Biomedical subjects

Robert S Wilson

Publications and source records attributed to Robert S Wilson.

At least 19 recordsLinked to original sources

PubMed2007

Change in motor function and risk of mortality in older persons.

OBJECTIVES: To assess the association between change in motor function and mortality. DESIGN: Prospective, observational cohort study. SETTING: Approximately 40 retirement communities across the Chicago metropolitan area participating in the Rush Memory and Aging Project. PARTICIPANTS: Eight hundred thirty-seven community-based older persons without dementia. MEASUREMENTS: Change in composite measures of motor performance and muscle strength. RESULTS: During a mean follow-up of 2.2 years, 81 persons died. In a proportional hazards model adjusted for age, sex, education, and body mass index, each 1-unit increase in the level of baseline motor performance was associated with an approximately 10% decrease in risk of mortality (hazard ratio (HR)=0.901, 95% confidence interval (CI)=0.863-0.941), and each unit of annual increase in motor performance was associated with an approximately 11% decrease in the risk of mortality (HR=0.887, 95% CI=0.835-0.942). In a similar model, each 1-unit increase in the level of baseline strength was associated with an approximately 9% decrease in the risk of mortality (HR=0.906, 95% CI=0.859-0.957), and each 1-unit annual increase in strength was associated with an approximately 10% decrease in the risk of mortality (HR=0.898, 95% CI=0.809-0.996). These results were similar when men and women were analyzed separately and after controlling for physical activity, cognition, and chronic disorders. When motor performance and muscle strength were examined in a single model, only baseline and annual change in motor performance were associated with mortality. CONCLUSION: Level and rate of change in strength and motor performance are associated with mortality. The attenuation of the association between strength and mortality by motor performance suggests that motor function is not a unitary process and that its components may vary in their associations with adverse health consequences in older persons.

Aged, 80 and over↗

PubMed2006

Decision rules guiding the clinical diagnosis of Alzheimer's disease in two community-based cohort studies compared to standard practice in a clinic-based cohort study.

We developed prediction rules to guide the clinical diagnosis of Alzheimer's disease (AD) in two community-based cohort studies (the Religious Orders Study and the Rush Memory and Aging Project). The rules were implemented without informant interviews, neuroimaging, blood work or routine case conferencing. Autopsies were performed at death and the pathologic diagnosis of AD made with a modified version of the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) criteria. We compared the positive predictive value of the clinical diagnosis in the two community-based studies to the positive predictive value of the clinical diagnosis of AD made by standard clinical practice in a clinic-based cohort study using AD pathology as the gold standard. Of 306 clinic cases with probable AD, 286 (93.5%) met CERAD neuropathologic criteria for AD; the results were comparable for those with possible AD (51 of 54, 94.4%). Of 141 study subjects with probable AD, 130 (92.2%) met CERAD neuropathologic criteria for AD; the results were lower but acceptable for those with possible AD (26 of 37, 70.3%). The results were similar in secondary analyses using alternate neuropathologic criteria for AD. The clinical diagnosis of AD can be made in community-based studies without the use of informant interviews, neuroimaging, blood work or routine case conferencing. This approach holds promise for reducing the operational costs of epidemiologic studies of aging and AD.

Aged↗

PubMed2006

Association of daytime napping and Parkinsonian signs in Alzheimer's disease.

BACKGROUND AND PURPOSE: Excessive daytime sleepiness (EDS) is reported in Alzheimer's disease (AD), with unstable sleep-wake rhythms that worsen with advancing disease stage. EDS is also very common in Parkinson's disease (PD), regardless of disease severity. The purpose of this study was to determine whether more Parkinsonian motor signs exist in AD patients with more reported daytime napping compared to AD patients without daytime napping. PATIENTS AND METHODS: AD patients ((National Institute of Neurological and Communicative Diseases and Stroke/Alzheimer's Disease and Related Disorders Association) NINCDS/ADRDA criteria) were prospectively evaluated in a dementia clinic. Parkinsonian motor signs were assessed using a modified motor Unified Parkinson's Disease Rating Scale (mmUPDRS). AD patients were grouped according to daytime napping frequency: (1) minimal napping (AD-Naps), or (2) napping at least once a day (AD+Naps). Wilcoxon rank-sum tests and chi2-tests computed differences between groups for mmUPDRS, nighttime sleep disturbances, and the Mini Mental State Examination (MMSE). Statistical significance was set at P<0.05. RESULTS: AD patients were classified as AD-Naps (n=155) or AD+Naps (n=180). Compared with AD-Naps patients, AD+Naps patients had higher total mmUPDRS scores (P<0.001), higher rigidity scores (P<0.005), and more gait impairment (P<0.001). CONCLUSION: AD patients with more reported daytime napping had more Parkinsonian motor signs, suggesting that this subgroup may have an increased propensity for sleepiness resembling PD. Longitudinal studies with objective measures are needed to determine whether causal relationships exist between sleepiness and Parkinsonism in AD.

Adult↗

PubMed2006

Chronic psychological distress and risk of Alzheimer's disease in old age.

Clinical and pathological data from the Rush Memory and Aging Project were used to test the hypothesis that distress proneness is associated with increased risk of Alzheimer's disease (AD). More than 600 older persons without dementia completed a 6-item measure of neuroticism, a stable indicator of proneness to psychological distress. At annual intervals thereafter, they underwent uniform evaluations that included clinical classification of AD and administration of 18 cognitive tests. Those who died underwent brain autopsy from which composite measures of AD pathology were derived. During a mean of about 3 years of follow-up, 55 people were clinically diagnosed with AD. In analyses that controlled for age, sex, and education, persons with a high level of distress proneness (score = 24, 90th percentile) were 2.7 times more likely to develop AD than those not prone to distress (score = 6, 10th percentile). Adjustment for depressive symptomatology or frequency of cognitive, social, and physical activity did not substantially change this effect. Distress proneness was also associated with more rapid cognitive decline. Among 45 participants who died and underwent brain autopsy, distress proneness was unrelated to diverse measures of AD pathology and was inversely related to cognition after controlling for AD pathology. The results support the hypothesis that distress proneness is associated with increased risk of dementia and suggest that neurobiologic mechanisms other than AD pathology may underlie the association.

Aged↗

PubMed2006

The relation of cigarette smoking to incident Alzheimer's disease in a biracial urban community population.

The relationship between smoking status and incident Alzheimer's disease (AD) was investigated in a random stratified sample of a biracial community in Chicago. Analyses are based on 1,064 persons (of 1,134 evaluated) who had data on smoking status, disease incidence, and key covariates such as apolipoprotein allele status. During a mean of about 4 years of follow-up, 170 persons met criteria for incident AD. Current smoking was associated with increased risk of incident AD (OR = 3.4, 95% CI = 1.4-8.0) compared to persons who never smoked. There was no apparent increase in risk of AD for former smokers compared to persons who never smoked (OR = 0.9, 95% CI = 0.5-1.7). Apolipoprotein E allele status modified this association in that former smokers with a upsilon4 allele were less likely to develop AD (p = 0.04) than those who never smoked. Former smokers also appeared to have a reduced risk of developing AD as their pack-years of smoking increased (p = 0.02)such that the odds of developing AD increased by 50% for every 10 years of smoking cessation (OR = 1.3, CI = 0.9-1.7). The results suggest that older people who currently smoke are more likely to develop AD compared to those who never smoked; the relation between those who used to smoke but quit and the risk of AD is complex and requires further research.

Black or African American↗

PubMed2006

Motor dysfunction in mild cognitive impairment and the risk of incident Alzheimer disease.

BACKGROUND: Little is known about motor function in mild cognitive impairment (MCI) and its relation to the risk of Alzheimer disease (AD). OBJECTIVE: To examine motor function in persons with MCI and its relation to risk of AD. DESIGN: Longitudinal cohort study. SETTING: More than 40 Catholic religious orders across the United States. PARTICIPANTS: We studied 816 older Catholic clergy members from the Religious Orders Study. At the baseline evaluation, they were classified as having no cognitive impairment (n = 558), MCI (n = 198), or dementia (n = 60). MAIN OUTCOME MEASURES: Motor function was assessed at baseline using performance-based measures of upper and lower extremity function and a modified version of the motor section of the Unified Parkinson's Disease Rating Scale, from which previously established measures of parkinsonian signs were derived. Clinical evaluations for dementia and AD were repeated annually for up to 10 years. All analyses controlled for age, sex, educational level, and possession of at least 1 apolipoprotein E epsilon4 allele. RESULTS: At baseline, individuals with MCI had impaired motor function relative to those without cognitive impairment and superior motor function vs those with dementia. Among those with MCI, baseline levels of lower extremity motor performance, parkinsonian gait, and bradykinesia were inversely related to risk of AD, even after controlling for clinical stroke. Thus, a person with impaired lower limb performance or parkinsonian gait (10th percentile) was 2 to 3 times more likely to develop AD than a person with good lower limb function (90th percentile). CONCLUSIONS: Persons with MCI also have impaired motor function, and the degree of impairment in lower extremity function is related to the risk of AD.

Age Factors↗

PubMed2006

Dietary copper and high saturated and trans fat intakes associated with cognitive decline.

BACKGROUND: Evidence from prospective epidemiologic studies and animal models suggests that intakes of dietary fats and copper may be associated with neurodegenerative diseases. OBJECTIVE: To examine whether high dietary copper intake is associated with increased cognitive decline among persons who also consume a diet high in saturated and trans fats. DESIGN: Community-based prospective study. SETTING: Chicago, Ill. Patients Chicago residents 65 years and older. MAIN OUTCOME MEASURES: Cognitive function was assessed using 4 cognitive tests administered during in-home interviews at 3-year intervals for 6 years. Dietary assessment was performed with a food frequency questionnaire. Dietary intakes of copper and fats were related to change in global cognitive score (the mean of the 4 tests) among 3718 participants. RESULTS: Among persons whose diets were high in saturated and trans fats, higher copper intake was associated with a faster rate of cognitive decline. In multiple-adjusted mixed models, the difference in rates for persons in the highest (median, 2.75 mg/d) vs lowest (median, 0.88 mg/d) quintiles of total copper intake was -6.14 standardized units per year (P<.001) or the equivalent of 19 more years of age. There was also a marginally statistically significant association (P = .07) with the highest quintile of food intake of copper (median, 1.51 mg/d) and a strong dose-response association with higher copper dose in vitamin supplements. Copper intake was not associated with cognitive change among persons whose diets were not high in these fats. CONCLUSION: These data suggest that high dietary intake of copper in conjunction with a diet high in saturated and trans fats may be associated with accelerated cognitive decline.

Aged↗

PubMed2006

Substantia nigra tangles are related to gait impairment in older persons.

OBJECTIVE: Parkinsonian signs, especially gait impairment, are common and associated with morbidity and mortality in older persons. Our objective was to test the hypothesis that substantia nigra neurofibrillary tangles (NFTs) are related to parkinsonian signs in older persons with and without dementia. METHODS: We studied 86 deceased older Catholic clergy without idiopathic Parkinson's disease from the Religious Order Study, a longitudinal clinical-pathological study. Mean age at death was 85.3 years. Signs of gait disturbance, bradykinesia, rigidity, and tremor were assessed proximate to death using a modified Unified Parkinson's Disease Rating Scale. Forty-micrometer paraffin-embedded sections of substantia nigra were bleached before tau immunohistochemistry and the optical disector was used to count NFTs. We used multivariable linear regression to examine parkinsonian signs as a function of nigra NFTs, controlling for age, sex, education, and cortical NFTs. RESULTS: Substantia nigra NFTs were present in 67 of 86 persons (77.9%). After controlling for age, sex, education, and cortical NFTs, nigra NFTs were related to gait impairment (p < 0.001), but not bradykinesia, rigidity, or tremor. Results were not confounded by dementia, Braak score, neuroleptic medication, cerebral infarcts, or Lewy bodies. INTERPRETATION: NFTs in the substantia nigra are associated with gait impairment in older persons with and without dementia.

Aged, 80 and over↗

PubMed2006

Cognitive decline and survival in Alzheimer's disease.

OBJECTIVE: To test the association of rate of cognitive decline, an indicator of the severity of the underlying disease process, with risk of death in Alzheimer's disease (AD). METHODS: A total of 472 persons with clinically diagnosed AD were recruited from a memory disorders clinic and day care centers in the Chicago area. They completed a uniform clinical evaluation at baseline and a battery of nine cognitive tests at six-month intervals for a mean of about three years. A previously established measure of global cognition was derived from the nine tests. RESULTS: During follow-up, 168 persons (36%) died. In a proportional hazards model that controlled for age, sex, race, education, and baseline level of cognition, individual rate of global cognitive decline, estimated with least squares regression, was linearly related to mortality risk. Thus, a person declining minimally (increase of 0.04 unit per year, 90th percentile) was 2.7 times less likely to die during the study period than a person declining rapidly (decrease of 0.76 unit per year, 10th percentile). Controlling for baseline disability did not substantially affect results. The association of cognitive decline with mortality was substantially stronger for white persons compared to African Americans and in those with less compared to more education. CONCLUSION: The results indicate that the rate at which cognition declines in AD is robustly related to survival.

Adult↗

PubMed2006

The effect of social networks on the relation between Alzheimer's disease pathology and level of cognitive function in old people: a longitudinal cohort study.

BACKGROUND: Few data are available about how social networks reduce the risk of cognitive impairment in old age. We aimed to measure this effect using data from a large, longitudinal, epidemiological clinicopathological study. METHODS: 89 elderly people without known dementia participating in the Rush Memory and Aging Project underwent annual clinical evaluation. Brain autopsy was done at the time of death. Social network data were obtained by structured interview. Cognitive function tests were Z scored and averaged to yield a global and specific measure of cognitive function. Alzheimer's disease pathology was quantified as a global measure based on modified Bielschowsky silver stain. Amyloid load and the density of paired helical filament tau tangles were also quantified with antibody-specific immunostains. We used linear regression to examine the relation of disease pathology scores and social networks to level of cognitive function. FINDINGS: Cognitive function was inversely related to all measures of disease pathology, indicating lower function at more severe levels of pathology. Social network size modified the association between pathology and cognitive function (parameter estimate 0.097, SE 0.039, p=0.016, R(2)=0.295). Even at more severe levels of global disease pathology, cognitive function remained higher for participants with larger network sizes. A similar modifying association was observed with tangles (parameter estimate 0.011, SE 0.003, p=0.001, R(2)=0.454). These modifying effects were most pronounced for semantic memory and working memory. Amyloid load did not modify the relation between pathology and network size. The results were unchanged after controlling for cognitive, physical, and social activities, depressive symptoms, or number of chronic diseases. INTERPRETATION: These findings suggest that social networks modify the relation of some measures of Alzheimer's disease pathology to level of cognitive function.

Aged↗

PubMed2006

Cognitive decline in old age: separating retest effects from the effects of growing older.

Repeated administration of cognitive tests improves test performance, making it difficult for researchers to gauge the true extent of age-related cognitive decline. The authors examined this issue using data from the Rush Religious Orders Study and linear mixed-effects models. At annual intervals for up to 8 years, more than 800 older Catholic clergy members completed the same set of 19 cognitive tests from which previously established composite measures of cognitive domains were derived. Retest effects on some measures were substantial and continued to accumulate even after 8 annual test readministrations, but effects on other measures were minimal. Across cognitive measures, retest effects were not related to age, sex, or education. Individual differences in retest effects were substantial but not consistent across cognitive measures. The results suggest that retest-based improvement in cognitive test performance can be substantial and persistent.

Aged↗

PubMed2006

Is lower cognitive function in one spouse associated with depressive symptoms in the other spouse?

This study examines whether lower cognitive function in one spouse is associated with depressive symptoms in the other spouse. The subjects were 528 community-dwelling spouse pairs aged 65+ who participated in the Chicago Health and Aging Project (CHAP), an ongoing longitudinal, bi-racial, population-based study of risk factors for incident Alzheimer's disease and other age-related chronic conditions. CHAP participants were assessed at 3-year intervals over a period of nearly ten years. The results show a cross-sectional association of wives' lower cognitive function at baseline with depressive symptoms in husbands; however, husbands' cognitive function was not associated with wives' depressive symptoms. There was no longitudinal association of cognitive function at baseline with increased depressive symptoms over time. Furthermore, change in cognitive function over time had no effect on depressive symptoms in either spouse. The relationship between cognitive function and depressive symptoms in spouse pairs is complex. Our findings suggest that husbands may be particularly psychologically vulnerable to the negative effects of their wives' cognitive impairment. This vulnerability may have a range of long-term health and caregiving implications.

Activities of Daily Living↗

PubMed2006

The Word Accentuation Test - Chicago.

A reading test for Spanish speakers in the United States was developed called the Word Accentuation Test-Chicago. The construction and validation of this 40 item test was modeled after reading tests developed in Spain and Argentina, and is based on irregular accentuation of words. The Word Accentuation Test-Chicago was validated on 45 community participants using the Wechsler Adult Intelligence Scale-III in Spanish. Better reading performance was associated with higher intelligence test performance, with an additional 5% of the variation in intelligence score accounted for by reading performance after controlling for age and education. These results indicate that the Word Accentuation Test-Chicago is a psychometrically sound measure of Spanish reading ability that is robustly related to general cognitive ability.

Adult↗

PubMed2006

Personality and incident disability in older persons.

OBJECTIVE: to examine the relation of personality to the development of disability in old age. METHODS: participants are 813 older Catholic nuns, priests and brothers without dementia or disability at study onset. As part of a uniform baseline evaluation, they completed standard measures of the five principal dimensions of personality. Disability was assessed at baseline and annually thereafter with the Katz scale. The relation of each trait to incident disability was assessed in proportional hazard models controlled for age, sex, education and selected clinical variables. RESULTS: during a mean of about 6 years of observation, 255 persons (31%) became dependent on at least one activity of daily living. Risk of becoming disabled was 85% [95% confidence interval (CI) = 80.5-89.6%] lower in persons with high (90th percentile) compared to low (10th percentile) extraversion and 50% (95% CI = 46.6-54.2%) lower in those with high compared to low conscientiousness, and controlling for chronic medical conditions, depressive symptoms or social and cognitive activity did not substantially affect these associations. By contrast, neuroticism had a marginal association with disability risk that was eliminated after controlling for depressive symptomatology, and openness and agreeableness were unrelated to disability risk. CONCLUSIONS: The results suggest that higher levels of extraversion and conscientiousness may be associated with a reduced risk of incident disability in old age.

Activities of Daily Living↗

PubMed2006

Blood pressure and lower limb function in older persons.

BACKGROUND: Factors contributing to gait difficulties in elderly persons are considered to be multifactorial and are not well understood. The purpose of this study was to examine the association of blood pressure (BP) with change in lower limb function in older persons. METHODS: Eight hundred eighty-eight older Catholic clergy members without baseline dementia or Parkinson's disease were recruited from about 40 groups across the United States. At baseline, BP was measured, the presence of vascular diseases and diabetes was recorded, cognitive function was assessed, and medications were inspected. At baseline and subsequent annual visits, gait and balance were assessed using performance-based tasks from which a previously established composite measure of lower limb function was derived. RESULTS: In a general estimating equation analysis controlling for age, education, and gender, a 10 mmHg increment in systolic blood pressure (SBP) was associated with greater decline in lower limb function (estimate of interaction = -6.35 x 10(-3), standard error = 2.49 x 10(-3), p =.011). Thus, on average, lower limb function declined 28.7% faster in persons with an SBP of 160 mmHg than in persons with an SBP of 120 mmHg. This effect was unchanged after controlling for baseline vascular diseases, diabetes, or cognition. However, censoring individuals who developed stroke during the study made the relationship between SBP and change in lower limb function nonsignificant. CONCLUSIONS: SBP may be associated with decline in lower limb function in older persons.

Aged↗

PubMed2006

Childhood adversity and psychosocial adjustment in old age.

OBJECTIVE: The objective of this study was to test the hypothesis that higher level of childhood adversity is associated with lower level of psychosocial adjustment in old age. METHOD: Participants are 253 older persons (mean age: 79.8, standard deviation: 2.1; 73.9% women) from the Rush Memory and Aging Project, a clinicopathologic study of common chronic conditions of old age. Childhood adversity was assessed with a 16-item measure based on portions of the Childhood Trauma Questionnaire and other inventories. Psychosocial adjustment was assessed with multiple measures of neuroticism (i.e., proneness to negative emotions) and social engagement. RESULTS: Based in part on a factor analysis, composite measures of total adversity, emotional neglect, parental intimidation, parental violence, family turmoil, and financial need were developed. In a series of linear regression models adjusted for age, sex, own education, and parental education, the composite measure of childhood adversity was associated with all facets of neuroticism and accounted for more than 13% of the variance in the composite neuroticism measure. Emotional neglect and parental intimidation had the strongest associations with neuroticism. Childhood adversity was not related to frequency of participation in social activities, but more adversity was associated with having a smaller network (accounting for 3% of the variance) and feeling more emotionally isolated (accounting for 7% of the variance). CONCLUSION: Childhood adversity is associated with less adaptive psychosocial functioning in old age.

Aged↗

PubMed2005

Odor identification and decline in different cognitive domains in old age.

The authors examined the association of odor identification with rate of decline in different cognitive systems. Participants are 481 older persons from the Rush Memory and Aging Project. At baseline, the Brief Smell Identification Test was administered. At annual intervals for up to 3 years, a battery of 19 cognitive tests was administered from which previously established composite measures of 5 cognitive domains were derived. In mixed-effects models adjusted for age, sex, and education, lower odor identification score was associated with lower function at baseline in each cognitive domain. Lower score was also associated with more rapid decline in perceptual speed (estimate=0.015, SE=0.006, p=0.013) and episodic memory (estimate=0.012, SE=0.006, p=0.030) but not with rate of decline in semantic memory, working memory, or visuospatial ability. Thus, on average, a person with a low odor identification score (6, 10th percentile) declined more than twice as rapidly in perceptual speed and episodic memory as a person with a high score (11, 90th percentile). Results were unchanged in subsequent analyses that controlled for cigarette smoking or clinically diagnosed stroke. The results indicate that impaired odor identification in old age is associated with impaired global cognition and more rapid decline in perceptual processing speed and episodic memory.

Aged↗

PubMed2005

Change in cognitive function in Alzheimer's disease in African-American and white persons.

Few studies have examined the association of race with change in cognitive function in Alzheimer's disease (AD). We studied the rate of decline in global and specific measures of cognitive function in a cohort of 410 older African-Americans and whites with clinically diagnosed AD. Persons were examined annually for an average of 3.5 years, and follow-up participation among survivors exceeded 90%. In mixed-effects models that controlled for age, gender, education, and premorbid reading activity, African-Americans scored lower than whites at baseline on a composite measure of global cognition and on specific measures of visuoconstruction and naming. However, they experienced less rapid decline in episodic memory (p < 0.01), with similar but not quite significant effects for global cognition (p = 0.06), perceptual speed (p = 0.07) and naming (p = 0.08). The results suggest that the rate of cognitive decline in AD is slower in African-Americans compared with whites, particularly for episodic memory.

Aged↗