Interactive Relations Across Dimensions of Interpersonal-Level Discrimination and Depressive Symptoms to Carotid Intimal-Medial Thickening in African Americans.

OBJECTIVE: This study aimed to examine within-race interactions of multiple dimensions of self-reported discrimination with depressive symptoms in relation to carotid intimal-medial thickness (IMT), a subclinical marker of atherosclerosis prospectively implicated in stroke incidence, in middle-aged to older African American and white adults. METHODS: Participants were a socioeconomically diverse group of 1941 African Americans (56.5%) and whites from the Healthy Aging in Neighborhoods of Diversity across the Life Span study (30-64 years old, 47% men, 45.2% with household income <125% federal poverty threshold) who underwent carotid IMT measurement. Discrimination was assessed across four dimensions (everyday, frequency across various social statuses, racial, and lifetime burden). The Center for Epidemiologic Studies Depression scale was used to assess depressive symptoms. RESULTS: In cross-sectional hierarchical regression analyses, two interactions were observed in African Americans: more frequent discrimination across various social statuses (b < 0.001, p = .006) and a higher lifetime discrimination burden (b < 0.001, p = .02) were each related to thicker carotid IMT in those with greater depressive symptoms. No significant findings were observed within whites. CONCLUSIONS: Among African Americans, those reporting high levels of discrimination and depressive symptoms have increased carotid atherosclerosis and may be at greater risk for clinical end points compared with those reporting one or neither of these risk factors. Findings suggest that assessment of interactive relationships among social and psychological factors may elucidate novel pathways for cardiovascular disease, including stroke, among African Americans.

Distributions of Subclinical Cardiovascular Disease in a Socioeconomically and Racially Diverse Sample.

BACKGROUND AND PURPOSE: Differential subgroup vulnerability to subclinical cardiovascular disease is likely, and yet few, if any, studies have addressed interactive relations of age, sex, race, and socioeconomic status (SES) to these conditions to examine nuances of known health disparities. We examined distributions of carotid atherosclerosis and arterial stiffness in a socioeconomically diverse, biracial, urban sample. METHODS: Participants (n=2270) in the population-based HANDLS study (Healthy Aging in Neighborhoods of Diversity Across the Life Span; 30-64 years old, 44% men, 57% African American, 39% with household income <125% federal poverty threshold) underwent carotid intimal medial thickness (IMT) and pulse wave velocity assessment. RESULTS: In cross-sectional hierarchical regression analyses, interactive race×SES effects were identified for IMT and pulse wave velocity, such that high SES African Americans had significantly thicker IMTs and faster pulse wave velocities than all other subgroups (ie, low SES African Americans, low SES whites, and high SES whites). A race×sex effect was also identified for IMT, such that the IMT discrepancy between white men and women was more pronounced than the discrepancy between African American men and women. Finally, an SES×sex effect indicated that while IMTs of high SES and low SES men did not significantly differ, high SES women had marginally thicker IMTs than low SES women. CONCLUSIONS: High SES African Americans may be particularly vulnerable to subclinical cardiovascular diseases, placing them at enhanced risk for clinical cardiovascular diseases, including stroke. These findings suggest that male sex, low SES, and African American ancestry may represent imprecise generalizations as risk factors for subclinical cardiovascular disease.

Renal function and long-term decline in cognitive function: the Baltimore Longitudinal Study of Aging.

BACKGROUND: Renal disease has been associated with greater risk of dementia and greater cognitive impairment. However, the relationship of lower renal function with long-term decline in specific domains of cognitive function remains unclear among community-dwelling, non-demented individuals. METHODS: Stroke- and dementia-free participants (n = 2,116) were enrolled in the Baltimore Longitudinal Study of Aging, a community-based, prospective, longitudinal study. Renal function was estimated by the inverse of serum creatinine adjusted for age, sex and race and (in sensitivity analyses) estimated glomerular filtration rate (eGFR) using the MDRD formula. Outcome measures were changes in scores on 6 cognitive tests encompassing a range of cognitive functions, measured at 2-year intervals. Mixed-effects regression models examined the longitudinal relations of renal function with cognitive functions after adjusting for demographics, comorbidity and other potential confounders. RESULTS: Mean age at initial testing was 53.9 years (SD 17.1), and 94 participants (4.4%) had an eGFR <60 ml/min/1.73 m(2) and 18.5% had at least one comorbidity. With increasing age, longitudinal increases in creatinine concentrations were associated with more rapid decline in performance on several cognitive measures, including the learning slope of the California Verbal Learning Test, a test of verbal learning (p < 0.01), and the Benton Visual Retention Test, a test of visual memory (p < 0.01). Associations were similar for changes in eGFRMDRD, which was also associated with the rate of decline in verbal memory. CONCLUSION: In a community-based adult population, declines in renal function independently associated with greater long-term declines in visual memory and verbal memory and learning.

Psychometric limitations of the mini-mental state examination among nondemented older adults: an evaluation of neurocognitive and magnetic resonance imaging correlates.

UNLABELLED: BACKGROUND/STUDY CONTEXT: Although many of the Mini-Mental State Examination's (MMSE) limitations are well accepted among geriatricians, neuropsychologists, and other interested clinicians and researchers, its continued use in psychometrically unsound ways suggests that additional investigation and dissemination of information are sorely needed. The authors aimed to describe the reliability and validity of the MMSE as a measure of cognitive function among healthy older adults. METHODS: The authors examined MMSE performance in 124 stroke- and dementia-free, community-dwelling older adults (65% male; mean age = 66.5 years). All participants were administered an extensive neuropsychological battery composed of measures of attention, executive function, memory, and visuospatial function. A subset of 99 participants also underwent magnetic resonance imaging (MRI). MMSE test-retest reliability was examined among 65 participants who underwent repeat MMSE testing over an average interval of 83.2 days. RESULTS: Spearman test-retest correlation for total MMSE scores was r S = .35 (p = .004), for Serial Sevens was r S = .40 (p = .001), and for Word Recall was r S = -.01 (p = .96). Total MMSE performance correlated significantly with a minority of neuropsychological tests and MRI-derived indices of white matter disease and brain atrophy. A subset of 17% of participants demonstrated inappropriate intrusion of MMSE Pentagon Copy during another test of visuospatial recall. CONCLUSIONS: Overall, MMSE scores exhibited ceiling effects, poor test-retest reliability, limited sensitivity to subtle brain abnormalities, and a high rate of intrusion elsewhere in the neuropsychological battery. Individual MMSE items demonstrated poor construct validity. These qualities illustrate the serious limitations of the MMSE in detecting individual differences in cognitive function among healthy older adults.

Carotid atherosclerosis and prospective risk of dementia.

BACKGROUND AND PURPOSE: Although vascular risk factors have been implicated in the development of all-cause dementia and Alzheimer disease (AD), few studies have examined the association between subclinical atherosclerosis and prospective risk of dementia. METHODS: Participants from the Baltimore Longitudinal Study of Aging (n=364; age, 60-95 years; median age, 73; 60% male; 82% white) underwent initial carotid atherosclerosis assessment and subsequently were assessed for dementia and AD annually for up to 14 years (median, 7.0). Cox proportional hazards models predicting all-cause dementia and AD were adjusted for age, sex, race, education, blood pressure, cholesterol, cardiovascular disease, diabetes mellitus, and smoking. RESULTS: Sixty participants developed dementia, with 53 diagnosed as AD. Raw rates of future dementia and AD among individuals initially in the upper quintile of carotid intimal medial thickness or with bilateral carotid plaque were generally double the rates of individuals with intimal medial thickness in the lower quintiles or no plaque at baseline. Adjusted proportional hazards models revealed >2.5-fold increased risk of dementia and AD among individuals in the upper quintile of carotid intimal medial thickness, and approximately 2.0-fold increased risk of dementia among individuals with bilateral plaque. CONCLUSIONS: Multiple measures of carotid atherosclerosis are associated with prospective risk of dementia. Individuals in the upper quintile of carotid intimal medial thickness or bilateral carotid plaque were at greatest risk. These findings underscore the possibility that early intervention to reduce atherosclerosis may help delay or prevent onset of dementia and AD.

Incremental utility of an extended stroop task for identifying subtle differences in cognitive performance among healthy older adults.

The Stroop Color and Word Test is a test of processing speed, response inhibition, and executive functioning (EF). This project examined whether extending the Stroop Color-Word trial beyond the standard time limit could more accurately assess performance on EF measures. Cognitively healthy older individuals (n = 198) enrolled in a study of cardiovascular health completed the Stroop as part of a neuropsychological battery. Two scores were computed for the Color-Word trial: the number of items completed within the first 45 seconds (traditional Color-Word score) and the speed of page completion beyond the first 45 seconds (Stroop-Extended score). Criterion measures included the Trail-Making Test Part B (TMT-B), Digit Span Backward, Symbol Digit Modalities Test, Short Category Test, and measures of verbal fluency. Results from hierarchical linear regression analyses indicated that the extended Stroop score accounted for small but statistically significant variance in TMT-B (additional 2.6%) and Digit Span Backwards (additional 2.6%) beyond the standard Color-Word score. These findings suggest that extending the Stroop Color-Word trial beyond the first 45 seconds provides a limited increase in predictive power within a healthy sample with restricted range of performance. The extended Stroop requires additional examination in heterogeneous samples, including clinical populations, to determine its predictive utility.

Reliability and validity of the Conners' Continuous Performance Test.

The Conners' Continuous Performance Test-Second Edition (CCPT-2) is a widely used measure of attention and impulsivity, however, only a minimal amount is known about its reliability. To clarify the psychometric properties of the CCPT-2, we assessed its performance stability and related it to criterion measures. A total of 91 undergraduate students completed the CCPT-2, the State-Trait Personality Inventory (STPI), and reported on sleep during two sessions approximately one week apart. They completed the Behavior Rating Inventory of Executive Function-Adult Version (BRIEF-A) at session one and the Stroop Color and Word Test at session two. Findings indicated that the CCPT-2 had strong internal consistency, adequate test-retest reliability for commission errors and response time, poor test-retest reliability for omission errors, and practice effects for omission and commission errors. The CCPT-2 was largely unrelated to the BRIEF-A, Stroop Color and Word Test, and the STPI. More sleep was related to a quicker response time and more commission errors on the CCPT-2, and the BRIEF-A's Behavior Regulation Index was positively related to commission errors. Relative to the omission error component of the CCPT-2, commission errors and response time may be useful and stable measures of sustained attention and impulsivity.

Subclinical carotid atherosclerosis and neurocognitive function in an urban population.

BACKGROUND AND AIMS: Examine age, sex, race, and socioeconomic status as modifiers of the association between carotid intimal medial thickness (IMT) and neurocognitive performance in a socioeconomically diverse, biracial, urban, adult population. METHODS: Participants were 1712 community-dwelling adults (45% men, 56% African-American, 38% below poverty threshold, aged 30-64 years) enrolled in the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study. Participants underwent initial carotid ultrasonography followed by cognitive testing on up to two occasions over 4 years. Mixed-effects regression analyses were adjusted for demographic, behavioral, and biomedical covariates. RESULTS: Significant cross-sectional IMT × race × poverty interactions were identified for measures of delayed recall memory, auditory-verbal attention, and working memory. An IMT × race interaction also appeared for auditory-verbal learning. Higher IMT was generally associated with worse cognitive performance, but the disadvantage was most pronounced among those with higher socioeconomic status and white participants. No longitudinal associations were identified. CONCLUSIONS: Carotid IMT-cognition associations differed as a function of race and socioeconomic status and were most compelling for measures of attention, executive function, and memory. These findings highlight the possibility that subclinical atherosclerosis may be differentially informative as a predictor of cognitive performance among varied demographic subgroups.

Nonlinear associations between plasma cholesterol levels and neuropsychological function.

OBJECTIVE: Although both high and low levels of total and low-density lipoprotein (LDL) cholesterol have been associated with poor neuropsychological function, little research has examined nonlinear effects. We examined quadratic relations of cholesterol to performance on a comprehensive neuropsychological battery. METHOD: Participants were 190 older adults (53% men, ages 54-83) free of major medical, neurologic, and psychiatric disease. Measures of fasting plasma total and high-density lipoprotein (HDL) cholesterol were assayed, and LDL cholesterol was calculated. Participants completed neuropsychological measures of attention, executive function, memory, visuospatial judgment, and manual speed and dexterity. Multiple regression analyses examined cholesterol levels as quadratic predictors of each measure of cognitive performance, with age (dichotomized as <70 vs. 70+) as an effect modifier. RESULTS: A significant quadratic effect of Total Cholesterol² × Age was identified for Logical Memory II (b = -.0013, p = .039), such that the 70+ group performed best at high and low levels of total cholesterol than at midrange total cholesterol (U-shaped) and the <70 group performed worse at high and low levels of total cholesterol than at midrange total cholesterol (inverted U shape). Similarly, significant U- and J-shaped effects of LDL Cholesterol² × Age were identified for Visual Reproduction II (b = -.0020, p = .026) and log of the Trail Making Test, Part B (b = .0001, p = .044). Quadratic associations between HDL cholesterol and cognitive performance were nonsignificant. CONCLUSIONS: Results indicate differential associations between cholesterol and neuropsychological function across different ages and domains of function. High and low total and LDL cholesterol may confer both risk and benefit for suboptimal cognitive function at different ages. (PsycINFO Database Record

Relations of blood pressure and head injury to regional cerebral blood flow.

Hypertension confers increased risk for cognitive decline, dementia, and cerebrovascular disease. These associations have been attributed, in part, to cerebral hypoperfusion. Here we posit that relations of higher blood pressure to lower levels of cerebral perfusion may be potentiated by a prior head injury. Participants were 87 community-dwelling older adults - 69% men, 90% white, mean age=66.9years, 27.6% with a history of mild traumatic brain injury (mTBI) defined as a loss of consciousness ≤30min resulting from an injury to the head, and free of major medical (other than hypertension), neurological or psychiatric comorbidities. All engaged in clinical assessment of systolic and diastolic blood pressure (SBP, DBP) and single photon emission computed tomography (SPECT). Computerized coding of the SPECT images yielded relative ratios of blood flow in left and right cortical and select subcortical regions. Cerebellum served as the denominator. Sex-stratified multiple regression analyses, adjusted for age, education, race, alcohol consumption, smoking status, and depressive symptomatology, revealed significant interactions of blood pressure and head injury to cerebral blood flow in men only. Specifically, among men with a history of head injury, higher systolic blood pressure was associated with lower levels of perfusion in the left orbital (ß=-3.21, p=0.024) and left dorsolateral (ß=-2.61, p=0.042) prefrontal cortex, and left temporal cortex (ß=-3.36, p=0.014); higher diastolic blood pressure was marginally associated with lower levels of perfusion in the left dorsolateral prefrontal cortex (ß=-2.79, p=0.051). Results indicate that men with a history of head injury may be particularly vulnerable to the impact of higher blood pressure on cerebral perfusion in left anterior cortical regions, thus potentially enhancing risk for adverse brain and neurocognitive outcomes.

Nonlinear longitudinal trajectories of cholesterol and neuropsychological function.

OBJECTIVE: Prior literature has identified inconsistent longitudinal associations between total cholesterol and cognitive decline. The authors examined prospective nonlinear relations of coincident trajectories of total cholesterol and cognitive function among persons free of stroke, dementia, and other neurological disease. METHOD: Up to 1,601 participants from the Baltimore Longitudinal Study of Aging (aged 19-93, 51% male, 75% White) underwent fasting cholesterol measurement and neuropsychological assessment on up to 12 occasions (M = 3.2, SD = 2.1) over up to 19 years (M = 6.4, SD = 5.3) of follow-up. Mixed-effects regression analyses were adjusted for age, sex, race, education, systolic blood pressure, body mass index, cardiovascular disease, lipid-lowering medication use, smoking, alcohol use, and depressive symptoms. RESULTS: Analyses revealed significant longitudinal associations between quadratic total cholesterol and performance on measures of global mental status, verbal learning, executive function, and language (all ps < .05). In general, higher total cholesterol was associated with poorer middle-aged or young-old (60-69 years) cognitive performance, but better old-old (80-89 years) cognitive performance. Linear models also revealed an association between lower total cholesterol and accelerated decline in visual memory performance. CONCLUSIONS: Overall, results indicate nonlinear longitudinal relations of total cholesterol to cognitive decline. Whereas higher cholesterol levels were associated with cognitive decline in the middle-aged or young-old, lower cholesterol levels were related to cognitive decline among old-old participants.

Cardiorespiratory fitness and accelerated cognitive decline with aging.

BACKGROUND: Growing evidence suggests that self-reported physical activity accounts for variability in cognitive function among older adults, and aerobic intervention may improve cognitive function in this population. However, much less is known about the longitudinal association between direct measures of cardiorespiratory fitness and cognitive function across the life span. The present study examined the prospective association between symptom-limited maximal oxygen consumption (VO2max) and longitudinal performance on a comprehensive neuropsychological battery. METHODS: Up to 1,400 participants aged 19-94 years underwent initial VO2max assessment and completed subsequent tests of memory, attention, perceptuomotor speed, language, and executive function, in addition to cognitive screening measures, on up to six occasions (mean, M = 2; standard deviation, SD = 1) for up to 18 years (M = 7, SD = 3). Mixed-effects regression models were adjusted for demographic, biomedical, and behavioral confounders. RESULTS: Analyses revealed significant longitudinal associations between baseline VO2max and trajectory of performance on multiple measures of verbal and visual memory, as well as on a cognitive screening test (all ps < .05). Individuals with lower VO2max demonstrated accelerated trajectories of cognitive decline over time. CONCLUSIONS: Baseline cardiorespiratory fitness is related to longitudinal neuropsychological performance, and memory appears to be a particularly vulnerable domain. Evidence that aerobic fitness is associated with accelerated cognitive decline emphasizes the possible importance of behavioral interventions to optimize cognitive aging over time.

Judgment of Line Orientation: an examination of eight short forms.

The Judgment of Line Orientation (JLO) test is a commonly used measure of visuospatial perception. Because of its length, several short forms have appeared in the literature. We examined the internal consistency of the JLO and eight of its published short forms among 128 undergraduates, 203 healthy older adults, and 55 chronic kidney disease patients. The full test demonstrated good reliability for traditional neuropsychological assessment, but the majority of short forms were adequate only for screening purposes, where greater measurement error is typically permitted in exchange for brevity. In contrast, a recently developed short form based upon item response theory demonstrated promise as a stand-alone measure.

Neuropsychological performance of native versus non-native English speakers.

Relatively little is known about differences in English-administered, clinical neuropsychological test performance between native versus non-native English speakers, with prior literature yielding mixed findings. The purpose of this study was to examine the performance of native and non-native English speakers with similar age and educational backgrounds on a variety of cognitive tests. Participants were 153 university students (115 native and 38 non-native English speakers) who completed a neuropsychological battery during two testing sessions. Multiple regression analyses examined relations of native language to cognitive performance after adjustment for age, education, sex, and depressive symptomatology. Results showed that native English speakers outperformed non-native English speakers on several language-mediated tasks-Letter and Category Fluency and the Cognitive Estimation Test-as well as Trails A (p's < .05). The two groups performed similarly on tests of executive functions, perceptuo-motor speed, verbal memory, and visuospatial abilities. These results suggest that non-native English language may have a negative influence predominantly on language-dependent tasks.

Interactive relations of blood pressure and age to subclinical cerebrovascular disease.

OBJECTIVE: To examine interactive relations of blood pressure (BP) and age to MRI indices of subclinical cerebrovascular disease in middle-aged to older adults. METHODS: One hundred and thirteen stroke-free and dementia-free, community-dwelling adults (ages 54-81 years; 65% men; 91% white) engaged in (1) clinical assessment of resting SBP and DBP; (2) MRI rated for periventricular white matter hyperintensities (WMH) and deep WMH silent brain infarction (SBI) and brain atrophy (i.e. ventricular enlargement and sulcal widening ). Principal components analysis of the MRI ratings yielded a two-component solution--(1) periventricular and deep WMH SBI; and (2) ventricular enlargement, sulcal widening. RESULTS: Relations of SBP, DBP and pulse pressure (PP) (and their interactions with age) to each MRI component were examined in multiple regression analyses adjusted for age, sex, fasting plasma glucose and cholesterol, and antihypertensives. For component 1, results indicated significant interactions of SBP and PP with age (P < 0.05); higher levels of SBP and PP were associated with greater white matter disease and brain infarction at younger ages (≤ 68 years). Significant interactions of SBP and DBP with age were also noted for component 2 (P < 0.05); higher levels of BP were associated with greater brain atrophy at younger ages (≤ 63 years). CONCLUSION: : Higher BP and PP are associated with greater subclinical cerebrovascular disease most prominently in the 'young old'. Appropriate management of hypertension and arterial stiffening may be critical to the preservation of brain structure with ageing.

Greater coffee intake in men is associated with steeper age-related increases in blood pressure.

BACKGROUND: Administration of caffeine or caffeinated coffee in laboratory and ambulatory settings results in small to moderate acute increases in blood pressure (BP). However, habitual coffee intake has not been linked conclusively to long-term increases in basal BP, and findings are inconsistent by sex. This study examined longitudinal relations of habitual coffee use to resting BP and pulse pressure. METHODS: In a sample of 2,442 participants from the Baltimore Longitudinal Study of Aging (BLSA), coffee consumption was used to predict resting systolic and diastolic BP and pulse pressure using longitudinal mixed-effects regression models adjusted for age, education, antihypertensive, and antihyperlipidemic use, smoking, and body mass index (BMI). Analyses were stratified by sex (865 women and 1,577 men), and age and BMI were examined as possible effect modifiers. RESULTS: In men, we identified a significant three-way interaction among coffee intake (nonlinear), baseline age, and length of follow-up for systolic BP (SBP) and pulse pressure. A significant interaction of coffee intake and BMI (nonlinear) was also noted for SBP in men. There were no significant relations of coffee intake to BP or pulse pressure in women. CONCLUSION: Greater coffee intake in men was associated with steeper age-related increases in SBP and pulse pressure, particularly beyond 70 years of age and in overweight to obese men.