The SF-36 component summary scales and the daytime diurnal cortisol profile.

PURPOSE: Higher daytime cortisol output has been associated with higher levels of perceived stress and worse mental and physical health outcomes. Hypothalamic-pituitary-adrenal (HPA) axis dysregulation, such as elevated secretion of daytime cortisol, occurs in many mental and physical illnesses. However, the nature of the association between functional health status and daytime cortisol production has not been established. METHODS: Healthy adult volunteers (n=68, 45 females) provided saliva samples 3, 6, 9 and 12 h after waking, for two consecutive days, in everyday settings. Bivariate correlations between log salivary cortisol concentrations were calculated, and the SF-36 component summary scores were calculated. Latent growth curve modeling was used to model the daytime profile and adjust for covariates (age, sex and waking time). RESULTS: Higher PCS scores were not associated with cortisol three hours after waking (cortisol intercept), or the diurnal decline (cortisol slope). Higher MCS scores were correlated with faster cortisol decline across the day (r=-.31, P<.01) but not with cortisol intercepts. In a latent growth curve model adjusting for age, sex and waking time, the association was no longer statistically significant. CONCLUSIONS: Large scale epidemiological studies involving salivary cortisol would benefit from measuring SF-36 component summary scores. Cortisol intercepts and slopes may be differentially related to the PCS and MCS, although greater statistical power is needed to test this hypothesis more fully. Associations between daytime cortisol and the PCS or MCS could reflect the regulatory competence of bodily systems, common causes or unmeasured confounding factors.

Haemorheological predictors of cognitive decline: the Edinburgh Artery Study.

INTRODUCTION: vascular risk factors and diseases can negatively impact cognitive function. Determinants of blood flow are implicated in thrombogenesis and ischaemic events, yet little is known about their relationship with cognition. METHODS: blood rheology data were collected in 1987/88, and cognitive testing was performed in 1998/99 when the mean (+ or - standard deviation) age of the study sample was 73.1 years (+ or - 5.0). Follow-up assessment was performed 4 years later. Information was collected on verbal declarative memory, non-verbal reasoning, verbal fluency, information processing speed and a general cognitive factor representing the variance common to the individual test scores. RESULTS: after controlling for age, sex and cognitive performance in 1998/99, blood viscosity (BV) (P < 0.05) and fibrinogen (P < 0.05) predicted decline in non-verbal reasoning over 4 years. When estimated from pre-morbid level, decline in general cognition (P < 0.05), non-verbal reasoning (P < 0.05) and information processing speed (P < 0.01) was associated with BV levels. Haematocrit (HCT) had similar effects (P < 0.01 to P < 0.001). All associations persisted after control for multiple confounders. When examined together, HCT but not BV independently predicted cognitive decline. CONCLUSIONS: blood rheology is independently related to cognitive decline in older people. The value of strategies aimed at preserving cognition through influencing blood rheology needs investigation.

The effect of happiness and sadness on alerting, orienting, and executive attention.

OBJECTIVE: According to the attention network approach, attention is best understood in terms of three functionally and neuroanatomically distinct networks-alerting, orienting, and executive attention. An important question is whether the experience of emotion differentially influences the efficiency of these networks. METHOD: This study examines 180 participants were randomly assigned to a happy, sad, or control condition and undertook a modified version of the Attention Network Test. RESULTS: The results showed no effect of happiness or sadness on alerting, orienting, or executive attention. However, sad participants showed reduced intrinsic alertness. CONCLUSION: This suggests that sadness reduces general alertness rather than impairing the efficiency of specific attention networks.

Five Factor Model personality traits and all-cause mortality in the Edinburgh Artery Study cohort.

OBJECTIVE: To examine whether personality traits are related to all-cause mortality in a general adult population in Scotland. METHODS: The Edinburgh Artery Study began in 1987 to 1988 by recruiting 1592 men and women aged 55 to 74 years to be followed-up for atherosclerotic diseases. The NEO Five-Factor Inventory (NEO-FFI) was completed by 1035 surviving participants in 1995 to 1996. Deaths from all causes were examined in relation to personality traits and social and physical risk factors for mortality. RESULTS: During follow-up, 242 (37.1%) men and 165 (24.6%) women died. For the whole sample, there was a 28% lower rate of all-cause mortality for each 1 SD increase in NEO-FFI openness (95% CI, 0.61-0.84) and a 18% lower rate of all-cause mortality for each 1 SD increase in NEO-FFI conscientiousness (95% CI, 0.70-0.97). In men, the risk of all-cause mortality was 0.63 (95% CI, 0.5-10.78) for a 1 SD increase in openness and 0.75 (95% CI, 0.61-0.91) for a 1 SD increase in conscientiousness. In women, none of the personality domains were significantly associated with all-cause mortality. Well fitting structural equation models in men (n = 652) showed that the relationships between conscientiousness and openness and all-cause mortality were not substantially explained by smoking, or other variables in the models. CONCLUSION: High conscientiousness and openness may be protective against all-cause mortality in men. Further investigations are needed on the mechanisms of these associations, and the influence of personality traits on specific causes of death.

Mental ability in childhood and cognitive aging.

BACKGROUND: Identifying the determinants of cognitive aging is a research priority; however, few studies are able to examine the influence of pre-morbid cognitive ability on later changes in cognitive function. OBJECTIVE: To examine the association between childhood cognitive ability and cognitive change from age 79 to 83 in the presence of other demographic and lifestyle indicators. METHODS: The participants took a test of mental ability when aged 11 as part of the Scottish Mental Survey 1932. Cognitive ability based on Raven's Matrices, Verbal Fluency, and Logical Memory was assessed at ages 79 and 83. We used both linear regression and latent variable growth curve modeling to compare methods and results. RESULTS: Using linear regression, childhood mental ability was a significant predictor of cognitive change from 79 to 83, accounting for about 1.4% of the variance. Sex, education, social class, smoking status and alcohol intake were non-significant. In contrast, using latent variable growth curve modeling, there was no association between childhood mental ability and cognitive change. Sex (male), years of education, drinking status (positive), and childhood IQ were associated with better cognitive ability at age 79. The difference in results was due to the inability of linear regression to account completely for test-specific variance. CONCLUSION: Within a group of non-demented older people, greater childhood mental ability was associated with level of cognitive ability at age 79, but not with change in cognitive ability to age 83. To obtain accurate results regarding covariates of change, it is important to use methodology that can appropriately allocate all measured sources of variance.

Cardiovascular diseases and decline in cognitive function in an elderly community population: the Edinburgh Artery Study.

OBJECTIVE: To investigate cognitive performance and 4-year change in cognitive function in relation to different clinical manifestations of atherosclerotic disease in an elderly community population. METHODS: The Edinburgh Artery Study is a population cohort study of men and women who were recruited to a baseline survey in 1987 and 1988. From the time of study entry, the participants have been invited to two follow-up clinical examinations and continuously monitored for major fatal and nonfatal vascular events. All alive and eligible subjects were invited for cognitive testing in two study years when the mean age of the sample was 73.1 (standard deviation = 5.0) years. A follow-up cognitive assessment was performed in 2002 and 2003 on 452 survivors. RESULTS: In multivariate analyses controlling for demographic characteristics, depression, and major atherosclerotic risk factors, stroke was associated with a significantly worse performance on tests of verbal memory (p = .02) and letter fluency (p = .002). In addition, stroke was related to a significantly steeper 4-year decline in verbal memory performance (p = .04). Among the subjects who had not had an overt stroke, those with symptomatic peripheral arterial disease experienced a significantly greater 4-year decline in verbal memory functioning (p = .04). CONCLUSIONS: In older people, stroke is associated with both worse performance on cognitive tests and progressive verbal memory decline. Elderly individuals with vascular diseases other than stroke may also be vulnerable to a greater decline in verbal memory function. A relationship between vascular diseases and verbal memory decline may exist independently of depressed mood and major atherosclerotic risk factors.

Cognitive decline and markers of inflammation and hemostasis: the Edinburgh Artery Study.

OBJECTIVES: To determine whether circulating markers of activated inflammation and hemostasis are associated with cognitive decline in older people. DESIGN: Prospective cohort study (Edinburgh Artery Study). SETTING: Eleven general practices in Edinburgh, Scotland. PARTICIPANTS: A sample of 452 men and women followed for 16 years. MEASUREMENTS: Biomarker data were collected in 1987/88, and cognitive assessment was first conducted in 1998/99, when the mean age of the sample +/- standard deviation was 73.1+/-5.0), and subsequently in 2002/03. Information was obtained on verbal declarative memory (Wechsler Logical Memory Test (LMT)), nonverbal reasoning (Raven's Standard Progressive Matrices), verbal fluency (Verbal Fluency Test), information processing speed (Wechsler Digit Symbol Test), and a general cognitive factor representing the variance common to the individual test scores. RESULTS: In age-adjusted analyses, plasma fibrinogen, interleukin-6 (IL-6), and intercellular adhesion molecule 1 (ICAM-1) were negatively associated with performance on all cognitive measures in 2002/03 except the LMT (correlation coefficients from -0.10 to -0.24). In multivariate analyses controlling for demographic characteristics, depression, and cardiovascular morbidity and risk factors, fibrinogen independently predicted 4-year decline in nonverbal reasoning (P<.05). Also, when cognitive change was estimated from peak prior level, IL-6 turned out to be inversely related to decline in information processing speed (P<.05). Similarly, ICAM-1 was associated with a greater decline in general cognitive ability (P<.05) and nonverbal ability (P<.05). CONCLUSION: Systemic markers of inflammation and hemostasis are associated with a progressive decline in general and specific cognitive abilities in older people, independent of major vascular comorbidity.

Ankle brachial index as a predictor of cognitive impairment in the general population: ten-year follow-up of the Edinburgh Artery Study.

OBJECTIVES: To determine whether the ankle brachial index (ABI, a marker of generalized atherosclerosis) is associated with cognitive impairment after 10 years in older people. DESIGN: Cohort study (Edinburgh Artery Study). SETTING: Eleven general practices in Edinburgh, Scotland. PARTICIPANTS: Seven hundred seventeen men and women aged 55 to 74 from the general population, followed for 10 years. MEASUREMENTS: ABI measured at baseline and major cognitive functions (including premorbid function using the National Adult Reading Test, NART) tested after 10 years. RESULTS: After adjustment for age and sex, a low ABI was associated with lower scoring (bottom tertile vs top tertile) on Raven's Matrices (odds ratio (OR)=1.6, 95% confidence interval (CI) =1.0-2.6), Verbal Fluency (OR =1.8, 95% CI =1.1-3.0), and Digit Symbol Test (OR =2.3, 95% CI =1.3-4.2), suggesting that the ABI is predictive of poorer performance in nonverbal reasoning, verbal fluency, and information processing speed. The association between ABI and the Digit Symbol Test remained significant after further adjustment for premorbid cognitive function (tested using the NART), suggesting that the ABI is also predictive of decline in information processing speed (from premorbid ability to that measured here in older age). CONCLUSION: The ABI may be useful in identifying older individuals at higher risk of cognitive impairment. In the future, preventive measures developed to target individuals with a low ABI should consider measures to reduce vascular-related cognitive decline as well as cardiovascular events, in an effort to reduce the incidence and consequences of subsequent cognitive impairment and dementia.

Apolipoprotein e gene variability and cognitive functions at age 79: a follow-up of the Scottish mental survey of 1932.

Apolipoprotein E (APOE) genotype is a possible influence on nonpathological cognitive aging. The authors studied 462 community-dwelling, 79-year-old people born in 1921, whose childhood IQ had been assessed in the Scottish Mental Survey of 1932 (Scottish Council for Research in Education, 1933). Adjusting for sex, childhood IQ, and self-reported illnesses, the authors found that those with an APOE e4 allele had significantly lower Wechsler Logical Memory (D. Wechsler, 1987) scores than those without an e4 allele. Those people with APOE s2/e3 genotypes had significantly higher Wechsler Logical Memory scores than e3/s3, who were significantly higher than e3/e4. Neither nonverbal reasoning nor verbal fluency were affected. In this sample, APOE genotype contributed to verbal memory in old age.

The impact of childhood intelligence on later life: following up the Scottish mental surveys of 1932 and 1947.

The Scottish Mental Surveys of 1932 and 1947 collected valid IQ-type test scores for almost everyone born in 1921 and 1936 and attending school on June 1, 1932 (N=89,498) and June 4, 1947 (N=70,805). These surveys are described. This research, using the surveys' data, examined (a) the stability of intelligence differences across the life span, (b) the determinants of cognitive change from childhood to old age, and (c) the impact of childhood intelligence on survival and health in old age. Surviving participants of the Scottish Mental Surveys were tested, and the surveys' data were linked with public and health records. Novel findings on the stability of IQ scores from age 11 to age 80; sex differences in cognitive aging; the dedifferentiation hypothesis of cognitive aging; and the effect of childhood IQ on all-cause and specific mortality, morbidity, and frailty in old age are presented.

Lack of association between polymorphisms in angiotensin-converting-enzyme and methylenetetrahydrofolate reductase genes and normal cognitive ageing in humans.

The hypothesis that polymorphisms at two candidate genes that code for angiotensin-converting-enzyme (ACE) and methylenetetrahydrofolate reductase (MTHFR) are associated with normal cognitive ageing was tested using a sample (n=536) of healthy 80-year-old people who were born in 1921 and whose cognitive ability at age 11 was measured in the Scottish Mental Survey 1932. Cognitive ability at age 11 and age 80 was assessed using the Moray House Test. Cognitive ageing was defined as the change in IQ from age 11 to 80. There was no significant association between the tested ACE and MTHFR polymorphisms and IQ score at age 11, IQ at age 80, and IQ change (all P>0.05). The ACE genotypes deviated significantly from Hardy-Weinberg equilibrium proportions (P=0.02), which could indicate that this gene is under selection. Polymorphisms at the two studied genes are unlikely to be risk factors for normal cognitive ageing.

Cognitive change and the APOE epsilon 4 allele.

There is a marked variation in whether people retain sufficient cognitive function to maintain their quality of life and independence in old age, even among those without dementia, so it would be valuable to identify the determinants of normal age-related cognitive change. We have retested non-demented 80-year-olds who were participants in the Scottish Mental Survey of 1932, and find that the variation in their non-pathological cognitive change from age 11 to 80 is related to their apolipoprotein E (APOE) genotype. This effect of the APOE epsilon 4 allele on normal cognitive ageing may be mediated by a mechanism that is at least partly independent of its predisposing effect towards Alzheimer's disease.