Menopause depression: Under recognised and poorly treated.

Menopause is a biological process experienced by all people assigned female at birth. A significant number of women experience mental ill health related to the major brain gonadal hormone shifts that occur in their midlife. There is poor understanding and management of the complex mental ill health issues, with the biological brain hormone changes receiving little formal attention. The current treatment advice is to manage this special type of mental ill health in the same way that all mental ill health is managed. This leads to poor outcomes for women and their families. Many women leave the workforce earlier than expected due to menopause-related depression and anxiety, with subsequent loss of salary and superannuation. Others describe being unable to adequately parent or maintain meaningful relationships - all ending in a poor quality of life. We are a large and diverse group of national and international clinicians, lived experience and social community advocates, all working together to innovate the current approaches available for women with menopausal mental ill health. Above all, true innovation is only possible when the woman with lived experience of menopause is front and centre of this debate.

Alzheimer's disease research progress in Australia: The Alzheimer's Association International Conference Satellite Symposium in Sydney.

The Alzheimer's Association International Conference held its sixth Satellite Symposium in Sydney, Australia in 2019, highlighting the leadership of Australian researchers in advancing the understanding of and treatment developments for Alzheimer's disease (AD) and other dementias. This leadership includes the Australian Imaging, Biomarker, and Lifestyle Flagship Study of Ageing (AIBL), which has fueled the identification and development of many biomarkers and novel therapeutics. Two multimodal lifestyle intervention studies have been launched in Australia; and Australian researchers have played leadership roles in other global studies in diverse populations. Australian researchers have also played an instrumental role in efforts to understand mechanisms underlying vascular contributions to cognitive impairment and dementia; and through the Women's Healthy Aging Project have elucidated hormonal and other factors that contribute to the increased risk of AD in women. Alleviating the behavioral and psychological symptoms of dementia has also been a strong research and clinical focus in Australia.

Factors associated with improved walking in older people during hospital rehabilitation: secondary analysis of a randomized controlled trial.

BACKGROUND: Older people are often admitted for rehabilitation to improve walking, yet not everyone improves. The aim of this study was to determine key factors associated with a positive response to hospital-based rehabilitation in older people. METHODS: This was a secondary data analysis from a multisite randomized controlled trial. Older people (n= 198, median age 80.9 years, IQR 76.6- 87.2) who were admitted to geriatric rehabilitation wards with a goal to improve walking were recruited. Participants were randomized to receive additional daily physical therapy focused on mobility (n = 99), or additional social activities (n = 99). Self-selected gait speed was measured on admission and discharge. Four participants withdrew. People who changed gait speed ≥0.1 m/s were classified as 'responders' (n = 130); those that changed <0.1m/s were classified as 'non-responders' (n = 64). Multivariable logistic regression explored the association of six pre-selected participant factors (age, baseline ambulation status, frailty, co-morbidities, cognition, depression) and two therapy factors (daily supervised upright activity time, rehabilitation days) and response. RESULTS: Responding to rehabilitation was associated with the number of days in rehabilitation (OR 1.04; 95% CI 1.00 to 1.08; p = .039) and higher Mini Mental State Examination scores (OR 1.07, 95% CI 1.00 - 1.14; p = .048). No other factors were found to have association with responding to rehabilitation. CONCLUSION: In older people with complex health problems or multi-morbidities, better cognition and a longer stay in rehabilitation were associated with a positive improvement in walking speed. Further research to explore who best responds to hospital-based rehabilitation and what interventions improve rehabilitation outcomes is warranted. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12613000884707; ClinicalTrials.gov Identifier NCT01910740 .

The impact of hippocampal segmentation methods on correlations with clinical data.

BACKGROUND: In vivo measurement of hippocampal volume with magnetic resonance imaging (MRI) has become an important element in neuroimaging research. However, hippocampal volumetric findings and their relationship with cardiovascular risk factors and memory performance are still controversial and inconsistent for non-demented adults. PURPOSE: To compare total and regional hippocampal volumes from manual tracing and automated Freesurfer segmentation methods and their relationship with mid-life clinical data and late-life verbal episodic memory performance in older women. MATERIAL AND METHODS: This study used structural MRI datasets from 161 women who were scanned in 2012 and underwent neuropsychological assessments. Of these participants, 135 women had completed baseline measures of cardiovascular risk factors in 1992. RESULTS: Our results showed a significant correlation between manual tracing and automated Freesurfer output segmentations of total (r = 0.71), anterior (r = 0.65), and posterior (r = 0.38) hippocampal volumes. Mid-life Framingham Cardiovascular Risk Profile score is not associated with late-life hippocampal volumes, adjusted for intracranial volume, age, education, and apolipoprotein E gene ε4 status. Anterior hippocampal volume segmented either with manual tracing or automated Freesurfer software is sensitive to changes in mid-life high-density lipoprotein (HDL) cholesterol level, while posterior hippocampal volume is linked with verbal episodic memory performance in elderly women. CONCLUSION: These findings support the use of Freesurfer automated segmentation measures for large datasets as being highly correlated with the manual tracing method. In addition, our results suggest intervention strategies that target mid-life HDL cholesterol level in women.

Do replicable profiles of multimorbidity exist? Systematic review and synthesis.

This systematic review aimed to synthesise multimorbidity profiling literature to identify replicable and clinically meaningful groupings of multimorbidity. We searched six electronic databases (Medline, EMBASE, PsycINFO, CINAHL, Scopus, and Web of Science) for articles reporting multimorbidity profiles. The identified profiles were synthesised with multidimensional scaling, stratified by type of statistical analysis used in the derivation of profiles. The 51 studies that met inclusion criteria reported results of 98 separate analyses of multimorbidity profiling, with a total of 407 multimorbidity profiles identified. The statistical techniques used to identify multimorbidity profiles were exploratory factor analysis, cluster analysis of diseases, cluster analysis of people, and latent class analysis. Reporting of methodological details of statistical methods was often incomplete. The discernible groupings of multimorbidity took the form of both discrete categories and continuous dimensions. Mental health conditions and cardio-metabolic conditions grouped along identifiable continua in the synthesised results of all four methods. Discrete groupings of chronic obstructive pulmonary disease with asthma, falls and fractures with sensory deficits and of Parkinson's disease and cognitive decline where partially replicable (identifiable in the results of more than one method), while clustering of musculoskeletal conditions and clustering of reproductive systems were each observed only in one statistical approach. The two most replicable multimorbidity profiles were mental health conditions and cardio-metabolic conditions. Further studies are needed to understand aetiology and evolution of these multimorbidity groupings. Guidelines for strengthening the reporting of multimorbidity profiling studies are proposed.

Association between structural changes in brain with muscle function in sarcopenic older women: the women's healthy ageing project (WHAP).

OBJECTIVES: The involvement of changes in brain structure in the pathophysiology of muscle loss (sarcopenia) with aging remains unclear. In this study, we investigated the associations between brain structure and muscle strength in a group of older women. We hypothesized that structural changes in brain could correlate with functional changes observed in sarcopenic older women. METHODS: In 150 women (median age of 70 years) of the Women's Healthy Ageing Project (WHAP) Study, brain grey (total and cortex) volumes were calculated using magnetic resonance imaging (MRI) analyses. Grip strength and timed up and go (TUG) were measured. The brain volumes were compared between sarcopenic vs. non-sarcopenic subjects and women with previous falls vs. those without. RESULTS: Based on handgrip strength and TUG results respectively, 27% and 15% of women were classified as sarcopenic; and only 5% were sarcopenic based on both criteria. At least one fall was experienced by 15% of participants. There was no difference in brain volumetric data between those with vs. without sarcopenia (p>0.24) or between women with falls (as a symptom of weakness or imbalance) vs. those without history of falls (p>0.25). CONCLUSIONS: Brain structure was not associated with functional changes or falls in this population of older women.

Longitudinal nutritional changes in aging Australian women.

BACKGROUND AND OBJECTIVES: The importance of diet for the maintenance of health during aging is attracting a growing body of research interest. Given dietary intakes, along with BMI, are substantial contributors to disease burden, this study aimed to investigate prospective changes in dietary patterns and nutrient intakes in a sample of mid to late-life women over 14 years. METHODS AND STUDY DESIGN: Participants were from the Women's Healthy Ageing Project (WHAP); a longitudinal cohort of Australian-born women within the Melbourne metropolitan area. 173 participants were included in this analysis, their mean age in 1998 was 55 years (range 51-62) and in 2012 was 70 years (range 66-76). Diet was assessed using the Dietary Questionnaire for Epidemiological Studies Version 2 in 1998 and 2012. Nutritional intakes, Dietary Inflammatory Index (DII®) scores, Mediterranean Diet (MD) scores, sociodemographic and physical measures were calculated for all participants at both time points. RESULTS: Energy intake was found to significantly decrease over time (p<0.005). Energy-adjusted (i.e., energy density) total fat, saturated fat, monounsaturated fat and cholesterol intakes increased over time (all p<0.002), while energy-adjusted and absolute carbohydrate intake decreased (p<0.002). Adherence to the MD decreased over time (p<0.001) whilst DII scores increased slightly over time, although this result was not significant. CONCLUSIONS: This study shows significant changes in the intake of energy and several nutrients in a cohort of aging Australian women in the Melbourne metropolitan area over a period of 14 years. Between 1998 and 2012, changes in indices reflecting overall diet were consistently in the direction of a poorer diet.

Predictive Factors for Verbal Memory Performance Over Decades of Aging: Data from the Women's Healthy Ageing Project.

BACKGROUND: Abnormalities in brain structure and function can occur several decades prior to the onset of cognitive decline. It is in the preceding decades that an intervention is most likely to be effective, when informed by an understanding of factors contributing to the disease prodrome. Few studies, however, have sufficient longitudinal data on relevant risks to determine the optimum targets for interventions to improve cognition in aging. In this article we examine the timing and exposure of factors contributing to verbal memory performance in later life. METHODS: 387 participants from the population-based Women's Healthy Ageing Project, mean age at baseline of 49.6 years (range: 45-55 years), had complete neuropsychiatric assessments, clinical information, physical measures, and biomarkers collected at baseline, with at least three follow-up visits that included at least one cognitive reassessment. Mixed linear models were conducted to assess the significance of risk factors on later-life verbal memory. We explored the influence of early, contemporaneous, and cumulative exposures. RESULTS: Younger age and better education were associated with baseline memory test performance (CERAD). Over the 20 years of study follow-up, cumulative mid- to late-life physical activity had the strongest effect on better later life verbal memory (0.136 [0.058, 0.214]). The next most likely contributors to verbal memory in late life were the negative effect of cumulative hypertension (-0.033 [-0.047, -0.0.18] and the beneficial effect of HDL cholesterol (0.818 [0.042, 1.593]). CONCLUSIONS: Findings suggest that midlife interventions focused on physical activity, hypertension control, and achieving optimal levels of HDL cholesterol will help maintain later-life verbal memory skills.

Semi-automated hippocampal segmentation in people with cognitive impairment using an age appropriate template for registration.

BACKGROUND: To evaluate a new semi-automated segmentation method for calculating hippocampal volumes and to compare results with standard software tools in a cohort of people with subjective memory complaints (SMC) and mild cognitive impairment (MCI). METHODS: Data from 58 participants, 39 with SMC (17 male, 22 female, mean age 72.6) and 19 with MCI (6 male, 13 female, mean age 74.3), were analyzed. For each participant, T1-weighted images were acquired using an MPRAGE sequence on a 3 Tesla MRI system. Hippocampal volumes (left, right, and total) were calculated with a new, age appropriate registration template, based on older people and using the advanced software tool ANTs (Advanced Normalization Tools). The results were compared with manual tracing (seen as the reference standard) and two widely accepted automated software tools (FSL, FreeSurfer). RESULTS: The hippocampal volumes, calculated by using the age appropriate registration template were significantly (P < 0.05) more accurate (mean volume accuracy more than 90%) than those obtained with FreeSurfer and FSL (both less than 70%). Dice coefficients for the hippocampal segmentations with the new template method (75.3%) were slightly, but significantly (P < 0.05) higher than those from FreeSurfer (72.4%). CONCLUSION: These results suggest that an age appropriate registration template might be a more accurate alternative to calculate hippocampal volumes when manual segmentation is not feasible.

Effect of amyloid on memory and non-memory decline from preclinical to clinical Alzheimer's disease.

High amyloid has been associated with substantial episodic memory decline over 18 and 36 months in healthy older adults and individuals with mild cognitive impairment. However, the nature and magnitude of amyloid-related memory and non-memory change from the preclinical to the clinical stages of Alzheimer's disease has not been evaluated over the same time interval. Healthy older adults (n = 320), individuals with mild cognitive impairment (n = 57) and individuals with Alzheimer's disease (n = 36) enrolled in the Australian Imaging, Biomarkers and Lifestyle study underwent at least one positron emission tomography neuroimaging scan for amyloid. Cognitive assessments were conducted at baseline, and 18- and 36-month follow-up assessments. Compared with amyloid-negative healthy older adults, amyloid-positive healthy older adults, and amyloid-positive individuals with mild cognitive impairment and Alzheimer's disease showed moderate and equivalent decline in verbal and visual episodic memory over 36 months (d's = 0.47-0.51). Relative to amyloid-negative healthy older adults, amyloid-positive healthy older adults showed no decline in non-memory functions, but amyloid-positive individuals with mild cognitive impairment showed additional moderate decline in language, attention and visuospatial function (d's = 0.47-1.12), and amyloid-positive individuals with Alzheimer's disease showed large decline in all aspects of memory and non-memory function (d's = 0.73-2.28). Amyloid negative individuals with mild cognitive impairment did not show any cognitive decline over 36 months. When non-demented individuals (i.e. healthy older adults and adults with mild cognitive impairment) were further dichotomized, high amyloid-positive non-demented individuals showed a greater rate of decline in episodic memory and language when compared with low amyloid positive non-demented individuals. Memory decline does not plateau with increasing disease severity, and decline in non-memory functions increases in amyloid-positive individuals with mild cognitive impairment and Alzheimer's disease. The combined detection of amyloid positivity and objectively-defined decline in memory are reliable indicators of early Alzheimer's disease, and the detection of decline in non-memory functions in amyloid-positive individuals with mild cognitive impairment may assist in determining the level of disease severity in these individuals. Further, these results suggest that grouping amyloid data into at least two categories of abnormality may be useful in determining the disease risk level in non-demented individuals.

Prehypertension in midlife is associated with worse cognition a decade later in middle-aged and older women.

BACKGROUND: previous studies raised the possibility that adverse health effects associated with elevated blood pressure (BP) begin at prehypertension levels (BP = 120-139/80-89 mmHg), yet few studies have examined the effects of prehypertension on cognitive functioning. OBJECTIVE: to examine the relationship between BP categories and cognitive functions in middle-aged and older women. SUBJECTS AND METHODS: two hundred and forty-seven women from the Women's Healthy Ageing Project had their BP measured twice, at mean ages 50 and 60 years. Tests of executive function, processing speed and verbal episodic memory were also administered at follow-up. Analyses of co-variance were performed to evaluate the associations between BP categories and cognitive performance. RESULTS: prehypertensive BP at age 50 years is a significant predictor of reduced processing speed and verbal episodic memory a decade later. Cross-sectional measurements at age 60 years showed that untreated hypertensive women performed significantly worse on verbal episodic memory compared with their prehypertensive peers. CONCLUSION: hypertension is a modifiable cardiovascular risk factor, and our results suggest that reducing midlife BP, even at prehypertensive levels, may be an effective prevention strategy to reduce risk for subsequent cognitive decline in middle-aged and older women.

Genetic algorithm with logistic regression for prediction of progression to Alzheimer's disease.

BACKGROUND: Assessment of risk and early diagnosis of Alzheimer's disease (AD) is a key to its prevention or slowing the progression of the disease. Previous research on risk factors for AD typically utilizes statistical comparison tests or stepwise selection with regression models. Outcomes of these methods tend to emphasize single risk factors rather than a combination of risk factors. However, a combination of factors, rather than any one alone, is likely to affect disease development. Genetic algorithms (GA) can be useful and efficient for searching a combination of variables for the best achievement (eg. accuracy of diagnosis), especially when the search space is large, complex or poorly understood, as in the case in prediction of AD development. RESULTS: Multiple sets of neuropsychological tests were identified by GA to best predict conversions between clinical categories, with a cross validated AUC (area under the ROC curve) of 0.90 for prediction of HC conversion to MCI/AD and 0.86 for MCI conversion to AD within 36 months. CONCLUSIONS: This study showed the potential of GA application in the neural science area. It demonstrated that the combination of a small set of variables is superior in performance than the use of all the single significant variables in the model for prediction of progression of disease. Variables more frequently selected by GA might be more important as part of the algorithm for prediction of disease development.

Predicting Alzheimer disease with ß-amyloid imaging: results from the Australian imaging, biomarkers, and lifestyle study of ageing.

OBJECTIVE: Biomarkers for Alzheimer disease (AD) can detect the disease pathology in asymptomatic subjects and individuals with mild cognitive impairment (MCI), but their cognitive prognosis remains uncertain. We aimed to determine the prognostic value of ß-amyloid imaging, alone and in combination with memory performance, hippocampal atrophy, and apolipoprotein E ε4 status in nondemented, older individuals. METHODS: A total of 183 healthy individuals (age = 72.0 ± 7.26 years) and 87 participants with MCI (age = 73.7 ± 8.27) in the Australian Imaging, Biomarkers, and Lifestyle study of ageing were studied. Clinical reclassification was performed after 3 years, blind to biomarker findings. ß-Amyloid imaging was considered positive if the (11) C-Pittsburgh compound B cortical to reference ratio was ≥1.5. RESULTS: Thirteen percent of healthy persons progressed (15 to MCI, 8 to dementia), and 59% of the MCI cohort progressed to probable AD. Multivariate analysis showed ß-amyloid imaging as the single variable most strongly associated with progression. Of combinations, subtle memory impairment (Z score = -0.5 to -1.5) with a positive amyloid scan was most strongly associated with progression in healthy individuals (odds ratio [OR] = 16, 95% confidence interval [CI] = 3.7-68; positive predictive value [PPV] = 50%, 95% CI = 19-81; negative predictive value [NPV] = 94%, 95% CI = 88-98). Almost all amnestic MCI subjects (Z score ≤ -1.5) with a positive amyloid scan developed AD (OR = ∞; PPV = 86%, 95% CI = 72-95; NPV = 100%, 95% CI = 80-100). Hippocampal atrophy and ε4 status did not add further predictive value. INTERPRETATION: Subtle memory impairment with a positive ß-amyloid scan identifies healthy individuals at high risk for MCI or AD. Clearly amnestic patients with a positive amyloid scan have prodromal AD and a poor prognosis for dementia within 3 years.

Anxiety symptoms, cerebral amyloid burden and memory decline in healthy older adults without dementia: 3-year prospective cohort study.

Although beta-amyloid, anxiety and depression have linked cross-sectionally to reduced memory function in healthy older adults without dementia, prospective data evaluating these associations are lacking. Using data an observational cohort study of 178 healthy older adults without dementia followed for 3 years, we found that anxiety symptoms significantly moderated the relationship between beta-amyloid level and decline in verbal (Cohen's d = 0.65) and episodic (Cohen's d = 0.38) memory. Anxiety symptoms were additionally linked to greater decline in executive function, irrespective of beta-amyloid and other risk factors. These findings suggest that interventions to mitigate anxiety symptoms may help delay memory decline in otherwise healthy older adults with elevated beta-amyloid.

Sexual function in the late postmenopause: a decade of follow-up in a population-based cohort of Australian women.

INTRODUCTION: There is a paucity of longitudinal studies assessing sexual function of women in the late postmenopause. AIM: This study aims to describe sexual function of women in the late postmenopause and to investigate change from early postmenopause. METHODS: Cross-sectional analysis of 2012/13 and longitudinal analysis from 2002/04 of the population based, Australian cohort of the Women's Healthy Ageing Project, applying validated instruments: Short Personal Experience Questionnaire (SPEQ), Female Sexual Distress Scale (FSDS), Hospital Anxiety and Depression Scale, Geriatric Depression Scale, and California Verbal Learning Test. MAIN OUTCOME MEASURES: Sexual activity, SPEQ, and FSDS. RESULTS: Two hundred thirty women responded (follow-up rate 53%), mean age was 70 years (range 64-77), 49.8% were sexually active. FSDS scores showed more distress for sexually active women (8.3 vs. 3.2, P<0.001). For 23 (23%) sexually active and for five (7%) inactive women, the diagnosis of female sexual dysfunction could be made. After adjustment, available partner (odds ratio [OR] 4.31, P<0.001), no history of depression (OR 0.49, P=0.036), moderate compared with no alcohol consumption (OR 2.43, P=0.019), and better cognitive function score (OR1.09, P=0.050) were significantly predictive for sexual activity. Compared with early postmenopause, 18% more women had ceased sexual activity. For women maintaining their sexual activity through to late postmenopause (n=82), SPEQ and FSDS scores had not changed significantly, but frequency of sexual activity had decreased (P=0.003) and partner difficulties had increased (P=0.043). [Correction added on 10 July 2014, after first online publication: Mean age of respondents was added.] CONCLUSIONS: In late postmenopause, half of the women were sexually active. Most important predictors were partner availability and no history of depression. However, being sexually active or having a partner were associated with higher levels of sexual distress. Compared with early postmenopause, sexual function scores had declined overall but were stable for women maintaining sexual activity. Further research into causes of sexual distress and reasons for sexual inactivity at this reproductive stage is warranted.

Lack of reliable evidence for a distinctive ε4-related cognitive phenotype that is independent from clinical diagnostic status: findings from the Australian Imaging, Biomarkers and Lifestyle Study.

Individuals who carry the apolipoprotein E ε4 polymorphism have an increased risk of late-onset Alzheimer's disease. However, because possession of the ε4 allele confers an increased risk for the diagnosis of dementia, it has proven problematic in older individuals to dissociate the influence of ε4 on cognitive capacity per se as distinct from its influence on clinical diagnostic status. We report a statistical approach that attempts to partial out the influence of diagnostic group membership (Alzheimer's disease, mild cognitive impairment, healthy control) from the influence of apolipoprotein ε4 genetic status on cognitive functioning. The cognitive phenotype hypothesis predicts that ε4-positive individuals will show cognitive deficits (relative to matched ε4-negative individuals) independent of the development of Alzheimer's disease. By contrast, the prodromal/preclinical Alzheimer's disease hypothesis proposes that the effect of apolipoprotein E status on cognitive performance is a function of the increased risk of dementia in individuals with the ε4 allele. We evaluated these hypotheses in the Australian Imaging, Biomarkers and Lifestyle cohort (n = 1112). We first determined whether previously reported findings concerning ε4 status and age-related neuropsychological performance could be explained by the inadvertent recruitment of people with mild cognitive impairment into the healthy control group. We then tested each diagnostic group in isolation to identify any neuropsychological patterns that may be attributed to the ε4 allele. Finally, as interactions between the ε4 allele and age have previously been reported in cognitive functioning within healthy elderly populations, we attempted to determine whether the inclusion of mild cognitively impaired individuals in the sample may drive this relationship. An extensive battery of standardized, well-validated neuropsychological tasks was administered to a final sample of 764 healthy control subjects, 131 individuals with mild cognitive impairment and 168 individuals with Alzheimer's disease. The effect of the ε4 allele on cognitive performance was assessed using a statistical mediation analysis and supplemented with Bayesian methods to address a number of the limitations associated with Fisherian/Neyman-Pearsonian significance testing. Our findings support the prodromal/preclinical Alzheimer's disease hypothesis and do not support the concept of a distinctive ε4-related cognitive phenotype.

Autobiographical narratives relate to Alzheimer's disease biomarkers in older adults.

BACKGROUND: Autobiographical memory (ABM), personal semantic memory (PSM), and autonoetic consciousness are affected in individuals with mild cognitive impairment (MCI) but their relationship with Alzheimer's disease (AD) biomarkers are unclear. METHODS: Forty-five participants (healthy controls (HC) = 31, MCI = 14) completed the Episodic ABM Interview and a battery of memory tests. Thirty-one (HC = 22, MCI = 9) underwent ß-amyloid positron emission tomography (PET) and magnetic resonance (MR) imaging. Fourteen participants (HC = 9, MCI = 5) underwent one imaging modality. RESULTS: Unlike PSM, ABM differentiated between diagnostic categories but did not relate to AD biomarkers. Personal semantic memory was related to neocortical ß-amyloid burden after adjusting for age and apolipoprotein E (APOE) ɛ4. Autonoetic consciousness was not associated with AD biomarkers, and was not impaired in MCI. CONCLUSIONS: Autobiographical memory was impaired in MCI participants but was not related to neocortical amyloid burden, suggesting that personal memory systems are impacted by differing disease mechanisms, rather than being uniformly underpinned by ß-amyloid. Episodic and semantic ABM impairment represent an important AD prodrome.

Rates of diagnostic transition and cognitive change at 18-month follow-up among 1,112 participants in the Australian Imaging, Biomarkers and Lifestyle Flagship Study of Ageing (AIBL).

BACKGROUND: The Australian Imaging, Biomarkers and Lifestyle (AIBL) Flagship Study of Ageing is a prospective study of 1,112 individuals (211 with Alzheimer's disease (AD), 133 with mild cognitive impairment (MCI), and 768 healthy controls (HCs)). Here we report diagnostic and cognitive findings at the first (18-month) follow-up of the cohort. The first aim was to compute rates of transition from HC to MCI, and MCI to AD. The second aim was to characterize the cognitive profiles of individuals who transitioned to a more severe disease stage compared with those who did not. METHODS: Eighteen months after baseline, participants underwent comprehensive cognitive testing and diagnostic review, provided an 80 ml blood sample, and completed health and lifestyle questionnaires. A subgroup also underwent amyloid PET and MRI neuroimaging. RESULTS: The diagnostic status of 89.9% of the cohorts was determined (972 were reassessed, 28 had died, and 112 did not return for reassessment). The 18-month cohort comprised 692 HCs, 82 MCI cases, 197 AD patients, and one Parkinson's disease dementia case. The transition rate from HC to MCI was 2.5%, and cognitive decline in HCs who transitioned to MCI was greatest in memory and naming domains compared to HCs who remained stable. The transition rate from MCI to AD was 30.5%. CONCLUSION: There was a high retention rate after 18 months. Rates of transition from healthy aging to MCI, and MCI to AD, were consistent with established estimates. Follow-up of this cohort over longer periods will elucidate robust predictors of future cognitive decline.

Aß and cognitive change: examining the preclinical and prodromal stages of Alzheimer's disease.

BACKGROUND: High ß-amyloid (Aß) is associated with faster memory decline in healthy individuals and adults with mild cognitive impairment (MCI). However, longer prospective studies are required to determine if Aß-related memory decline continues and whether it is associated with increased rate of disease progression. METHODS: Healthy controls (HCs; n = 177) and adults with MCI (n = 48) underwent neuroimaging for Aß and cognitive assessment at baseline. Cognition was reassessed 18 and 36 months later. RESULTS: Compared with low-Aß HCs, high-Aß HC and MCI groups showed moderate decline in episodic and working memory over 36 months. Those with MCI with low Aß did not show any cognitive decline. Rates of disease progression were increased in the high-Aß HC and MCI groups. CONCLUSIONS: In healthy individuals, high Aß likely indicates that Alzheimer's disease (AD)-related neurodegeneration has begun. Once commenced, the rate of decline in cognitive function remains constant across the preclinical and prodromal stages of AD.

Changes in plasma amyloid beta in a longitudinal study of aging and Alzheimer's disease.

BACKGROUND: A practical biomarker is required to facilitate the preclinical diagnosis of Alzheimer's disease (AD). METHODS: Plasma amyloid beta (Aß)1-40, Aß1-42, Aßn-40, and Aßn-42 peptides were measured at baseline and after 18 months in 771 participants from the Australian Imaging Biomarkers and Lifestyle (AIBL) study of aging. Aß peptide levels were compared with clinical pathology, neuroimaging and neuropsychological measurements. RESULTS: Although inflammatory and renal function covariates influenced plasma Aß levels significantly, a decrease in Aß1-42/Aß1-40 was observed in patients with AD, and was also inversely correlated with neocortical amyloid burden. During the 18 months, plasma Aß1-42 decreased in subjects with mild cognitive impairment (MCI) and in those transitioning from healthy to MCI. CONCLUSION: Our findings are consistent with a number of published plasma Aß studies and, although the prognostic value of individual measures in any given subject is limited, the diagnostic contribution of plasma Aß may demonstrate utility when combined with a panel of peripheral biomarkers.