A longitudinal study of factors predicting change in cognitive test scores over time, in an older hypertensive population

Smoking is associated with impaired verbal learning and memory performance in women more than men

Vascular contributions to cognitive impairment and dementia (VCID) include structural and functional blood vessel injuries linked to poor neurocognitive outcomes. Smoking might indirectly increase the likelihood of cognitive impairment by exacerbating vascular disease risks. Sex disparities in VCID have been reported, however, few studies have assessed the sex-specific relationships between smoking and memory performance and with contradictory results. We investigated the associations between sex, smoking, and cardiovascular disease with verbal learning and memory function. Using MindCrowd, an observational web-based cohort of ~ 70,000 people aged 18-85, we investigated whether sex modifies the relationship between smoking and cardiovascular disease with verbal memory performance. We found significant interactions in that smoking is associated with verbal learning performance more in women and cardiovascular disease more in men across a wide age range. These results suggest that smoking and cardiovascular disease may impact verbal learning and memory throughout adulthood differently for men and women.

Depression and Cognitive Impairment in Institutionalized Older Adults

BACKGROUND

In the last three decades, the relationship between depression and cognition in geriatric patients has been a popular topic among researchers and clinicians. Clinical and epidemiological research has focused on the identification of risk factors that could be modified in pre-dementia syndromes, at a preclinical and early clinical stage of dementia disorders, with specific attention to the role of depression. The objective of this work was to determine the relationship between depressive disorder and cognitive deterioration in institutionalized older adults.

METHODS

In this descriptive, correlational study, data were gathered from two nursing homes in the province of Jaen (Spain), from a random sample of 140 older adults (70 nondependent and 70 dependent). The variables were measured using comprehensive geriatric assessment, the Cambridge Cognitive Test (CAMCOG), and the Geriatric Depression Scale (GDS).

RESULTS

Depression was correlated with cognitive level in the nondependent older adult sample (r = -0.471, p = 0.004). Age was inversely associated with the score obtained in the CAMCOG of the nondependent older adult sample (r = -0.352, p = 0.038). The functional capacity in several activities of daily living was correlated with the score obtained in the CAMCOG in each of the two groups. Depression was more prevalent in the dependent than in the nondependent older adults (82.85 vs. 57.14%). No association was observed between institutionalization time and the score obtained on the cognitive and affective scales (GDS and CAMCOG) in both groups (GDS-nondependent, r = -0.209, p = 0.234; CAMCOG-nondependent, r = 0.007, p = 0.967; GDS-dependent, r = 0.251, p = 0.152; CAMCOG-dependent, r = -0.021, p = 0.907).

CONCLUSION

Depressive symptomatology is associated with cognitive deterioration. Depression is prevalent in institutions that care for older, more dependent adults.

Genome-wide association study of rate of cognitive decline in Alzheimer's disease patients identifies novel genes and pathways

INTRODUCTION

Variability exists in the disease trajectories of Alzheimer's disease (AD) patients. We performed a genome-wide association study to examine rate of cognitive decline (ROD) in patients with AD.

METHODS

We tested for interactions between genetic variants and time since diagnosis to predict the ROD of a composite cognitive score in 3946 AD cases and performed pathway analysis on the top genes.

RESULTS

Suggestive associations (P < 1.0 × 10-6 ) were observed on chromosome 15 in DNA polymerase-γ (rs3176205, P = 1.11 × 10-7 ), chromosome 7 (rs60465337,P = 4.06 × 10-7 ) in contactin-associated protein-2, in RP11-384F7.1 on chromosome 3 (rs28853947, P = 5.93 × 10-7 ), family with sequence similarity 214 member-A on chromosome 15 (rs2899492, P = 5.94 × 10-7 ), and intergenic regions on chromosomes 16 (rs4949142, P = 4.02 × 10-7 ) and 4 (rs1304013, P = 7.73 × 10-7 ). Significant pathways involving neuronal development and function, apoptosis, memory, and inflammation were identified.

DISCUSSION

Pathways related to AD, intelligence, and neurological function determine AD progression, while previously identified AD risk variants, including the apolipoprotein (APOE) ε4 and ε2 variants, do not have a major impact.

Depression is more strongly associated with cognition in elderly women than men with type 2 diabetes

Depression and cognitive impairment are highly prevalent in type 2 diabetes (T2D), yet little is known about how their relationship varies by sex. We examined this question in a large T2D sample (N = 897) of non-demented elderly (≥ 65) participating in the Israel Diabetes and Cognitive Decline (IDCD) Study. Cognition was evaluated by a comprehensive neuropsychological battery and depressive symptoms were assessed by the Geriatric Depression Scale (GDS). The results showed that in all but the executive function domain, the association of depressive symptoms with poorer cognitive function was stronger in women than men, with a significant interaction for language/semantic categorization and missed significance for episodic memory. When defining clinical depression as GDS of ≥6, women with depression had significantly poorer language/semantic categorization, episodic memory, and overall cognitive function. Inclusion of antidepressants in the model did not alter substantively the associations. Our results suggest that depressed T2D women may have poorer cognitive performance, highlighting the significance of sex-specific personalized management of depression in elderly diabetics.

Depressive Symptoms During Adolescence Predict Adulthood Obesity Among Black Females

AIM

This study aimed to investigate gender differences in the association between baseline depressive symptoms and subsequent changes in obesity in a sample of urban Black youth in the USA.

METHODS

The current study followed 681 Black youth (335 male and 346 female) for up to 18 years from 1994 to 2012. All youth were selected from an economically disadvantaged urban area in MI, USA. The main independent variable was baseline depressive symptoms measured in 1994. The main outcome was change in body mass index (BMI) from 1999 to 2012, calculated based on self-reported height and weight. Scio-demographics (age, number of parents in the household, and parental employment) were covariates. Gender was the focal moderator. We used linear regressions to test the predictive role of baseline depressive symptoms on change in BMI (from 1999 to 2012) in the pooled sample, and also based on gender.

RESULTS

Among Black females, but not Black males, baseline depressive symptoms predicted the BMI change from 1999 to 2012. The association remained significant for Black females after controlling for covariates.

CONCLUSION

High depressive symptoms at baseline better predict BMI change over the next decade for female than male Black youth. As a result, detection and reduction of depressive symptoms may be a vital element of obesity prevention programs for Black females. Policies and programs that address determinants of psychological distress as a strategy to prevent obesity among female Black youth in disadvantaged neighborhoods may be especially useful.

Gender Differences in Alzheimer Disease: Brain Atrophy, Histopathology Burden, and Cognition

Multiple studies suggest that females are affected by Alzheimer disease (AD) more severely and more frequently than males. Other studies have failed to confirm this and the issue remains controversial. Difficulties include differences in study methods and male versus female life expectancy. Another element of uncertainty is that the majority of studies have lacked neuropathological confirmation of the AD diagnosis. We compared clinical and pathological AD severity in 1028 deceased subjects with full neuropathological examinations. The age of dementia onset did not differ by gender but females were more likely to proceed to very severe clinical and pathological disease, with significantly higher proportions having a Mini-Mental State Examination score of 5 or less and Braak stage VI neurofibrillary degeneration. Median neuritic plaque densities were similar in females and males with AD but females had significantly greater tangle density scores. In addition, we found that AD-control brain weight differences were significantly greater for females, even after adjustment for age, disease duration, and comorbid conditions. These findings suggest that when they are affected by AD, females progress more often to severe cognitive dysfunction, due to more severe neurofibrillary degeneration, and greater loss of brain parenchyma.

Nationwide Inpatient Prevalence, Predictors, and Outcomes of Alzheimer's Disease among Older Adults in the United States, 2002-2012

In the inpatient setting, prevalence, predictors, and outcomes [mortality risk (MR), length of stay (LOS), and total charges (TC)] of Alzheimer's disease (AD) are largely unknown. We used data on older adults (60+ y) from the Nationwide Inpatient Sample (NIS) 2002-2012. AD prevalence was ∼3.12% in 2012 (total weighted discharges with AD ± standard error: 474, 410 ± 6,276). Co-morbidities prevailing more in AD inpatient admissions included depression (OR = 1.67, 95% CI: 1.63-1.71, p <  0.001), fluid/electrolyte disorders (OR = 1.25, 95% CI: 1.22-1.27, p <  0.001), weight loss (OR = 1.26, 95% CI: 1.22-1.30, p <  0.001), and psychosis (OR = 2.59, 95% CI: 2.47-2.71, p <  0.001), with mean total co-morbidities increasing over time. AD was linked to higher MR and longer LOS, but lower TC. TC rose in AD, while MR and LOS dropped markedly over time. In AD, co-morbidities predicting simultaneously higher MR, TC, and LOS (2012) included congestive heart failure, chronic pulmonary disease, coagulopathy, fluid/electrolyte disorders, metastatic cancer, paralysis, pulmonary circulatory disorders, and weight loss. In sum, co-morbidities and TC increased over time in AD, while MR and LOS dropped. Few co-morbidities predicted occurrence of AD or adverse outcomes in AD.

Distribution of depressive disorders in the elderly

BACKGROUND

The community-based mental health studies have revealed that the point prevalence of depressive disorders in the elderly population of the world varies between 10% and 20% depending on cultural situations.

OBJECTIVE

To determine the median prevalence rates of depressive disorders in the elderly population of India and various other countries in the world.

MATERIALS AND METHODS

A retrospective study based on meta-analysis of various study reports.

SETTING

Community-based mental health surveys on geriatric depressive disorders conducted in the continents of Asia, Europe, Australia, North America, and South America.

STUDY PERIOD

All the studies that constituted the sample were conducted between 1955 and 2005.

SAMPLE SIZE

After applying the inclusion and exclusion criteria on published and indexed articles, 74 original research studies that surveyed a total of 4,87,275 elderly individuals in the age group of 60 years and above, residing in various parts of the world were included for the final analysis.

INCLUSION CRITERIA

The researchers had included only community-based cross-sectional surveys and some prospective studies that had not excluded depression on baseline. These studies were conducted on homogenous community of elderly population in the world, who were selected by simple random sampling technique.

EXCLUSION CRITERIA

All the unpublished reports and unavailable or unanalyzed or inaccessible articles from the internet were excluded from the study.

STATISTICAL ANALYSIS

The median prevalence rate and its corresponding interquartile range (IQR), Chi-square test, and Chi-square for Linear Trend were applied. A P value < 0.05 was considered as statistically significant.

RESULTS AND CONCLUSION

The median prevalence rate of depressive disorders in the world for the elderly population was determined to be 10.3% [IQR = (4.7%-16.0%)]. The median prevalence rate of depression among the elderly Indian population was determined to be 21.9% [IQR = (11.6%-31.1%)]. Although there was a significant decrease trend in world prevalence of geriatric depression, it was significantly higher among Indians in recent years than the rest of the world.

Blood pressure lowering in patients without prior cerebrovascular disease for prevention of cognitive impairment and dementia

BACKGROUND

This is an update of a previous review (McGuinness 2006).Hypertension and cognitive impairment are prevalent in older people. Hypertension is a direct risk factor for vascular dementia (VaD) and recent studies have suggested hypertension impacts upon prevalence of Alzheimer's disease (AD). Therefore does treatment of hypertension prevent cognitive decline?

OBJECTIVES

To assess the effects of blood pressure lowering treatments for the prevention of dementia and cognitive decline in patients with hypertension but no history of cerebrovascular disease.

SEARCH STRATEGY

The Specialized Register of the Cochrane Dementia and Cognitive Improvement Group, The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL, LILACS as well as many trials databases and grey literature sources were searched on 13 February 2008 using the terms: hypertens$ OR anti-hypertens$.

SELECTION CRITERIA

Randomized, double-blind, placebo controlled trials in which pharmacological or non-pharmacological interventions to lower blood pressure were given for at least six months.

DATA COLLECTION AND ANALYSIS

Two independent reviewers assessed trial quality and extracted data. The following outcomes were assessed: incidence of dementia, cognitive change from baseline, blood pressure level, incidence and severity of side effects and quality of life.

MAIN RESULTS

Four trials including 15,936 hypertensive subjects were identified. Average age was 75.4 years. Mean blood pressure at entry across the studies was 171/86 mmHg. The combined result of the four trials reporting incidence of dementia indicated no significant difference between treatment and placebo (236/7767 versus 259/7660, Odds Ratio (OR) = 0.89, 95% CI 0.74, 1.07) and there was considerable heterogeneity between the trials. The combined results from the three trials reporting change in Mini Mental State Examination (MMSE) did not indicate a benefit from treatment (Weighted Mean Difference (WMD) = 0.42, 95% CI 0.30, 0.53). Both systolic and diastolic blood pressure levels were reduced significantly in the three trials assessing this outcome (WMD = -10.22, 95% CI -10.78, -9.66 for systolic blood pressure, WMD = -4.28, 95% CI -4.58, -3.98 for diastolic blood pressure). Three trials reported adverse effects requiring discontinuation of treatment and the combined results indicated no significant difference (OR = 1.01, 95% CI 0.92, 1.11). When analysed separately, however, more patients on placebo in Syst Eur 1997 were likely to discontinue treatment due to side effects; the converse was true in SHEP 1991. Quality of life data could not be analysed in the four studies. Analysis of the included studies in this review was problematic as many of the control subjects received antihypertensive treatment because their blood pressures exceeded pre-set values. In most cases the study became a comparison between the study drug against a usual antihypertensive regimen.

AUTHORS' CONCLUSIONS

There is no convincing evidence from the trials identified that blood pressure lowering in late-life prevents the development of dementia or cognitive impairment in hypertensive patients with no apparent prior cerebrovascular disease. There were significant problems identified with analysing the data, however, due to the number of patients lost to follow-up and the number of placebo patients who received active treatment. This introduced bias. More robust results may be obtained by conducting a meta-analysis using individual patient data.

Prevalence and distribution of cognitive impairment no dementia (CIND) among the aged population and the analysis of socio-demographic characteristics: the community-based cross-sectional study

The epidemiology on "cognitive impairment no dementia" (CIND) and its natural history are of great importance for understanding the transition from normal aging to dementia. Epidemiologic studies of CIND, however, are limited in China. The goal of our study was to determine the prevalence and distribution of CIND in the aged population and analyze socio-demographic factors. To accomplish this, we performed cluster random sampling of 6192 people aged over 65 years in Taiyuan, a metropolitan city located in northern China. Socio-demographic factors were surveyed by self-administered questionnaires. Neuropsychologic testing consisting of the Mini-Mental State Examination, Boston Naming Test, Trail Making Tests A and B, Block Design, Rey Auditory Verbal Learning Test, Visual Reproduction, Logical Memory, letter and category fluency, the National Adult Reading Test, the Geriatric Depression Scale, and the "state" section of the State-Trait Anxiety Inventory was also obtained. Pearson chi statistics and odds ratio with 95% confidence intervals were used to identify the relationship between CIND and socio-demographic factors. Logistic regression modeling was undertaken to identify potential risk factors. Results showed that an overall prevalence of CIND was 9.70% (95% confidence intervals: 9.62%-9.77%). Univariate analyses showed that the prevalence of CIND differed significantly according to age, sex, education level, monthly household income, and marital status (P<0.01), but not by occupational achievement (P>0.05). In a multiple logistic regression analysis, age, sex, marital status, educational level, and occupation were significantly associated with increased risk for CIND (P<0.01). This study confirms the high prevalence of CIND among the elderly population of China, similar to previous epidemiologic studies in other countries. Nearly all socio-demographic characteristics are associated with CIND. The putative risk factors identified merit further study.

Smoking, dementia and cognitive decline in the elderly, a systematic review

BACKGROUND

Nicotine may aid reaction time, learning and memory, but smoking increases cardiovascular risk. Cardiovascular risk factors have been linked to increased risk of dementia. A previous meta-analysis found that current smokers were at higher risk of subsequent dementia, Alzheimer's disease, vascular dementia and cognitive decline.

METHODS

In order to update and examine this further a systematic review and meta-analysis was carried out using different search and inclusion criteria, database selection and more recent publications. Both reviews were restricted to those aged 65 and over.

RESULTS

The review reported here found a significantly increased risk of Alzheimer's disease with current smoking and a likely but not significantly increased risk of vascular dementia, dementia unspecified and cognitive decline. Neither review found clear relationships with former smoking.

CONCLUSION

Current smoking increases risk of Alzheimer's disease and may increase risk of other dementias. This reinforces need for smoking cessation, particularly aged 65 and over. Nicotine alone needs further investigation.

Obesity and central obesity as risk factors for incident dementia and its subtypes: a systematic review and meta-analysis

While dementia affects 6-10% of persons 65 years or older, industrialized countries have witnessed an alarming rise in obesity. However, obesity's influence on dementia remains poorly understood. We conducted a systematic review and meta-analysis. PUBMED search (1995-2007) resulted in 10 relevant prospective cohort studies of older adults (40-80 years at baseline) with end points being dementia and predictors including adiposity measures, such as body mass index (BMI) and waist circumference (WC). There was a significant U-shaped association between BMI and dementia (P = 0.034), with dementia risk increased for obesity and underweight. Pooled odds ratios (OR) and 95% confidence intervals (CI) for underweight, overweight and obesity compared with normal weight in relation to incident dementia were: 1.36 (1.07, 1.73), 0.88 (0.60, 1.27) and 1.42 (0.93, 2.18) respectively. Pooled ORs and 95% CI for obesity and incident Alzheimer's disease (AD) and vascular dementia were 1.80 (1.00, 3.29) vs. 1.73 (0.47, 6.31) and were stronger in studies with long follow-up (>10 years) and young baseline age (<60 years). Weight gain and high WC or skin-fold thickness increased risks of dementia in all included studies. The meta-analysis shows a moderate association between obesity and the risks for dementia and AD. Future studies are needed to understand optimal weight and biological mechanisms.

Neurocognitive costs and benefits of psychotropic medications in older adults

Psychotropic medications are widely used in older adults and may cause neurocognitive deficits. Older adults are at increased risk of developing adverse effects because of age-related pharmacodynamic and pharmacokinetic changes. This article provides a comprehensive review of the undesirable, and at times beneficial, effects of psychotropic medications. The review covers a wide range of medications that impair executive function, memory, and attention, as well as a much smaller group of medications that lead to improved neurocognitive function. Some of the most commonly used psychotropic medications in older adults, namely, antidepressants, sedatives, and hypnotics, are among the drugs that most consistently lead to cognitive impairments. Medications with anticholinergic properties almost invariably lead to neurocognitive dysfunction, despite symptom improvement. The neurocognitive costs and benefits of psychiatric medications should be considered in the context of disease treatment in older adults.

Prevention of Alzheimer's disease

The already considerable public health burden of Alzheimer's disease will likely worsen as populations around the world age. As a result, there is considerable motivation to develop effective strategies for preventing the disease. A wide variety of such strategies are under investigation and include pharmaceuticals, nutriceuticals, diet, physical activity and cognitive activity. We review here the most promising candidates and the epidemiologic evidence for their efficacy. Although none of these have yet to be definitively shown to prevent Alzheimer's disease, further research should help to clarify what role they may play in reducing the burden of this disease.

New treatment options for vascular dementia

Clinical trials performed in patients defined as affected by vascular dementia have so far achieved unsatisfactory results. Recently, preliminary results have been published demonstrating a generally stable performance in cognitive tasks, with a slightly better performance in executive functions and a better behavioral response, in a group of subcortical vascular dementia patients treated with rivastigmine. A recent proposal is that vascular dementia is not an univocal and unique pathology: the etiopathogenesis of multi-infarct dementia is quite different to that of subcortical vascular dementia. Future studies need to consider those entities separately to obtain good results for a group of patients for whom, until now, there have been few therapeutic options. The aim of this review is to summarize the consolidated notions, perspectives and new therapeutic options to better define the possible future treatment of vascular dementia.

Relationship between serum NR2a antibodies and cognitive dysfunction in systemic lupus erythematosus

OBJECTIVE

To assess the association between serum NR2a antibodies and cognitive dysfunction in systemic lupus erythematosus (SLE).

METHODS

The study population consisted of English-speaking adults who met American College of Rheumatology (ACR) criteria for SLE and had at least 1 serum sample stored in the Hospital for Special Surgery Autoimmune Registry and Repository. Demographic and clinical information was obtained, and patients completed the neuropsychological test battery recommended by the ACR, the Center for Epidemiologic Studies Depression Scale, and the Spielberger State-Trait Anxiety Inventory. Cognitive impairment was defined as scores >1.5 SD below the mean of age-matched published normative data on at least 2 neuropsychological tests. Sera were tested for NR2a antibodies by enzyme-linked immunosorbent assay. Performance on neuropsychological tests was compared between NR2a-positive and NR2a-negative patients.

RESULTS

Of the 93 patients, 24 (25.8%) were positive for NR2a antibodies. Of the 48 patients who were cognitively impaired based on test results, 31% were positive for NR2a antibodies, compared with 20% of those who were not cognitively impaired (P = 0.24). Among antibody-positive patients, the mean +/- SD number of neuropsychological tests with abnormal results was 2.3 +/- 2.2, compared with 2.0 +/- 1.8 in the antibody-negative group (P = 0.59). Similar nonsignificant differences were found when impairment was defined using a more stringent definition (i.e., test scores >2.0 SD below the mean) and using a neuropsychologist's clinical ratings. No association was detected between NR2a antibody positivity and depressive symptoms (P = 0.73) or anxiety (P = 0.42).

CONCLUSION

No significant association was found between NR2a antibody positivity and cognitive dysfunction, depressive symptoms, or anxiety. These results indicate that the presence of these antibodies alone does not have a direct effect on cognitive functioning or any other neuropsychiatric manifestation of SLE.

The effects of blood pressure lowering on development of cognitive impairment and dementia in patients without apparent prior cerebrovascular disease

BACKGROUND

Hypertension and cognitive impairment are prevalent in older people. It is known that hypertension is a direct risk factor for vascular dementia and recent studies have suggested hypertension also impacts upon prevalence of Alzheimer's disease. The question is therefore whether treatment of hypertension lowers the rate of cognitive decline.

OBJECTIVES

To assess the effects of blood pressure lowering treatments for the prevention of dementia and cognitive decline in patients with hypertension but no history of cerebrovascular disease.

SEARCH STRATEGY

The trials were identified through a search of CDCIG's Specialised Register, CENTRAL, MEDLINE, EMBASE, PsycINFO and CINAHL on 27 April 2005.

SELECTION CRITERIA

Randomized, double-blind, placebo controlled trials in which pharmacological or non-pharmacological interventions to lower blood pressure were given for at least six months.

DATA COLLECTION AND ANALYSIS

Two independent reviewers assessed trial quality and extracted data. The following outcomes were assessed: incidence of dementia, cognitive change from baseline, blood pressure level, incidence and severity of side effects and quality of life.

MAIN RESULTS

Three trials including 12,091 hypertensive subjects were identified. Average age was 72.8 years. Participants were recruited from industrialised countries. Mean blood pressure at entry across the studies was 170/84 mmHg. All trials instituted a stepped care approach to hypertension treatment, starting with a calcium-channel blocker, a diuretic or an angiotensin receptor blocker. The combined result of the three trials reporting incidence of dementia indicated no significant difference between treatment and placebo (Odds Ratio (OR) = 0.89, 95% CI 0.69, 1.16). Blood pressure reduction resulted in a 11% relative risk reduction of dementia in patients with no prior cerebrovascular disease but this effect was not statistically significant (p = 0.38) and there was considerable heterogeneity between the trials. The combined results from the two trials reporting change in Mini Mental State Examination (MMSE) did not indicate a benefit from treatment (Weighted Mean Difference (WMD) = 0.10, 95% CI -0.03, 0.23). Both systolic and diastolic blood pressure levels were reduced significantly in the two trials assessing this outcome (WMD = -7.53, 95% CI -8.28, -6.77 for systolic blood pressure, WMD = -3.87, 95% CI -4.25, -3.50 for diastolic blood pressure). Two trials reported adverse effects requiring discontinuation of treatment and the combined results indicated a significant benefit from placebo (OR = 1.18, 95% CI 1.06, 1.30). When analysed separately, however, more patients on placebo in SCOPE were likely to discontinue treatment due to side effects; the converse was true in SHEP 1991. Quality of life data could not be analysed in the three studies. There was difficulty with the control group in this review as many of the control subjects received antihypertensive treatment because their blood pressures exceeded pre-set values. In most cases the study became a comparison between the study drug against a usual antihypertensive regimen.

AUTHORS' CONCLUSIONS

There was no convincing evidence from the trials identified that blood pressure lowering prevents the development of dementia or cognitive impairment in hypertensive patients with no apparent prior cerebrovascular disease. There were significant problems identified with analysing the data, however, due to the number of patients lost to follow-up and the number of placebo patients given active treatment. This introduced bias. More robust results may be obtained by analysing one year data to reduce differential drop-out or by conducting a meta-analysis using individual patient data.

Sex, Age, and Training Modulate Spatial Memory in the Rhesus Monkey (Macaca mulatta)

The authors tested 90 rhesus monkeys (Macaca mulatta) on a task of spatial memory, the spatial Delayed Recognition Span Test. The results showed that performance declined significantly with age, males had greater scores than females, and the rate of apparent decline with age was greater in males than in females. Both working and reference memory declined with age, but only working memory showed sex differences. The authors compared these data with that of 22 monkeys who were trained on a simpler version of the task before formal testing. Training had no effect on males but dramatically improved working memory in young females. The results confirm a male advantage in spatial working memory at a young age and confirm a greater decline with age in males than in females. It is important to note that prior training completely reverses the deficits of young females.

Blood pressure-related cognitive decline: does age make a difference?

Systolic and diastolic blood pressures have been inversely related to cognitive performance in prospective and cross-sectional studies. However, in large, community-based samples, these findings have been limited to older adults. In this 20-year longitudinal study, we examined the relationship between baseline blood pressure and cognitive decline for 529 participants using 2 age groups (18 to 46 years and 47 to 83 years). Cognitive performance was measured over multiple examinations with the Wechsler Adult Intelligence Scale from which 4 scores were derived by factor analysis. A 2-stage growth curve method of analysis was used to model cognitive change. Results indicated that higher levels of baseline systolic blood pressure, diastolic blood pressure, mean arterial pressure, and blood pressure categories as defined by the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure were significantly associated with decline in Visualization/Fluid abilities in both younger and older age groups. Young adults are as susceptible to blood pressure-related longitudinal decline in cognitive performance as are older adults.

The prevalence of "cognitive impairment no dementia" in community-dwelling elderly: a pilot study

OBJECTIVE

To determine the prevalence of "cognitive impairment no dementia" (CIND) and "amnestic mild cognitive impairment" (aMCI) in a population sample of 70-79-year-olds and the risk factors for CIND.

METHOD

Cross sectional population survey.

SETTING

Sutherland Shire, Sydney, Australia.

SUBJECTS

150 community-dwelling 70-79-year-olds were screened by telephone, 42 of whom were assessed at home.

MEASURES

Demographics, subjective ratings of physical and emotional health and memory, cardiovascular risk factors, medications, the Mini-Mental State Examination, Boston Naming Test, Trail Making Tests A and B, Block Design, Rey Auditory Verbal Learning Test (RAVLT), Visual Reproduction, Logical Memory, letter and category fluency, the National Adult Reading Test (NART), the Geriatric Depression Scale (GDS) and the "state" section of the State-Trait Anxiety Inventory (STAI-S).

RESULTS

From the 400 subjects contacted initially, 150 consented to be interviewed and 131 eligible subjects were recruited. Of a 1-in-3 random sample of 42 subjects assessed at home, 14 (33.3%) subjects met criteria for CIND, 1 (2.4%) had possible dementia and the 27 remaining (64.3%) were cognitively normal. Four (9.5%) met criteria for aMCI. Subjects with CIND were older, had lower ranking occupations and were less likely to be currently working than those classified as cognitively normal. Ten subjects with CIND did not meet criteria for aMCI because they lacked subjective memory impairment (n = 3) or had cognitive deficits other than memory (n = 7). All subjects with aMCI met criteria for CIND.

CONCLUSIONS

One-third of individuals in this population sample met criteria for CIND. CIND is a broader definition than aMCI. Further research is needed to determine the longitudinal course and clinical utility of these definitions of cognitive impairment.

Effects of habitual cigarette smoking on higher cortical function in patients with unruptured cerebral aneurysms

Postoperative changes in higher cortical function and cerebral blood flow (CBF) were investigated in patients with unruptured cerebral aneurysms to assess the effect of habitual smoking on the known transient changes after aneurysm surgery. Fifty-six adults with unruptured cerebral aneurysms, including 11 heavy smokers (smoking index > or = 600) and 45 non-smokers, were evaluated using three neuropsychological examinations, the Mini-Mental State Examination, the Maze test, and the Kana-hiroi test, and single photon emission computed tomography to measure CBF before and after surgery. Neuropsychological changes were assessed by reliable change indices to take into account the practice effects. The scores of at least one examination decreased in 15 of 56 patients 1 month after surgery. On the Maze test, five of 11 heavy smokers and five of 45 non-smokers deteriorated after surgery, showing a significant difference (p = 0.018). The CBF in heavy smokers often decreased after surgery, but there was no statistically significant difference in logistic regression. Three months after surgery, the neuropsychological scores of 13 of the 15 deteriorated patients recovered to the preoperative level. Higher cortical function in heavy smokers with unruptured cerebral aneurysms often decreases transiently after operation, compared to non-smokers. Therefore, surgery planning for heavy smokers with unruptured cerebral aneurysms should consider this outcome.

Nicotine's effect on neural and cognitive functioning in an aging population

Tobacco is a dangerous and addictive drug being consumed by more than 13% of Americans over the age of 65. Of the people in this cohort it has been estimated that between 24% and 85% experience some form of age related cognitive decline and 30-50% of the population will be diagnosed with Alzheimer's disease by the age of 85. Recent advances in nicotine research have pointed to a number of cognitive and neurological benefits that have been linked to the ingestion of nicotine. These discoveries hold the potential of new drugs and therapies that retain and improve upon nicotine's benefits while eliminating the negative impact that both nicotine and tobacco possess. This article examines cognitive decline in the elderly and looks at nicotine's potential role in ameliorating this decline. In service to this, the neurological and cognitive actions of nicotine are reviewed, as are theories on the neurological degeneration associated with Alzheimer's disease (AD).

Social relationships, social support, and patterns of cognitive aging in healthy, high-functioning older adults: MacArthur studies of successful aging

This study examines the relationship of social ties and support to patterns of cognitive aging in the MacArthur Studies of Successful Aging (see L. F. Berkman et al., 1993), a cohort study of 1,189 initially high-functioning older adults. Baseline and longitudinal data provide information on initial levels as well as changes in cognitive performance over a 7.5-year period. Linear regression analyses revealed that participants receiving more emotional support had better baseline performance, as did those who were unmarried and those reporting greater conflict with network members. Greater baseline emotional support was also a significant predictor of better cognitive function at the 7.5-year follow-up, controlling for baseline cognitive function and known sociodemographic, behavioral, psychological, and health status predictors of cognitive aging. The findings suggest the potential value of further research on the role of the social environment in protecting against cognitive declines at older ages.

The heritability of cognitive functioning in very old adults: evidence from Danish twins aged 75 years and older

Heritable influences on cognitive functioning were investigated in a sample of 403 pairs of like-sex Danish twins aged 75 years and older. Twins completed the Mini-Mental State Examination and 3 other cognitive tests. Genetic factors accounted for 26-54% of the variance on these measures, with the balance being due to environmental factors that create differences rather than similarities among reared-together relatives. Deleting twins with severe cognitive impairment had little effect on the results, indicating that the heritability of cognitive functioning was not due entirely to genes affecting dementia. Neither age nor gender moderated twin similarity, and differential social contact could not account for correlation differences between monozygotic and dizygotic twins. These results replicate G. E. McClearn et al.'s (1997) study in indicating substantial genetic influences on late-life cognitive functioning.

An overview of common non-alzheimer dementias

Approximately 20% to 40% of dementia is caused by diseases other than Alzheimer's disease. This article reviews the major categories of non-Alzheimer dementia, including dementia associated with cerebrovascular disease, dementia associated with extrapyramidal features, and the frontotemporal dementias. Dementia associated with cerebrovascular disease is a heterogeneous condition the importance of which is often misunderstood. Dementia with Lewy bodies, the most common of the dementias associated with extrapyramidal disease, is becoming better recognized for its unique management issues. At least some of the frontotemporal dementias, which in this article encompass the progressive aphasias, have mutations in the tau gene that account for some of the phenotypic variations.

Vascular risk and cognitive impairment in an older, British, African-Caribbean population

OBJECTIVES

In an older, British, African-Caribbean population with high prevalence rates of hypertension and diabetes mellitus, we ascertained clinical vascular disease (stroke or ischemic heart disease) and vascular risk (including hypertension, diabetes, and lipid profile) and investigated their associations with cognitive impairment.

DESIGN

Cross-sectional community-based study.

SETTING

The sample was drawn from registration lists for seven primary care services in south London, United Kingdom.

PARTICIPANTS

278 individuals, age 55 to 75, who were born in a Caribbean nation.

MEASUREMENTS

Participants were interviewed and examined for cardiovascular risk factors, including a blood test for lipid profile and fibrinogen. A battery of 11 psychometric tests was administered blind to medical status. Cognitive impairment was defined on the basis of a composite measure derived from individual test scores.

RESULTS

Seventy-nine (28%) subjects were classified as having relative cognitive impairment and were compared with the remainder of the sample. Marked differences were seen between low and normal/high educational levels in the strength of associations between measures of vascular risk and cognitive impairment. Hypertension, diabetes, and raised triglycerides were significant factors in those with lower levels of education. Low fibrinogen (negatively associated), high cholesterol, and manual occupation were significant factors in those with normal/high levels of education. Physical exercise was negatively associated with cognitive impairment: an association that persisted after adjustment for age, occupation, depression, and physical disability and after excluding subjects with the most severe imipairment.

CONCLUSION

Measures of vascular risk were associated with relative cognitive impairment in this population. These associations were modified by previous educational attainment. Physical activity was negatively associated with cognitive impairment.

Long-term predictors of cognitive outcome in a cohort of older people with hypertension

BACKGROUND

Deteriorating cognitive function in late life substantially increases the risk for dementia, for other non-cognitive morbidity, for dependency, and early death.

AIMS

To identify early predictors of late-life cognitive outcome.

METHOD

Cognitive function, premorbid IQ, and cardiovascular risk exposure were recorded on 1083 subjects on entry to a hypertension treatment trial in 1983-1984. We followed up this cohort 9-12 years later to assess cognitive function with the Mini-Mental State Examination (MMSE), to update exposure status, and to obtain genomic material. Multivariate analysis was used to identify independent baseline predictors of cognitive outcome 9-12 years later.

RESULTS

We followed up 387 subjects (58.6% of survivors). After adjusting for baseline cognition, poorer cognitive outcome was found to be independently associated with a family history of dementia, increasing age, less decline in systolic blood-pressure, lower premorbid IQ (rather than limited education), and abstinence from alcohol.

CONCLUSIONS

Reduction in systolic blood pressure (among hypertensives) and moderate alcohol intake could protect against cognitive deterioration in late life.

Smoking, drinking, and incident cognitive impairment: a cohort community based study included in the Gospel Oak project

OBJECTIVES

Recent longitudinal studies have reported that smoking increases risk for cognitive impairment and that moderate alcohol intake could be preventive. The association between both cigarette smoking and alcohol drinking and incident cognitive impairment was studied in a representative population.

METHODS

This is a 1 year prospective population based cohort study of all residents aged 65 or over in the electoral ward of Gospel Oak in London, UK (n=889). Cognitive impairment was assessed at baseline and 1 year later using the organic brain syndrome (OBS) cognitive impairment scale from the short CARE structured assessment. Subjects who were cognitively impaired at baseline were excluded from this analysis.

RESULTS

The prevalence of OBS cognitive impairment was 10.4% at index assessment and the 1 year cumulative incidence of cognitive impairment was 5.7%. Cognitive impairment was not associated with use of alcohol, although there was a non-significant association in the direction of a protective effect against onset of cognitive impairment for moderate drinkers compared with non-drinkers and heavy drinkers. Current smoking status predicted cognitive impairment (risk ratio (RR) 3.7; (95% confidence interval (95% CI)=1.1-12.3) independently from sex, age, alcohol, occupational class, education, handicap, depression, and baseline cognitive function.

CONCLUSIONS

Smoking seems to be a prospective risk factor for incident cognitive impairment; thus encouragement of older people to stop smoking could be considered as part of a strategy to reduce the incidence of cognitive impairment.

Blood pressure and cognitive decline in the elderly

Elevated blood pressure is associated with cognitive decline in elderly people. Classically, hypertension was thought to lead to end-organ damage of the brain manifested by neuropsychological deficits. This review examines recent evidence for this hypothesis and also considers other possible causal mechanisms for the observed relationship between blood pressure and mental ability.

The relationship between cardiac function and neuropsychological status among heart transplant candidates

BACKGROUND

Cognitive deficits among heart transplant candidates have been well documented. This study was designed to examine the hypothesis that impaired cognitive test performance among heart transplant candidates may be attributed, in part, to decreased cerebral perfusion secondary to poor cardiac function.

METHODS AND RESULTS

Sixty-two patients participated in the study who underwent heart catheterization within 1 day of completing a battery of cognitive tests. Multiple demographic and patient characteristics were examined for their potential moderating role in the relationship between measures of cardiac function and cognitive performance including age, education, race, gender, psychiatric history, medication usage, cardiac surgical history, and self-reported symptoms of depression and anxiety. Only age and education were significantly related to cognitive performance (P < .01). Thus, partial correlation analyses controlling for age and education were used to examine the relationship between cardiac function and cognitive performance. In general, increasing hemodynamic pressure variables (ie, pulmonary artery pressure and right atrial pressure), and to a lesser extent cardiac output and cardiac index, were related (r = - .32 to - .43; P < .01) to decreased performance on cognitive tasks that assessed simple attention, speed of mental processing, and mental flexibility (Digit Span-Forward, Trail Making Test-Part B, Symbol Digits Modalities Test, and Stroop Neuropsychological Screening Test). Left ventricular ejection fraction, systemic and pulmonary vascular resistance, and mean arterial pressure were largely unrelated to cognitive performance in this sample of patients with end stage cardiac disease.

CONCLUSIONS

Hemodynamic pressure variables seem to be most consistently related (ie, inversely) to cognitive functioning among heart transplant candidates.

Systolic blood pressure tracking over 25 to 30 years and cognitive performance in older adults

OBJECTIVE

To determine the extent to which individual changes in systolic blood pressure (SBP) over a 30-year interval are associated with differential neuropsychological outcomes in old age.

METHODS

Seven hundred seventeen survivors from the Western Collaborative Group Study, a longitudinal study of cardiovascular risk factors now in its 38th year of follow-up, with blood pressures measured in middle age (mean=45 years) and in old age (mean=75 years) and neuropsychological tests administered at follow-up were included in this analysis. Participants were grouped according to 30-year change in SBP (increased, decreased, or "normal"). Analyses focused on comparisons of neuropsychological performance of "high SBP trackers" (ie, those with persistent SBP>/=140 mm Hg throughout adult life) and of SBP "decreasers" with the performance of those whose SBP was either stable or changed in an expected way over time.

RESULTS

Only 7.5% of participants had elevated SBP in middle age, but 43.8% of participants had elevated SBP in old age. After adjustment for age, education, depression, clinically defined stroke, and use of antihypertensive medications and after exclusion of individuals with impaired cognitive performance at follow-up, high SBP trackers, 5.0% (n=36), performed consistently less well than the "normal" SBP subgroups on a composite measure of verbal learning and memory (P=0.04). When compared with the "normal" SBP subgroup, the SBP decreasers, 5.3% (n=38), performed less well on speeded performance (P=0.03).

CONCLUSIONS

There is a relatively small group of people who maintain elevated SBP throughout their adult lives. These persons are at increased risk for reduced verbal learning and memory function. There is also a group of individuals who experience a decrease in SBP and who are at risk for decreased psychomotor speed. Delineation of these 2 SBP subgroups may lead to further clarification of the effects of SBP on neurobehavioral function in older adults.

Blood pressure reduction, cardiovascular diseases, and cognitive decline in the mini-mental state examination in a community population of normal very old people: a three-year follow-up

We observed the decline in cognitive functioning in a community cohort of 924 persons aged > or =75 years with initially good cognition. Cognitive performance was indexed with the Mini-Mental State Examination (MMSE) on two occasions, 3 years apart. The average decline in MMSE score was 0.4 points per year. However, 23.4% of the participants lost more than 10% of their baseline MMSE scores. Women declined more rapidly than men. Baseline advanced age, lower education, and stroke predicted the greater decline in women. It appears that the relation of lower education and stroke with cognitive decline was more pronounced in men, but age did not predict cognitive decline in men. In addition, there was a correlation between systolic pressure reduction and cognitive decline in women, which was not accounted for by other factors. In summary, although the cognitive ability is generally spared longitudinally, in terms of the entire population, a considerable proportion of individuals show substantial decline that is related to several factors such as advanced age, female gender, lower education, stroke, and systolic pressure reduction.

Five-year incidence and prediction of dementia and cognitive decline in a population sample of women aged 70-79 at baseline

OBJECTIVE

To determine the incidence of dementia and cognitive decline and their predictors in a population sample.

SETTINGS

A rural geographically defined population served by a single health centre.

SAMPLE

75% of the 70-74-year-old, 100% of the 75-79-year-old women registered with the practice.

METHOD

Interview the total sample using an augmented version of CAMDEX, including informant interview, and reaction times at baseline and 5 years later. IQ was estimated at baseline only.

RESULTS

365 women were interviewed at baseline, 237 at follow-up. Incidence of dementia of all severities was 3.1% per annum (95% CI, 2.2-4.3). CAMCOG declined by 12.6 points in those who became demented, MMSE by 3 points. Observed, self-reported and informant-reported cognitive difficulty at baseline all predicted later incidence of dementia. The additional use of estimated IQ and reaction times did not increase the efficiency of either cross-sectional detection of dementia or prediction of dementia at 5 years.

CONCLUSIONS

The incidence of dementia was in the range reported by other studies; slight cognitive decline was noted in the total population, increasing with age and marked in incident dementia. Of clinical importance was the finding that both the individuals and the informants of those who subsequently demented were aware of decline 5 years earlier. Simple and relatively easily administered cognitive tests were found to be the most efficient method of detection of dementia.

The evolving face of psychiatric epidemiology

In 1978, Michael Shepherd gave a Maudsley Bequest Lecture in which it was necessary for him to argue from first principles for the need for epidemiological research within clinical psychiatry (Shepherd, 1978). This paper will take stock of the 20 years since his lecture and point to the new directions for this research approach. Shepherd listed the contributions of psychiatric epidemiology as follows: (a)