Medical and cognitive correlates of denture wearing in older community-dwelling adults

OBJECTIVES

To examine the association between denture wearing and use of dental services, oral function limitations, and medical and cognitive status in a community-based cohort of rural older adults enrolled in an epidemiological study.

DESIGN

This cross-sectional study was part of a larger cohort study, the Monongahela Valley Independent Elders Survey. Dental data were collected during the fifth wave of assessments (10 years after the start of the study in 1987).

SETTING

Monongahela Valley, a rural western Pennsylvania community.

PARTICIPANTS

The 805 participants were English-speaking community-dwelling (noninstitutionalized) persons, aged 73 and older, with at least a sixth grade education.

MEASUREMENTS

A questionnaire was used to collect data on denture-wearing status, oral function limitations, and recency of the last dental visit. Other data collected included demographics, self-rated health, medication usage, depression, cognitive status using the Mini-Mental State Examination, and self-reports of weight loss and appetite.

RESULTS

There were 44.7% of participants who had full dentures. Those with complete dentures were more likely to complain of oral function limitation, report poor health status, and take prescription medications. Additionally, 93.6% of those with complete dentures had not seen a dentist in more than 1 year.

CONCLUSION

Denture wearing and edentulism are common in older patients and can be related to poor quality of life and risk for undiagnosed oral disease and may be a marker for other medical comorbidities. Geriatricians need to include oral health status evaluations and understand that attention to the oral cavity should be part of an older adult's care.

Depression After Stroke: A Prospective Epidemiological Study

OBJECTIVES

To elucidate the relationship between stroke and depressive symptoms and to determine whether disability or cerebrovascular risk factors mediate that relationship.

DESIGN

A prospective longitudinal epidemiological survey.

SETTING

The mid-Monongahela Valley, a rural, nonfarm, low-socioeconomic-status community.

PARTICIPANTS

Random sample of 1,134 subjects aged 65 and older.

MEASUREMENTS

The dependent variable was clinically significant depressive symptoms, as defined by five or more symptoms on the modified Center for Epidemiological Studies Depression scale. The independent variables were demographics (age, sex, education), stroke, number of impaired instrumental activities of daily living (IADLs), diabetes mellitus, hypertension, atherosclerotic heart disease, and smoking. Logistic regression analyses were conducted for cross-sectional and longitudinal models examining whether stroke was associated with or predicted depressive symptoms, with other associated factors included as covariates.

RESULTS

Clinically significant depressive symptoms were cross-sectionally associated with stroke (odds ratio (OR)=3.5, 95% confidence interval (CI)=1.4-8.3), diabetes mellitus (OR=2.8, 95% CI=1.7-4.6; P</=.05), and IADL impairment (OR=1.6, 95% CI=1.4-1.8; P<.05). Longitudinal analysis demonstrated that stroke (OR=6.3, 95% CI=1.7-23.2) and depressive symptoms at baseline (OR=15, 95% CI=7.7-29.5) predicted subsequent clinically significant depressive symptoms measured 2 years later, whereas education was protective (OR=0.4, 95% CI=0.2-0.8).

CONCLUSION

Stroke survivors have a greatly elevated risk for clinically significant depressive symptoms even 2 or more years after index stroke, independent of functional disability, cerebrovascular risk factors, and previous depressive symptoms.

Predictors of Nursing Facility Admission: A 12-Year Epidemiological Study in the United States

OBJECTIVES

To identify predictors of institutionalization in a community-based cohort of older adults.

DESIGN

Prospective, longitudinal. After initial assessment at study entry, surviving participants were reassessed in a series of approximately biennial waves until October 2001; baseline for the current analysis was Wave 2 (1989-91).

SETTING

Largely rural, blue-collar community in the mid-Monongahela Valley of southwestern Pennsylvania.

PARTICIPANTS

A population-based cohort of 1,147 adults, aged 66 and older (mean 74.1) at baseline, who were not already institutionalized and who had complete data on all variables of interest.

MEASUREMENTS

Cox proportional hazards models were used to identify predictors of institutionalization from among selected variables measured at baseline, including age, sex, education, marital status, living arrangements, ability to perform instrumental activities of daily living (IADLs), depressive symptoms, number of prescription medications (as an index of overall morbidity), self-reported social support, hospitalization during the preceding year, and cognitive functioning. Dementia was defined according to the operational criteria of the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised, and by a Clinical Dementia Rating of 0.5 or greater, based on a standardized clinical assessment. The outcome variable was institutionalization, defined as entry into in a nursing home.

RESULTS

Significant predictors of institutionalization were dementia (hazard ratio (HR)=5.09, 95% confidence interval (CI)=2.92-8.84), measured as a time-dependent variable; older age (HR=1.06, 95% CI=1.03-1.10); IADL disability (HR=1.31, 95% CI=1.15-1.50); worse/less social support (HR=1.27, 95% CI=1.10-1.46); and number of prescription medications (HR=1.21, 95% CI=1.11-1.32), measured at baseline. The interaction between number of prescription drugs and dementia was also significant, suggesting that prescription medication count had less effect on institutionalization in those with dementia than in those without.

CONCLUSION

Dementia emerged as the most potent risk factor for institutionalization in this 12-year community-based epidemiological study. Medical burden conferred greater vulnerability to institutionalization in nondemented persons than in those with dementia.

Gambling Participation and Social Support Among Older Adults: A Longitudinal Community Study

The purpose of this preliminary study was to examine associations between leaving home to engage in bingo or gambling activity and indices of physical and mental health and social support among a representative community cohort of 1016 elderly people. Cross-sectional and longitudinal data gathered from a prospective epidemiological study in a rural, low socio-economic status, area of Pennsylvania was employed. The cohort had a mean age of 78.8 (SD = 5.1) (range 71-97) and participated in three consecutive biennial "waves" of data collection. Nearly half (47.7) of the cohort reported gambling. To predict gambling, the independent variables included age, sex, education, employment, social support, depressive symptoms, self-rated health, alcohol use, cigarette use, and cognitive functioning. In cross-sectional, univariate analyses, gambling was associated with younger age, sex (male), fewer years of education, greater social support, lower depression scores, better self-rated health, alcohol use in the past year, and higher cognitive functioning. In a cross-sectional multiple regression model, younger age, greater social support, and alcohol use in the past year remain strongly and independently associated with gambling activity. Longitudinally, age, sex, social support, alcohol use, and gambling are predictive of future gambling activity. The results revealed that gambling may offer a forum of social support to older adults who are often isolated as they age.

The Mini-Cog as a screen for dementia: validation in a population-based sample

OBJECTIVES

To test the Mini-Cog, a brief cognitive screening test, in an epidemiological study of dementia in older Americans.

DESIGN

A population-based post hoc examination of the sensitivity and specificity of the Mini-Cog for detecting dementia in an existing data set.

SETTING

The Monongahela Valley in Western Pennsylvania.

PARTICIPANTS

A random sample of 1,119 older adults enrolled in the Monongahela Valley Independent Elders Survey (MoVIES).

MEASUREMENTS

The effectiveness of the Mini-Cog in detecting independently diagnosed dementia was compared with that of the Mini-Mental State Examination (MMSE) and a standardized neuropsychological battery.

RESULTS

The Mini-Cog, scored by an algorithm as "possibly impaired" or "probably normal," and the MMSE, at a cutpoint of 25, had similar sensitivity (76% vs 79%) and specificity (89% vs 88%) for dementia, comparable with that achieved using a conventional neuropsychological battery (75% sensitivity, 90% specificity).

CONCLUSION

When applied post hoc to an existing population, the Mini-Cog was as effective in detecting dementia as longer screening and assessment instruments. Its brevity is a distinct advantage when the goal is to improve identification of older adults in a population who may be cognitively impaired. Prior evidence of good performance in a multiethnic community-based sample further supports its validity in the ethnolinguistically diverse populations of the United States in which widely used cognitive screens often fail.

Tracking cognitive functioning over time: ten-year longitudinal data from a community-based study

Over 10 years, a community-based sample age 65> or = years, with a starting cohort size of 1,206, was assessed biennially with the Mini-Mental State Exam; the Consortium to Establish a Registry for Alzheimer's Disease battery; Immediate and Delayed Recall of a Story; Verbal Fluency for P and S, Fruits and Animals; Clock Drawing; Temporal Orientation; and Trail Making tests. We report distributions of scores over time, at each wave, in (a) all individuals who were assessed at that wave, whether or not they participated in all waves, and (b) the Survivor subgroup of 425 participants who completed all tests at all 5 waves. Scores and factor structures remained remarkably stable over the study period. The most marked decline over time was seen on the Trail Making tests. As the survivors are de facto a largely healthy and motivated group, their data can be considered population-based healthy norms and may serve as a reference for other studies conducting repeated evaluations using the same tests.

Blood pressure and cognitive impairment in India and the United States: a cross-national epidemiological study

OBJECTIVE

To evaluate the relationship between blood pressure (BP) and cognitive impairment in elderly populations in India and the United States in a cross-national epidemiological study.

DESIGN

Cross-sectional comparisons, using standardized cognitive screening and BP measurements.

PARTICIPANTS

We examined 4810 subjects 55 years and older, of whom 595 were 75 years and older, from Ballabgarh, India, and 636 subjects 75 years and older from the Monongahela Valley, Pennsylvania.

MAIN OUTCOME MEASURES

General cognitive impairment, defined as scores at or below the 10th percentile of each cohort on a general mental status test-the Mini-Mental State Examination (United States) and the Hindi Mental State Examination (India)-and memory impairment, defined as scores at or below the 10th percentile of delayed recall of word lists at both sites.

RESULTS

Mean systolic BP (SBP) and diastolic BP (DBP) were 115 and 75 mm Hg (India) and 141 and 76 mm Hg (United States). Logistic regression adjusting for age, sex, and education or literacy was used to calculate odds ratios (ORs) and associated 95% confidence intervals (CIs) for cognitive impairment. In Ballabgarh, for every 10 mm Hg increase in SBP there was a 10% reduction in cognitive impairment (OR, 0.90; 95% CI, 0.83-0.97), and there was a 13% reduction in cognitive impairment (OR, 0.87; 95% CI, 0.76-0.99) with every 10 mm Hg increase in DBP. In the Monongahela Valley, a similar association between DBP and cognitive impairment did not remain significant after adjustment for confounders (OR, 0.83; 95% CI, 0.65-1.06).

CONCLUSIONS

In both Indian and American samples, lower DBP was inversely related to cognitive impairment, although not significantly in the latter. Low BP may be an effect of, or a potential risk factor for, degenerative brain disease.

Sedative-hypnotic use of diphenhydramine in a rural, older adult, community-based cohort: effects on cognition

OBJECTIVE

The authors sought to identify patterns and associations of prescription and over-the-counter sedative-hypnotic use in an older, rural, blue-collar, community-based cohort in southwestern Pennsylvania over 10 years.

METHODS

A group of 1,627 individuals age 65 and over were recruited and assessed during 1987-1989 and re-assessed during approximately biennial waves. Data included sleep medications, demographics, depressive symptoms, sleep complaints, and cognitive functioning (Mini-Mental State Exam [MMSE]).

RESULTS

At Waves 1 through 5, the mean age of the cohort increased from 73.4 to 80.5 years. Use of prescription sedative-hypnotics (primarily benzodiazepines) increased from 1.8% to 3.1%, and over-the-counter sedative-hypnotic use (primarily diphenhydramine) increased from 0.4% to 7.6%. At Wave 5 (1996-1998), 8.17% of the sample reported using diphenhydramine as a sleep aid. After adjusting for age and sex, diphenhydramine use was associated with higher education and more depressive symptoms, the latter becoming nonsignificant after controlling for initial insomnia. MMSE became significantly associated with diphenhydramine use when 143 subjects with dementia were excluded from the analysis.

CONCLUSION

As the cohort aged, prescription sedative-hypnotic use remained relatively stable, whereas over-the-counter sedative use, principally diphenhydramine, increased substantially. The association of this drug with cognitive impairment in persons without dementia highlights its potential for causing adverse reactions in older adults.

Serum anticholinergic activity in a community-based sample of older adults: relationship with cognitive performance

BACKGROUND

Serum anticholinergic activity (SAA), as measured by a radioreceptor assay, quantifies a person's overall anticholinergic burden caused by all drugs and their metabolites. In several small geriatric patient groups, SAA has been associated with cognitive impairment or frank delirium. To our knowledge, there has not yet been any systematic study of the prevalence of SAA and its effect on cognition in a community-based population.

METHODS

Serum anticholinergic activity was measured in 201 subjects who were randomly selected among the participants in an epidemiological community study, based on their age and sex. Cognitive performance was assessed with use of the Mini-Mental State Examination. The association between SAA and cognitive performance was examined using a univariate analysis and a multiple logistic regression model, adjusting for age, sex, educational level, and number of medications.

RESULTS

Serum anticholinergic activity was detectable in 180 (89.6%) participants (range, 0.50-5.70 pmol/mL). Univariate testing showed a significant association between SAA and Mini-Mental State Examination scores. Logistic regression analysis indicated that subjects with SAA at or above the sample's 90th percentile (ie, SAA >/=2.80 pmol/mL) were 13 times (odds ratio, 1.08-152.39) more likely than subjects with undetectable SAA to have a Mini-Mental State Examination score of 24 (the sample's 10th percentile) or below.

CONCLUSIONS

To our knowledge, this is the largest analysis of SAA and the first to examine its extent and relationship with cognitive performance in a community sample. Its results suggest that SAA can be detected in most older persons in the community and confirm that even low SAA is associated with cognitive impairment.

Functional transitions and active life expectancy associated with Alzheimer disease

CONTEXT

The concept of active life expectancy, the number of years a person can expect to live without disability, is used for the first time, to our knowledge, to examine the effect of Alzheimer disease (AD) on total life expectancy with different degrees of disability.

OBJECTIVES

To estimate and compare total life expectancy and average duration lived with different degrees of disability, between persons with and without AD.

DESIGN

Ten-year prospective epidemiologic study.

SETTING

A largely blue-collar rural community in Southwestern Pennsylvania.

PARTICIPANTS

A population-based cohort of 1201 subjects (at the beginning of follow-up) with a mean age of 75 years.

MAIN OUTCOME MEASURES

At age 70 and every 2 years thereafter, among persons with AD and nondemented persons, (1) the total expectancy of remaining life and (2) the duration lived with different numbers of impaired instrumental activities of daily living (IADLs), grouped as 0 to 1, 2 to 5, and 6 to 7 impairments.

RESULTS

Alzheimer disease greatly shortened the total life expectancy to a similar extent in men and women, with the most pronounced reduction among those who were younger. Besides their shorter survival, men and women with AD spent more absolute years, and also a greater proportion of their remaining lives, with 6 to 7 IADL impairments than did their nondemented age peers. Nondemented women spent more years with 2 to 5 IADL impairments than nondemented men, while women with AD spent more years with 6 to 7 IADL impairments than men with AD.

CONCLUSION

The concept of active life expectancy adds a useful new dimension to the study of outcomes in AD.

Rates and predictors of mortality in an aging, rural, community-based cohort: the role of depression

CONTEXT

Depression, functional disability, cognitive impairment, and self-rated health all predict mortality in the elderly population. There is no consensus on their relative contributions when examined together.

OBJECTIVES

To measure rates and identify predictors of mortality in an aging community-based cohort.

DESIGN

Ten-year prospective epidemiological study. Predictor variables examined in Cox proportional hazards models were self-rated health, ability to perform instrumental activities of daily living (IADLs), depressive symptoms, and cognitive functioning, controlling for age, sex, education, and number of prescription drugs.

SETTING

A largely blue-collar rural community in southwestern Pennsylvania.

PARTICIPANTS

A population-based cohort of 1064 adults, 67 years or older at the beginning of follow-up.

MAIN OUTCOME MEASURES

Mortality at 3, 5, and 10 years (133, 218, and 482 deaths, respectively).

RESULTS

Mortality rates were similar to those of the 1990 US population. Older age, male sex, IADL disability, and number of prescription drugs measured at baseline were significant predictors of mortality at all 3 follow-up end points. Depression at baseline predicted earlier (3- and 5-year) mortality but not later (10-year) mortality. The interaction between self-rated health and depression independently and strongly predicted mortality at all end points. Cognitive functioning predicted mortality only when IADL disability was excluded from the model.

CONCLUSIONS

Age, sex, depression, and functional disability are strong and consistent independent predictors of mortality in older adults in the community, in addition to objective medical burden (prescription drugs). Depression alone predicts mortality in the shorter rather than longer term, but in combination with poor self-rating of health, it strongly predicts mortality at all end points.

Use of lipid-lowering drugs in older adults with and without dementia: a community-based epidemiological study

OBJECTIVES

To compare the use of lipid-lowering drugs in community-dwelling older adults with and without dementia.

DESIGN

Comparison of lipid-lowering drug use by demented cases and nondemented controls based on secondary analysis of data from a longitudinal epidemiologic study.

SETTING

Longitudinal study of a largely rural, low- socioeconomic-status, community-based cohort of older persons residing in the mid-Monongahela Valley of South-west Pennsylvania (the Monongahela Valley Independent Elders Survey).

PARTICIPANTS

Eight hundred forty-five individuals of mean +/- standard deviation (SD) age of 80.5 +/- 4.6, participating in the fifth biennial wave of data collection.

MEASUREMENTS

Demographics; medical history; medication regimen (including examination of prescription bottle labels); self-report of most recent visit to primary care physician (PCP); and standardized clinical assessment to determine presence of dementia, including Clinical Dementia Rating (CDR).

RESULTS

One hundred seventy participants (20.1% of total subject cohort) had dementia, with a CDR of 0.5 or greater. Mean ages of demented and nondemented individuals were 83.5 +/- 5.1 and 79.8 +/- 4.2, respectively. Similar proportions, 87.7% and 89.5%, of these groups reported PCP visits in the previous year. Of the total sample, 9.4% (3.5% of the demented and 10.8% of the nondemented) were taking lipid-lowering drugs. After adjustment for age, sex, education, visit with PCP within the past year, and potential confounding clinical and lifestyle variables (self-reported heart disease, stroke or transient ischemic attacks, hypertension, smoking, and alcohol consumption), dementia was associated with a lower likelihood of taking a lipid-lowering drug (odds ratio = 0.39, 95% confidence interval = 0.16-0.95). In post hoc subgroup analyses, similar results were found when restricting lipid-lowering drugs to statins alone but were not statistically significant. Drug use was not associated with severity of dementia (CDR = 0.5 vs CDR >or= 1).

CONCLUSIONS

Demented individuals were less likely than their nondemented counterparts to be taking lipid-lowering drugs. This finding could reflect different prescribing patterns by physicians for demented and nondemented patients or a possible protective effect of these drugs against dementia.

Data management and quality assurance for an International project: the Indo-US Cross-National Dementia Epidemiology Study

BACKGROUND

Data management and quality assurance play a vital but often neglected role in ensuring high quality research, particularly in collaborative and international studies.

OBJECTIVE

A data management and quality assurance program was set up for a cross-national epidemiological study of Alzheimer's disease, with centers in India and the United States.

METHODS

The study involved (a) the development of instruments for the assessment of elderly illiterate Hindi-speaking individuals; and (b) the use of those instruments to carry out an epidemiological study in a population-based cohort of over 5000 persons. Responsibility for data management and quality assurance was shared between the two sites. A cooperative system was instituted for forms and edit development, data entry, checking, transmission, and further checking to ensure that quality data were available for timely analysis. A quality control software program (CHECKS) was written expressly for this project to ensure the highest possible level of data integrity.

CONCLUSIONS

This report addresses issues particularly relevant to data management and quality assurance at developing country sites, and to collaborations between sites in developed and developing countries.

Speed and capacity of language processing test: normative data from an older American community-dwelling sample

This study presents normative data for the Speed and Capacity of Language Processing (SCOLP) testfrom an older American sample. The SCOLP comprises 2 subtests: Spot-the-Word, a lexical decision task, providing an estimate of premorbid intelligence, and Speed of Comprehension, providing a measure of information processing speed. Slowed performance may resultfrom normal aging, brain damage (e.g., head injury), or dementing disorders or may represent the intact performance of someone who always performed at the low end of normal. The SCOLP enables the clinician to differentiate between these possibilities. Adequate age-appropriate norms to differentiate dementia from normal aging do not exist. We present data from 424 older community-dwelling Americans (75-94 years old). The results confirm that information processing speed slows with increasing age. By contrast, increasing age has little effect on lexical decision. Thus, our data suggest that the SCOLP shows promise as a tool to help distinguish between normal aging and the early stages of dementia.

Genetic variation in alpha(1)-antichymotrypsin and its association with Alzheimer's disease

Alzheimer's disease (AD) is a devastating neurodegenerative disorder characterized by extracellular neuritic plaques and intracellular neurofibrillary tangles in brain parenchyma. Alpha-1-antichymotrypsin (ACT) is a component of plaque cores, can bind to Abeta, and has been proposed as a possible candidate gene for AD susceptibility. The genetic association between the ACT codon -17*A allele of the signal peptide polymorphism and AD has been shown in some, but not in all studies. One hypothesis is that the ACT codon -17*A allele is in linkage disequilibrium with unknown functional mutation(s) in the ACT gene. This study was undertaken to identify new mutation(s) in the ACT gene by PCR-SSCP-sequencing and, in conjunction with known mutations, to assess their role in affecting the risk of AD. A total of seven new point mutations were observed: 5'UTR(A-->G), Asp128Asn(G-->A), Ser250Ser(C-->T), Leu301Pro(T-->C), Thr324Thr(A-->G), G-->A in intron 4, and 3'UTR C-->A. Of these, mutations at codon 250, codon 324, intron 4 and 3'UTR showed a frequency of 1% or more. Of the known mutations, Thr-17Ala(A-->G), Lys76Lys(A-->G) and Leu241Leu(G-->A) occur at a polymorphic level. The ACT codon -17*A allele was associated with increased risk of AD (OR for AA vs TT: 1.71; 95% CI: 1.16-2.53; P=0.007), especially in the presence of the APOE*4 allele (OR for AA vs TT: 2.35; 95% CI: 1.13-4.85; P=0.02). The codon 241*A allele and the codon 250*T allele were associated with protective effects against AD (OR: 0.36; 95% CI: 0.13-0.86; P=0.02) (OR:0.39; 95% CI: 0.18-0.85; P=0.02). irrespective of the APOE*4 status. The codon 324*G allele was associated with a marginal protective effect (OR:0.57; 95% CI: 0.26-1.26; P=0.17). While the codon 241*A allele was in linkage disequilibrium with the codon -17*A allele, the codon 250*T and codon 324*G alleles were non-randomly associated with the codon -17*T allele. In contrast, the codon 76*G (OR:1.34; 95% CI: 0.92-1.95; P=0.13), codon 227*G (OR:3.96; 95% CI: 0.83-18.8; P=0.08) and intron 4*G (OR:1.47; 95% CI: 0.88-2.29; P=0.15) alleles were associated with a modest risk of AD, and all were in linkage disequilibrium with the codon -17*A allele. EH-based haplotype analysis showed that certain haplotypes are associated with either higher or lower risk of AD. Our data indicate that the ACT gene harbors several potentially important variable sites, which are associated with either an increased or decreased risk of AD. The non-random combination of risk and protective alleles may explain, in part, why the association studies regarding the ACT codon -17*A have been inconsistent, especially if the frequency of other ACT mutations varies between populations.

Sensitivity and specificity of cognitive and functional screening instruments for dementia: the Indo-U.S. Dementia Epidemiology Study

There is a shortage of adequate screening instruments for dementia in poorly educated populations and non-English-speaking groups. An epidemiological survey was conducted in a population-based, largely illiterate, sample of 5,126 individuals aged 55 and older in 28 villages in the rural community of Ballabgarh in northern India. All participants were administered a general mental status test, the Hindi Mental State Examination (HMSE), and a brief battery of neuropsychological tests. Their informants answered a questionnaire assessing functional ability, the Everyday Abilities Scale for India (EASI). Six hundred thirty-two participants underwent clinical diagnostic evaluation for dementia. We investigated whether the sensitivity, specificity, and predictive value for dementia of the mental status test could be improved by the addition of the brief neuropsychological test battery or the functional questionnaire, comparing the instruments alone and in combination. In participants who could be tested cognitively, the HMSE, the neuropsychological battery, and EASI had sensitivities of 81.3%, 81.3%, and 62.5%, respectively, with specificities of 60.2%, 74.5%, and 89.7%, respectively. The combination of all three was 93.8% sensitive and 41.8% specific. The sensitivity of the HMSE alone was nonsignificantly improved by the addition of either the EASI or the neuropsychological battery, whereas its specificity was significantly decreased by either addition. An advantage of the EASI was that it could also be administered to informants of subjects who were cognitively untestable. In this largely illiterate community, with a low prevalence of dementia, the combination of cognitive tests and a functional ability questionnaire had substantial value for population screening.

Hypothyroidism and cognition: preliminary evidence for a specific defect in memory

The effect(s) of hypothyroidism on adult brain cognitive function are poorly understood. We performed a series of neuropsychological tests in 13 thyroid cancer patients while they continued to take their usual dose of levothyroxine (LT4) and again after discontinuing thyroid hormone. Three euthyroid subjects were also tested twice to assess the effect of repeated testing on performance. The tests assessed memory, mood, and attentional resources and controlled for the practice effects of repeated testing. The mean thyrotropin (TSH) on LT4 was 0.56 +/- 0.76 mU/L and while hypothyroid was 69 +/- 33 mU/L. While hypothyroid, the mean Beck depression score was significantly higher (15.31 +/- 9.41 hypothyroid vs. 7.31 +/- 4.82 on LT4) and the subjects rated themselves worse relative to functional memory, concentration, thinking, alertness, and motivation. Hypothyroidism was associated with a decrease in retrieval from memory (p = 0.0034), and this effect could not be attributed to depression or to practice effects. Thyroid state did not affect immediate recall, verbal learning, inhibitory efficiency, information processing speed, or attention switching. Athyrosis is associated with a decrement in delayed recall of verbal information but not in other objective measures of cognition, suggesting that the memory decrement of hypothyroidism is not caused by a generalized reduction in attentional resources.

Incidence of Alzheimer's disease in a rural community in India: the Indo-US study

OBJECTIVE

To determine overall and age-specific incidence rates of AD in a rural, population-based cohort in Ballabgarh, India, and to compare them with those of a reference US population in the Monongahela Valley of Pennsylvania.

METHODS

A 2-year, prospective, epidemiologic study of subjects aged > or =55 years utilizing repeated cognitive and functional ability screening, followed by standardized clinical evaluation using the Diagnostic and Statistical Manual of Mental Disorders, 4th edition, and the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria for the diagnosis, and the Clinical Dementia Rating scale for the staging, of dementia and AD.

RESULTS

Incidence rates per 1000 person-years for AD with CDR > or =0.5 were 3.24 (95% CI: 1.48-6.14) for those aged > or =65 years and 1.74 (95% CI: 0.84-3.20) for those aged > or =55 years. Standardized against the age distribution of the 1990 US Census, the overall incidence rate in those aged > or =65 years was 4.7 per 1000 person-years, substantially lower than the corresponding rate of 17.5 per 1000 person-years in the Monongahela Valley.

CONCLUSION

These are the first AD incidence rates to be reported from the Indian subcontinent, and they appear to be among the lowest ever reported. However, the relatively short duration of follow-up, cultural factors, and other potential confounders suggest caution in interpreting this finding.

Patterns of cognitive decline in presymptomatic Alzheimer disease: a prospective community study

BACKGROUND

Specific patterns of decline over time were evaluated across a spectrum of cognitive measures in presymptomatic Alzheimer disease (AD) within a community sample.

METHODS

A total of 551 individuals completed a battery of standard cognitive tests 3.5 and 1.5 years before outcome (clinical onset of AD vs continued nondemented status) within a prospective community-based study of AD. Test score changes in 68 cases (who subsequently developed symptomatic AD) and 483 controls (who remained nondemented) on each of 15 cognitive measures were transformed into z scores adjusted for age, sex, and education. A case-control rate ratio of the proportions of individuals who showed "cognitive decline" on each test was calculated, representing the relative magnitude of cognitive decline on each test in presymptomatic AD compared with normal aging.

RESULTS

Declines in Trail-Making Tests A and B and Word List delayed recognition of originals and third immediate learning trial had the highest rate ratios, larger than 3.0 (P<.01). These were followed by Word List delayed recognition of foils and delayed recall, Consortium to Establish a Registry for Alzheimer's Disease Praxis, Clock Drawing, the Boston Naming Test, and Orientation, with rate ratios between 1.7 and 3.0 (P<.05).

CONCLUSIONS

Memory and executive dysfunction showed the greatest decline over time in individuals who would clinically manifest AD 1.5 years later. These findings might help us understand the underlying evolution of the early neurodegenerative process. They highlight the importance of executive dysfunction early in the disease process and might facilitate early detection of AD.

Genetic polymorphism in the cathepsin G gene and the risk of Alzheimer's disease

Alzheimer's disease (AD) is a complex disease with the possible involvement of several genes. The APOE*4 allele has been documented to be a major risk factor for sporadic late-onset AD, but it is neither necessary nor sufficient to cause the disease. Cathepsin G, a serine protease found commonly in the azurophillic granules of neutrophils, has been reported to possess some beta-secretase like properties, and thus may be involved in the processing of amyloid precursor protein (APP). Recently, an A-->G polymorphism has been reported in exon 4 of the cathepsin G gene, which changes the codon AAC ((125) Asp) to AGC ((125)Ser). In this study, we have investigated the association of this polymorphism with sporadic late-onset AD. We screened DNA samples from 464 late-onset AD cases and 310 age-matched controls. No significant association was seen between this polymorphism and AD. When the data were stratified by the APOE*4 carrier status, no significant difference was seen either. Our data show no effect of this cathepsin G polymorphism in AD. Characterization of additional polymorphisms in this gene may provide more conclusive answers.

Practice parameter: early detection of dementia: mild cognitive impairment (an evidence-based review). Report of the Quality Standards Subcommittee of the American Academy of Neurology

OBJECTIVE

The goal of this project was to determine whether screening different groups of elderly individuals in a general or specialty practice would be beneficial in detecting dementia.

BACKGROUND

Epidemiologic studies of aging and dementia have demonstrated that the use of research criteria for the classification of dementia has yielded three groups of subjects: those who are demented, those who are not demented, and a third group of individuals who cannot be classified as normal or demented but who are cognitively (usually memory) impaired.

METHODS

The authors conducted computerized literature searches and generated a set of abstracts based on text and index words selected to reflect the key issues to be addressed. Articles were abstracted to determine whether there were sufficient data to recommend the screening of asymptomatic individuals. Other research studies were evaluated to determine whether there was value in identifying individuals who were memory-impaired beyond what one would expect for age but who were not demented. Finally, screening instruments and evaluation techniques for the identification of cognitive impairment were reviewed.

RESULTS

There were insufficient data to make any recommendations regarding cognitive screening of asymptomatic individuals. Persons with memory impairment who were not demented were characterized in the literature as having mild cognitive impairment. These subjects were at increased risk for developing dementia or AD when compared with similarly aged individuals in the general population.

RECOMMENDATIONS

There were sufficient data to recommend the evaluation and clinical monitoring of persons with mild cognitive impairment due to their increased risk for developing dementia (Guideline). Screening instruments, e.g., Mini-Mental State Examination, were found to be useful to the clinician for assessing the degree of cognitive impairment (Guideline), as were neuropsychologic batteries (Guideline), brief focused cognitive instruments (Option), and certain structured informant interviews (Option). Increasing attention is being paid to persons with mild cognitive impairment for whom treatment options are being evaluated that may alter the rate of progression to dementia.

Performance of elderly African American and White community residents on the CERAD Neuropsychological Battery

The CERAD Neuropsychological Battery, includes 7 measures: Verbal Fluency; Modified Boston Naming; Mini-Mental State: Word List Learning, Recall and Recognition; Constructional Praxis. It was originally developed to evaluate patients with a clinical diagnosis of Alzheimer's disease, but is increasingly used in epidemiological studies of the incidence and prevalence of dementia in the elderly. The current study reports norms for African American and White representative community residents 71 years of age and older in North Carolina, and compares performance with that of African Americans in Indianapolis and with Whites in the Monongahela Valley, Pennsylvania. For all 3 studies, increased education and younger age was related to better performance on each of the 7 measures. Sex differences, when present, tended to favor women. Although on average African Americans performed more poorly than Whites, with demographic characteristics controlled, no significant racial differences were found in the North Carolina sample. Both African American and White participants in North Carolina performed more poorly than their racial counterparts in the other 2 studies, possibly because of selection-induced differences in health and educational status. Nevertheless, the use of an identical evaluation battery, such as the CERAD neuropsychologic instrument, facilitates comparisons not otherwise possible, and should be encouraged.

APOE polymorphism in a rural older population-based sample in India

Allele frequencies are most often reported from small convenience samples of unknown demographics and limited generalizability. We determined the distribution of apolipoprotein E genotype (APOE) and allele frequencies for a large, well-defined, representative, rural, population-based sample (n = 4450) aged 55-95 years in Ballabgarh, in the northern Indian state of Haryana. The overall APOE E*2, E*3, and E*4 allele frequencies were 0.039, 0.887, and 0.073, respectively; frequencies are also reported by age, sex, and religious/caste groups. The APOE*4 frequency is among the lowest reported anywhere in the world. APOE allele frequencies did not vary significantly by age or sex in this study. To our knowledge, this is the largest Indian sample ever genotyped for the APOE polymorphism. The representativeness of the sample and its known demographics provide a much-needed normative background for studies of gene-disease associations.

Lack of association between alpha2-macroglobulin polymorphisms and Alzheimer's disease

This study was undertaken to investigate the role of two alpha2-macroglobulin (A2M) polymorphisms, an intronic 5-bp deletion and Ile1000Val, in the development of Alzheimer's disease (AD) and to evaluate the interaction between the apolipoprotein E (APOE) and A2M polymorphisms. The A2M polymorphisms were screened by using polymerase-chain-reaction-based assays in 555 white late-onset AD cases and 446 controls. The gentoype distributions of the 5-bp deletion and Ile1000Val polymorphisms were comparable between cases and controls (P = 0.158 and P = 0.148, respectively). Likewise, there was no significant difference in allele frequencies of each polymorphism among cases and controls (P = 0.361 and P = 0.062, respectively). The stratification of data by APOE*4 status also did not yield any significant association. In conclusion, we observed no association between either the intronic deletion polymorphism or the Ile1000Val polymorphism of A2M and AD in our case-control cohort.

Cognitive tests that best discriminate between presymptomatic AD and those who remain nondemented

OBJECTIVE

To identify the most accurate cognitive measures in discriminating between individuals with presymptomatic AD and individuals who remained nondemented.

METHODS

During a 10-year prospective community study, 120 nondemented subjects completed a battery of standard cognitive tests and clinically manifested AD 1.5 years later. Performance on each of 16 cognitive tests was compared between these 120 presymptomatic cases and 483 controls who remained nondemented over the 10-year follow-up period. The area under the receiver operating characteristic (AUC) curve for each test was used to measure its accuracy of discrimination between cases and controls.

RESULTS

Among the 16 neuropsychological tests, Word List Delayed Recall discriminated best between cases and controls (AUC = 0.806), followed by the Word List 3rd Learning Trial (0.787), Word List 1st Learning Trial (0.774), and Trail-making Test B (0.773), compared to the Mini-Mental State Examination (MMSE) (0.726). Both Word List Delayed Recall and Word List 3rd Learning Trial were significantly more accurate than the MMSE. The combination of Word List Delayed Recall and Trail-making Test B comprised the optimal set of cognitive measures, with the highest AUC (0.852).

CONCLUSION

Measures of delayed recall and executive functions were the best discriminators between those who would manifest AD 1.5 years later and those who would remain nondemented. These findings are relevant for the early detection of AD and, therefore, for prevention and early intervention trials. Executive dysfunction may be a subtle manifestation of incipient AD, along with memory dysfunction.

Epidemiology of dementia: concepts and overview

This article reviews current knowledge about the prevalence and incidence of dementia and the risk and protective factors for dementia. Relevant epidemiologic concepts and methodological issues are reviewed, focusing on the implications of designing and interpreting epidemiologic studies of dementia and illustrating the integrative role of epidemiology.

Relationships between cerebrovascular events, APOE polymorphism and Alzheimer's disease in a community sample

To investigate whether the APOE*4 allele modified the relationship between cerebrovascular events and Alzheimer's disease (AD), we collected evidence of previous stroke or transient ischemic attack (TIA) and determined APOE genotype among 102 subjects with AD and 375 nondemented subjects in a community-based study of dementia. Subjects with a history of stroke or TIA were twice as likely to have AD as subjects without such a history. However, APOE*4 carriers with a history of stroke/TIA were 5 times more likely than APOE*4 carriers without such a history to have AD (odds ratio = 5.3, 95% confidence interval = 1.4-20.9). History of stroke/TIA had little effect on the likelihood of having AD in subjects without an APOE*4 allele.

Genetic polymorphisms in the cathespin D and interleukin-6 genes and the risk of Alzheimer's disease

Alzheimer's disease (AD) is a complex multi-factorial disease with the involvement of several possible genes. The apolipoprotein E*4 (APOE*4) allele of the known susceptibility gene, APOE, is neither necessary nor sufficient to cause AD. This has prompted the search for other candidate genes associated with the risk of AD. Cathepsin D (Cat D) is an intracellular aspartyl protease that has been reported to have in vitro beta and gamma-secretase activity. The presence of a C-->T (Ala-->Val) polymorphism in exon 2 of the Cat D gene has been reported to be associated with an increased risk of AD. Further, as inflammation is reported to play a prominent role is AD pathogenesis, IL-6, a known mediator of inflammation, is another candidate gene proposed to be associated with the risk of AD. Genetic variation in the IL-6 gene has been reported to be associated with the risk of AD. We performed a genetic screening of sporadic, late-onset AD cases and age-matched controls to evaluate the role of Cat D and IL-6 polymorphisms in AD. Our data indicate no significant association between these polymorphisms and the risk of AD. When the data were stratified by APOE*4 status, no significant difference was seen either between cases and controls. These data suggest that the Cat D and IL-6 polymorphisms do not significantly alter the risk of AD in our case-control cohort.

Apolipoprotein E polymorphism and Alzheimer disease: The Indo-US Cross-National Dementia Study

BACKGROUND

The APOE*E4 allele of the gene for apolipoprotein E (APOE) has been reported as a risk factor for Alzheimer disease (AD) to varying degrees in different ethnic groups.

OBJECTIVE

To compare APOE*E4-AD epidemiological associations in India and the United States in a cross-national epidemiological study.

DESIGN

Case-control design within 2 cohort studies, using standardized cognitive screening and clinical evaluation to identify AD and other dementias and polymerase chain reaction to identify APOE genotyping.

PARTICIPANTS

Rural community samples, aged 55 years or older (n=4450) in Ballabgarh, India, and 70 years or older (n=886) in the Monongahela Valley region of southwestern Pennsylvania.

MAIN OUTCOME MEASURES

Criteria of the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association for probable and possible AD and Clinical Dementia Rating (CDR) scale for dementia staging.

RESULTS

Frequency of APOE*E4 was significantly lower (P<.001) in Ballabgarh vs the Monongahela Valley (0.07 vs 0.11). Frequency of probable or possible AD, with CDR of at least 1.0, in the Indian vs US samples, was as follows: aged 55 to 69 years, 0.1% (Indian sample only); aged 70 to 79 years, 0.7% vs 3.1%; aged 80 years or older, 4.0% vs 15.7%. Among those aged 70 years or older, adjusted odds ratios (95% confidence interval) for AD among carriers of APOE*E4 vs noncarriers were 3.4 (1.2-9.3) and 2.3 (1.3-4.0) in the Indian and US samples, respectively, and not significantly different between cohorts (P=. 20).

CONCLUSION

This first report of APOE*E4 and AD from the Indian subcontinent shows very low prevalence of AD in Ballabgarh, India, but association of APOE*E4 with AD at similar strength in Indian and US samples. Arch Neurol. 2000.

Analysis of genetic polymorphisms in the transforming growth factor-beta1 gene and the risk of Alzheimer's disease

Alzheimer's disease (AD) is a complex disease involving several genetic and environmental components. Genetic studies have yet to identify all the genes involved in the pathogenesis of AD. Transforming growth factor-beta1 (TGF-beta1) is a candidate gene for AD. It is a multifunctional cytokine whose overexpression has been shown to promote the deposition of amyloid-beta peptide. The goal of this study was to investigate the association of three polymorphisms in TGF-beta1 with the risk of AD. Two of the polymorphisms are located in the 5' region at positions -800 (G-->A) and -509 (C-->T), and the third is in exon 5 at codon 263 (Thr-->Ile). We screened DNA samples from 428 sporadic, late-onset patients and 421 controls by PCR-based assays. There was no statistically significant difference in genotype or allele frequency distributions between cases and controls for the -800 or codon 263 polymorphisms (P=0.38 and P=0.60, respectively). The overall genotype distribution at the -509 site was significantly different between cases and controls. (P=0.017). The frequency of the -509/TT genotype was significantly higher in AD patients than controls (P=0.015). We further tested whether this polymorphism may alter the regulation of the TGF-beta1 gene using dual luciferase reporter assay. We subcloned the 5' flanking region, which contained the -509 C/T polymorphic sites, in front of the firefly luciferase reporter gene in pGL-3 basic vector and co-transfected with the pRL-CMV vector containing Renilla luciferase gene as a control for transfection efficiency in COS-1 cells. The activity of each promoter allele was directly measured by the ratio of firefly luciferase activity to Renilla luciferase activity. The -509 T allele was associated with marginally higher transcriptional activity of TGF-beta compared with the -509 C allele (P=0.051). These data suggest that the -509 polymorphism of TGF-beta1 may be modestly associated with the risk of AD. However, these data should be interpreted with caution as the differences associated with the -509 alleles in both the genetic association and the transfection studies were modest.

Ten-year incidence of dementia in a rural elderly US community population: the MoVIES Project

OBJECTIVE

To determine incidence rates by age, sex, and education of overall dementia and probable/ possible AD in a largely rural community.

METHODS

Ten-year prospective study of a randomly selected community sample aged 65+; biennial cognitive screening followed by standardized clinical evaluation. Incidence rates were estimated for overall dementia (Diagnostic and Statistical Manual of Mental Disorders, 3rd ed., revised, criteria and Clinical Dementia Rating [CDR]) and for probable/possible AD (National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria).

RESULTS

The cohort consisted of 1,298 individuals free of dementia at study entry. Among these, 199 incident (new) cases of overall (all-cause) dementia with CDR stage > or = 0.5, including 110 with CDR > or = 1, were detected during follow-up. Among the incident cases, 153 (76.9%) had probable/ possible AD. Age-specific incidence rates are reported for all dementia and for probable/possible AD, by sex and CDR stage. Among all-cause dementias with CDR = 0.5, controlling for age and education, men had a higher incidence rate than women. In the same group, those with less than high school education had significantly higher incidence rates than those with more education. Rates did not vary significantly by sex or education for probable/possible AD or for dementia with CDR > or = 1.

CONCLUSIONS

Incidence rates of all dementias and of AD increased with age; men and those with lesser education had higher rates of possible/incipient dementia (CDR = 0.5) in this community. Potential explanations for these sex and education effects are discussed.

APOE 4 and hip fracture risk in a community-based study of older adults

OBJECTIVES

To investigate whether the APOE 4 allele was associated with increased risk of hip fracture in an older community-based sample and whether such an increased risk was independent of dementia and history of falling.

DESIGN

Case-control study nested within a prospective community study.

SETTING

The Monongahela Valley Independent Elders Survey (MoVIES), an ongoing prospective community study of older adults in southwestern Pennsylvania.

PARTICIPANTS

A total of 899 MoVIES participants (63.9% women; mean age, 76.2 years, SD = 4.9 years), who provided both information on hip fractures and blood samples for genotyping.

MEASUREMENTS

Interview questions regarding hip fractures and falls, polymerase chain reaction to determine APOE genotype, and clinical assessment using a standardized protocol to determine the presence or absence of dementia.

RESULTS

Twenty-five subjects reported having hip fractures in the year preceding screening interviews. Subjects with one or two APOE 4 alleles were twice as likely as subjects without an APOE 4 allele to report hip fractures (age-adjusted OR = 2.1, 95% CI: 0.9-4.7). Based on multivariate analysis, subjects with a history of falling were more likely to report hip fractures (OR = 4.7, 95% CI: 2.1-10.8). After adjusting for history of falls and diagnosis of dementia, subjects with an APOE 4 allele were still twice as likely to report hip fractures (adjusted OR = 2.1, 95% CI: 0.9 - 4.7).

CONCLUSIONS

The APOE 4 allele appears to be a risk factor for hip fracture, independent of the effect of dementia and falling. Theoretically, this may be mediated by alterations in vitamin K metabolism. Caution should be used in interpreting these results, because the 95% confidence intervals for the odds ratios include 1.

Epidemiology and diagnosis of depression in late life

Depression is a significant concern in elderly patients. Reported prevalence rates differ greatly depending on the definition of depression and the population of interest, with increases reported in settings where comorbid physical illnesses are more common. In community-dwelling elderly patients, prevalences of depressive symptoms and major depressive disorder are 15% and 1% to 3%, respectively. Factors associated with depression in the elderly include female gender, alcohol and substance abuse, pharmaceuticals, family history, and medical conditions such as stroke, Alzheimer's disease, cancer, and heart disease. Recognition of depression is complex because patients often deny their depression, present with somatic complaints, or may have comorbid anxiety or cognitive impairment. Depression is underrecognized and undertreated in the elderly, despite evidence that the benefits of treatment outweigh potential risks.

Depressive symptoms, cognitive impairment and functional impairment in a rural elderly population in India: a Hindi version of the geriatric depression scale (GDS-H)

OBJECTIVE

To measure depressive symptomatology in a largely illiterate elderly population in India, using a new Hindi version of the Geriatric Depression Scale (GDS-H), and to examine its distribution and associations with age, gender, literacy, cognitive impairment and functional impairment.

DESIGN

A Hindi version of the Geriatric Depression Scale was developed and administered to participants along with measures of demographic characteristics, cognitive functioning and functional ability.

SETTING

The rural community of Ballabgarh in northern India.

PARTICIPANTS

A community sample of 1554 mostly illiterate Hindi-speaking residents of Ballabgarh aged 55+.

MEASURES

The Hindi version of the Geriatric Depression Scale (GDS-H); the Hindi Mental State Exam (HMSE); the Everyday Abilities Scale for India (EASI); age, gender and literacy.

RESULTS

The GDS-H had high internal consistency and a factor structure comparable to the original English language version. The overall distribution of scores was higher than reported from other populations. Greater numbers of depressive symptoms, as measured by higher scores on the GDS-H, were associated with older age and illiteracy. Among the illiterate, there was no gender difference while among the literate, higher GDS-H scores were found among women. Cognitive impairment and functional disability were independently associated with higher scores on the GDS-H after adjustment for age, gender and literacy.

CONCLUSION

A reliable and valid Hindi version of the GDS has been developed. Depressive symptoms as measured by the GDS-H were prominent in this elderly illiterate northern Indian population and strongly associated with both cognitive and functional impairment.

Elders with dementia living in the community with and without caregivers: an epidemiological study

BACKGROUND

Previous studies of dementia and family caregiving have focused on individuals seeking diagnosis and treatment, and have rarely been conducted in representative community samples. Identifying demented individuals participating in a community survey, we determined (a) the factors associated with demented elderly living alone; (b) the factors associated with the demented elderly having caregivers; (c) the factors associated with increased levels of burden among caregivers of persons with dementia.

POPULATION AND METHODS

During an epidemiological survey of a mostly rural U.S. community, the authors identified 116 noninstitutionalized elderly individuals with dementia. These individuals were classified into those living alone and those living with others; both groups were further classified into those with and without identifiable family caregivers. Characteristics of both caregivers and care recipients were examined.

RESULTS

Approximately a third of the subjects with dementia lived alone, and only half of them had caregivers. The average age of the caregivers was 67.4 years, and 73% of them were women. Almost half of the caregivers were spouses, whereas almost a third were offspring, of the demented individuals. Over two thirds of caregivers lived with the subjects. Female caregivers were significantly younger than male caregivers. Multivariate analyses revealed that subjects with dementia who were living alone were independently and significantly more likely to be women and to have dementias of shorter duration, lesser severity, and lesser functional impairment than those living with others. Demented subjects with caregivers were more likely to have greater dementia severity, functional impairment, and cognitive impairment and more current cognitive and behavioral symptoms than those without caregivers. Demented subjects whose caregivers reported higher levels of burden were more likely to be women and to have greater dementia severity, functional impairment, and cognitive impairment and more current symptoms than those whose caregivers had no/minimal burden.

CONCLUSIONS

These results draw attention to the problems of persons with dementia living alone, particularly those without caregivers. Our data also provide epidemiological confirmation of previous clinical/volunteer studies of dementia caregiving, as well as a preliminary assessment of need in the community at large. Living arrangements and caregiver issues should be taken into account when planning services for the elderly.

Small head size is related to low Mini-Mental State Examination scores in a community sample of nondemented older adults

The objective of this analysis was to determine the relationship, if any, of head size to performance on a cognitive screening test among elderly nondemented adults participating in a community-based survey. The study sample included 825 subjects (533 women, 292 men), age 70 to 95 years. Multivariate analyses, with adjustment for age and education, revealed that smaller head size was associated with low Mini-Mental State Examination (MMSE) scores (i.e., below the 10th percentile) in both men and women. For every 1-centimeter increment in head size, there was a corresponding reduction of approximately 20% in the probability of a low MMSE score.

Reporting of dementia on death certificates: a community study

OBJECTIVE

To determine the extent to which conditions suggesting dementia are reported on death certificates of older adults and to identify the factors associated with reporting of dementia.

DESIGN

A prospective epidemiological study in which community-dwelling subjects with and without dementia were identified and followed until death, after which their death certificates were examined.

POPULATION

A total of 527 individuals who died during 8 years of follow-up of a population-based cohort of 1422 persons aged 65 and older at study entry.

MEASUREMENTS

Demographic; study diagnoses, including Clinical Dementia Rating (CDR) Scale stages and diagnoses of Probable and Possible Alzheimer's disease (AD) by NINCDS-ADRDA criteria; disorders listed on death certificates as immediate, underlying, or contributory causes of death.

RESULTS

Of 172 deceased subjects with study diagnoses of dementia, 30.2% had CDR = .5 and 69.8% had CDR > or = 1. Of 168 subjects in which dementia subtype could be diagnosed, Probable AD was diagnosed in 31.0% and Possible AD in 38.7%. On their death certificates, conditions indicating or suggesting dementia were reported in 23.8% of dementias overall; in 1.9% of those with CDR = .5 and 33.3% of those with CDR > or = 1; in 36.5% of those with Probable AD and 21.5% of those with Possible AD. In a multiple logistic regression model, variables associated independently with the reporting of dementia in demented individuals were: higher CDR stage of dementia (odds ratio (OR) 22.6; 95% confidence interval (CI), 2.9-174.7); likely etiology of dementia, Probable AD (OR = 3.5; CI, 1.1-10.6); and place of death, long-term care institution (OR = 3.8; 95% CI, 1.6-9.0).

CONCLUSIONS

Although Alzheimer's disease is widely regarded as a leading cause of death, dementias are reported on the death certificates of only a quarter of demented individuals in the population at large. Reporting is more likely in those with more advanced dementia, with Probable Alzheimer's disease, and those who die in long-term care institutions.

The temporal relationship between depressive symptoms and dementia: a community-based prospective study

BACKGROUND

The temporal relationship between the appearance of depressive symptoms and the clinical onset of dementia and Alzheimer disease was evaluated in a community sample.

METHODS

An original sample of 1366 subjects aged 65 years or older, selected randomly from a rural Pennsylvania community, was cognitively screened at study entry and every 2 years thereafter. A subset of 954 survivors of this cohort without dementia was screened for depressive symptoms at the second and subsequent data-collection waves. A "depression cluster" was identified by the presence of 5 or more depressive symptoms, including depressed mood, at the time of screening. Cognitively impaired subjects and a sample of unimpaired controls underwent standardized clinical evaluation to determine the presence of incident dementia (by DSM-III-R criteria) and probable or possible Alzheimer disease (by criteria of the National Institute of Neurological and Communicative Disorders and Stroke and the Alzheimer's Disease and Related Disorders Association) and to estimate the clinical onset of dementia symptoms.

RESULTS

A highly increased probability of the depression cluster developing existed among subjects following the onset of dementia (15.4% [6/39]) and Alzheimer disease (17.6% [6/34]) compared with subjects without dementia (3.2% [23/712]). The odds ratios, after adjustment for age, sex, education level, and self reported memory loss, for the development of depression were 6.5 (95% confidence interval, 2.2-19.1) in subjects with Alzheimer disease and 5.2 (95% confidence interval, 1.8-15.2) in subjects with overall dementia. Depressive symptoms did not confer a significantly increased relative risk of dementia (1.27; 95% confidence interval, 0.55-2.93) or Alzheimer disease (1.28; 95% confidence interval, 0.51-3.20).

CONCLUSION

Depressive symptoms appeared to be early manifestations, rather than predictors, of Alzheimer disease in this community sample.

Development of an activities of daily living scale to screen for dementia in an illiterate rural older population in India

OBJECTIVE

to develop a measure of activities of daily living appropriate for use in assessing the presence of dementia in illiterate rural elderly people in India.

DESIGN

identification of relevant items, pre-testing of items and refinement of administrative procedures and scoring in four successive groups of 30 subjects each, pilot testing in a group of 100 subjects comparable to those for whom the measure is intended, administration to a representative sample of 387 people aged 55 and older, and assessment of the reliability of the final measure.

SETTING AND SUBJECTS

age-stratified random sample of older men and women in rural areas of Ballabgarh, Northern India.

RESULTS

the original pool of 35 items covering mobility, instrumental and personal care activities was reduced to an 11-item unidimensional scale (to which an additional item on mobility was added) with internal consistency (Cronbach's alpha)=0.82, perfect inter- and intra-rater reliability, test-retest reliability (intraclass correlation)=0.82 (any disability) and 0.92 (unable to perform for 'mental' reasons). Women, older subjects, the totally illiterate and subjects with poorer cognitive function performed significantly more poorly (P < or = 0.02 for all). PRODUCT: a brief, reliable and valid activities of daily living measure, with norms, which is appropriate for use in assessing dementia in illiterate rural elderly people in India.

Genetic polymorphism in the persyn (gamma-synuclein) gene and the risk of Alzheimer's disease

Alzheimer's disease (AD) is a complex disease with the possible involvement of several genes. Genetic studies on sporadic late-onset AD have determined APOE*4 to be the major risk factor. Members of the synuclein gene family are potential candidates for the risk of AD. The persyn gene (gamma-synuclein) has recently been characterized and a common polymorphism (Glu110Val) has been identified. In this study we investigated the association of this polymorphism with sporadic late-onset AD patients. We screened DNA samples of 313 late-onset cases and 352 controls. No significant association was observed between the missense mutation and AD. When the data were stratified by APOE*4 carriers and non-APOE*4 carriers, no difference was seen for the Glu110Val polymorphism. There was also no difference in genotype or allele frequency when stratified by the ACT*A allele. Although our data show no effect of this persyn polymorphism in AD, characterization of additional polymorphisms in this gene may provide more conclusive answers.

A follow-up comparison of study participants and refusers within a rural elderly population

BACKGROUND

Survey rates are known to decline with age. Survey results can be affected by response bias if nonresponders are more, or less, likely than participants to suffer from the condition being studied. For instance, it is possible that older adults with dementia would be less likely to participate in a study of dementing disorders.

METHODS

A random sample of a rural U.S. population aged 65+ years yielded 1,422 participants and 912 refusers in addition to others who were ineligible, inaccessible, or untestable. Participants and refusers were compared on age, sex, 5-year mortality, and causes of death suggestive of dementia as listed on death certificates.

RESULTS

Compared to participants, refusers were significantly older and more likely to be women, with mortality similar to that of participants at approximately 5-year follow-up. Death certificate data revealed no significant differences in reported causes of death indicating or suggesting dementia.

CONCLUSIONS

In this population, those who refused to participate in a dementia survey were not more likely to be ill or demented than those who did participate.

Practical issues in cognitive screening of elderly illiterate populations in developing countries. The Indo-US Cross-National Dementia Epidemiology Study

The study of the epidemiology of dementia, specifically Alzheimer's disease, in developing countries requires specialized instruments and personnel. Cultural and sub-cultural differences among populations are highly relevant to the design of such instruments. Over and above the cultural issues, it is widely recognized that low education and illiteracy pose considerable challenges to reliable and valid cognitive screening. The overall objectives of the Indo-US Cross-National Dementia Epidemiology Study were: a) to determine the prevalence and incidence of, and risk factors for, Alzheimer's and other dementias in a defined Indian community; and b) to compare these results with those found in a defined American community. To achieve these epidemiological objectives, our first task was to develop, systematically and empirically, suitable cognitive and activities assessment screening instruments for use in India, which would 1) be culturally fair, psychometrically sound, and valid for a population with little or no education; 2) be optimally sensitive and specific for dementia; and 3) allow not only the identification but also the more detailed characterization of dementia, and of normal and abnormal cognitive aging. In this paper we address the practical issues involved in the development and administration of the modified cognitive screening battery in our rural Indian context.

Prevalence of Alzheimer's disease and other dementias in rural India: the Indo-US study

OBJECTIVE

To determine the prevalence of AD and other dementias in a rural elderly Hindi-speaking population in Ballabgarh in northern India.

DESIGN

The authors performed a community survey of a cohort of 5,126 individuals aged 55 years and older, 73.3% of whom were illiterate. Hindi cognitive and functional screening instruments, developed for and validated in this population, were used to screen the cohort. A total of 536 subjects (10.5%) who met operational criteria for cognitive and functional impairment and a random sample of 270 unimpaired control subjects (5.3%) underwent standardized clinical assessment for dementia using the Diagnostic and Statistical Manual of Mental Disorders-fourth edition diagnostic criteria, the Clinical Dementia Rating Scale (CDR), and National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) criteria for probable and possible AD.

RESULTS

We found an overall prevalence rate of 0.84% (95% CI, 0.61 to 1.13) for all dementias with a CDR score of at least 0.5 in the population aged 55 years and older, and an overall prevalence rate of 1.36% (95% CI, 0.96 to 1.88) in the population aged 65 years and older. The overall prevalence rate for AD was 0.62% (95% CI, 0.43 to 0.88) in the population aged 55+ and 1.07% (95% CI, 0.72 to 1.53) in the population aged 65+. Greater age was associated significantly with higher prevalence of both AD and all dementias, but neither gender nor literacy was associated with prevalence.

CONCLUSIONS

In this population, the prevalence of AD and other dementias was low, increased with age, and was not associated with gender or literacy. Possible explanations include low overall life expectancy, short survival with the disease, and low age-specific incidence potentially due to differences in the underlying distribution of risk and protective factors compared with populations with higher prevalence.

Neurologic factors associated with cognitive impairment in a rural elderly population in India: the Indo-US Cross-National Dementia Epidemiology Study

Few reports exist of cognitive impairment and associated factors in developing countries. An age-stratified random sample of 388 men and women, 55 years and older, was drawn from a community-based population in the rural area of Ballabgarh in northern India. We classified as "cognitively impaired" those subjects who had scores below the 10th percentile of the population on a general mental status test (the Hindi Mental State Exam, HMSE) and, separately, on a memory test (Delayed Recall of a 10-Item Word List, DRWL). Three hundred seventy-six subjects also underwent a standardized neurologic history and examination. Neurologic factors associated with cognitive impairment, after adjusting for age, gender, and literacy, were history of impaired consciousness and findings of gait disturbance, diminished deep tendon reflexes, and the presence of at least one primitive reflex. We speculate that there may be unique risk factors in developing countries such as nutritional deficiencies leading to focal deficits and cognitive impairment.