Cognitive decline after hospitalization in a community population of older persons.

OBJECTIVE: To test the hypothesis that hospitalization in old age is associated with subsequent cognitive decline. METHODS: As part of a longitudinal population-based cohort study, 1,870 older residents of an urban community were interviewed at 3-year intervals for up to 12 years. The interview included a set of brief cognitive tests from which measures of global cognition, episodic memory, and executive function were derived. Information about hospitalization during the observation period was obtained from Medicare records. RESULTS: During a mean of 9.3 years, 1,335 of 1,870 persons (71.4%) were hospitalized at least once. In a mixed-effects model adjusted for age, sex, race, and education, the global cognitive score declined a mean of 0.031 unit per year before the first hospitalization compared with 0.075 unit per year thereafter, a more than 2.4-fold increase. The posthospital acceleration in cognitive decline was also evident on measures of episodic memory (3.3-fold increase) and executive function (1.7-fold increase). The rate of cognitive decline after hospitalization was not related to the level of cognitive function at study entry (r = 0.01, p = 0.88) but was moderately correlated with rate of cognitive decline before hospitalization (r = 0.55, p = 0.021). More severe illness, longer hospital stay, and older age were each associated with faster cognitive decline after hospitalization but did not eliminate the effect of hospitalization. CONCLUSION: In old age, cognitive functioning tends to decline substantially after hospitalization even after controlling for illness severity and prehospital cognitive decline.

Educational attainment and cognitive decline in old age.

BACKGROUND: Level of education is a well-established risk factor for Alzheimer disease but its relation to cognitive decline, the principal clinical manifestation of the disease, is uncertain. METHODS: More than 6,000 older residents of a community on the south side of Chicago were interviewed at approximately 3-year intervals for up to 14 years. The interview included administration of four brief tests of cognitive function from which a previously established composite measure of global cognition was derived. We estimated the associations of education with baseline level of cognition and rate of cognitive change in a series of mixed-effects models. RESULTS: In an initial analysis, higher level of education was related to higher level of cognition at baseline, but there was no linear association between education and rate of change in cognitive function. In a subsequent analysis with terms to allow for nonlinearity in education and its relation to cognitive decline, rate of cognitive decline at average or high levels of education was slightly increased during earlier years of follow-up but slightly decreased in later years in comparison to low levels of education. Findings were similar among black and white participants. Cognitive performance improved with repeated test administration, but there was no evidence that retest effects were related to education or attenuated education's association with cognitive change. CONCLUSIONS: The results suggest that education is robustly associated with level of cognitive function but not with rate of cognitive decline and that the former association primarily accounts for education's correlation with risk of dementia in old age.

Relation of cognitive activity to risk of developing Alzheimer disease.

BACKGROUND: Frequent cognitive activity in old age has been associated with reduced risk of Alzheimer disease (AD), but the basis of the association is uncertain. METHODS: More than 700 old people underwent annual clinical evaluations for up to 5 years. At baseline, they rated current and past frequency of cognitive activity with the current activity measure administered annually thereafter. Those who died underwent a uniform postmortem examination of the brain. Amyloid burden, density of tangles, and presence of Lewy bodies were assessed in eight brain regions and the number of chronic cerebral infarctions was noted. RESULTS: During follow-up, 90 people developed AD. More frequent participation in cognitive activity was associated with reduced incidence of AD (HR = 0.58; 95% CI: 0.44, 0.77); a cognitively inactive person (score = 2.2, 10th percentile) was 2.6 times more likely to develop AD than a cognitively active person (score = 4.0, 90th percentile). The association remained after controlling for past cognitive activity, lifespan socioeconomic status, current social and physical activity, and low baseline cognitive function. Frequent cognitive activity was also associated with reduced incidence of mild cognitive impairment and less rapid decline in cognitive function. Among 102 persons who died and had a brain autopsy, neither global nor regionally specific measures of neuropathology were related to level of cognitive activity before the study, at study onset, or during the course of the study. CONCLUSION: Level of cognitively stimulating activity in old age is related to risk of developing dementia.

Socioeconomic characteristics of the community in childhood and cognition in old age.

We examined the relation of early life socioeconomic circumstances to cognition in older residents of a biracial urban community. Participants had brief cognitive testing three times at approximately 3-year intervals. At baseline, information about early life household and county socioeconomic level was collected. In mixed-effects models adjusted for age, sex, race, and education, both early life household and county socioeconomic levels were positively associated with baseline level of cognition but unrelated to cognitive decline. The results suggest that socioeconomic conditions in early life are associated with level of cognitive function in old age but not with rate of cognitive decline.

Dietary niacin and the risk of incident Alzheimer's disease and of cognitive decline.

BACKGROUND: Dementia can be caused by severe niacin insufficiency, but it is unknown whether variation in intake of niacin in the usual diet is linked to neurodegenerative decline. We examined whether dietary intake of niacin was associated with incident Alzheimer's disease (AD) and cognitive decline in a large, prospective study. METHODS: This study was conducted in 1993-2002 in a geographically defined Chicago community of 6158 residents aged 65 years and older. Nutrient intake was determined by food frequency questionnaire. Four cognitive tests were administered to all study participants at 3 year intervals in a 6 year follow up. A total of 3718 participants had dietary data and at least two cognitive assessments for analyses of cognitive change over a median 5.5 years. Clinical evaluations were performed on a stratified random sample of 815 participants initially unaffected by AD, and 131 participants were diagnosed with 4 year incident AD by standardised criteria. RESULTS: Energy adjusted niacin intake had a protective effect on development of AD and cognitive decline. In a logistic regression model, relative risks (95% confidence intervals) for incident AD from lowest to highest quintiles of total niacin intake were: 1.0 (referent) 0.3 (0.1 to 0.6), 0.3 (0.1 to 0.7), 0.6 (0.3 to 1.3), and 0.3 (0.1 to 0.7) adjusted for age, sex, race, education, and ApoE e4 status. Niacin intake from foods was also inversely associated with AD (p for linear trend = 0.002 in the adjusted model). In an adjusted random effects model, higher food intake of niacin was associated with a slower annual rate of cognitive decline, by 0.019 standardised units (SU) per natural log increase in intake (mg) (p = 0.05). Stronger associations were observed in analyses that excluded participants with a history of cardiovascular disease (beta = 0.028 SU/year; p = 0.008), those with low baseline cognitive scores (beta = 0.023 SU/year; p = 0.02), or those with fewer than 12 years' education (beta = 0.035 SU/year; p = 0.002) CONCLUSION: Dietary niacin may protect against AD and age related cognitive decline.

Blood pressure and late-life cognitive function change: a biracial longitudinal population study.

OBJECTIVE: To examine the relation of blood pressure (BP) to subsequent decline in cognitive function among persons age 65 or over. METHODS: All persons age 65 or over in a geographically defined community were invited to participate in a longitudinal study of problems of the elderly. Interviews were conducted in the participants' homes and included two BP measures and four tests of cognitive function. Follow-up interviews 3 and 6 years after baseline repeated the cognitive function tests. These analyses included 4,284 individuals who had baseline and at least one follow-up measure of cognitive function. The average of z scores of the individual cognitive function tests was used as a global measure of cognitive function. RESULTS: In random effects analyses controlling for age, sex, education, and race, there was no significant linear association of either systolic or diastolic BP with 6-year change in global cognitive function score. There was no significant curvilinear association with systolic BP. In tests for a curvilinear association with diastolic BP, there was a suggestion of increased decline among those with low or high diastolic BP (p = 0.03 for the quadratic diastolic term). At baseline, 50% of participants took some type of medication affecting BP. CONCLUSION: In this community population where BP treatment was common, there was no association of either high systolic or high diastolic BP at the beginning of the observation interval with 6-year cognitive decline.

Annual incidence of Alzheimer disease in the United States projected to the years 2000 through 2050.

Alzheimer disease will affect increasing numbers of people as baby boomers (persons born between 1946 and 1964) age. This work reports projections of the incidence of Alzheimer disease(AD) that will occur among older Americans in the future. Education adjusted age-specific incidence rates of clinically diagnosed probable AD were obtained from stratified random samples of residents 65 years of age and older in a geographically defined community. These rates were applied to U.S. Census Bureau projections of the total U.S. population by age and sex to estimate the number of people newly affected each year. The annual number of incident cases is expected to more than double by the midpoint of the twenty-first century: from 377,000 (95% confidence interval = 159,000-595,000) in 1995 to 959,000 (95% confidence interval = 140,000-1,778,000) in 2050. The proportion of new onset cases who are age 85 or older will increase from 40% in 1995 to 62% in 2050 when the youngest of the baby boomers will attain that age. Without progress in preventing or delaying onset of Alzheimer disease, both the number of people with Alzheimer disease and the proportion of the total population affected will increase substantially.

Association of incident Alzheimer disease and blood pressure measured from 13 years before to 2 years after diagnosis in a large community study.

BACKGROUND: It is uncertain whether high blood pressure increases the risk of developing Alzheimer disease (AD). OBJECTIVE: To examine the association between incident AD and blood pressure measured up to 13 years before diagnosis. DESIGN: Longitudinal cohort study conducted from 1982 to 1988, with blood pressure measured every 3 years in home interviews, and in 1973 for a portion (60%) of the sample. SETTING: Community of East Boston, Mass. PARTICIPANTS: Six hundred thirty-four subjects 65 years or older and without AD were selected as a stratified random sample of participants of the East Boston Established Populations for Epidemiologic Studies of the Elderly. MAIN OUTCOME MEASURE: Alzheimer disease was diagnosed by a neurologist using a structured clinical evaluation. RESULTS: High blood pressure was not associated with an increased risk of AD in logistic regression models adjusted for age, sex, and level of education. There was no association with systolic pressure measured 13 years before diagnosis (odds ratio = 1.03/10 mm Hg; 95% confidence interval, 0.80-1.32) and an inverse association with systolic pressure measured 4 years before diagnosis (odds ratio = 0.82/10 mm Hg; 95% confidence interval, 0.72-0.95). Associations for diastolic pressure were in the same direction as those for systolic pressure except with wider confidence intervals. The odds ratios were not materially different with further adjustment for cardiovascular risk factors and diseases. CONCLUSION: In this large community study, high blood pressure was not associated with an increased risk of AD.

Is the risk of developing Alzheimer's disease greater for women than for men?

A large proportion of people with Alzheimer's disease (AD) are women; however, it is not clear whether this is due to higher risk of disease or solely to the larger number of women alive at ages when AD is common. Beginning in 1982, two stratified random samples of people aged > or =65 years in East Boston, Massachusetts underwent detailed, structured clinical evaluation for prevalent (467 people) and incident (642 people from a cohort previously ascertained to be disease-free) probable AD. The prevalence sample was followed for mortality for up to 11 years (through December 1992). The age-specific incidence of AD did not differ significantly by sex (for men vs. women, odds ratio = 0.92; 95% confidence interval (CI): 0.51, 1.67). Controlled for age, prevalence also did not differ significantly by sex (for men vs. women, odds ratio = 1.29; 95% CI: 0.67, 2.48). The increase in risk of mortality due to AD did not vary by sex. The odds ratio for women with AD compared with women without AD was 2.07 (95% CI: 1.21, 3.56). For men, the odds ratio was 2.22 (95% CI: 1.02, 4.81). These findings suggest that the excess number of women with AD is due to the longer life expectancy of women rather than sex-specific risk factors for the disease.

Comparison of informal caregiving by black and white older adults in a community population.

OBJECTIVES: To examine the prevalence of informal caregiving and demographic factors associated with caregiving time in older community residents and compare caregiving prevalence and time spent providing care by black and white residents. DESIGN: A cross-sectional, population-based study. SETTING: The study was conducted as part of the Chicago Health and Aging Project (CHAP) in a geographically defined community of black and white residents aged 65 and older. PARTICIPANTS: Participants were 5,924 community residents (61.4% black; 38.6% white) who answered questions about informal caregiving responsibilities during a structured interview about a broad range of health and social factors. METHODS: Data were collected during an in-home interview. Multiple logistic and linear regression models were used to examine the association between caregiving and race, gender, age, marital status, and education. RESULTS: More than 16% of residents had provided care to others during the previous 12 months, and 10.3% were currently providing care. Compared with whites, blacks were 30% more likely to be caregivers, spent almost 13 more hours each week in caregiving activities, and were more likely to assist friends. The probability of caregiving increased significantly with age for married persons, decreased with age for unmarried persons, and was lower for men compared with women. The time spent providing care each week increased significantly with age for married persons and did not differ between men and women. CONCLUSIONS: Although physicians and other healthcare providers typically view older people as the recipients of informal care, individuals older than age 65 provide a substantial amount of care to others with health problems and disability. Most research has focused on the needs of young and middle-aged caregivers, and little is known about the needs of these older caregivers. Future research should use sampling strategies that provide adequate numbers of white and non-white participants for meaningful comparisons. This will permit identification of racial and cultural differences in caregiving so that interventions can be tailored to specific groups.

Decline of language among women and men with Alzheimer's disease.

Previous research raises the possibility that gender differences occur in language function in Alzheimer's disease, but this hypothesis has not been evaluated systematically in longitudinal studies. The authors examined the association of gender with rate of decline in language and other cognitive functions among 410 persons with Alzheimer's disease. Participants were recruited from a dementia clinic and followed for up to 5 annual evaluations. Follow-up participation among survivors exceeded 90%. Decline in a composite score based on 8 language tests was evaluated in random effects models with age, education, and race controlled. Annual decline was 0.71 standard units (95% confidence interval [CI] = 0.62-0.79) for women and 0.74 units (95% CI = 0.61-0.86) for men, not a significant difference. Decline on the individual language tests and on composite measures of memory, perception, and global cognition also indicated no significant association with gender. These results suggest that Alzheimer's disease affects language and other cognitive functions similarly in women and men.

Late conduction defects following aortic valve replacement.

BACKGROUND AND AIM OF THE STUDY: The study aim was to determine the incidence and clinical significance of late cardiac conduction defects (CD) after aortic valve replacement (AVR). METHODS: An analysis was made of 100 consecutive cases after AVR in a prospective outpatient evaluation program. RESULTS: The perioperative (30-day) mortality rate was 5%, and incidence of perioperative pacemaker implantation 3%. Among patients, 19% had CDs before surgery; a normal ECG was present during all periods in 45% of patients. The most frequent perioperative CD was left anterior hemiblock (LAHB; n = 8), and the most frequent late CD was left bundle branch block (LBBB; n = 8). Overall, 13.7% of operative survivors with normal preoperative and perioperative ECGs developed late CDs; one patient (1%) required pacemaker implantation 82 months after AVR. A further three patients (3%) had worsening of pre-existent CDs. Late CDs occurred over a wide time range (3 to 102 months) after surgery. CONCLUSION: There is an important incidence of CDs that occur late after AVR, even if the perioperative ECGs are normal; however, a need for late pacemaker implantation is rare. As CDs may occur at any time after surgery, regular follow up with precise evaluation of ECGs is called for.

The cross-sectional association between blood pressure and Alzheimer's disease in a biracial community population of older persons.

BACKGROUND: The relation of blood pressure to Alzheimer's disease (AD) is complex because both an association of high blood pressure with increased risk of the disease and lower blood pressure as a consequence of the disease are possible. METHODS: We examined the cross-sectional association of blood pressure and AD in the Chicago Health and Aging Project (CHAP), a study of a geographically defined, biracial community. After in-home interviews with 6.162 residents > or =65 years, a stratified random sample of 729 participants was clinically evaluated; 709 had blood pressures measured, and 243 were diagnosed with AD. RESULTS: In logistic regression models adjusted for age, sex, education, and race there was no association between blood pressure measured as a continuous variable and Alzheimer's disease. In categorical analyses, however, prevalence of Alzheimer's disease was significantly higher among persons with low systolic pressure (<130 mmHg) compared with the referent group of 130-139 mmHg (odds ratio [OR] = 2.2, 95% confidence interval [CI]: 1.2,4.1), and with low diastolic pressure (<70 mmHg) compared to the referent of 70-79 mmHg (OR = 1.8, 95% CI: I. 1,3.1). High systolic and diastolic categories were not statistically different from the referent group, although there was some evidence that the associations differed by race. The odds ratios changed little with further adjustment for apolipoprotein E genotype, antihypertensive medications, body mass, stroke, diabetes, and heart disease. CONCLUSION: These findings are consistent with previous studies showing associations between low blood pressure and AD, but longitudinal studies are needed to characterize cause-and-effect associations.

Cognitive activity in older persons from a geographically defined population.

Patterns of cognitive activity, and their relation to cognitive function, were examined in a geographically defined, biracial population of persons aged 65 years and older. Persons (N = 6,162) were given cognitive performance tests and interviewed about their participation in common cognitive activities, like reading a newspaper. Overall, more frequent participation in cognitive activities was associated with younger age, more education, higher family income, female gender, and White race; participation in activities judged to be more cognitively intense was not strongly related to age, but was associated with more education, higher family income, male gender, and White race. Substantial heterogeneity in activity patterns remained after accounting for demographic factors, however. In an analysis controlling for demographic variables, level of cognitive function on performance tests was positively related to composite measures of the frequency and intensity of cognitive activity. Longitudinal studies are needed to assess the relation of cognitive activity patterns to stability and change in cognitive function in older persons.

Current and remote blood pressure and cognitive decline.

CONTEXT: Previous studies raise the possibility that blood pressure (BP) in middle age predicts later cognitive decline. OBJECTIVE: To examine prospectively the relationship of BP with level of and change in cognitive function in the elderly. DESIGN: Longitudinal, population-based study comprising subjects enrolled in the East Boston component of the Established Populations for the Epidemiologic Study of the Elderly (EPESE) (1982-1983) and the Hypertension Detection and Follow-Up Program (HDFP) (1973-1974). SETTING: East Boston, Mass. PARTICIPANTS: Of the 3657 participants in the EPESE with baseline BP measurements, 2068 also participated in the HDFP. Subjects were aged 65 to 102 years at baseline in the EPESE and had mental status and memory assessed at baseline and 3 and 6 years. MAIN OUTCOME MEASURES: Numbers of errors on the Short Portable Mental Status Questionnaire and the East Boston Memory Test and rates of change in these numbers of errors. Subjects had BP measured both at baseline in the EPESE and 9 years before, as part of the HDFP. RESULTS: In analyses adjusted for age, sex, and education, there was no strong linear association between BP and cognition. The associations found were fairly small in magnitude, and varied according to which test was used to measure cognition. There was little evidence for an effect of BP on change in cognitive function with either test, or for an effect on level of function on the memory test. In analyses of level of mental status questionnaire performance, however, elevated systolic BP (> or =160 mm Hg) 9 years before baseline was associated with a 14% (95% confidence interval [CI], 4%-25%) increase in error rate, relative to the referent (130-139 mm Hg). Baseline systolic BP had a U-shaped association with the number of errors; error rates were 9% higher compared with the referent group among those with systolic BP lower than 130 mm Hg (95% CI, 1%-17%) and 7% greater (95% CI, 0%-15%) among those with elevated systolic BP. Diastolic BP 9 years before baseline also had a U-shaped association with errors on the mental status questionnaire. CONCLUSION: The findings do not suggest a linear association of BP with cognitive decline, but they are consistent with a more complex relationship between BP and cognition than previously appreciated.

Vitamin E and vitamin C supplement use and risk of incident Alzheimer disease.

Oxidative stress may play a role in neurologic disease. The present study examined the relation between use of vitamin E and vitamin C and incident Alzheimer disease in a prospective study of 633 persons 65 years and older. A stratified random sample was selected from a disease-free population. At baseline, all vitamin supplements taken in the previous 2 weeks were identified by direct inspection. After an average follow-up period of 4.3 years, 91 of the sample participants with vitamin information met accepted criteria for the clinical diagnosis of Alzheimer disease. None of the 27 vitamin E supplement users had Alzheimer disease compared with 3.9 predicted based on the crude observed incidence among nonusers (p = 0.04) and 2.5 predicted based on age, sex, years of education, and length of follow-up interval (p = 0.23). None of the 23 vitamin C supplement users had Alzheimer disease compared with 3.3 predicted based on the crude observed incidence among nonusers (p = 0.10) and 3.2 predicted adjusted for age, sex, education, and follow-up interval (p = 0.04). There was no relation between Alzheimer disease and use of multivitamins. These data suggest that use of the higher-dose vitamin E and vitamin C supplements may lower the risk of Alzheimer disease.

Accuracy of survey questions for geriatric urinary incontinence.

PURPOSE: Risk factors, natural history, consequences, therapeutic responses and costs are all likely related to type of urinary incontinence, for example stress or urge. Yet few epidemiologic type specific data are available and only 1 study has been validated urodynamically. We compare the accuracy of a typical questionnaire used in a large epidemiologic study with the criterion standard of multichannel video urodynamic testing. MATERIALS AND METHODS: The questionnaire was administered before urodynamic testing to 132 subjects 65 years old or older, of whom 80% were women, all were mobile and none was severely demented. Responses to questionnaire items were compared to the criterion standard, singly and in combination, using a total of 4 a priori and post hoc strategies, including a computerized regression tree program. RESULTS: Overall, no analytic strategy correctly classified more than 67% of patients and none accurately classified even a single type of incontinence, including stress incontinence. CONCLUSIONS: Short questionnaires commonly used in epidemiologic studies correlated poorly with video urodynamic testing in incontinent older adults. Previously published information regarding prevalence of the types of incontinence should be reviewed in the light of these data.

Screening for cognitive impairment in general practice: toward a consensus.

We considered whether general practitioners should examine all older patients over a certain age for cognitive impairment in screening for early dementia. We invited presentations from key experts, selectively reviewed the literature, and developed a consensus statement. The efficacy of and benefits from unselective use of cognitive testing and informant questionnaires for detecting early dementia in older patients attending general practice are limited. Positive predictive values of cognitive screening for dementia are less than 50%, even for older patient populations. Higher values may be obtained by testing patients who have a relevant history of cognitive or functional decline. Whatever procedures are adopted for screening older general practice attenders for cognitive impairment or early dementia, investigation is still required into the relative merits of different health professionals performing the screening, the positive and negative effects on patients and their families, and the cost-benefit ratio. The majority view of workshop participants was that cognitive testing should occur for older patients when there is a reason to suspect dementia. Testing may occur in an individual considered to be at risk because of an informant history of cognitive or functional decline, clinical observation, or, sometimes, very old age. No single instrument for cognitive screening is suitable for global use. Screening programs must be supported by training and supplemented by education for professionals and families in management of dementia.

Education and other measures of socioeconomic status and risk of incident Alzheimer disease in a defined population of older persons.

OBJECTIVE: To assess the relations of 3 measures of socioeconomic status (education, occupational prestige, and income) to risk of incident clinically diagnosed Alzheimer disease (AD). DESIGN: Cohort study with an average observation of 4.3 years. SETTING: East Boston, Mass. a geographically defined community. PARTICIPANTS: A stratified random sample of 642 community residents 65 years of age and older who were free of AD at baseline. MAIN OUTCOME MEASURE: Clinical diagnosis of probable AD according to standard criteria, using structured uniform evaluation. RESULTS: The relations of the 3 measures of socioeconomic status to risk of disease were assessed using logistic regression analyses. In individual analyses, fewer years of formal schooling, lower income, and lower occupational status each predicted risk of incident AD; risk of disease decreased by approximately 17% for each year of education. In an analysis including all 3 measures, the effect of education on risk for disease remained approximately the same, but the effects of the other 2 measures were somewhat less and did not attain formal statistical significance, compared with separate analysis of each measure. CONCLUSIONS: Markers of lower socioeconomic status predict risk of developing incident AD. The mechanism of this relation is uncertain, but the possibility that it reflects unidentified and potentially reversible risk factors for the disease deserves careful investigation.