Positive affect and its relationship to free recall memory performance in a sample of older Dutch adults from the Maastricht Aging Study.

OBJECTIVE: A Dutch translation of the Positive and Negative Affect Scale (PANAS) was used to measure Positive Affect (PA) and its relationship to episodic memory in a sample of Dutch adults between the ages of 40 to 82 years. Specifically, the role of PA was examined as a predictor of performance on a serial list learning task that included a recognition and free recall component. METHODS: Participants were divided into two age groupings representing middle-age (40 to 64 years) and older (65 to 82 years) adults with respect to the study sample. RESULTS: PA was not related to recognition performance in either age grouping. In the older age group, however, PA predicted free recall. CONCLUSIONS: PA facilitated episodic memory in older adults when unsupported tasks conditions were present that placed heavy demands on processing resources.

Interaction of atherosclerosis and inflammation in elderly subjects with poor cognitive function.

OBJECTIVE: To test the hypothesis that a pro-inflammatory response is associated with cognitive impairment among individuals with cardiovascular disease. METHOD: All 85-year-old inhabitants of Leiden (n = 599) were visited at their place of residence. A history of cardiovascular disease and an EKG were used as indicators of atherosclerosis. Production of the pro-inflammatory cytokine tumor necrosis factor-alpha and the anti-inflammatory cytokine interleukin-10 was assessed in a whole-blood assay using lipopolysaccharide as a stimulus. Global cognitive functioning was determined with the Mini-Mental State Examination (MMSE); attention, cognitive speed, and memory were determined with four neuropsychological tests; and a history of dementia was obtained. RESULTS: In subjects with cardiovascular disease, median MMSE scores were lower in those with a pro-inflammatory response when compared with those with an anti-inflammatory response (p = 0.02). Similar associations were found for the Stroop Test, measuring attention (p < 0.01), the Coding Test measuring cognitive speed (p = 0.02), the Word Learning Test measuring memory (p < 0.01), and the presence of dementia (p = 0.04). The associations remained unaltered after adjustments for possible confounders such as gender, level of education, use of nonsteroidal anti-inflammatory drugs, use of cardiovascular drugs, and cardiovascular risk factors. In contrast, outcomes of the cognitive tests and presence of dementia were not dependent on the inflammatory response when cardiovascular disease was absent. CONCLUSION: The combination of cardiovascular disease and a pro-inflammatory cytokine response may be associated with cognitive impairment and dementia.

Atherosclerosis and cognitive impairment are linked in the elderly. The Leiden 85-plus Study.

Post-mortem analyses suggest that atherosclerosis more often contributes to late-onset dementia than hitherto expected. We set out to further unravel the relation between atherosclerosis and cognitive impairment. We therefore tested the hypothesis that the number of cardiovascular pathologies is positively associated with cognitive impairment in elderly subjects, and that the smaller number of cardiovascular pathologies in women explains the better cognitive function of elderly women. Within the Leiden 85-plus Study, we assessed the atherosclerotic burden by counting the number of cardiovascular pathologies in the medical histories of a population-based sample of 599 subjects aged 85 years (response 87%). Significantly more men than women had a history of cardiovascular pathologies (67% compared to 59%, P<0.001). In addition, cognitive function was assessed. All subjects completed the Mini-Mental State Examination (MMSE). Cognitive speed and memory were determined with specific neuro-psychological tests in those with a MMSE-score above 18 points. There was a highly significant dose-response relationship between the number of cardiovascular pathologies and cognitive impairment for both men and women. The median MMSE-score was 26 points in subjects without cardiovascular disease and decreased to 25 points for subjects who had two or more cardiovascular pathologies (P for trend =0.003). Similar associations were found for cognitive speed but not for memory. Our data confirm that in old age atherosclerosis significantly contributes to cognitive impairment. Since treatments for atherosclerosis appear to be particularly effective in elderly people, we consider our finding of utmost clinical importance in possibly preventing cognitive impairment and late-onset dementia.

Testing cognitive function in elderly populations: the PROSPER study. PROspective Study of Pravastatin in the Elderly at Risk.

OBJECTIVES: For large scale follow up studies with non-demented patients in which cognition is an endpoint, there is a need for short, inexpensive, sensitive, and reliable neuropsychological tests that are suitable for repeated measurements. The commonly used Mini-Mental-State-Examination fulfils only the first two requirements. METHODS: In the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER), 5804 elderly subjects aged 70 to 82 years were examined using a learning test (memory), a coding test (general speed), and a short version of the Stroop test (attention). Data presented here were collected at dual baseline, before randomisation for active treatment. RESULTS: The tests proved to be reliable (with test/retest reliabilities ranging from acceptable (r=0.63) to high (r=0.88) and sensitive to detect small differences in subjects from different age categories. All tests showed significant practice effects: performance increased from the first measurement to the first follow up after two weeks. CONCLUSION: Normative data are provided that can be used for one time neuropsychological testing as well as for assessing individual and group change. Methods for analysing cognitive change are proposed.

Predictors of attrition in a longitudinal cognitive aging study: the Maastricht Aging Study (MAAS).

A large sample of older participants of the Maastricht Aging Study (MAAS) were compared to drop-outs at the 3-year follow-up with respect to socio-demographic, health, and cognitive characteristics. In addition, the impact of selective drop-out on measures of cognitive change was examined. To this end, hypothetical scores were estimated for drop-outs by using single and multiple imputation methods. Of the initial sample of 539 subjects, aged 49 years and older at baseline, 116 (22 %) did not return for the follow-up (n = 32 had died, n = 84 refused participation). Drop-outs who refused to participate in the follow-up were more often women, had lower educational levels, and had lower baseline scores on neurocognitive tests. Follow-up drop-outs who had died were more often men, older, and had a poorer performance on cognitive tests than the follow-up participants. Although follow-up participants and drop-outs differed in terms of socio-demographic and cognitive characteristics, attrition appeared to have little effect on the estimates of cognitive change.

Cognitive function in the oldest old: women perform better than men.

OBJECTIVE: Limited formal education is associated with poor cognitive function. This could explain sex differences in cognitive function in the oldest old. Whether limited formal education explains differences in cognitive function between elderly women and men was explored. METHODS: The Leiden 85-plus Study is a population based study investigating all 85 year old inhabitants of Leiden with an overall response rate of 87%. A sample of 599 participants were visited at their place of residence. The mini mental state examination was completed by all participants. Cognitive speed and memory were determined with four neuropsychological tests in participants with a mini mental state examination score higher than 18 points. RESULTS: The proportion of women with limited formal education was significantly higher than that of men (70% v 53%, p=0.001), but women had better scores for cognitive speed and memory than men (p<0.05). After adjustment for differences in limited formal education and the presence of depressive symptoms, the odds ratio for women to have a higher cognitive speed than men was 1.7 (95% CI; 1.0 to 2.6), and for them to have a better memory the odds ratio was 1.8 (95%CI; 1.2 to 2.7). CONCLUSION: Women have a better cognitive function than men, despite their lower level of formal education. Limited formal education alone, therefore, cannot explain the differences in cognitive function in women and men. These findings support the alternative hypothesis that biological differences, such as atherosclerosis, between women and men account for the sex differences in cognitive decline.

The assessment of postoperative cognitive function.

Postoperative cognitive function (POCD) has been subject to extensive research. In the literature, large differences are apparent in methodology such as the test batteries, the interval between sessions, the endpoints to be analysed, statistical methods, and how neuropsychological deficits are defined. Traditionally, intelligence tests or tests developed for clinical neuropsychology have been used. The tests for detecting POCD should be based on well-described sensitivity and suitability in relation to surgical patients. In tests using scores, floor/ceiling effects may compromise the evaluation if the tests are either too easy or to difficult. Uncontrolled testing facilities and change of test personnel may affect the test performance. Practice effects are pronounced in neuropsychological tests but have generally been ignored. The use of a suitable normative population is essential to allow correction for practice effects and variability between sessions. Missing follow-up may severely compromise valid conclusions since subjects unable or unwilling to be examined are particularly prone to suffer from POCD. In the statistical analysis of the test results, the evaluation should be based on differences between pre- and postoperative performance. Parametric statistical tests are not relevant unless the appropriate Gaussian distributions are present, perhaps after transformation of data. The definition of cognitive dysfunction should be restrictive and the criteria should be fulfilled in only a small proportion of volunteers. In the literature, these requirements often have not been fulfilled. This precludes a reasonable estimation of the incidence of POCD and the conclusions of comparative studies should be interpreted with great caution. In this review article, we present a number of recommendations for the design and execution of studies within this area. In addition, the critical reader may use these recommendations in the evaluation of the literature.

Does migraine headache affect cognitive function in the elderly? Report from the Maastricht Aging Study (MAAS).

The aim of this study was to examine two aspects of cognitive functioning-information processing speed and memory-in both young/middle-aged and older subjects with and without migraine, using data from a large population-based sample. We found that, although age had a large effect on processing speed and memory, migraine did not influence cognitive performance. In addition, there was no significant interaction between age and migraine on processing speed and memory. Our results suggest that, in the general population, migraine does not seriously affect cognitive functioning in young/middle-aged or older adults.

Pesticide exposure and risk of mild cognitive dysfunction.

Little is known about the adverse effects of substances, such as pesticides and metals, on the development of mild cognitive dysfunction (MCD). Cross-sectional and prospective data from the Maastricht Aging Study were used to find out the potential neurotoxicity of particular substances. Exposure to pesticides, for example by arable farmers and gardeners, was associated with increased risks of MCD. Exposure to metals and organic solvents was not associated with MCD. Our findings might reflect subtle changes in brain function among people exposed to pesticides.

Mild hearing impairment can reduce verbal memory performance in a healthy adult population.

We studied to what extent immediate and delayed recall in an auditory verbal learning paradigm was affected by basic information processing speed (digit copying) and hearing acuity (average hearing acuity at 1, 2 and 4 KHz at the better ear). A group of 453 individuals in the age between 23 and 82 years with no overt hearing pathology was recruited from a larger study of cognitive aging (Maastricht Aging Study, MAAS). After controlling for age, sex, educational level, and processing speed it was found that a mild to moderate hearing loss predicted lower verbal memory performance. Auditory administered verbal memory tests can underestimate true memory performance, particularly in older individuals with unknown hearing status.

Habitual caffeine consumption and its relation to memory, attention, planning capacity and psychomotor performance across multiple age groups.

The present study evaluated the association between habitual caffeine intake via coffee and tea and cognitive performance. This was done as part of a larger research programme into the determinants of cognitive ageing (the Maastricht Aging Study: MAAS). Possible withdrawal effects that may have explained in part the positive association between performance and intake in an earlier study were controlled for. In addition, all cognitive tests in this study were administered under strict laboratory conditions. A group of 1875 healthy adults, stratified for age (range 24 - 81 years), sex, and general ability, were screened for habitual intake of coffee and tea and took part in extensive cognitive testing. Multiple regression analysis with control for age, sex, socio-demographic variables, and substance use showed that habitual caffeine consumption was significantly related to better long-term memory performance and faster locomotor speed. No relationships were found between habitual caffeine consumption and short-term memory, information processing, planning, and attention as measured with the Stroop Test. Moreover, no difference in sensitivity to caffeine intake between different age groups was found, suggesting that caffeine intake did not counteract age-related cognitive decline. Several recommendations are made to improve the design of future studies in this field. Copyright 2000 John Wiley & Sons, Ltd.

Cognition after major surgery in the elderly: test performance and complaints.

There is evidence that older people in particular have a higher risk of cognitive dysfunction after surgery under general anaesthesia. We have investigated the severity and character of postoperative cognitive dysfunction after major non-cardiac surgery in patients older than 65 yr. Also, cognitive complaints were studied. Cognitive function was assessed using cognitive tests measuring memory and attention, such as ability to shift between two sequences, ability to ward off distractions, simple cognitive speed and speed of general information processing. These tests were performed before, 1 week (short-term) and 3 months (long-term) after surgery. Cognitive performance of the patients was compared with that of healthy subjects not undergoing surgery who were also subjected to repeated cognitive measurements. After 1 week, patients had a poorer performance on tests measuring simple cognitive speed and speed of general information processing. Three months after surgery, patients and controls showed improved cognitive performance compared with the first measurement. These results suggest that major non-cardiac surgery in older patients causes short-term but not long-term cognitive dysfunction. However, after 6 months, 14 of 48 patients (29%) reported having experienced a decline in cognitive abilities after discharge from hospital. Eight of these 14 patients (17%) were still experiencing these cognitive complaints and reported 'not being the same since the operation'. These findings emphasize that cognitive complaints after major surgery may not reflect actual changes in cognitive performance but may be caused by other factors such as depression or awareness of age-related changes.

Is nondipping in 24 h ambulatory blood pressure related to cognitive dysfunction?

OBJECTIVE: Associations between the outcome of 24 h ambulatory monitoring and cognitive performance were studied in order to evaluate the potential relevance of ambulant blood pressure status to brain function. It was hypothesized that a small daytime-night-time difference in mean blood pressure (nondipping) is associated with reduced cognitive performance, in line with studies in hypertensive subjects that have reported associations between nondipping and target-organ damage. METHODS: The study followed a cross-sectional design and was part of a larger research programme on determinants of cognitive aging (Maastricht Aging Study, MAAS). A group of 115 community residents aged 28-82 years was recruited from a general practice population and screened for cardiovascular events and medication use. All underwent 24 h blood pressure monitoring. Cognitive performance was measured with tests of verbal memory, attention, simple speed and information processing speed. RESULTS: Mean daytime or night-time levels of both systolic and diastolic blood pressure were unrelated to cognitive outcome, when age, sex and educational level were controlled for. Differences between mean daytime and night-time blood pressure (based on both narrow and wide measurement intervals for day and night-time periods) were positively associated with memory function (5-9% of additional variance explained) and one sporadic positive association was found on the sensorimotor speed score (4%). Nondippers (n=15) showed lower levels of both memory and sensorimotor speed scores. CONCLUSIONS: Ambulatory blood pressure status was not associated with cognitive performance. A reduced nocturnal blood pressure drop was associated with quite specific cognitive deficits, but the underlying mechanism remains to be determined.

An operation under general anesthesia as a risk factor for age-related cognitive decline: results from a large cross-sectional population study.

OBJECTIVE: To evaluate the factor 'operation under general anesthesia' as a possible risk factor for age-related cognitive decline. DESIGN: A retrospective, population-based, cross-sectional study. SETTING: Maastricht Aging Study (MAAS), Maastricht, The Netherlands. PARTICIPANTS: 1257 normal healthy subjects aged 24 to 86 years. Of the 1257 healthy subjects, 946 subjects appeared to have undergone at least one operation under general anesthesia. MEASUREMENTS: The history of an operation under general anesthesia, number of operations, duration of anesthesia, cognitive performance, subjective health, and subjective memory were measured. RESULTS: A history of an operation under general anesthesia, the number of operations, and the total duration of anesthesia significantly contributed to the number of subjective health-related complaints but did not predict cognitive performance or memory complaints. Subjects with a history of an operation under general anesthesia felt less healthy than subjects who had never undergone an operation under general anesthesia. No interactions with age were found. CONCLUSION: The present study found no support for the notion that a history of an operation under general anesthesia is a determinant or risk factor for accelerated age-related cognitive decline.

[The Maastricht aging study (MAAS). The longitudinal perspective of cognitive aging]. / De Maastricht aging study (MAAS). Het longitudinaal perspectief van cognitieve veroudering.

The Maastricht Aging Study (MAAS) was designed to specify the usual and pathological aging of cognitive function. In short, the main questions of MAAS are: who deteriorates when in which aspects of cognitive function, and what biomedical or psychosocial factors can be identified that may act as mediators in this process? The study comprises four independent panel studies in which a group of 1,900 initially healthy individuals are followed for a period of 12 years with respect to health characteristics and neurocognitive status. For this purpose a sample was drawn from a patient register of collaborating general practitioners, stratified by age (range 24 to 81 years), sex and general ability level. Rationale and design of MAAS are discussed and some findings from the cross-sectional baseline measurement are summarized: general aspects of memory and attention in aging, cognitive functioning after brain trauma and general anesthesia, physical condition (fitness, morbidity and vascular risk factors, such as blood pressure) as predictors of cognitive function, and finally cognitive complaints and metamemory.

Effects of age on performance in a finger-precuing task.

This study investigated age-related precuing effects in the finger-precuing task (J. Miller, 1982). In this task, a spatial precue provides partial advance information about which fingers to use for responding. Results indicated a substantial age-related deficit in preparing 2 fingers on 2 hands, but not on 1 hand. This disparate set of findings does not provide strong support for A. A. Hartley's (1993) hypothesis that anterior brain attention systems responsible for selection-for-action are compromised with advancing age. Finally, the authors report that advancing age increasingly slows reaction time more to the inner than to the outer stimulus-response positions. A possible mechanism of this age-related bowed stimulus-response position effect is discussed.

The relation between morbidity and cognitive performance in a normal aging population.

BACKGROUND: Factors related to physical health have been implicated in both normal and pathological aging of cognitive abilities. To substantiate this notion, we studied existing morbidity, as diagnosed by the general practitioner according to well-defined criteria, as a potential predictor of cognitive test performance. METHODS: A sample of 1360 individuals, aged 24-81 years and living in the community, was stratified for age, sex, and general ability. Active and total morbidity in this group were classified according to the International Classification of Primary Care. Neurocognitive tests were used to assess the domains of verbal memory, sensorimotor speed, and cognitive flexibility. RESULTS: Multiple regression analyses with adjustment for age, sex, and educational level showed both insulin-dependent and noninsulin-dependent diabetes to be negatively associated with all cognitive measures. More specific negative associations were found for chronic bronchitis (performance speed) and presbyacusia (memory). Single or aggregated cardiovascular morbidity (including hypertension) was unrelated to test performance. CONCLUSIONS: Existing morbidity as a whole contributes only modestly (up to 3.5%) to total variance in cognitive function. However, some specific, relatively common diseases of the elderly, such as diabetes and chronic bronchitis, may aggravate the age-related decline in cognitive ability.

Long-term postoperative cognitive dysfunction in the elderly ISPOCD1 study. ISPOCD investigators. International Study of Post-Operative Cognitive Dysfunction.

BACKGROUND: Long-term postoperative cognitive dysfunction may occur in the elderly. Age may be a risk factor and hypoxaemia and arterial hypotension causative factors. We investigated these hypotheses in an international multicentre study. METHODS: 1218 patients aged at least 60 years completed neuropsychological tests before and 1 week and 3 months after major non-cardiac surgery. We measured oxygen saturation by continuous pulse oximetry before surgery and throughout the day of and the first 3 nights after surgery. We recorded blood pressure every 3 min by oscillometry during the operation and every 15-30 min for the rest of that day and night. We identified postoperative cognitive dysfunction with neuropsychological tests compared with controls recruited from the UK (n=176) and the same countries as study centres (n=145). FINDINGS: Postoperative cognitive dysfunction was present in 266 (25.8% [95% CI 23.1-28.5]) of patients 1 week after surgery and in 94 (9.9% [8.1-12.0]) 3 months after surgery, compared with 3.4% and 2.8%, respectively, of UK controls (p<0.0001 and p=0.0037, respectively). Increasing age and duration of anaesthesia, little education, a second operation, postoperative infections, and respiratory complications were risk factors for early postoperative cognitive dysfunction, but only age was a risk factor for late postoperative cognitive dysfunction. Hypoxaemia and hypotension were not significant risk factors at any time. INTERPRETATION: Our findings have implications for studies of the causes of cognitive decline and, in clinical practice, for the information given to patients before surgery.

Leeftijdsgeassocieerde cognitieve functiestoornissen: Cognitive aging in a longitudinal perspective: the Maastricht Aging Study (MAAS).

Cognitive dysfunctions in old individuals can be a precursor of dementia. The Maastricht Aging Study (MAAS) was designed to characterize the usual and pathological aging of cognitive function. The study involves a group of 1,900 initially healthy individuals who will be followed-upfor a period of 12 years with respect to health characteristics and neurocognitive status. For this purpose a sample was drawn from a patient register of collaborating family practices, stratified for age (range 24 to 81 years), sex and general ability level. Rationale and design of MAAS are discussed and also some findings from the cross-sectional baseline measurement: general aspects of memory and attention, cognitive functioning after brain trauma and general anesthesia, physical condition (fitness, morbidity and vascular risk factors) as predictor of cognitive function, and finally cognitive complaints and metamemory.

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.