Interrelationships among biological markers of aging, health, activity, acculturation, and cognitive performance in late adulthood.

In this study a structural equation model of predictors of age differences in cognitive performance in late adulthood was developed. Biological markers of aging (vision, hearing, vibration sense, forced expiratory volume, and grip strength) were used as indicators of a latent variable called BioAge. A sample of 180 community-dwelling women aged 60 to 90 years was assessed. Results showed that BioAge explained all of the age-related variance in cognitive test performance. Physical health and physical activity had direct effects on BioAge. Measures of acculturation explained non-age-related variance in cognitive test performance. Some variables used as biomarkers also explained individual differences in measures of crystallized intelligence and perceptual speed. It is concluded that the association between biomarkers and cognition in old age is due to more than a common statistical association with age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive decline from estimated premorbid status predicts neurodegeneration in Alzheimer's disease.

This study investigated the relationship between premorbid and current cognitive function with respect to the clinical features of patients with various types of neurodegeneration in the form of Alzheimer's disease (AD), mild cognitive impairment (MCI), and subjective cognitive impairment (SCI), as compared with a healthy control group (C). Clinical features (MMSE, cognitive and depressive symptoms), genetics (apolipoprotein E; APOE) and measures of neurodegeneration (Aβ42, t-tau, and p-tau) were examined, as well as present cognitive function. Various methods of assessing premorbid cognitive function were compared, including a Swedish NART-analogous test (Irregularly Spelled Words; ISW), a Swedish lexical decision test (SLDT), a Hold test (Information in WAIS-R), Best current performance test, and combined demographic characteristics. Results showed that cognitive decline (premorbid minus current cognitive function) based on SLDT and ISW was a significant predictor for MMSE and Aβ42, whereas corresponding associations for present cognitive function and decline measures based on other methods were less powerful. Results also showed that specific verbal abilities (e.g., SLDT and ISW) were insensitive to AD and that these abilities indicated premorbid cognitive function in retrospect. In conclusion, cognitive decline from premorbid status reflects the disease processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Strength in the lower limbs, visual contrast sensitivity, and simple reaction time predict cognition in older women.

The authors investigated the association between sensorimotor variables indicative of biological aging and cognition. A community sample of 202 women ages 60–86 was assessed on 5 measures of lower limb strength, visual contrast sensitivity (VCS), and reaction time (RT). Hierarchical multiple regression revealed that the sensorimotor variables explained age-related variance in measures of reasoning and total variance in measures of reasoning after education, health, mood, and physical activity were controlled for. It is concluded that in addition to better known predictors of cognitive aging, such as RT and VCS, lower limb strength is an important predictor of performance on cognitive tests. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit category learning performance predicts rate of cognitive decline in nondemented patients with Parkinson's disease.

Nondemented patients with Parkinson's disease (PD) are impaired in learning to categorize simple perceptual stimuli when category membership is defined by a nonlinear relationship between stimulus dimensions but not when the relationship is linear (J. V. Filoteo, W. T. Maddox, D. P. Salmon, & D. D. Song, 2005). In the present study, the authors examined whether performance in either of these 2 category learning conditions was predictive of global cognitive decline following a mean of 1.6 years since the time patients were 1st seen. Results indicated that final block accuracy in the nonlinear condition, but not the linear condition, predicted global cognitive decline. Performance on the Wisconsin Card Sorting Test (WCST) did not significantly predict global cognitive decline, although there was a trend for this to be the case. In addition, the association between nonlinear category learning and global cognitive decline was not impacted by patients' performance on the WCST. Results suggest that nonlinear category learning predicts cognitive decline in nondemented patients with PD and that nonlinear category learning and WCST performances may provide independent measures of integrity of the posterior and anterior caudate, respectively. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Different cognitive profiles for single compared with recurrent fallers without dementia.

Relationships between self-reported retrospective falls and cognitive measures (executive function, reaction time [RT], processing speed, working memory, visual attention) were examined in a population based sample of older adults (n = 658). Two of the choice RT tests involved inhibiting responses to either targets of a specific color or location with hand and foot responses. Potentially confounding demographic variables, medical conditions, and postural sway were controlled for in logistic regression models, excluding participants with possible cognitive impairment. A factor analysis of cognitive measures extracted factors measuring RT, accuracy and inhibition, and visual search. Single fallers did not differ from nonfallers in terms of health, sway or cognitive function, except that they performed worse on accuracy and inhibition. In contrast, recurrent fallers performed worse than nonfallers on all measures. Results suggest that occasional falls in late life may be associated with subtle age-related changes in the prefrontal cortex leading to failures of executive control, whereas recurrent falling may result from more advanced brain ageing that is associated with generalized cognitive decline. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Relationships between hearing loss and cognition in normally hearing aged persons

The relationships between mild hearing losses and cognitive functioning were studied for two independently selected samples of aged subjects whose hearing was within normal limits. One group had 47 males of mean age 71.5 (SD 4.8) who were selected for their excellent health status. The second group consisted of 38 females of mean age 75.9 (SD 5.3), all of whom had some significant physical pathology. Hearing losses at various frequency levels (from 125 to 8000 cps) were correlated with performance on cognitive tests such as the WAIS, with age effects then being partialled out. The results reveal substantial associations between hearing losses and scores achieved on the intellectual measures for both samples. Verbal type tests show these relationships much more extensively than the performance tests. The findings imply that aged subjects may be more intellectually capable than their test performances suggest and that hearing is an important variable to be considered in the assessment of their cognitive functioning.     

Predicting impending death: Inconsistency in speed is a selective and early marker.

Among older adults, deficits in both level and variability of speeded performance are linked to neurological impairment. This study examined whether and when speed (rate), speed (inconsistency), and traditional accuracy-based markers of cognitive performance foreshadow terminal decline and impending death. Victoria Longitudinal Study data spanning 12 years (5 waves) of measurement were assembled for 707 adults aged 59 to 95 years. Whereas 442 survivors completed all waves and relevant measures, 265 decedents participated on at least 1 occasion and subsequently died. Four main results were observed. First, Cox regressions evaluating the 3 cognitive predictors of mortality replicated previous results for cognitive accuracy predictors. Second, level (rate) of speeded performance predicted survival independent of demographic indicators, cardiovascular health, and cognitive performance level. Third, inconsistency in speed predicted survival independent of all influences combined. Fourth, follow-up random-effects models revealed increases in inconsistency in speed per year closer to death, with advancing age further moderating the accelerated growth. Hierarchical prediction patterns support the view that inconsistency in speed is an early behavioral marker of neurological dysfunction associated with impending death. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predictors of longitudinal changes in memory, visuospatial, and verbal functioning in very old demented adults

Longitudinal changes in memory, visuospatial and verbal functioning in a sample of demented persons were examined. The role of several demographic, psychometric, and biological indices in predicting the rate of cognitive deterioration was also investigated. The sample consisted of 31 very old (mean age at entry = 83.5 years, range = 75-95) persons with Alzheimer's disease (n = 22) and vascular dementia (n = 9) from a community-based study. Subjects were tested on two occasions separated by approximately 2.5 years. Results indicated significant longitudinal decline in verbal fluency and visuospatial ability, but only on 1 of 3 measures of episodic memory. Results from regression analyses indicated that a variety of putatively important variables, including age, gender, education, digit span, as well as a number of biological (vitamin B12, TSH), dementia etiology, and psychometric (digit span) indicators, exhibited no relationship to rate of memory, visuospatial, or verbal decline. The results suggest that the rate of cognitive deterioration in dementia is highly variable, and this variability in change appears to include a variety of characteristics. A possible reason thereof may be that the role of individual-difference variables for cognitive functioning in dementia is overshadowed by the pathogenetic process itself.     

Cognition and depression in a cohort of aging men: Results from the Western Collaborative Group Study.

Relationships between cognitive performance and self-ratings of depression on the Center for Epidemiologic Studies Depression scale (CES-D; L.S. Radloff, 1977) were examined for 1,217 older men. After controlling for demographic variables and both objective and subjective measures of health, significant associations were observed between several CES-D variables and measures of cognitive mental status, memory, and psychomotor speed. The Well-Being factor of the CES-D was the most robust predictor of cognitive scores. Therefore, for older adults with generally favorable health and socioeconomic resources, there may be a link between positive affect and maintenance of cognitive effectiveness. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Person-specific paths of cognitive decline in Alzheimer's disease and their relation to age.

Change in global and specific measures of cognitive function was studied in a cohort of 410 persons with Alzheimer's disease. Persons completed up to 5 annual evaluations; follow-up participation among survivors exceeded 90%. Average annual decline was 0.57 standard score units (95% confidence interval [CI]: -0.51 to -0.62) on a composite measure based on 17 individual tests and 3.26 points (95% CI: -3.06 to -3.46) on the Mini-Mental State Examination, but substantial heterogeneity was apparent. On both global and specific measures, rate of cognitive decline was reduced in older persons compared with younger persons. A similar effect was observed for estimated age of disease onset. The effect of age was approximately linear and was not attributable to education, sex, race, other conditions that impair cognition, or mortality. The results indicate that person-specific paths of cognitive decline in Alzheimers disease vary substantially and suggest that in clinical settings some of this variability is related to age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structural equation models of relationships between exercise and cognitive abilities.

Data were obtained from 300 men and women aged 55 to 91. Separate structural equation models of relationships between physical exercise and 3 cognitive performance variables—reaction time (RT), working memory, and reasoning—fit the data well. Other variables in the models were age, health, education, and morale. Age and exercise affected each performance variable directly; education had a direct effect on reasoning only. There were also indirect effects of age and health on performance variables, mediated through exercise. The main hypothesis of the study, that exercise contributes to performance, was supported. A large decrease in model fit resulted when the path from exercise to each variable was deleted. Hypotheses that age-related deficits are primarily accounted for by lack of exercise or by poor health were not supported. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging, vascular risk, and cognition: Blood glucose, pulse pressure, and cognitive performance in healthy adults.

Advanced age is associated with decline in many areas of cognition as well as increased frequency of vascular disease. Well-described risk factors for vascular disease, such as diabetes and arterial hypertension, have been linked to cognitive deficits beyond those associated with aging. To examine whether vascular health indices such as fasting blood glucose levels and arterial pulse pressure can predict subtle deficits in age-sensitive abilities, the authors studied 104 healthy adults (ages 18 to 78) without diagnoses of diabetes or hypertension. Whereas results revealed a classic pattern of age-related differences in cognition, preprandial blood glucose level and pulse pressure independently and differentially affected cognitive performance. High-normal blood glucose levels were associated with decreased delayed associative memory, reduced accuracy of working memory processing among women, and slower working memory processing among men. Elevated pulse pressure was associated with slower perceptual–motor processing. Results suggest that blood glucose levels and pulse pressure may be sensitive indicators of cognitive status in healthy adults; however, longitudinal research is needed to determine whether such relatively mild elevations in this select group predict age-related cognitive declines. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Health-related quality of life in cardiovascular disease.

Early mortality and reduced quality of life in the years prior to death are the most important health outcomes associated with cardiovascular disease. Other measures of cardiovascular status, including blood pressure, ejection fraction, and electrocardiogram (ECG) abnormalities, are only of interest because of their known association with poor health outcomes. Quality of life measures have gained increasing attention as outcome variables in studies of cardiovascular disease. This article reviews several current approaches to the assessment of health outcomes. A general health policy model is offered as a method for comparing program options in cardiovascular disease that may have very different objectives. Examples taken from the evaluation of hypertension screening and treatment, of heart transplantation programs, and of primary prevention of heart disease are offered. Methods for measuring the cost/utility of alternative procedures are also discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Everyday cognition and mortality: Performance differences and predictive utility of the Everyday Cognition Battery.

In this article, the authors examine the relationship between everyday cognition and mortality. Data were initially collected in 1996-1997 from 171 community-dwelling older people ranging in age from 60 to 92 years old (M = 74 years, SD = 7.38). Participants completed the Everyday Cognition Battery (ECB; J. C. Allaire & M. Marsiske, 1999, 2002) as well as basic cognitive ability tests. Results indicated that participants who died since testing (n = 56) had performed significantly worse than did still-living participants on all measures. Additionally, performance on the ECB Knowledge Test was a significant predictor of death even after controlling for basic cognitive abilities, demographics, and self-rated health. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Marital distress and the metabolic syndrome: Linking social functioning with physical health.

Mechanisms by which poor relationship functioning contributes to poor health are not fully understood. We conducted a study to evaluate the association between marital distress and the metabolic syndrome (MetS), which refers to a clustering of characteristics that have individually been shown to be associated with elevated risk of cardiovascular disease and diabetes and which collectively have been shown to increase risk for cardiovascular disease, diabetes, stroke, and mortality. A population-based English sample of couples (N = 671 couples) in which both partners were between the ages of 52 and 79 years old completed a self-report measure of marital distress and a nurse visit that included collection of blood pressure, blood samples, and anthropometric measures. Results indicated that for women, after controlling for demographic variables, greater marital distress was significantly associated with increasing likelihood of meeting criteria for the MetS and with the individual MetS criteria of elevated blood pressure and elevated fasting glucose. The association between marital distress and the MetS remained significant for women when additionally controlling for depressive symptoms and health habits (smoking status, physical activity). Marital distress was not significantly associated with the MetS or any of the individual MetS criteria for men. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of death within 11 years on cognitive performance in old age.

Six different cognitive tests and the Beck Depression Inventory (BDI) were given to 3,572 active community residents aged 49 to 93 years. Causes of death were ascertained for 443 who died between 36 and 3,903 days later. Subsequent survival predicted test scores during the 3,903 days and independently during Days 36 to 1,826 and Days 1,827 to 3,903. Scores on the BDI and cumulative verbal learning and vocabulary tests predicted mortality after demographics and performance on other cognitive tests had been considered. Predictors were similar for deaths from heart disease, malignancies, and other causes. A new finding that cognitive tests did not predict survival duration within the sample of deceased explains previous findings of greater terminal decline in performance for young than for elderly adults. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hearing loss and cognition in the Baltimore Longitudinal Study of Aging.

Objective: To determine the relationship between hearing loss and cognitive function as assessed with a standardized neurocognitive battery. We hypothesized a priori that greater hearing loss is associated with lower cognitive test scores on tests of memory and executive function. Method: A cross-sectional cohort of 347 participants ≥55 years in the Baltimore Longitudinal Study of Aging without mild cognitive impairment or dementia had audiometric and cognitive testing performed in 1990–1994. Hearing loss was defined by an average of hearing thresholds at 0.5, 1, 2, and 4 kHz in the better-hearing ear. Cognitive testing consisted of a standardized neurocognitive battery incorporating tests of mental status, memory, executive function, processing speed, and verbal function. Regression models were used to examine the association between hearing loss and cognition while adjusting for confounders. Results: Greater hearing loss was significantly associated with lower scores on measures of mental status (Mini-Mental State Exam), memory (Free Recall), and executive function (Stroop Mixed, Trail Making B). These results were robust to analyses accounting for potential confounders, nonlinear effects of age, and exclusion of individuals with severe hearing loss. The reduction in cognitive performance associated with a 25 dB hearing loss was equivalent to the reduction associated with an age difference of 6.8 years. Conclusion: Hearing loss is independently associated with lower scores on tests of memory and executive function. Further research examining the longitudinal association of hearing loss with cognitive functioning is needed to confirm these cross-sectional findings. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Public health nihilism vs pragmatism: history, politics, and the control of tuberculosis

Tuberculosis (TB) began to decline in the Western world in the mid- to late 1800s. In the United States, the disease receded until the mid-1980s, when that trend was reversed. Although the TB epidemic in the United States subsided in response to public health interventions, it sparked a controversy regarding the relative value of targeted public health measures vs broad social reform. That controversy, which echoed earlier debates calling for structural reform over public health programs, was further strengthened by the historical and demographic studies of Thomas McKeown. His influential thesis maintains that clinical and primary prevention efforts had little effect on TB mortality. In this paper, the historical literature is used to examine whether public health had a significant impact on the decline of TB mortality rates in several countries. Specifically, the paper describes the arguments for and data affirming the efficacy of 2 major public health interventions over time: segregation of those infected with pulmonary TB and eradication of bovine TB. This review finds support for the hypothesis that public health measures, along with other factors, led to falling rates of TB mortality beginning in the late 19th century.     

Intellectual and cognitive functions in Parkinson's disease.

Compared the performance of 25 parkinson's disease patients and 25 normals matched for age, race, sex, and education on 32 behavioral variables including the wechsler-bellevue intelligence scale (form i), halstead neuropsychological battery, and R. Reitan's trail making test. Ss with parkinson's disease had lower mean scores than controls on all 32 measures. Statistical comparisons indicated these differences were significant beyond the .001 level for 25 tests, and on only 1 measure was the probability level greater than .05. Results indicate that parkinson's disease patients have suffered marked deterioration not only in motor abilities but also in problem-solving, sensory, memory, general cognitive, and abstracting and organizing abilities. (23 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Test anxiety, academic performance, and cognitive appraisals.

Investigated the impact of test anxiety on test performance and the cognitive appraisals of test-anxious students. To overcome limitations of previous research, state and dispositional measures of test anxiety were used over repeated performance trials. 62 Ss who were enrolled in an undergraduate statistics course that required multiple examinations were administered the State-Trait Anxiety Inventory and served as Ss. Ss' expectations, thoughts, and performance were assessed at each of the 4 examination occasions. Results indicate that test anxiety was related to poor test performance both early and late in the term. When state anxiety levels were controlled for, the test anxiety–test performance relation was apparent only during the later stages of the course. The pattern of Ss' anxiety and appraisals suggests that test-anxious Ss experienced most doubt and concern early in the term. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)