impairment was also predictive of mortality in older Mexicans (HR = 1.45, P <.001). Two-year declines in cognitive functioning, particularly in persons who had declined to the moderate-severe impairment category (HR = 2.23, P <.001) and those who dropped at least four points on the MMSE (HR = 1.30, P <.001), were predictive of mortality 3 years later, after controlling for important variables.

CONCLUSIONS

Baseline moderate-severe and mild cognitive status and 2-year decline in cognitive functioning independently predict mortality in older Mexican Americans. Although age and selected medical conditions have been reported as the more salient predictors of mortality, cognitive functioning should be considered part of identifying older persons at high risk for underlying medical conditions and mortality.

Cognitive change 5 years after coronary artery bypass surgery

A longitudinal study of cognitive function after coronary artery bypass surgery examined 107 participants using 11 tests, preoperatively and at 6 days, 8 weeks, and 5 years after surgery. The overall neuropsychological (NP) change score declined at 6 days, showed some recovery at 8 weeks, and declined again at 5 years. The number of microemboli recorded during surgery, postoperative short-term cognitive change, and degree of recovery at 8 weeks were identified as predictors of change in NP score to 5 years. This suggests that even over a 5-year period, operative damage is detectable. Patients' vulnerability to short-term deterioration and resilience or ability to recover over a few weeks from operative cerebral insult are important processes of unknown mechanisms.

Terminal change in cognitive function: an updated review of longitudinal studies

We provide an update to Siegler's (1975) review of the terminal change literature. Articles identified through MEDLINE, CANCERLIT, PUBMED, and PSYCINFO from 1975 to 2000 were examined. Lower levels of cognitive function are related to increased risk of mortality; however, the relationship between rate of cognitive change and mortality is less clear. Although there has been an increase in the number of studies since our last review, prior studies have been limited by a lack of medical data, consideration of dementia, small sample sizes, and poor cognitive measures. The emphasis on Alzheimer's disease and the growth of epidemiology of aging in the past 25 years have provided well-characterized population studies with serial cognitive measures that provide an opportunity to test the theory of terminal change.

Risk of mortality for dementia in a developing country: the Yoruba in Nigeria

BACKGROUND

Limited data exist on the impact of dementia in developing nations, including its association with mortality.

OBJECTIVE

The purpose of this paper is to assess the relationship between dementia and five-year mortality on a community dwelling elderly Yoruba population in the developing country of Nigeria and to compare those results with those from an elderly African-American community in Indianapolis.

METHODS

A two-phase design was used to ascertain dementia status in two sites. In the first phase, the Community Screening Instrument for Dementia (CSI-D) was administered. In the second phase, subjects were sampled for the clinical assessment according to their CSI-D performance category. Proportional hazards regression was used to assess the relationship between mortality and cognitive status at both sites after adjusting for demographics and chronic disease conditions.

RESULTS

For the entire screened population, poor and intermediate performance on the CSI-D is associated with increased mortality at both sites; however the effect of CSI-D performance did not significantly differ between the two sites. For the clinically assessed sample, dementia was significantly associated with increased mortality at both sites (Ibadan RR = 2.83, Indianapolis RR = 2.05), but the effect was not significantly different across the two sites.

CONCLUSION

Dementia resulted in an increased risk of mortality for Yoruba of a magnitude similar to African-Americans suggesting that the impact of dementia on mortality risk may be similar for developing and developed countries.

Cognition and survival: an exploration in a large multicentre study of the population aged 65 years and over

BACKGROUND

Understanding the patterns in determinants of survival becomes increasingly important as the population ages. Dementia is known to shorten survival as is impaired cognition. Whether this is a continuous phenomenon and independent of other explanatory variables is less clear.

OBJECTIVES

To examine a population-based dataset in which a measure of cognitive function (Mini-Mental State Examination [MMSE]), self-reported physical health and lifestyle variables were measured at outset, with monitoring for mortality thereafter.

METHODS

The five identical sites of the Medical Research Council Cognitive Function and Ageing Study (MRC CFAS) were analysed, with populations in rural Cambridgeshire, Gwynedd, Newcastle, Nottingham and Oxford. Survival curves were modelled and stratified analyses carried out, with physical disease, sociodemographic variables and lifestyle variables as covariates.

RESULTS

There was a strong and consistent reduction in survival probability for each decrement in MMSE. Adjustment for known confounders did not alter this pattern. Social class and education in particular had no additional effect. Self-reported health was the only other associated variable.

CONCLUSION

Cognitive function appears to be a marker of capacity for survival in the UK. Terminal decline can account for some of this. Actuarial survival provided here can give carers and service providers an idea of prognosis at given ages and levels of cognition, and provide baseline data for those planning interventions in similar groups.