Biomedical subjects

Kaarin J Anstey

Publications and source records attributed to Kaarin J Anstey.

At least 19 recordsLinked to original sources

PubMed2007

APOE genotype and cognitive functioning in a large age-stratified population sample.

There is evidence that the cognitive effects of Alzheimer's disease can be seen decades before disease diagnosis. If this is the case, then the apolipoprotein E (APOE) *E4 allele might be expected to have effects on cognitive functioning earlier in the life span. To assess such effects, the authors examined data on the *E4 allele and cognitive functioning from a population sample of 6,560 Caucasians covering the age groups of 20-24, 40-44, and 60-64 years. Participants were assessed on tests of episodic memory, working memory, mental speed, reaction time, and reading vocabulary. Although performance on all tests except reading vocabulary declined across age groups, there was no effect of the APOE *E4 allele at any age. These results indicate that APOE *E4 does not have preclinical effects early in the life span on these cognitive functions. Cognitive aging effects between the ages of 20 and 64 years must not be due to preclinical Alzheimer's disease.

Adult↗

PubMed2006

The brain reserve hypothesis, brain atrophy and aging.

BACKGROUND: Researchers have used the concept of brain reserve to explain the dissociation between pathological brain damage and cognitive and functional performance. A variety of brain reserve hypotheses exist, and different empirical strategies have been employed to investigate these variants. OBJECTIVE: The study investigates (i) the relationship between measures of brain burden (atrophy, white matter hyperintensities (WMH)) and measures of reserve (education, creativity, and intelligence); (ii) the relationship between cognitive decline and reserve; (iii) whether measures of reserve mediate the effect of atrophy on estimated cognitive change, and (iv) the association between brain risk factors, education and atrophy. METHODS: A cross-sectional study of a sample of 446 individuals 60-64 years of age who underwent MRI scans as part of a large epidemiological study. Measures were taken of education, intelligence, creativity, cognitive speed, brain volume, WMH, estimated cognitive decline from earlier in life and brain atrophy. RESULTS: No association was found between estimated cognitive decline and brain burden (atrophy, WMH). Risk factors for brain insult were not associated with greater brain atrophy in the less well educated. Neither education, nor any other measure including intelligence or creativity, provided a buffer for cognitive decline in individuals with high levels of brain atrophy. CONCLUSION: Little support was found for the brain reserve hypothesis.

Aging↗

PubMed2006

Effects of cerebrovascular risk factors on gray matter volume in adults aged 60-64 years: a voxel-based morphometric study.

The effect of putative cerebrovascular risk factors on gray matter volume in a community-dwelling, non-demented 60- to 64-year-old cohort was investigated. Cranial T1-weighted MRI scans were obtained in 337 adults and voxel-based morphometric analyses were applied to detect regional gray matter volume differences related to hypertension, diabetes, smoking, and hyperlipidemia in men and women, respectively. Hypertension-related gray matter volume reduction was found in right superior, bilateral medial frontal, left superior temporal and left precentral gyri in men. No regional differences in gray matter related to hypertension were seen in women. Conversely, female but not male smokers had more gray matter volume in right fusiform gyrus and right temporal subgyral gray matter. No differences were observed in gray matter volume in association with diabetes or hyperlipidemia for men or women. Our results suggest that there are different patterns of regional effects in gray matter volume in relation to different cerebrovascular risk factors, and sex differences for the same risk factors.

Brain↗

PubMed2006

Mental health and the timing of men's retirement.

BACKGROUND: Analysis of the Psychiatric Morbidity Survey of Great Britain showed that the prevalence of common mental disorders was lower amongst men at or above Britain's state pension age of 65, relative to younger men. Retirees below this age had consistently higher rates of mental disorders than working men. In contrast, the low prevalence of mental disorders amongst retirees aged 65 and older was similar to that of their working peers. The aim of this analysis was to investigate this pattern of results in a national sample of Australian men, and the mediating role of socio-demographic factors. METHOD: Data were from the Household, Income and Labour Dynamics (HILDA) in Australia survey (2003). The analyses included men aged 45-74 years who were active in the labour force (n = 1309), or retired (n = 635). Mental health was assessed using the mental health scale from the Short-Form 36 Health Questionnaire. RESULTS: Retirees were more likely to have mental health problems than their working peers, however this difference was progressively smaller across age groups. For retirees above, though not below, the age of 55 this difference was explained by poorer physical functioning. When age at retirement was considered it was found that early retirees who were now at or approaching the conventional retirement age did not display the substantially elevated rates of mental health problems seen in their younger counterparts. Further, men who had retired at age 60 or older did not display an initially elevated rate of mental health problems. CONCLUSIONS: The association between retirement and mental health varies across older adulthood. Retired British and Australian men below the conventional retirement age of 65 are more likely to have mental health problems relative to their working peers, and retirees above this age. However, poor mental health appears to be linked to being retired below this age rather than an enduring characteristic of those who retire early.

Age Factors↗

PubMed2006

Hormone replacement therapy, brain volumes and white matter in postmenopausal women aged 60-64 years.

Research on the structural and functional effects of hormone replacement therapy on the brain has produced inconsistent results. This paper reports on cross-sectional associations between hormone replacement therapy use and volumes of brain structures measured using magnetic resonance imaging in 213 postmenopausal women aged 60-64 years recruited from a large population study. Of these, 64 were current hormone replacement therapy users, 69 previous users and 80 had never used hormone replacement therapy. No differences were observed between groups in total grey matter, white matter, hippocampal or amygdalar volumes, severity or volume of white matter hyperintensities, or in different measures of brain atrophy. While acknowledging the limitations of a cross-sectional study, the results argue against hormone replacement therapy being protective against brain changes associated with ageing in women in their early 60s.

Brain↗

PubMed2006

Sex and symmetry differences in hippocampal volumetrics: before and beyond the opening of the crus of the fornix.

Published normative volumetrics of the hippocampus (HC) vary substantially. While the protocol suggested by Watson et al. (Neurology 42 (1992) 1743-1750; Arch Neurology 54 (1997) 1521-1531) is the most frequently adhered to, this leaves the posterior section of the HC tail unmeasured, which has been estimated to be in the order of 2-4 mm, representing 5-10% of total HC volume. The objective of the current study was to compare HC volumes according to the method of Watson et al. (Neurology 42 (1992) 1743-1750; Arch Neurology 54 (1997) 1521-1531) against those measured to include the posterior tail section. From a random community sample of 60-64 yr old individuals, 478 subjects underwent magnetic resonance imaging brain scans. Of these, 452 scans (238 males and 214 females) were adequate for hippocampal measurement. The scans comprised whole brain T1- weighted and T2-weighted FLAIR images. One hundred and fifty scans were randomly selected for the measurement of HC volumes beyond the opening of the crus of the fornix by manual tracings on T1-weighted images by a trained operator. Intracranial volume (ICV) and total brain volume (TBV) were measured using an automated program. We found that the posterior HC tail extended for a mean of just over 5 mm and comprised 11% of total HC volume. Males had significantly larger raw HC volumes, and while normalization with ICV or TBV reversed this pattern, it was significant only when the posterior HC tail was included in the measurement. In conclusion, this study showed that including the posterior part of the tail can influence the results of HC measurement. An argument is presented that accurate HC volumes should include the entire HC and not exclude the tail.

Adult↗

PubMed2006

The effect of cataract surgery on neuropsychological test performance: a randomized controlled trial.

Recent cross-sectional studies have reported strong associations between visual and cognitive function, and longitudinal studies have shown relationships between visual and cognitive decline in late life. Improvement in cognitive performance after cataract surgery has been reported in patients with Mild Cognitive Impairment. We investigated whether improving visual function with cataract surgery would improve neuropsychological performance in healthy older adults. A randomized clinical trial of cataract surgery performed at acute hospitals was conducted on 56 patients (mean age 73) with bilateral cataract, after excluding a total of 54 patients at the screening stage, of whom 53 did not meet visual acuity criteria and one did not have cataract. In-home assessments included visual and neuropsychological function, computerized cognitive testing and health questionnaires. Results showed no cognitive benefits of cataract surgery in cognitively normal adults. We conclude that visual improvement following cataract surgery is not strongly associated with an improvement in neuropsychological test performance in otherwise healthy adults. Joint associations between visual and cognitive function in late life are likely to be due to central factors, and unlikely to be strongly related to eye disease. Short-term increased neural stimulation from improved visual function does not appear to affect cognitive performance.

Aged↗

PubMed2006

Hopelessness, demoralization and suicidal behaviour: the backdrop to welfare reform in Australia.

OBJECTIVES: To estimate rates of suicidal ideation and attempts, and psychological characteristics of demoralization among Australian income support recipients. To provide information for policy-makers to inform the current welfare reform discussion. METHOD: Data from the 1997 National Survey of Mental Health and Wellbeing were analysed using sequential logistic regression models, comparing working age people dependent on government income support payments with those having other main sources of income. RESULTS: Three groups of income support recipients, unemployed, lone mothers and disability payment recipients, reported significantly higher levels on all psychological measures related to demoralization (hopelessness, worthlessness and dissatisfaction with life) than non-recipients. A similar pattern was demonstrated for measures of suicidal ideation and reported suicide attempts, with increased odds of between 3 and 9 for these high-risk groups of welfare recipients. The elevated rates of suicidal ideation, attempts and demoralization among income support recipients were in part explained by sociodemographic characteristics (socioeconomic status, age, educational qualification, experience of serious violence, loneliness, experience of psychiatric disorders), though the unemployed and disability payment recipients remained elevated on the psychological measures. CONCLUSIONS: Demoralization, poor mental health and suicidal behaviour are common among income support recipients targeted by recently announced welfare reforms. This needs to be considered in the design and implementation of Australian Government policies. Psychiatric epidemiology has a key role in policy development and evaluation.

Adolescent↗

PubMed2006

Measuring physical and mental health using the SF-12: implications for community surveys of mental health.

OBJECTIVE: The effects of using different approaches to scoring the SF-12 summary scales of physical and mental health were examined with a view to informing the design and interpretation of community-based survey research. METHOD: Data from a population-based study of 7485 participants in three cohorts aged 20-24, 40-44 and 60-64 years were used to examine relationships among measures of physical and mental health calculated from the same items using the SF-12 and RAND-12 approaches to scoring, and other measures of chronic physical conditions and psychological distress. RESULTS: A measure of physical health constructed using the RAND-12 scoring showed a monotonic negative association with psychological distress as measured by the Goldberg depression and anxiety scales. However, a non-monotonic association was evident in the relationship between SF-12 physical health scores and distress, with very high SF-12 physical health scores corresponding with high levels of distress. These relationships highlight difficulties in interpretation that can arise when using the SF-12 summary scales in some analytical contexts. CONCLUSIONS: It is recommended that community surveys that measure physical and mental functioning using the SF-12 items generate summary scores using the RAND-12 protocol in addition to the SF-12 approach. In general, researchers should be wary of using factor scores based on orthogonal rotation, which assumes that measures are uncorrelated, to represent constructs that have an actual association.

Adult↗

PubMed2006

Prevalence, risk factors and treatment for substance abuse in older adults.

PURPOSE OF REVIEW: This paper briefly outlines new research on the epidemiology of alcohol and drug use in the older population, describes mental and cognitive consequences of substance use and summarizes recent treatment trials for alcohol dependence. RECENT FINDINGS: Cross-sectional and longitudinal studies indicate that alcohol use is less prevalent in older groups, and it decreases over time. Comorbidity (alcohol and other drugs, alcohol with mental health disorders) is high. An inverse-U-shaped curve describes the association between alcohol consumption and cognitive impairment with increased impairment for abstainers and high users as compared with moderate users. Trials of alcohol use in the older population are rare, but they suggest that brief patient education may reduce drinking levels in primary care populations, and that, for some users, integrated primary care may be more useful than referral to specialist care. SUMMARY: The basis for higher risk in abstainers is not resolved. More randomized controlled trials are needed, which target alcohol use and dependence and also focus on comorbid disorders.

Aged↗

PubMed2006

The impact of cataract surgery on visual functioning, vision-related disability and psychological distress: a randomized controlled trial.

PURPOSE: Determine whether there are changes in visual functioning, vision-related disability, health status and mood after cataract surgery. METHODS: 45 adults (mean age = 73.7 years) with bilateral cataract needing surgery for the first eye were recruited from public ophthalmology clinics. The Visual Functioning-14 survey assessed visual disability. Minimal angle of resolution tested visual acuity, and the Melbourne Edge Test examined contrast sensitivity. Demographic, psychological, health and medication use variables were examined. Participants were randomized to either an intervention or control arm. Controls were assessed on two occasions at a 3-month interval before having surgery. The intervention group was assessed 1-2 weeks before surgery and then reassessed 3 months after surgery. RESULTS: Visual functioning improved for those who had cataract surgery with better visual acuity in the better (P = 0.010) and worse (P = 0.028) eye compared with controls. The intervention group reported fewer difficulties with overall vision-related disability (P = 0.0001), reading (P = 0.004) and instrumental activities of daily living (P = 0.010) post-surgery compared with controls. People with improved depression scores (P = 0.048) after surgery had less difficulty with reading compared with those with unchanged or worsened depression scores. Cataract surgery did not improve health status. CONCLUSIONS: First eye cataract surgery is effective in improving outcomes in visual functioning and disability. Improved mood after surgery was related to less vision-related disability compared with unchanged or worse depression.

Aged↗

PubMed2006

Predicting driving cessation over 5 years in older adults: psychological well-being and cognitive competence are stronger predictors than physical health.

OBJECTIVES: To examine psychological, medical, and sensorimotor risk factors that predict driving cessation in older adults. DESIGN: Prospective cohort study including five waves of data collected in 1992, 1993, 1994, 1995, and 1997. SETTING: The Australian Longitudinal Study of Aging. PARTICIPANTS: One thousand four hundred sixty-six men and women aged 70 and older drawn from the electoral roll and including 753 drivers at baseline. MEASUREMENTS: Interviews, including assessments of self-rated health (indicating general well-being); medical conditions; driving status; and clinical assessments of vision, hearing, cognitive function, and grip strength, were conducted in 1992 (baseline) and 1994. Information on current driving status was obtained at baseline and four subsequent waves (1993, 1994, 1995, and 1997). Drivers and nondrivers were compared at baseline. Risk factors for driving cessation were identified using logistic regression. RESULTS: Drivers were younger and more likely to be male and had better self-rated health, vision, hearing, and cognitive performance than nondrivers at baseline. Seventeen percent of drivers in the study had vision of 6/18 or worse, and 7.3% were classified as possibly cognitively impaired. In those identified as drivers at baseline, subsequent cessation was associated with increasing age, low grip strength, poorer cognitive performance, and poorer self-rated health. CONCLUSION: Self-rated health and cognitive function were more important than medical conditions or sensory function for predicting driving cessation.

Age Factors↗

PubMed2006

An 8-year prospective study of the relationship between cognitive performance and falling in very old adults.

OBJECTIVES: To determine whether cognitive performance, as distinct from cognitive impairment, predicts falling during an 8-year follow-up in a community-based sample of very old adults and to evaluate how cognitive change is associated with falling. DESIGN: Prospective cohort study including three waves of data collected in 1992, 1994, and 2000. SETTING: Population based, with the baseline sample drawn from the electoral roll. PARTICIPANTS: Inclusion criteria were completion of at least three cognitive tests at baseline and completion of the falls questionnaire at Wave 6 (N=539). MEASUREMENTS: Assessments of health and medical conditions, visual acuity, cognitive function, functional reach, semitandem stand, and grip strength were conducted in 1992 (baseline), 1994, and 2000. Self-report information on falls in the previous 12 months was obtained on each of these occasions. Marginal models using generalized estimating equations were used to assess the association between baseline cognitive performance and falling over 8 years, adjusting for sociodemographic, health, and sensorimotor variables. Random effects models were used to assess the relationship between change in cognitive performance and change in fall rate and fall risk over 8 years. RESULTS: Mini-Mental State Examination and verbal reasoning at baseline predicted rate of falling over an 8-year period. Within individuals, declines in verbal ability, processing speed, and immediate memory were associated with increases in rates of falling and fall risk. CONCLUSION: Cognitive performance is associated with falling over 8 years in very old adults and should be assessed in clinical practice when evaluating short- and long-term fall risk.

Accidental Falls↗

PubMed2006

Between- and within-individual effects of visual contrast sensitivity on perceptual matching, processing speed, and associative memory in older adults.

BACKGROUND: Although cross-sectional studies have demonstrated associations between visual contrast sensitivity and cognitive test performance, it remains unclear whether peripheral visual or perceptual factors explain the association. OBJECTIVE: We aimed at determining whether reducing static contrast of the study stimuli would simulate the performance deficits on measures of processing speed and associative memory that are associated with aging. METHODS: We investigated the mechanism by which vision and memory are associated in a sample of 91 volunteers aged 60-87 years. In tests of perceptual matching, digit-symbol matching, and associative memory, the level of static contrast of the stimuli was manipulated, with three contrast levels. The duration of stimuli presentation was also manipulated in the associative memory task in a full-factorial experimental design. Accuracy and response latencies (for correct trials) were measured. RESULTS: Experimental results showed that within subjects, lower contrast was associated with longer latencies, indicating an effect on information processing speed. Regression analyses replicated previous findings of a moderate to strong association between visual contrast sensitivity and cognitive performance in cross-sectional studies. CONCLUSION: These results provide support for a theory in which visual aging is associated with slower encoding of information as well as being involved at a more central level.

Age Factors↗

PubMed2005

Clinical and neuroimaging correlates of mild cognitive impairment in a middle-aged community sample: the personality and total health through life 60+ study.

This cross-sectional study aimed at determining the clinical and structural brain magnetic resonance imaging correlates of mild cognitive impairment (MCI). The data presented here are from the first wave of the longitudinal Personality and Total Health through Life 60+ project. 2,551 community-dwelling individuals in the age range of 60-64 years were recruited randomly through the electoral roll. They were screened using Mini-Mental State Examination and a short cognitive battery. Those who screened positive underwent detailed medical and neuropsychological assessments. Of the 224 subjects who screened positive, 117 underwent a detailed assessment. Twenty-nine subjects fulfilled the Mayo Clinic criteria for MCI. Magnetic resonance imaging scans were analyzed for 26 subjects with MCI as well as normal controls. Subjects were clinically evaluated for depressive symptoms and major and minor depression syndromes. Logistic regression analysis was performed predicting MCI from anterior and mid-ventricular brain ratios, cortical atrophy measures, hippocampal volumes, volumes of amygdala and white matter hyperintensities after adjusting for age, gender, years of education, depression and physical disability. None of the neuroanatomical substrates appeared as predictors of MCI. The only predictors were higher depression scores and fewer years of education. Structural neuroimaging may not have an added advantage in the detection of MCI in middle-aged community-dwelling subjects. It may be that this age group is too young for such brain changes to be identified.

Amygdala↗

PubMed2005

Hormone replacement therapy and cognition in an Australian representative sample aged 60-64 years.

OBJECTIVE: To investigate the relationship between hormone replacement therapy (HRT) and level of cognitive performance intra-individual variability, and interactions with statin use, progesterone therapy and type of menopause. METHODS: A representative sample of 60-64 year olds was recruited from the Canberra and Queanbeyan regions in Australia. They were administered tests of verbal memory, working memory, speed of information processing, simple and complex reaction time, verbal intelligence and the Mini-Mental State Exam. Intra-individual variation (consistency) on performance on simple and complex reaction time tasks was calculated. Women provided information on HRT use and demographic, health and lifestyle variables. RESULTS: Four hundred and four (35.0%) current postmenopausal HRT users, 316 (27.4%) previous HRT users and 434 (37.6%) women who had never used HRT, were included in this study. There were significant overall differences between HRT current and previous users on age, prevalence of diabetes, alcohol use, body mass index, level of anxiety and lung function. After controlling for potentially confounding health and demographic variables, there were no significant main effects detected between HRT groups on any cognitive measure. Significant interactions were detected between HRT group and statin use on intra-individual variability on simple reaction time, and between HRT group and menopause type on intra-individual variability on choice reaction time. All other interactions were non-significant. CONCLUSIONS: HRT use had no effect on level of cognitive performance. Two interactions were detected between HRT use and statin use, and type of menopause on intra-individual variability. Given the large number of comparisons, little weight can be placed on these significant results.

Analysis of Variance↗

PubMed2005

Retirement and mental health: analysis of the Australian national survey of mental health and well-being.

Nation-wide research on mental health problems amongst men and women during the transition from employment to retirement is limited. This study sought to explore the relationship between retirement and mental health across older adulthood, whilst considering age and known risk factors for mental disorders. Data were from the 1997 National Survey of Mental Health and Well-being, a cross-sectional survey of 10,641 Australian adults. The prevalence of depression and anxiety disorders was analysed in the sub-sample of men (n = 1928) and women (n = 2261) aged 45-74 years. Mental health was assessed using the Composite International Diagnostic Instrument. Additional measures were used to assess respondents' physical health, demographic and personal characteristics. The prevalence of common mental disorders diminished across increasing age groups of men and women. Women aged 55-59, 65-69, and 70-74 had significantly lower rates of mental disorders than those aged 45-49. In contrast, only men aged 65-69 and 70-74 demonstrated significantly lower prevalence compared with men aged 45-49. Amongst younger men, retirees were significantly more likely to have a common mental disorder relative to men still in the labour force; however, this was not the case for retired men of, or nearing, the traditional retirement age of 65. Men and women with poor physical health were also more likely to have a diagnosable mental disorder. The findings of this study indicate that, for men, the relationship between retirement and mental health varies with age. The poorer mental health of men who retire early is not explained by usual risk factors. Given current policy changes in many countries to curtail early retirement, these findings highlight the need to consider mental health, and its influencing factors, when encouraging continued employment amongst older adults.

Age Factors↗

PubMed2005

Hormone replacement therapy and cognitive performance in postmenopausal women--a review by cognitive domain.

Laboratory, animal and neuroimaging evidences suggest that hormone replacement therapy (HRT) may be beneficial to human cognition. This systematic review includes 26 studies on the association between HRT and cognition and 17 studies on HRT and risk of dementia. It was hypothesised that HRT would have a positive association with cognitive speed and verbal memory and possibly visual memory but not with executive functioning, and would be associated with a decreased risk of dementia. Evidence for HRT's neuroenhancing and neuroprotective properties was also evaluated. There was significant statistical and clinical heterogeneity among studies precluding meta-analysis. Results showed no consistent relationship between HRT and performance in any cognitive domain. Cross-sectional studies tended to report more positive results than longitudinal studies and randomised-controlled trials, particularly in the areas of verbal memory and executive functioning. HRT was associated with decreased risk of dementia in observational studies, but with increased risk in one randomised-controlled trial. Cognitive improvement or maintenance are not secondary benefits of HRT.

Brain↗