A longitudinal study of neuropsychological performance by hypertensives and normotensives: a third measurement point

Factors associated with cognition in adults: the Seattle Longitudinal Study

A better understanding of factors that affect cognition could lead to improved health and greater independence for older adults. We examined the association of four modifiable factors (leisure-time physical activity, leisure-time cognitive activity, self-directed work, and hypertension) with changes in two aspects of fluid intelligence (verbal memory and inductive reasoning). Data for 626 adults collected over 14 years (three time points) were analyzed by multi-level modeling. A component of self-directed work, higher work control, was associated with better verbal memory (p < .05) and inductive reasoning (p < .01). There were no significant interactions among these factors. The findings suggest that a strong sense of control at work may be protective for fluid intelligence in adults.

Diagnosis of hypertension and high blood pressure levels negatively affect cognitive function in older adults

BACKGROUND

Hypertension is associated with diminished performance on tests of cognitive function. The degree to which those diagnosed with hypertension have controlled blood pressure (BP) levels may be a critical determinant of cognitive outcomes. Persons with hypertension and poorly controlled BP are likely to display the worst performance on cognitive tests.

PURPOSE

The purpose is to examine potential interactive relations of hypertension diagnostic status and current BP levels to cognitive function.

METHODS

Participants were 101 healthy older adults (ages 53-84, 62% male, 90% White, 29% diagnosed with hypertension) who engaged in biomedical and neuropsychological assessment.

RESULTS

After statistical adjustment for age and education, persons with high BP performed more poorly than those with normal BP on the Visual Reproductions-Immediate and Delayed Recall and the Grooved Pegboard tests. Diagnosed hypertension was related to poorer performance on the Grooved Pegboard tests. An interaction of diagnosed hypertension and BP level revealed that those diagnosed with hypertension and also having poorly controlled BP levels performed least well on the Grooved Pegboard tests and the Trail Making Test-Part A.

CONCLUSION

Irrespective of prior diagnostic status, individuals with high BP displayed compromised performance on tests of nonverbal memory, motor speed, and manual dexterity. However, as compared to the other groups, those diagnosed with hypertension and also having poorly controlled BP elevation were most vulnerable to difficulties on tests of perceptuo-motor speed, motor speed, and manual dexterity. These findings suggest the need for increased attention to preventative efforts with respect to BP assessment and control in older adults to help preserve cognitive function.

Impairment of executive function induced by hypertension in the rhesus monkey (Macaca mulatta)

The effects of chronic, untreated hypertension on executive function were investigated in a nonhuman primate model of hypertensive cerebrovascular disease. Executive function was assessed with the Conceptual Set-Shifting Task (CSST). a task adapted from the human Wisconsin Card Sorting Test (WCST). Like the WCST, the CSST requires abstraction of a stimulus set, followed by a series of set shifts. Performance on the CSST by 7 young adult monkeys (Macaca mulatta) with surgically induced hypertension was compared with that of 6 normotensive monkeys. The hypertensive group was significantly impaired relative to the normotensive group in abstraction and set shifting. Although the neural basis of this impairment is unclear, evidence from studies with humans and monkeys suggests that the prefrontal cortex may be the locus for this effect of hypertension.

Can the blood pressure predict cognitive task performance in a healthy population sample?

OBJECTIVES

To study the relation between the blood pressure and the neurocognitive function within the full adult age range in a large population sample.

DESIGN

A cross-sectional study of 936 healthy adults who were recruited from a register of family practices, stratified for age (24-81 years), sex, and occupational level, who took part in a medical and neurocognitive test program.

METHODS

The blood pressure status was studied in relation to five measures of cognitive ability, including verbal memory and speed of information processing. Other vascular risk factors were treated as control variables and included smoking, alcohol intake, body mass index, and body fat distribution. The blood pressure was measured five times using an automatic recording technique (with a Dinamap 8100 device).

RESULTS

After adjustment for age, sex, and educational level in a hierarchical regression analysis, we found no unequivocal association between the mean systolic and diastolic blood pressures (or any other studied vascular risk factor) and cognitive test performance both for the whole group and for the subgroup of subjects who were not being administered antihypertensive medication and whose medical history did not include cardiovascular events. Stratified analysis within four age levels revealed no age-specific associations between the blood pressure and the cognitive function. Subjects whose blood pressure was within the hypertensive range performed worse than did matched controls at letter digit copying, but not according to other cognitive measures.

CONCLUSIONS

With a population-based sample unselected for blood pressure status we found no linear relationship between the actual blood pressure level and various aspects of cognitive performance. Prospective studies are needed to investigate the possibility that the systemic blood pressure load over time is associated with a decline in specific cognitive abilities.

The relevance of continuous blood pressure monitoring in examining the relationship of memory efficiency with blood pressure characteristics

The study of the relationship between hypertension and cognitive decline is characterized by various difficulties of realization and, as a consequence, by incongruent results. One of the reasons for these difficulties may be explained by the occasional method of measurement of blood pressure (once a day). This study presents the results obtained in 27 normotensive and mild hypertensive subjects of both sexes (ages between 20 and 77 years) with a continuous blood pressure monitoring for 24 h. A noninvasive sphygmomanometric technique was used employing a portable recorder programmed to take a measure every 30 min. Both objective and subjective measures of memory, measures of attention efficiency, and IQ were correlated to the blood pressure measures. Continuous monitoring data of blood pressure were analyzed according to a model that included a macroscopic descriptive analysis, a microscopic rhythmometric analysis, and a microscopic integrative analyses where the effects of the interaction between level and duration of excess and the time of the day when the excess eventually appeared were considered. Results evidenced no differences in cognitive efficiency between those subjects identified with the traditional occasional measurement of blood pressure as hypertensives of mild severity and the normal subjects. Cognitive efficiency of our subjects was found correlated, independently from the clinical diagnosis, with the time of peak and with the duration of excess of their blood pressure when the results of the analyses on the continuous monitoring of blood pressure were considered.

Neuropsychological test performance, cognitive functioning, blood pressure, and age: the Framingham Heart Study

Interactions of three indices of blood pressure (systolic blood pressure, diastolic blood pressure, and chronicity of hypertension) and age-cohort membership were examined for a sample of 1,695 stroke-free participants of the Framingham Heart Study, ages 55-88 years. Blood pressure level and chronicity of hypertension were assessed over five biennial examinations performed between 1956 and 1964, a time when few hypertensives were being treated, and were related to neuropsychological tests administered between 1976 and 1978. Multiple linear regression methods were used to examine Age x Blood Pressure (or Chronicity of Hypertension) interactions in alternative analyses involving three age groups (55-64 years, 65-74 years, and 75-88 years) and age as a continuously distributed variable (age in years). Interactions were either statistically nonsignificant or trivial with respect to magnitude of effect. This was true when interaction terms (Age x Blood Pressure Level or Age x Chronicity of Hypertension) were controlled for blood pressure, age, education, occupation, cigarette smoking, alcohol consumption, gender, and antihypertensive treatment. The Age x Blood Pressure model as it pertains to older adults was not supported, but independent associations (with all covariables controlled) between the indices of blood pressure and cognitive functioning were statistically significant.

Hypertension and neuropsychological function: a lifespan perspective

This article explores the relationship of hypertension to neuropsychological performance from a lifespan perspective. First, I examine cross-sectional and longitudinal studies of neuropsychological performance in cohorts of young to middle-aged hypertensive patients (ages 20-60); older hypertensive patients (ages 60-80+); and the young, normotensive offspring of hypertensive parents (ages 18-25). The pattern of performance deficits associated with hypertension is generally found to differ from that related to hypertension risk. Next, I discuss potential mechanisms underlying hypertension-performance relationships in the aforementioned cohorts. I suggest that lowered levels of performance in the offspring of hypertensives reflect genetic risk for hypertension. Compromised neuropsychological function in young and middle-aged hypertensives may occur secondary to alterations in neurophysiological function that result from elevated blood pressure. Such neurophysiological changes may predispose to neuroanatomical changes in older hypertensive patients.

Neuropsychological function in older subjects with non-insulin-dependent diabetes mellitus

Neuropsychological function was compared in three well-matched groups of subjects: Group 1, 20 diabetic patients with hypertension, mean age 69.1 +/- 4.8 years, 14 males and 6 females; Group 2, 20 normotensive diabetic patients, mean age 69.0 +/- 6.2 years, 14 males and 6 females; Group 3, 20 healthy community controls, mean age 68.1 +/- 4.5 years, 13 males and 7 females. There were no significant differences between the groups in education or estimated IQ using the NART (National Adult Reading Test). Groups 1 and 2 did not differ significantly in duration of diabetes (mean 10.6 and 9.5 years, respectively), or mean glycosylated haemoglobin, HbA1 (mean 9.8 and 10.6%, respectively), or mean blood glucose before and after testing. On a battery neuropsychological tests, sensitive to cognitive impairment in older subjects, analysis of covariance using estimated IQ as the covariate showed no significant differences between the groups on tests of recall, with (Brown-Peterson Test) and without (Kendrick Object Learning Test) interference, forward and backward digit span, concentration (serial subtraction), verbal fluency, immediate and delayed prose recall, digit symbol substitution or psychomotor speed (Kendrick Digit Copying Test). These results provide no support for an association between cognitive deficits and Type 2 diabetes mellitus in older subjects or for the view that such deficits may also be mediated by hypertension.

Psychomotor performance and antihypertensive treatment

1. The aim of treatment of hypertension is prevention of cardiovascular complications without adverse drug reactions. Psychomotor performance can be measured objectively yet there remains uncertainty concerning the psychomotor effects of antihypertensive drugs during chronic treatment. This uncertainty is partly due to the confounding adverse effects of cerebrovascular disease and hypertension itself. There are as yet insufficient good quality data on psychomotor effects with which to differentiate between the commonly used agents. However, in general, the beneficial effect of lowering blood pressure tends to more than offset any adverse effects of the agent used.

Stroop interference: aging effects assessed with the Stroop Color-Word Test

A large, cross-sectional aging investigation of performance on the Stroop Color-Word Test (SCWT) was carried out. Subjects were 247 volunteers, ages 20-80 in seven age levels. Although all subjects thought themselves to be normal and healthy, a post hoc division could be made on the basis of biological life events (BLE). BLE are mild biological or environmental factors, such as repeated experiences of general anesthesia, that can hamper optimal brain functioning. Apart from the anticipated age effects, performance was poorer in subjects who had experienced one or more BLE: The slowing due to BLE was comparable to the effect of age, especially on the task involving language interference in color-naming. Education had a significant effect on performance: More highly educated subjects performed better than less educated subjects. No sex differences were observed. These findings replicate observations made with other tests in parallel studies. They are also in line with several other studies reporting interactions between the effects of aging and physical fitness. This study questions some of the validity of cognitive aging research, as our data suggest that screening for BLE as age-extrinsic factors in nondiseased subjects can reduce many of the performance deficits usually ascribed to aging per se.

Cognitive function and cardiovascular responsivity in subjects with a parental history of hypertension

College-age subjects with and without a parental history of hypertension completed a battery of tests of cognitive function on two separate occasions. Pulse rate and blood pressure were measured during performance of each task. In one session, subjects were told that their performance was being evaluated and videotaped from behind an observation mirror (Evaluation Condition). In the other session, subjects were told that their performance was not being observed (Nonevaluation Condition). Regardless of Evaluation Condition, Parental History subjects exhibited slower search of short-term memory than Non-Family History subjects during the first but not the second testing session. Parental History subjects displayed greater elevations in pulse rate than Nonparental History subjects during task performance. The results were interpreted as providing evidence that pathophysiological mechanisms associated with essential hypertension are not the only viable explanations of lower levels of cognitive performance exhibited by hypertensive subjects.

Systolic blood pressure and neuropsychological test performance of alcoholics

This study examined resting systolic blood pressure (SBP) as a mediator of neuropsychological (NP) test performance in nonhypertensive alcoholics and controls. A median-split was used to assign alcoholics and controls to low and high SBP groups. Results showed that: (1) When SBP level was not considered, alcoholics only performed worse than controls on the WAIS Comprehension subtest. (2) Alcoholics and controls in the high SBP groups had fewer correct items on the WAIS Comprehension and Raven's, Set I tests than subjects in the low SBP groups. (3) Significant Diagnostic Group by SBP Group interaction was found for the Sentence Writing test. For this test only controls in the High SBP Group did worse than controls in the Low SBP Group. (4) Individual group comparisons for all NP tests showed that alcoholics in the High SBP Group were more impaired than controls in the Low SBP Group on the WAIS Comprehension, Shipley Abstraction Age and Stark Visual-Spatial tests; but alcoholics in the Low SBP Group did not differ from, or outperformed, controls in the High SBP Group on the WAIS Comprehension, Shipley Abstraction Age, Raven's, Set I, and Stark Visual-Spatial tests. These data demonstrate that both alcoholism and high SBP adversely and differentially affect the NP test performance of alcoholics and controls.

Psychotic behavior after right hemispheric cerebrovascular accident: a case report

A 64-year-old man developed hallucinations, delusions, and agitation after a right hemispheric cerebrovascular accident (CVA) in the occipital, inferior temporal, and parietal regions of the posterior cerebral artery. A review of the literature suggests that psychotic behavior is rare after CVA, but when such behavior does occur, the lesion is usually in the right hemisphere. Two clinical presentations are seen. One presentation involves patients free of chronic disease who develop episodic psychotic behavior at a time remote from their CVA. Electroencephalogram often demonstrates epileptogenic foci, and these patients often improve with anticonvulsant medication. Another presentation involves patients with one or more chronic diseases, often resulting in brain atrophy, who display continuous abnormal behavior soon after their CVA; these patients respond variably to antipsychotic agents.

Importance of basic and applied research from the viewpoints of investigators in the psychology of aging

In this series of presentations, the importance and practical implications of many different research programs in the psychology of aging is presented from the viewpoints of the investigators themselves. These scientists discuss the implications and significance of their work for society as it affects other scientists, policy-makers, the media, and the public. The discussions make clear that the many of the problems associated with aging are essentially behavioral problems which can be prevented through behavioral change in the early as well as later years of the lifespan.

Structural modeling of mixed longitudinal and cross-sectional data

In this paper we describe some mathematical and statistical models for dealing with changes over age. We concentrate specifically on the use of a structural equation modeling (SEM) approach (using computer programs like LISREL) to deal with issues of: (1) group differences in regression parameters, (2) differences in longitudinal and cross-sectional results, (3) differences due to longitudinal attrition, and (4) mixtures of these problems. To illustrate these ideas we use data from a previous study of hypertension and intellectual abilities (from Schultz, Elias, Robbins, Streeten, and Blakeman, 1986).

Longitudinally measured blood pressure, antihypertensive medication use, and cognitive performance: the Framingham Study

The relation of longitudinally measured blood pressure to cognitive performance in the absence of clinically diagnosed cerebrovascular disease was investigated in the Framingham Study. In 1976-1978, neuropsychologic testing was administered to 1993 participants aged 55-89 years. Performance on an education-adjusted composite of these tests was examined in relation to measures of chronicity of hypertension as well as the average systolic and average diastolic blood pressure. All analyses were stratified by antihypertensive medication use during the 2 years prior to cognitive testing and adjusted for age, sex, occupation, alcohol consumption, and participation rate in prior examination cycles. Among subjects on drug therapy for hypertension, there was no association between cognitive performance and longitudinally measured blood pressure. The proportion of cycles in which hypertension was present and average systolic and diastolic blood pressure had a significant inverse relation with cognitive performance only in the group not on antihypertensive drug therapy. However, among subjects on antihypertensive medication at earlier cycles, there was a highly significant graded relation between cognitive impairment and the probability of being off medication at the time of testing. These results suggest that hypertension-related subclinical vascular disease is not an important cause of cognitive impairment in the elderly. Cognitive impairment may, however, be associated with a reduced adherence to drug treatment regimens.