Social networks, social integration, and social engagement determine cognitive decline in community-dwelling Spanish older adults

OBJECTIVES

To examine the influence of social networks and social engagement on cognitive decline in a population-based cohort of elderly people, and to assess gender differences in the effect of social relations on cognition.

METHODS

A longitudinal study of community-dwelling people over 65 was carried out. Cognitive function (orientation and memory) in 1997 and cognitive decline (absent, mild, and severe) over 4 years (1993-1997) were assessed using an instrument previously validated for populations with a low level of education. The effect of social networks, social integration, and social engagement with friends, children, and relatives on cognitive function and cognitive decline was estimated by multiple linear and logistic regressions after adjusting for age, sex, education, depressive symptoms, systolic and diastolic blood pressure, and functional status.

RESULTS

Poor social connections, infrequent participation in social activities, and social disengagement predict the risk of cognitive decline in elderly individuals. The probability of cognitive decline was lower for both men and women with a high frequency of visual contact with relatives and community social integration. Engagement with friends seemed to be protective for cognitive decline in women but not in men.

DISCUSSION

This longitudinal study indicates that few social ties, poor integration, and social disengagement are risk factors for cognitive decline among community-dwelling elderly persons. The nature of the ties that influence cognition may vary in men and women.

Frequency and course of mild cognitive impairment in a multiethnic community

OBJECTIVE

To examine incidence rates and antecedents of mild cognitive impairment (MCI) and Alzheimer's disease (AD) among diverse elders without dementia at the initial visit, and to examine the characteristics of elders with MCI who reverted to normal on follow-up examination.

METHODS

A total of 2,364 Caribbean Hispanic, black, or non-Hispanic white subjects, aged 65 or older, who were free of dementia at initial evaluation were followed up every 18 to 24 months. Incidence rate of MCI and AD was determined by examination of neurological, medical, psychiatric, and neuropsychological function.

RESULTS

Over 10,517 person-years, 21% of normal elderly subjects progressed to MCI (annual incidence rate, 5.1%; 95% confidence interval, 4.6-5.6%). Of those with MCI initially, 21.8% were subsequently diagnosed with AD (annual incidence rate, 5.4%; 95% confidence interval, 4.7-6.3%), 47% remained unchanged, and 31% reverted to normal. Those with MCI were 2.8 times more likely to experience development of AD than normal elderly subjects. MCI with impairment in memory and at least one other cognitive domain was associated with greatest risk for progression to AD and was also least likely to revert to normal at follow-up. Consistent diagnosis of MCI or incident probable or possible AD was 60% sensitive and 94% specific for the pathological diagnosis of AD.

INTERPRETATION

Impaired memory and language were useful predictors of transition to AD. Reversion to normal from MCI was frequent, but those with impairment in more than one cognitive domain were more likely to progress or remain impaired than those with single-domain impairment. Clinical diagnosis of MCI does not always predict AD neuropathology.

Social resources and cognitive decline in a population of older African Americans and whites

OBJECTIVE

To examine the relation of social resources and cognitive decline in older adults.

METHODS

Data are from the Chicago Health and Aging Project, an epidemiologic study of risk factors for Alzheimer disease (AD) and other common conditions in a geographically defined population of older persons. The sample consisted of 6,102 non-Hispanic African Americans (61.2%) and whites, aged > or = 65, who underwent up to three interviews during an average of 5.3 years of follow-up. Each interview included administration of four cognitive function tests from which a composite measure of cognition was formed. Social networks were based on the number of children, relatives, and friends seen at least once a month. Social engagement was measured with four items related to social and productive activity.

RESULTS

Higher number of social networks and level of social engagement were positively correlated with initial level of cognitive function (networks estimate = 0.003, engagement estimate = 0.060, both p < 0.001). Both resources were also associated with a reduced rate of cognitive decline. A high (90th percentile) number of networks reduced the rate of decline by 39% compared to a low level (10th percentile), and high social engagement reduced decline by 91%. These relations remained after controlling for socioeconomic status, cognitive activity, physical activity, depressive symptoms, and chronic medical conditions.

CONCLUSIONS

Greater social resources, as defined by social networks and social engagement, are associated with reduced cognitive decline in old age.

Documentation and evaluation of cognitive impairment in elderly primary care patients

OBJECTIVE

To describe the prevalence of cognitive impairment among elderly primary care patients and to compare diagnostic evaluations and use of health services among patients with and those without cognitive impairment.

DESIGN

Prospective cohort study.

SETTING

Academic primary care group practice.

PATIENTS

3954 patients aged 60 years and older who completed the Short Portable Mental Status Questionnaire during routine office visits.

MEASUREMENTS

Demographics and comorbid illness at baseline, diagnostic evaluations for cognitive impairment, use of standard and preventive health services, use of psychoactive drugs, and death in the year after the screening date.

RESULTS

The prevalence of cognitive impairment among all patients aged 60 years and older at baseline was 15.7%; 10.5% had mild impairment and 5.2% had moderate to severe impairment. Patients with moderate to severe impairment were significantly older than patients with no impairment (76.2 years and 67.4 years, respectively), were more likely to be black (85.8% and 61.3%), had fewer years of education (7.3 years and 9.2 years), and were more likely to have cerebrovascular disease (20.4% and 6.3%) and evidence of undernutrition (30.6% and 16.9%). Dementia was recorded as a diagnosis for less than 25% of patients with moderate to severe cognitive impairment, but patients with documented impairment were more likely to have been evaluated for reversible causes. In the year after screening, patients with moderate to severe impairment were more likely than those with no impairment both to be hospitalized (29.1% and 16.5%) and to visit the emergency department (55.8% and 38.5%) but had fewer outpatient visits (6.0 and 7.6) and greater mortality (8.2% and 2.8%).

CONCLUSIONS

Cognitive impairment is associated with increased use of health services and increased mortality. Patients with undocumented cognitive impairment were significantly less likely to be evaluated for reversible causes. Research is needed to determine if better documentation of cognitive impairment would improve not only diagnostic evaluations but also patient management, counseling, and outcomes.

Kidney function and cognitive impairment in US adults: the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study

BACKGROUND

The association between kidney function and cognitive impairment has not been assessed in a national sample with a wide spectrum of kidney disease severity.

STUDY DESIGN

Cross-sectional.

SETTING & PARTICIPANTS

23,405 participants (mean age, 64.9 +/- 9.6 years) with baseline measurements of creatinine and cognitive function participating in the REasons for Geographic And Racial Differences in Stroke (REGARDS) Study, a study of stroke risk factors in a large national sample.

PREDICTOR

Estimated glomerular filtration rate (eGFR).

OUTCOME

Cognitive impairment.

MEASUREMENTS

Chronic kidney disease (CKD) was defined as eGFR less than 60 mL/min/1.73 m(2). Kidney function was analyzed in 10-mL/min/1.73 m(2) increments in those with CKD, and in exploratory analyses, across the range of kidney function. Cognitive function was assessed using the 6-Item Screener, and participants with a score of 4 or less were considered to have cognitive impairment.

RESULTS

CKD was associated with an increased prevalence of cognitive impairment independent of confounding factors (odds ratio, 1.23; 95% confidence interval, 1.06 to 1.43). In patients with CKD, each 10-mL/min/1.73 m(2) decrease in eGFR less than 60 mL/min/1.73 m(2) was associated with an 11% increased prevalence of impairment (odds ratio, 1.11; 95% confidence interval, 1.04 to 1.19). Exploratory analyses showed a nonlinear association between eGFR and prevalence of cognitive impairment, with a significant increased prevalence of impairment in those with eGFR less than 50 and 100 mL/min/1.73 m(2) or greater.

LIMITATIONS

Longitudinal measures of cognitive function were not available.

CONCLUSIONS

In US adults, lower levels of kidney function are associated with an increased prevalence of cognitive impairment. The prevalence of impairment appears to increase early in the course of kidney disease; therefore, screening for impairment should be considered in all adults with CKD.

A normative study of the CERAD neuropsychological assessment battery in the Korean elderly

This study aimed to explore the effects of age, education and gender on the performance of eight tests in the Korean version of the CERAD neuropsychological assessment battery and to provide normative information on the tests in the Korean elderly. The battery was administered to 618 healthy volunteers aged from 60 to 90. People with serious neurological, medical and psychiatric disorders, including dementia, were excluded. Multiple linear regression analyses were performed to assess the relative contribution of the demographic factors on the score of each cognitive test. Age, education, and gender were found to have significant effects on the performance of many tests in the battery. Based on these results, 4 overlapping age normative tables (60 to 74, 65 to 79, 70 to 84, and 75 to 90 years of age) with 3 educational strata (0 to 3 years, 4 to 6 years, and 7 years and more) for both genders are presented. The normative information will be useful for a clinical interpretation of the CERAD neuropsychological battery in Korean elderly as well as for comparing the performance of the battery across countries.

Differential item functioning analysis with ordinal logistic regression techniques. DIFdetect and difwithpar

INTRODUCTION

We present an ordinal logistic regression model for identification of items with differential item functioning (DIF) and apply this model to a Mini-Mental State Examination (MMSE) dataset. We employ item response theory ability estimation in our models. Three nested ordinal logistic regression models are applied to each item. Model testing begins with examination of the statistical significance of the interaction term between ability and the group indicator, consistent with nonuniform DIF. Then we turn our attention to the coefficient of the ability term in models with and without the group term. If including the group term has a marked effect on that coefficient, we declare that it has uniform DIF. We examined DIF related to language of test administration in addition to self-reported race, Hispanic ethnicity, age, years of education, and sex.

METHODS

We used PARSCALE for IRT analyses and STATA for ordinal logistic regression approaches. We used an iterative technique for adjusting IRT ability estimates on the basis of DIF findings.

RESULTS

Five items were found to have DIF related to language. These same items also had DIF related to other covariates.

DISCUSSION

The ordinal logistic regression approach to DIF detection, when combined with IRT ability estimates, provides a reasonable alternative for DIF detection. There appear to be several items with significant DIF related to language of test administration in the MMSE. More attention needs to be paid to the specific criteria used to determine whether an item has DIF, not just the technique used to identify DIF.

Cognitive decline and literacy among ethnically diverse elders

Researchers on genetic and environmental influences on risk for Alzheimer's disease must be prepared for the growing ethnic and racial diversity of our participants. Within the investigation, years of education has typically served as a proxy for cognitive reserve, which may be one factor in influencing risk of cognitive decline among aging people. However, among ethnic minorities, years of education is a poor reflection of the value of educational experience and native ability. This study was conducted among 1002 ethnically diverse English-speaking residents of Northern Manhattan who were cognitively and functionally normal at a baseline evaluation. We found that literacy level was a better predictor of decline in memory, executive function, and language skills than was years of education. The results of this study suggest that in an ethnically diverse cohort, literacy level should be considered as a mediator of the interactions of biological and environmental factors on cognitive decline.

Cultural values underlying psychometric cognitive testing

It is proposed that culture (values, beliefs, styles of behavior) can affect neuropsychological testing. Cognitive testing represents a social situation that-as any social situation, it is one governed by implicit cultural rules. At least eight different culture-dependent values underlie cognitive testing: (1) One-to-one relationship, (2) Background authority, (3) Best performance, (4)Isolated environment (5) Special type of communication, (6) Speed, (7) Internal or subjective issues, and (8) The use of specific testing elements and strategies. In addition, it is proposed that"the distance" (e.g., gender, age, ethnicity) between the examiner and the examinee may potentially impact the testing situation. A special analysis regarding the function of instruction in cognitive tests is also presented emphasizing that test instruction interpretation is also culture-dependent. Some potential avenues of research are finally proposed.

Cognitive performance and informant reports in the diagnosis of cognitive impairment and dementia in African Americans and whites

BACKGROUND

The diagnosis of cognitive impairment and dementia must reflect an increasingly diverse and aging United States population. This study compared direct testing and informant reports of cognition with clinical diagnoses of cognitive impairment and dementia between African Americans and whites.

METHODS

Participants in the Aging, Demographics, and Memory Study completed in-person dementia evaluations, and were assigned clinical diagnoses (by a consensus panel of dementia experts) of normal; cognitive impairment, not demented (CIND); and dementia. The Consortium to Establish a Registry for Alzheimer's Disease (CERAD) total score and the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) were used to assess cognitive performance and reported cognitive decline.

RESULTS

A higher CERAD total score was associated with lower odds of CIND and dementia, at comparable ratios between African Americans and whites. Higher IQCODE scores were associated with increased odds of dementia in both African Americans and whites. Higher IQCODE scores were associated with increased odds of CIND among whites, but not among African Americans.

CONCLUSIONS

Cultural differences may influence informant reports of prevalent CIND and dementia. Our findings also highlight the need for more comparative research to establish the cultural validity of measures used to diagnose these conditions.

Diagnostic performance of two mental status tests in the older chinese: influence of education and age on cut-off values

AIMS

To (1) establish the clinical usefulness of the 10-item Abbreviated Mental Test (AMT) and the 18-item Chinese Mini-Mental Status Examination (CMMSE) for detecting cognitive impairment associated with dementia in the elderly Chinese; (2) determine how the tests' optimal cut-off scores varied with the patients' educational level and age; and (3) evaluate which was the more accurate test.

METHODS

151 cognitively-healthy, community dwelling elderly Chinese subjects and 95 elderly Chinese outpatients with dementia were administered the AMT and CMMSE. Receiver-Operating Characteristic (ROC) analysis was used to determine the tests' optimal cut-off scores for each of the education-by-age subgroups and their areas-under-the-curve were compared non-parametrically to evaluate which test was more accurate.

RESULTS

Both the AMT and CMMSE could identify cognitive impairment accurately, but higher cut-off values were necessary for the younger and more educated cohort, while lower values were adequate for the older and less educated subgroup. The AMT appeared to reach a ceiling effect in the more educated categories. The diagnostic accuracies of the two instruments were statistically equivalent; there was a trend, however, for the CMMSE to be performing better in the more educated subgroups.

CONCLUSIONS

To maximise the diagnostic efficiency of these two clinically useful mental status tests, it is important to adjust their cut-off scores for the patients' education and age. Though no clear superiority of either instrument was established in this study, we recommend the AMT for patients with 0-6 years of education, whereas for those with greater levels of literacy, we think it better to administer the CMMSE.

Metabolic syndrome and cognitive decline in elderly Latinos: findings from the Sacramento Area Latino Study of Aging study

OBJECTIVES

To investigate the effect of metabolic syndrome on cognitive function in an elderly Latino population and to determine whether inflammation modifies this association.

DESIGN

A longitudinal cohort study.

SETTING

Sacramento area and the surrounding California counties from 1998 to 1999.

PARTICIPANTS

One thousand six hundred twenty-four Latinos aged 60 and older who participated in the Sacramento Area Latino Study of Aging.

MEASUREMENTS

Baseline metabolic syndrome was calculated using the Third Adult Treatment Panel of the National Cholesterol Education Program. Cognitive function was measured using the Modified Mini-Mental State Examination (3MS) and the Delayed Word-List Recall (DelRec), a verbal memory test. The effect of metabolic syndrome on cognitive change scores was examined using random effects models; in addition, the effect of the individual components of the syndrome on cognitive change was examined.

RESULTS

Of the 1,624 participants, 718 (44%) had metabolic syndrome at baseline. Those with metabolic syndrome had worse 3-year change scores on 3MS (P=.04) and DelRec (P=.03). Multivariate adjustment attenuated the results for DelRec but not for 3MS. This association was especially pronounced in participants with a high serum level of inflammation, resulting in an average 3MS score 0.64 points lower per year (P=.03) for those with metabolic syndrome. Individual components of metabolic syndrome were not associated with cognitive decline except for elevated glucose on the DelRec (P=.02) and high blood pressure on 3MS (P=.05).

CONCLUSION

Metabolic syndrome and inflammation may both contribute to cognitive decline in older people of diverse backgrounds. The results also suggest that, in elderly Latinos, the composite measure of metabolic syndrome is a greater risk for cognitive decline than its individual components.

Relationship between frailty and cognitive decline in older Mexican Americans

OBJECTIVES

To examine the association between frailty status and change in cognitive function over time in older Mexican Americans.

DESIGN

Data used were from the Hispanic Established Population for the Epidemiological Study of the Elderly.

SETTING

Five southwestern states: Texas, New Mexico, Colorado, Arizona, and California.

PARTICIPANTS

One thousand three hundred seventy noninstitutionalized Mexican-American men and women aged 65 and older with a Mini-Mental State Examination (MMSE) score of 21 or higher at baseline (1995/96).

MEASUREMENTS

Frailty, defined as three or more of the following components: unintentional weight loss of more than 10 pounds, weakness (lowest 20% in grip strength), self-reported exhaustion, slow walking speed (lowest 20% in 16-foot walk time in seconds), and low physical activity level (lowest 20% on Physical Activity Scale for the Elderly score). Information about sociodemographic factors, MMSE score, medical conditions (stroke, heart attack, diabetes mellitus, arthritis, cancer, and hypertension), depressive symptoms, and visual impairment was obtained.

RESULTS

Of the 1,370 subjects, 684 (49.9%) were not frail, 626 (45.7%) were prefrail (1-2 components), and 60 (4.4%) were frail (>/=3 components) in 1995/96. Using general linear mixed models, it was found that frail subjects had greater cognitive decline over 10 years than not frail subjects (estimate=-0.67, standard error=0.13; P<.001). This association remained statistically significant after controlling for potential confounding factors.

CONCLUSION

Frail status in older Mexican Americans with MMSE scores of 21 or higher at baseline is an independent predictor of MMSE score decline over a 10-year period. Future research is needed to establish pathophysiological components that can clarify the relationship between frailty and cognitive decline.

Testing a Four-Factor Model of Psychopathy and Its Association With Ethnicity, Gender, Intelligence, and Violence

Although a 2-factor model has advanced research on the psychopathy construct, a 3-factor model was recently developed that emphasized pathological personality and eliminated antisocial behavior. However, dropping antisocial behavior from the psychopathy construct may not be advantageous. Using a large sample of psychiatric patients from the MacArthur Risk Assessment Study (J. Monahan & H. J. Steadman, 1994), the authors used confirmatory factor analysis to test a 4-factor model of psychopathy, which included interpersonal, affective, and behavioral impulsivity dimensions and an antisocial behavior dimension. Model fit was good for this 4-factor model, even when ethnicity, gender, and intelligence variables were included in the model. Structural equation modeling was used to compare the 3- and 4-factor models in predicting proximal (violence) and distal (intelligence) correlates of psychopathy.

Clinical and organizational factors associated with feeding tube use among nursing home residents with advanced cognitive impairment

CONTEXT

Empiric data and expert opinion suggest that use of feeding tubes is not beneficial for older persons with advanced dementia. Previous research has shown a 10-fold variation in this practice across the United States.

OBJECTIVE

To identify the facility and resident characteristics associated with feeding tube use among US nursing homes residents with severe cognitive impairment.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study of all residents with advanced cognitive impairment who had Minimum Data Set assessments within 60 days of April 1, 1999, (N = 186,835) and who resided in Medicare- or Medicaid-certified US nursing homes. Main Outcomes Measures Facility and resident characteristics described in the 1999 On-line Survey Certification of Automated Records and the 1999 Minimum Data Set. Multivariate analysis using generalized estimating equations determined the facility and resident factors independently associated with feeding tube use.

RESULTS

Thirty-four percent of residents with advanced cognitive impairment had feeding tubes (N = 63,101). Resident characteristics associated with a greater likelihood of feeding tube use included younger age, nonwhite race, male sex, divorced marital status, lack of advance directives, a recent decline in functional status, and no diagnosis of Alzheimer disease. Controlling for these patient factors, residents living in facilities that were for profit (adjusted odds ratio [OR], 1.09; 95% confidence interval [CI], 1.06-1.12); located in an urban area (OR, 1.14; 95% CI, 1.11-1.16); having more than 100 beds (OR, 1.04; 95% CI, 1.01-1.07); and lacking a special dementia care unit (OR, 1.11; 95% CI, 1.07-1.15) had a higher likelihood of having a feeding tube. Additionally, feeding tube use was more likely among residents living in facilities that had a smaller proportion of residents with do-not-resuscitate orders, had a higher prevalence of nonwhite residents, and lacked a nurse practitioner or physician assistant on staff.

CONCLUSIONS

More than one third of severely cognitively impaired residents in US nursing homes have feeding tubes. Feeding tube use is independently associated with both the residents' clinical characteristics and the nursing homes' fiscal, organizational, and demographic features.

Cognitive activity and cognitive decline in a biracial community population

BACKGROUND

Frequent participation in cognitively stimulating activities has been associated with reduced risk of AD in several prospective studies. However, the association of cognitive activity with cognitive decline, the principal manifestation of AD, is not well understood.

METHODS

More than 4,000 older residents of a geographically defined biracial community of Chicago were interviewed at approximately 3-year intervals for an average of 5.3 years. Each interview included administration of four cognitive function tests from which a previously established global measure was derived. At baseline, each person rated frequency of participation in cognitively stimulating activities (e.g., reading a magazine) from which a previously established composite measure of cognitive activity was derived.

RESULTS

Cognitive activity scores ranged from 1 to 5 (mean = 3.14, SD = 0.66), with higher scores indicating more frequent participation. More frequent cognitive activity was associated with reduced cognitive decline during follow-up. In a model that controlled for baseline level of cognition, age, sex, race, and education, a 1-point increase in cognitive activity score was associated with an approximately 19% decrease in annual rate of cognitive decline (p < 0.001). This effect remained when we controlled for depressive symptoms and chronic medical conditions (p < 0.001), and when we excluded persons with evidence of memory impairment at baseline (p < 0.001).

CONCLUSION

Frequent participation in cognitively stimulating activities is associated with reduced cognitive decline in older persons.

Vitamin D Status and Rates of Cognitive Decline in a Multiethnic Cohort of Older Adults

IMPORTANCE

Vitamin D (VitD) deficiency is associated with brain structural abnormalities, cognitive decline, and incident dementia.

OBJECTIVE

To assess associations between VitD status and trajectories of change in subdomains of cognitive function in a cohort of ethnically diverse older adults.

DESIGN, SETTING, AND PARTICIPANTS

Longitudinal multiethnic cohort study of 382 participants in an outpatient clinic enrolled between February 2002 and August 2010 with baseline assessment and yearly follow-up visits. Serum 25-hydroxyvitamin D (25-OHD) was measured, with VitD status defined as the following: deficient, less than 12 ng/mL (to convert to nanomoles per liter, multiply by 2.496); insufficient, 12 to less than 20 ng/mL; adequate, 20 to less than 50 ng/mL; or high, 50 ng/mL or higher. Subdomains of cognitive function were assessed using the Spanish and English Neuropsychological Assessment Scales. Associations were evaluated between 25-OHD levels (as continuous and categorical [deficient, insufficient, or adequate]) and trajectories of cognitive decline.

MAIN OUTCOMES AND MEASURES

Serum 25-OHD levels, cognitive function, and associations between 25-OHD levels and trajectories of cognitive decline.

RESULTS

Participants (N = 382 at baseline) had a mean (SD) age of 75.5 (7.0) years; 61.8% were women; and 41.4% were white, 29.6% African American, 25.1% Hispanic, and 3.9% other race/ethnicity. Diagnosis at enrollment included 17.5% with dementia, 32.7% with mild cognitive impairment, and 49.5% cognitively normal. The mean (SD) 25-OHD level was 19.2 (11.7) ng/mL, with 26.2% of participants being VitD deficient and 35.1% insufficient. The mean (SD) 25-OHD levels were significantly lower for African American and Hispanic participants compared with white participants (17.9 [15.8] and 17.2 [8.4] vs 21.7 [10.0] ng/mL, respectively; P < .001 for both). The mean (SD) 25-OHD levels were similarly lower in the dementia group compared with the mild cognitive impairment and cognitively normal groups (16.2 [9.4] vs 20.0 [10.3] and 19.7 [13.1] ng/mL, respectively; P = .006). The mean (SD) follow-up was 4.8 (2.5) years. Rates of decline in episodic memory and executive function among VitD-deficient (episodic memory: β = -0.04 [SE = 0.02], P = .049; executive function: β = -0.05 [SE = 0.02], P = .01) and VitD-insufficient (episodic memory: β = -0.06 [SE = 0.02], P < .001; executive function: β = -0.04 [SE = 0.02], P = .008) participants were greater than those with adequate status after controlling for age, sex, education, ethnicity, body mass index, season of blood draw, vascular risk, and apolipoprotein E4 genotype. Vitamin D status was not significantly associated with decline in semantic memory or visuospatial ability. Exclusion of participants with dementia did not substantially affect the associations between VitD status and rates of cognitive decline.

CONCLUSIONS AND RELEVANCE

Low VitD status was associated with accelerated decline in cognitive function domains in ethnically diverse older adults, including African American and Hispanic individuals who exhibited a high prevalence of VitD insufficiency or deficiency. It remains to be determined whether VitD supplementation slows cognitive decline.

Early life influences on cognitive impairment among oldest old Chinese

OBJECTIVES

This article examines the effects of early life socioeconomic conditions on the risk of cognitive impairment among oldest old persons in China. We also examine whether adult socioeconomic status mediates the association between early life socioeconomic status and cognitive impairment in old age.

METHODS

Data derived from two waves (1998-2000) of the Chinese Longitudinal Healthy Longevity Survey. We estimated logistic and multinomial regression models of cognitive impairment for a nationwide sample of people aged 80 to 105 (N = 8,444).

RESULTS

Among both men and women, urban residence in early life as well as education was associated with lower odds of cognitive impairment at baseline. We found modest support for a protective effect of advantaged childhood background on the odds of cognitive impairment onset during the 2-year follow-up, especially among women.

DISCUSSION

Our findings suggest that socioeconomic environment throughout the life course, early life in particular, can influence the risk of cognitive impairment in old age. Not only can public policy that targets illiteracy, hunger, and poverty improve the lives of tens of thousands of children, but ultimately such investments will pay significant dividends many decades later in enhancing the cognitive well-being of older persons.

Estimation de l’intelligence prémorbide chez les francophones

Knowledge of cognitive performance earlier in life is essential in order to characterize precisely the extent to which these abilities have declined when an individual is diagnosed as having a dementing illness. The National Adult Reading Test (NART) was developed by Nelson and O'Connell to estimate premorbid intellectual ability in patients suffering from intellectual deterioration due to dementia. The test consists of 50 words, graded in difficulty, whose pronunciation cannot be determined from their spelling. The ability to successfully read irregularly spelt words is relatively robust in the face of current cognitive impairment and is a sensitive marker of intellectual attainment. Because the NART relies on orthographic irregularities in the English language, the construction of analogues of the test in other languages is not simply a matter of translation of the test content. Rather, words in the target language that have comparable properties to those in the NART must be sought. A French adaptation of the NART--the fNART--was developed by Bovet and calibrated on a small French-speaking Swiss sample. In a sample of 30 nondemented subjects, number of words pronounced correctly correlated highly with WAIS-R verbal and total IQ scores and less strongly with performance IQ (r = 0.43). Data available from an epidemiological survey undertaken in Geneva, Switzerland provided an opportunity to establish the measurement properties and construct validity of the fNART in a large sample unselected with respect to cognitive decline. In addition to the fNART, the survey incorporated a brief test battery assessing the domains of crystallized intelligence, memory and cognitive speed. An interview that enabled the diagnosis of dementia according to DSM IV criteria, the Mini Mental State Examination and the Psychogeriatric Assessment Scales (PAS) were also administered. If the fNART measures intellectual ability, substantial correlations between it and the test battery would be expected. Further validation of the test was sought by exploring its relation with years of education. The stability of the fNART was assessed by comparing the scores of subjects with and without dementia, and by examining the relationship of fNART scores to an informant-based report of change in cognitive performance from earlier in life assessed in the PAS. If the fNART is stable in the face of cognitive deterioration, no between-group differences or association with reported cognitive change would be expected.

METHOD

Subjects were randomly selected from residents of the canton of Geneva aged over 65 years. The analyses reported here were undertaken on a sample of 368 persons who gave codable responses to at least 90% of the fNART items. They ranged in age from 65 to 94 years. Subjects were interviewed in their homes by trained lay interviewers.

RESULTS

Cronbach's alpha for the forty-item scale was high (0.89). The percentage of subjects correctly pronouncing words ranged from 7.3% for "chamsin" to 96.7% for "agenda". Item response theory (IRT) models were fitted to the data. In a three-parameter model the value of the guessing (asymptote) parameter was vanishing small for all items. Accordingly, a two-parameter model was adopted. The discriminating power (slope) of items ranged considerably from 0.281 (rébus) to 1.192 (béotien). The average slope was 0.656. This corresponds to average factor loading of 0.528 (range 0.270 to 0.766.) The items measure a broad range of ability (mean threshold--0.719, sd = 1.540). Most items, however, discriminate at moderate levels. The parameter values obtained in the current study were compared to those estimated in a French sample of persons at risk of dementia . The correlation between item pairs for slope and parameter estimates was 0.53 and 0.70 respectively. This indicated substantial concordance between the samples regarding the difficulty of the items, but some differences in the power of groups to differentiate ability. In particular, a small number of words that performed very well in the "at risk" sample showed more moderate discrimination in the current study. Scores on the fNART were correlated with measures of crystallised intelligence, memory and cognitive speed. All correlations were statistically significant. With all tests entered a regression equation the multiple correlation coefficient was 0.63. Mean fNART scores of those suffering from DSM IV dementia and those meeting only Criterion A (multiple cognitive deficits) were lower than those of subjects meeting neither set of criteria. However subjects in the first two groups were older than subjects in the undemented group and had significantly lower educational attainment. When these two factors were controlled in an analysis of covariance, the magnitude of the differences between the groups, while still overall significantly different, was substantially reduced. A similar pattern of results applied when psychometric measures of cognitive state--the MMSE and the PAS Cognitive Impairment Scale--were used instead of diagnostic categories. The partial correlations of the fNART with the MMSE and PAS cognitive impairment scale controlling for age and education were 0.25 (P < 0.01) and -0.33 (P < 0.01) respectively. fNART scores did not differ between the sexes, nor were they significantly correlated with PAS Depression, Stroke or Behaviour Change scales. There was a small but significant correlation between the fNART and informant-assessed Cognitive Decline on the PAS.

DISCUSSION

This study demonstrated the excellent measurement properties of a French adaptation of the National Adult Reading Test in a large probability sample of elderly native speakers and provided the first large-sample evidence to support the validity of the fNART as a test of intellectual functioning relatively robust to dementia status. The negligible values of the pseudo-guessing parameters suggest that the goal of choosing words whose pronunciation is not susceptible to guessing has been achieved. The average item discriminability was high and the words used covered the spectrum of ability. The finding of substantial relationships of cognitive performance and educational attainment with fNART scores is important in validating the test as a measure of premorbid cognitive ability. The low correlations of the fNART with informant-based assessment of cognitive decline and age support the fNART as being relative robust to decline in ability. The relationships observed in this French adaptation are comparable to those reported for the English instrument . However, subjects meeting DSM IV criteria for dementia or Criterion A only had lower scores than other subjects. Decline in NART scores with dementia has been observed, particularly in moderate and severe cases. Given that the mechanism of the fNART is the same as the NART it is to be expected that while generally robust to current dementia status, some decline in performance will occur with the progression of the disease. The relationships between the fNART and PAS scales was remarkably similar to those reported by Jorm et al. in an English-speaking sample between the PAS and NART. Although small, the correlation between the fNART and the PAS Cognitive Decline scale might have been expected to be non-significant if the measure were truly stable in the face of intellectual deterioration. However this correlation is mirrored in the original English instruments and may reflect the higher risk of dementia in persons of lower intellectual ability.

CONCLUSION

Further research is desirable to improve the precision of the calibration of the scale against the WAIS-R. Nevertheless, this study has demonstrated that the fNART is a reliable and valid method of assessing premorbid intellectual ability in French speakers.

The cognitive profile and multiple-deficit hypothesis in Chinese developmental dyslexia

The present study was conducted to examine the cognitive profile and multiple-deficit hypothesis in Chinese developmental dyslexia. Thirty Chinese dyslexic children in Hong Kong were compared with 30 average readers of the same chronological age (CA controls) and 30 average readers of the same reading level (RL controls) in a number of rapid naming, visual, phonological, and orthographic tasks. Chinese dyslexic children performed significantly worse than the CA controls but similarly to the RL controls on most of the cognitive tasks. The rapid naming deficit was found to be the most dominant type of cognitive deficit in Chinese dyslexic children. Over half of the dyslexic children exhibited deficits in 3 or more cognitive areas, and there was a significant association between the number of cognitive deficits and the degree of reading and spelling impairment. The present findings support the multiple-deficit hypothesis in Chinese developmental dyslexia.

Low folate status is associated with impaired cognitive function and dementia in the Sacramento Area Latino Study on Aging

BACKGROUND

Low folate status is associated with poor cognitive function and dementia in the elderly. Since 1998, grain products in the United States have been fortified with folic acid, which has reduced the prevalence of folate deficiency and hyperhomocysteinemia.

OBJECTIVE

We investigated whether folate status is associated with cognitive function and dementia in a cohort of elderly Latinos (aged >or= 60 y; n = 1789) exposed to folic acid fortification.

DESIGN

Global cognitive function was assessed by the Modified Mini-Mental State Examination (3MSE) and specific cognitive functions by cross-culturally validated neuropsychological tests. Dementia was diagnosed according to the American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders, 3rd edition revised, and California Alzheimer Disease Diagnostic and Treatment criteria. Red blood cell (RBC) folate was measured by automated chemiluminescence and total plasma homocysteine by HPLC.

RESULTS

The prevalence of folate deficiency (RBC folate <or= 160 ng/mL) was <1%. After control for confounding by homocysteine, vitamin B-12, creatinine, demographic variables, and depressive symptom score, RBC folate was directly associated with 3MSE (P = 0.005) and delayed recall (P = 0.007) scores. In addition, adjusted odds ratios for low 3MSE score (<or=78) and dementia diagnosis per unit increase in RBC folate were significantly below unity (P <or= 0.008), which indicated that the relative risks of cognitive impairment and dementia decreased with increasing RBC folate concentration. In contrast, adjusted odds ratios for low 3MSE score and dementia diagnosis per unit increase in homocysteine were not significant.

CONCLUSION

RBC folate is directly associated with cognitive function scores and is inversely associated with dementia in elderly Latinos despite folic acid fortification.

Adherence to a Mediterranean diet and risk of incident cognitive impairment

OBJECTIVE

We sought to determine the relationship of greater adherence to Mediterranean diet (MeD) and likelihood of incident cognitive impairment (ICI) and evaluate the interaction of race and vascular risk factors.

METHODS

A prospective, population-based, cohort of individuals enrolled in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study 2003-2007, excluding participants with history of stroke, impaired cognitive status at baseline, and missing data on Food Frequency Questionnaires (FFQ), was evaluated. Adherence to a MeD (scored as 0-9) was computed from FFQ. Cognitive status was evaluated at baseline and annually during a mean follow-up period of 4.0 ± 1.5 years using Six-item-Screener.

RESULTS

ICI was identified in 1,248 (7%) out of 17,478 individuals fulfilling the inclusion criteria. Higher adherence to MeD was associated with lower likelihood of ICI before (odds ratio [lsqb]OR[rsqb] 0.89; 95% confidence interval [lsqb]CI[rsqb] 0.79-1.00) and after adjustment for potential confounders (OR 0.87; 95% CI 0.76-1.00) including demographic characteristics, environmental factors, vascular risk factors, depressive symptoms, and self-reported health status. There was no interaction between race (p = 0.2928) and association of adherence to MeD with cognitive status. However, we identified a strong interaction of diabetes mellitus (p = 0.0134) on the relationship of adherence to MeD with ICI; high adherence to MeD was associated with a lower likelihood of ICI in nondiabetic participants (OR 0.81; 95% CI 0.70-0.94; p = 0.0066) but not in diabetic individuals (OR 1.27; 95% CI 0.95-1.71; p = 0.1063).

CONCLUSIONS

Higher adherence to MeD was associated with a lower likelihood of ICI independent of potential confounders. This association was moderated by presence of diabetes mellitus.

Frailty is associated with longer hospital stay and increased mortality in hospitalized older patients

INTRODUCTION

With the onset of frailty, there is often a rapid, progressive, and self- perpetuating downward spiral towards death. Frailty has enormous impact on acute hospital care and has been shown to be a more effective predictor of mortality than conventional clinical measures.

METHODS

Hospitalized older patients admitted in medical wards at a teaching public hospital were studied to determine the prevalence of frailty; its association with anemia, congestive heart failure, clinically active tuberculosis and cognitive impairment; as well as its impact upon short-term outcome.

RESULTS

A total of 250 older hospitalized patients were included, and their frailty status was assessed using Fried's criteria. Of these, 83 (33.2%) patients were frail, with frailty found to be significantly associated with increasing age. A lower mean level of haemoglobin (p, 0.002), higher chance of congestive heart failure (p, <0.001), lower mean MMSE score (p, <0.001), was found in frail older patients. Frail subjects had a higher median hospital stay. There were total of 5 deaths, all among the frail group.

CONCLUSION

Our study showed that almost a third of hospitalized older patients are frail, and have anemia, higher frequency of CHF, cognitive impairment, longer hospital stay and higher mortality.

Cognitive decline in the elderly: an analysis of population heterogeneity

BACKGROUND

studies of cognitive ageing at the group level suggest that age is associated with cognitive decline; however, there may be individual differences such that not all older adults will experience cognitive decline.

OBJECTIVE

to evaluate patterns of cognitive decline in a cohort of older adults initially free of dementia.

DESIGN, SETTING AND SUBJECTS

elderly Catholic clergy members participating in the Religious Orders Study were followed for up to 15 years. Cognitive performance was assessed annually.

METHODS

performance on a composite global measure of cognition was analysed using random effects models for baseline performance and change over time. A profile mixture component was used to identify subgroups with different cognitive trajectories over the study period.

RESULTS

from a sample of 1,049 participants (mean age 75 years), three subgroups were identified based on the distribution of baseline performance and change over time. The majority (65%) of participants belonged to a slow decline class that did not experience substantial cognitive decline over the observation period [-0.04 baseline total sample standard deviation (SD) units/year]. About 27% experienced moderate decline (-0.19 SD/year), and 8% belonged to a class experiencing rapid decline (-0.57 SD/year). A subsample analysis revealed that when substantial cognitive decline does occur, the magnitude and rate of decline is correlated with neuropathological processes.

CONCLUSIONS

in this sample, the most common pattern of cognitive decline is extremely slow, perceptible on a time scale measured by decades, not years. While in need of cross validation, these findings suggest that cognitive changes associated with ageing may be minimal and emphasise the importance of understanding the full range of age-related pathologies that may diminish brain function.

Olfactory identification deficits and MCI in a multi-ethnic elderly community sample

Odor identification deficits occur in Alzheimer's disease (AD) and mild cognitive impairment (MCI), and predict clinical conversion from MCI to AD. In an epidemiologic study conducted in a multi-ethnic community elderly sample (average 80 years old), the University of Pennsylvania Smell Identification Test (UPSIT, range 0-40) was administered to 1092 non-demented subjects. Women (mean 26.6, S.D. 6.6) scored higher than men (mean 24.4, S.D. 7.4, p<.02), and ethnic differences were not significant after controlling for age and education. UPSIT scores correlated inversely with age (r=-0.24, p<.0001) and positively with Selective Reminding Test immediate recall (r=0.33), delayed recall (r=0.28), category fluency (r=0.28) and the 15-item Boston Naming Test (r=0.23), all ps<.0001. In a sub-sample in which MRI was done, UPSIT scores showed a significant correlation with hippocampal volume (n=571, r=0.16, p<.001) but not entorhinal cortex volume nor total number of white matter hyperintensities. In ANOVA, UPSIT scores differed (p<.0001) as a function of MCI classification: no MCI (mean 26.6, S.D. 6.8), non-amnestic MCI (mean 24.4, S.D. 7.2), and amnestic MCI (mean 23.5, S.D. 6.7). The difference between amnestic MCI and no MCI remained significant after controlling for relevant covariates. These findings indicate that the predictive utility of olfactory identification deficits for decline from no MCI to MCI and AD needs to be assessed in longitudinal studies of elderly community samples.