A review of selected longitudinal studies on aging: past findings and future directions

Longitudinal Studies of Aging in Sub-Saharan Africa: Review, Limitations, and Recommendations in Preparation of Projected Aging Population

Background and Objectives

The United Nations has projected a 218% increase in older people in Sub-Saharan Africa (SSA) between 2019 and 2050, underscoring the need to explore changes that would occur over this time. Longitudinal studies are ideal for studying and proffering solutions to these changes. This review aims to understand the breadth and use of longitudinal studies on aging in the SSA regions, proffering recommendations in preparation for the projected aging population.

Research Design and Methods

This paper is the third of a four-part series paper of a previous systematic mapping review of aging studies in SSA. We updated the search (between 2021 and 2023) and screened the titles/abstracts and full-text articles by a pair of independent reviewers. Data were extracted using a standardized data-charting form, identifying longitudinal studies in SSA.

Results

We identified 193 studies leveraging 24 longitudinal study data sets conducted at 28 unique sites. The World Health Organization's Study on Global AGEing and Adult Health (WHO-SAGE) (n = 59, 30.5%) and Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa (HAALSI) (n = 51, 26.4%) were the most used longitudinal data sets. Four studies used more than one longitudinal study data set. Eighteen of the longitudinal study data sets were used only in 1-4 studies. Most (n = 150, 77.7%) of the studies used a cross-sectional analytical approach.

Discussion and Implications

Longitudinal studies on aging are sparingly being utilized in SSA. Most analyses conducted across the longitudinal data set were cross-sectional, which hindered the understanding of aging changes that occurred over time that could better inform aging policy and interventions. We call for funding bodies, such as WHO-SAGE, to develop funding competitions that focus on conducting longitudinal analyses, such as structural equation modeling, highlighting changes occurring among the aging population in SSA.

Measuring healthy ageing: current and future tools

Human ageing is a complex, multifactorial process characterised by physiological damage, increased risk of age-related diseases and inevitable functional deterioration. As the population of the world grows older, placing significant strain on social and healthcare resources, there is a growing need to identify reliable and easy-to-employ markers of healthy ageing for early detection of ageing trajectories and disease risk. Such markers would allow for the targeted implementation of strategies or treatments that can lessen suffering, disability, and dependence in old age. In this review, we summarise the healthy ageing scores reported in the literature, with a focus on the past 5 years, and compare and contrast the variables employed. The use of approaches to determine biological age, molecular biomarkers, ageing trajectories, and multi-omics ageing scores are reviewed. We conclude that the ideal healthy ageing score is multisystemic and able to encompass all of the potential alterations associated with ageing. It should also be longitudinal and able to accurately predict ageing complications at an early stage in order to maximize the chances of successful early intervention.

Measuring healthy ageing: current and future tools

Human ageing is a complex, multifactorial process characterised by physiological damage, increased risk of age-related diseases and inevitable functional deterioration. As the population of the world grows older, placing significant strain on social and healthcare resources, there is a growing need to identify reliable and easy-to-employ markers of healthy ageing for early detection of ageing trajectories and disease risk. Such markers would allow for the targeted implementation of strategies or treatments that can lessen suffering, disability, and dependence in old age. In this review, we summarise the healthy ageing scores reported in the literature, with a focus on the past 5 years, and compare and contrast the variables employed. The use of approaches to determine biological age, molecular biomarkers, ageing trajectories, and multi-omics ageing scores are reviewed. We conclude that the ideal healthy ageing score is multisystemic and able to encompass all of the potential alterations associated with ageing. It should also be longitudinal and able to accurately predict ageing complications at an early stage in order to maximize the chances of successful early intervention.

Educating dental students to provide compassionate age friendly care for older adults

As the world population ages, the need for age friendly care increases. In dentistry, age friendly care requires an appropriate comprehension of multiple factors that can be categorized in socio-economic circumstances, systemic health problems, and oral health conditions. In addition to the understanding of these factors and its relationships among each other, the future dental workforce should also be aware of unconscious and pervasive societal stereotypical perception of older persons, aging, and being old, which results in ageism and ageist attitudes. Dental schools can play an important role on raising ageism awareness and combating ageism in healthcare, thus preparing the future of the dental workforce to provide compassionate age friendly care. This paper will discuss ageism in dental schools and learning strategies used to combat it and increase compassionate care delivery for older adults.

The Upside of Negative Emotions: How Do Older Adults From Different Cultures Challenge Their Self-Growth During the COVID-19 Pandemic?

Background and Objective

The outbreak of Coronavirus Disease 2019 (COVID-19) has raised increased challenges for older adults' personal growth in diverse cultural settings. The aim of this study was to analyze negative emotions and their role on older adults' self-growth in Mexico, Italy, Portugal, and Spain, during the COVID-19 pandemic. For this purpose, a cross-national qualitative research was carried out.

Methods

Data were collected from 338 community-dwelling participants aged 65 years and older, using a semi-structured interview protocol. Older adults were asked about negative emotions that significantly contribute to their self-growth during the COVID-19 pandemic. Content analysis was used to identify key themes.

Results

Seven main negative emotions (fear, sadness, anger, grief, boredom, loneliness, and shame) significantly contributed to seven themes of self-growth, across the samples: sharing difficult experiences with others, supportive partner, spiritual practices, engagement with life, generativity, volunteering activities, and intimacy and sexual satisfaction. Sharing difficult experiences with others was most pertinent to Mexican (13.9%) and to Italian (3.0%) participants, and a supportive partner to Portuguese (12.1%), and to Spanish participants (6.5%).

Conclusion

The findings of this study indicate that negative emotions during the COVID-19 pandemic contributed to their older adults' self-growth. This study highlighted the cultural diversity of experiences during the pandemics and underlined the upside of negative emotions and its relation to older adults' self-growth during this period.

Beneficial Effect of High-Frequency Repetitive Transcranial Magnetic Stimulation for the Verbal Memory and Default Mode Network in Healthy Older Adults

Repetitive transcranial magnetic stimulation (rTMS) of the dorsolateral prefrontal cortex (DLPFC) is a non-invasive effective treatment for cognitive disorder, but its underlying mechanism of action remains unknown. The aim of this study was to explore the effect of a 2-week high-frequency (HF) active or sham 10 Hz rTMS on verbal memory in 40 healthy older adults. Resting-state functional magnetic resonance imaging (rs-fMRI) was used to measure functional connectivity (FC) within the default mode network (DMN). Verbal memory performance was evaluated using an auditory verbal learning test (AVLT). Additionally, we evaluated the relationship between memory improvement and FC changes within the DMN. The results revealed that HF-rTMS can enhance immediate recall and delayed recall of verbal memory and increased the FC of the bilateral precuneus (PCUN) within the DMN. The positive correlations between the immediate recall memory and the FC of the left PCUN after a 2-week intervention of HF-rTMS were detected. In conclusion, HF-rTMS may have the potential to improve verbal memory performance in older adults, which relation to FC changes in the DMN. The current findings are useful for increasing the understanding of the mechanisms of HF-rTMS, as well as guiding HF-rTMS treatment of cognitive disorders.

Dog Models of Aging

As the most phenotypically diverse mammalian species that shares human environments and access to sophisticated healthcare, domestic dogs have unique potential to inform our understanding of the determinants of aging. Here we outline key concepts in the study of aging and illustrate the value of research with dogs, which can improve dog health and support translational discoveries. We consider similarities and differences in aging and age-related diseases in dogs and humans and summarize key advances in our understanding of genetic and environmental risk factors for morbidity and mortality in dogs. We address health outcomes ranging from cancer to cognitive function and highlight emerging research opportunities from large-scale cohort studies in companion dogs. We conclude that studying aging in dogs could overcome many limitations of laboratory models, most notably, the ability to assess how aging-associated pathways influence aging in real-world environments similar to those experienced by humans.

Study of Longitudinal Aging in Mice: Presentation of Experimental Techniques

Aging is associated with functional and metabolic decline and is a risk factor for all noncommunicable diseases. Even though mice are routinely used for modeling human aging and aging-related conditions, no comprehensive assessment to date has been conducted on normative mouse aging. To address this gap, the Study of Longitudinal Aging in Mice (SLAM) was designed and implemented by the National Institute on Aging (NIA/NIH) as the mouse counterpart to the Baltimore Longitudinal Study of Aging (BLSA). In this manuscript, we describe the premise, study design, methodologies, and technologies currently employed in SLAM. We also discuss current and future study directions. In this large population mouse study, inbred C57BL/6J and outbred UM-HET3 mice of both sexes are longitudinally evaluated for functional, phenotypic, and biological health, and collection of biospecimens is conducted throughout their life span. Within the longitudinal cohorts, a cross-sectional arm of the study has also been implemented for the well-controlled collection of tissues to generate a biorepository. SLAM and studies stemming from SLAM seek to identify and characterize phenotypic and biological predictors of mouse aging and age-associated conditions, examine the degrees of functional and biomolecular variability that occur within inbred and genetically heterogeneous mouse populations with age, and assess whether these changes are consistent with alterations observed in human aging in BLSA. The findings from these studies will be critical for evaluating the utility of mouse models for studying different aspects of aging, both in terms of interpreting prior findings and designing and implementing future studies.

Omics in a Digital World: The Role of Bioinformatics in Providing New Insights Into Human Aging

Background

Aging is a complex phenotype influenced by a combination of genetic and environmental factors. Although many studies addressed its cellular and physiological age-related changes, the molecular causes of aging remain undetermined. Considering the biological complexity and heterogeneity of the aging process, it is now clear that full understanding of mechanisms underlying aging can only be achieved through the integration of different data types and sources, and with new computational methods capable to achieve such integration.

Recent Advances

In this review, we show that an omics vision of the age-dependent changes occurring as the individual ages can provide researchers with new opportunities to understand the mechanisms of aging. Combining results from single-cell analysis with systems biology tools would allow building interaction networks and investigate how these networks are perturbed during aging and disease. The development of high-throughput technologies such as next-generation sequencing, proteomics, metabolomics, able to investigate different biological markers and to monitor them simultaneously during the aging process with high accuracy and specificity, represents a unique opportunity offered to biogerontologists today.

Critical Issues

Although the capacity to produce big data drastically increased over the years, integration, interpretation and sharing of high-throughput data remain major challenges. In this paper we present a survey of the emerging omics approaches in aging research and provide a large collection of datasets and databases as a useful resource for the scientific community to identify causes of aging. We discuss their peculiarities, emphasizing the need for the development of methods focused on the integration of different data types.

Future Directions

We critically review the contribution of bioinformatics into the omics of aging research, and we propose a few recommendations to boost collaborations and produce new insights. We believe that significant advancements can be achieved by following major developments in bioinformatics, investing in diversity, data sharing and community-driven portable bioinformatics methods. We also argue in favor of more engagement and participation, and we highlight the benefits of new collaborations along these lines. This review aims at being a useful resource for many researchers in the field, and a call for new partnerships in aging research.

Physical Function Assessment in Older Hemodialysis Patients

RATIONALE & OBJECTIVE

Physical function is not routinely measured in older adults receiving dialysis. We evaluated the appropriateness of repeated measurements of physical function, including Short Physical Performance Battery (SPPB), handgrip strength, and activities of daily living (ADLs), in older adults receiving dialysis.

STUDY DESIGN

Prospective study.

SETTING & PARTICIPANTS

37 community-dwelling adults 65 years and older receiving in-center hemodialysis at 5 dialysis units located in North Carolina.

EXPOSURES

SPPB (an assessment of standing balance, chair stands, and gait speed), handgrip strength, and Katz and Lawton ADLs at baseline and subsequent 3-month intervals up to 6 months.

OUTCOMES

Completion rate, presence of floor or ceiling effects, and presence of clinically meaningful change in physical function measurements.

RESULTS

Of 55 potential participants, we enrolled 37 (67%) older adults receiving hemodialysis. Among 35 enrolled participants who completed baseline assessment in a dialysis unit, mean age was 70.1 (SD, 5) years, 46% (n = 16) were women, 77% (n = 27) were African American, and median time receiving dialysis was 2.7 (IQR, 0.6-5.0) years. There were 3 deaths within the observation period, and study retention at 3 and 6 months was 83% (n = 29) and 74% (n = 26), respectively. Participants tolerated measurements; only 2 participants did not attempt 1 of the performance-based tests at a study visit. Baseline median SPPB score, grip strength, and gait speed were 6 (IQR, 4-9), 55 (IQR, 42-70) kg, and 0.76 (IQR, 0.46-0.86) m/s, respectively. Baseline median for Katz and Lawton ADLs were 6 (IQR, 6-6) and 7 (IQR, 4-8), respectively; ceiling effects were observed for both measures. For some participants, clinically meaningful changes (improvement or decline) in SPPB score, grip strength, and gait speed occurred at each 3-month interval.

LIMITATIONS

Limited geographic and ethnic variation.

CONCLUSIONS

SPPB, handgrip strength, and gait speed alone are appropriate measures for interval physical function assessment in community-dwelling older adults receiving in-center hemodialysis.

The Aging Metabolome-Biomarkers to Hub Metabolites

Aging biology is intimately associated with dysregulated metabolism, which is one of the hallmarks of aging. Aging-related pathways such as mTOR and AMPK, which are major targets of anti-aging interventions including rapamcyin, metformin, and exercise, either directly regulate or intersect with metabolic pathways. In this review, numerous candidate bio-markers of aging that have emerged using metabolomics are outlined. Metabolomics studies also reveal that not all metabolites are created equally. A set of core "hub" metabolites are emerging as central mediators of aging. The hub metabolites reviewed here are nicotinamide adenine dinucleotide, reduced nicotinamide dinucleotide phosphate, α-ketoglutarate, and β-hydroxybutyrate. These "hub" metabolites have signaling and epigenetic roles along with their canonical roles as co-factors or intermediates of carbon metabolism. Together these hub metabolites suggest a central role of the TCA cycle in signaling and metabolic dysregulation associated with aging.

Comparing socio-economic inequalities in healthy ageing in the United States of America, England, China and Japan: evidence from four longitudinal studies of ageing

Healthy ageing has become a popular topic worldwide. So far, a consensus measure of healthy ageing has not been reached; and no studies have compared the magnitude of socio-economic inequality in healthy ageing outside Europe. This study aims to create a universal measure of healthy ageing and compare socio-economic inequalities in healthy ageing in the United States of America (USA), England, China and Japan. We included 10,305 American, 6,590 English, 5,930 Chinese and 1,935 Japanese participants for longitudinal analysis. A harmonised healthy ageing index (HAI) was developed to measure healthy ageing multi-dimensionally. Educational, income and wealth rank scores were derived accounting for the entire socio-economic distribution and the sample size of each category of socio-economic indicator. Associations between socio-economic rank scores and HAIs were assessed using multi-level modelling to calculate the Slope Indices of Inequality. Healthy ageing trajectories were predicted based on the full-adjusted age-cohort models. We found that education was a universally influential socio-economic predictor of healthy ageing. Moving from the highest to the lowest educational groups was associated with a 6.7 (5.2–8.2), 8.2 (6.0–10.4), 13.9 (11.4–16.3) and 6.1 per cent (3.9–8.2%) decrease in average HAI at 60 years in the USA, England, China and Japan, respectively. After 60 years, the educational inequality in healthy ageing kept increasing in the USA and China. The educational inequality in healthy ageing in China was also greater than any other socio-economic inequality in the four countries. Wealth was more influential in predicting healthy ageing inequality among American, English and Japanese participants, while income was more influential among Chinese participants. The socio-economic inequality in healthy ageing in Japan was relatively small. Chinese and American participants had worse healthy ageing profiles than Japanese and English participants.

On the horizon of aging and physical activity research

This viewpoint is the result of a Horizon Round Table discussion of Exercise and Aging held during the 2017 Saltin International Graduate School in Exercise and Clinical Physiology in Gatineau, Quebec. This expert panel discussed key issues and approaches to future research into aging, across human physiological systems, current societal concerns, and funding approaches. Over the 60-min round table discussion, 3 major themes emerged that the panel considered to be "On the Horizon" of aging research. These themes include (i) aging is a process that extends from womb to tomb; (ii) the importance of longitudinal experimental studies; and (iii) the ongoing need to investigate multiple systems using an integrative approach between scientists, clinicians, and knowledge brokers. With a focus on these themes, we aim to identify critical questions, challenges, and opportunities that face scientists in advancing the understanding of exercise and aging.

Integrative multi-view regression: Bridging group-sparse and low-rank models

Multi-view data have been routinely collected in various fields of science and engineering. A general problem is to study the predictive association between multivariate responses and multi-view predictor sets, all of which can be of high dimensionality. It is likely that only a few views are relevant to prediction, and the predictors within each relevant view contribute to the prediction collectively rather than sparsely. We cast this new problem under the familiar multivariate regression framework and propose an integrative reduced-rank regression (iRRR), where each view has its own low-rank coefficient matrix. As such, latent features are extracted from each view in a supervised fashion. For model estimation, we develop a convex composite nuclear norm penalization approach, which admits an efficient algorithm via alternating direction method of multipliers. Extensions to non-Gaussian and incomplete data are discussed. Theoretically, we derive non-asymptotic oracle bounds of iRRR under a restricted eigenvalue condition. Our results recover oracle bounds of several special cases of iRRR including Lasso, group Lasso, and nuclear norm penalized regression. Therefore, iRRR seamlessly bridges group-sparse and low-rank methods and can achieve substantially faster convergence rate under realistic settings of multi-view learning. Simulation studies and an application in the Longitudinal Studies of Aging further showcase the efficacy of the proposed methods.

Lifespan Intellectual Factors, Genetic Susceptibility, and Cognitive Phenotypes in Aging: Implications for Interventions

Along with rapid global population aging, the age-related cognitive disorders such as mild cognitive impairment (MCI) and dementia have posed a serious threat to public health, health care system, and sustainable economic and societal development of all countries. In this narrative review, we seek to summarize the major epidemiological studies from the life-course perspective that investigate the influence of genetic susceptibility [e.g., apolipoprotein (APOE) ε4 allele] and intellectual or psychosocial factors (e.g., educational attainments and leisure activities) as well as their interactions on cognitive phenotypes in aging. Numerous population-based studies have suggested that early-life educational attainments and socioeconomic status, midlife work complexity and social engagements, late-life leisure activities (social, physical, and mentally-stimulating activities), certain personality traits (e.g., high neuroticism and low conscientiousness), and depression significantly affect late-life cognitive phenotypes. Furthermore, certain intellectual or psychosocial factors (e.g., leisure activities and depression) may interact with genetic susceptibility (e.g., APOE ε4 allele) to affect the phenotypes of cognitive aging such that risk or beneficial effects of these factors on cognitive function may vary by carrying the susceptibility genes. Current evidence from the randomized controlled trials that support the cognitive benefits of cognitive training among cognitive healthy older adults remains limited. The cognitive reserve hypothesis has been proposed to partly explain the beneficial effects of lifetime intellectual and psychosocial factors on late-life cognitive function. This implies that, from a life-course perspective, preventive intervention strategies targeting multiple modifiable intellectual and psychosocial factors could interfere with clinical expression of cognitive disorders in old age and delay the onset of dementia syndrome, and thus, may help achieve healthy brain aging.

Sample attrition rate of a community study: An analysis of Lucknow urban and rural elderly follow-up over a period of 9 years

BACKGROUND

Longitudinal/follow-up studies of older adults are a tough task as sample attrition rates due to mortality and other factors may be high in this particular group. However, such studies are very much needed to assess the outcome of health status as well as explore preventive, protective, interventional aspects, as well as risk factors. Given this, a follow-up study was planned and carried out.

AIM

To discuss the rate of sample loss as well as the reasons over 9 years.

METHODS

An Indian Council of Medical Research (ICMR) supported follow-up study of urban and rural elderly was done during June, 2016-May, 2017; these subjects were studied in 2007-09 through two independent ICMR supported studies. Similar methodology and assessment tools were applied in these studies. During follow-up a semi structured proforma was developed to get the information of study cohort, obtained data was analyzed and presented applying percentage statistics.

RESULTS

The sample attrition rate was reported to be comparatively high in urban 52.1% (n= 633) cohort than their rural counterparts 36.3% (n= 457).

CONCLUSION

Over a period of 9 years chances of cohort loss due to mortality is about 32%-35%.

Performance Level and Cortical Atrophy Modulate the Neural Response to Increasing Working Memory Load in Younger and Older Adults

There is evidence that the neural response to increasing working memory (WM) load is modulated by age and performance level. For a valid interpretation of these effects, however, it is important to understand, whether and how they are related to gray matter atrophy. In the current work, we therefore used functional magnetic resonance imaging (fMRI) and voxel-based morphometry (VBM) to examine the association between age, performance level, spatial WM load-related brain activation and gray matter volume in 18 younger high-performers (YHP), 17 younger low-performers (YLP), 17 older high-performers (OHP), and 18 older low-performers (OLP). In multiple sub regions of the prefrontal cortex (PFC), load-related activation followed a linear trend with increasing activation at increasing load in all experimental groups. Results did not reveal differences between the sub groups. Older adults additionally showed a pattern of increasing activation from low to medium load but stable or even decreasing activation from medium to high load in other sub regions of the PFC (quadratic trend). Quadratic trend related brain activation was higher in older than in younger adults and in OLP compared to OHP. In OLP, quadratic trend related brain activation was negatively correlated with both performance accuracy and prefrontal gray matter volume. The results suggest an efficient upregulation of multiple PFC areas as response to increasing WM load in younger and older adults. Older adults and particularly OLP additionally show dysfunctional response patterns (i.e., enhanced quadratic trend related brain activation compared to younger adults and OHP, respectively) in other PFC clusters being associated with gray matter atrophy.

Factors Associated With Physical Performance Measures in a Multiethnic Cohort of Older Adults

Objective: To explore the association between ethnicity, sociodemographic, health, and lifestyle factors, and physical performance (PP) in ethnically diverse community-dwelling older adults from one geographic area. Method: We used multivariable linear regression to identify factors associated with upper (grip strength [GS], arm curls [AC]) and lower (chair stands [CS]) body strength and mobility (gait speed [GSp]) in 577 older adults (mean age 74 ± 8; 104 African American, 142 Afro-Caribbean, 123 Hispanic, and 208 European American) from South Florida. Results: Worse mental health was negatively associated with CS in African Americans and AC in Hispanics. Older age and higher body mass index (BMI) was associated with slower GSp in all except in Hispanics. Higher physical activity was associated with higher upper body strength in Hispanics and better mobility in African Americans and Afro-Caribbeans, but not in European Americans. Conclusion: Studies with large multiethnic cohorts are needed to further our understanding of ethnic differences in PP, which will help in tailoring interventions and recognizing unmet needs for health and social services.

Three-Year Changes in Physical Activity and Subsequent Loss of Ability to Walk 400 m in Older Adults: The InCHIANTI Study

We examined the associations of maintaining or increasing physical activity (PA) for a 3-yr follow-up with subsequent incident inability to complete the 400-m walk test (i.e., mobility disability) for 6 yrs of follow-up in older adults. This study included 421 participants 65 yrs and older. The 400-m walk test was assessed at baseline and at 3-, 6-, and 9-yr follow-up. Physical activity was self-reported through a 6-point rating scale at baseline and 3-yr follow-up. Three-year cumulative PA (i.e., average at baseline and at 3-yr follow-up) and its changes (i.e., from baseline to 3-yr follow-up) were linked to subsequent incidence of mobility disability for 6 yrs of follow-up (i.e., from 3- to 9-yr follow-up), after adjustment for potential covariates. After the 3-yr period, incidence of mobility disability for the subsequent 6 yrs of follow-up occurred in 129 participants. The odds ratio (95% confidence interval) of incident mobility disability associated with 1-category increase in cumulative PA was 0.63 (0.41-0.97, P = 0.036). The odds ratio (95% confidence interval) of incident mobility disability associated with 1-category increase in changes in PA was 0.56 (0.38-0.84, P = 0.005). Hence, maintaining or increasing PA levels is associated with a reduced risk of mobility disability among older adults.

Three-Year Changes in Physical Activity and Decline in Physical Performance Over 9 Years of Follow-Up in Older Adults: The Invecchiare in Chianti Study

OBJECTIVES

To examine the associations between cumulative physical activity (PA) and its changes over 3 years and changes over 9 years of follow-up in physical performance in older adults.

DESIGN

Longitudinal.

SETTING

Community-based.

PARTICIPANTS

Men and women aged 65 and older from the Invecchiare in Chianti study (N = 782).

MEASUREMENTS

Physical performance was assessed at baseline and at 3-, 6-, and 9-year follow-up using the Short Physical Performance Battery (SPPB). PA was assessed through an interviewer-administered questionnaire at baseline and 3-year follow-up. Analyses were adjusted for education, body mass index, smoking, alcohol intake, coronary heart disease, stroke, peripheral arterial disease, cancer, lung disease, lower extremity osteoarthritis, depression, and Mini-Mental State Examination.

RESULTS

Over 3 years of follow-up, 27.8% of participants were inactive, 52.2% were minimally active, and 20.0% were active, and the PA of 37.2% decreased, there was no change in PA of 50.1% and the PA of 12.7% increased. After adjustment for potential covariates, being mostly active (-1.08, 95% confidence interval (CI) = -1.43 to -0.73) and minimally active (-1.33, 95% CI = -1.53 to -1.12) over 3 years of follow-up was associated with less decline in SPPB score than being mostly inactive (-2.60, 95% CI = -2.92 to -2.27). When analyzing changes, increasing PA (-0.57, 95% CI = -1.01 to -0.12) was associated with less decline in SPPB score over 9 years than decreasing PA (-2.16, 95% CI = -2.42 to -1.89).

CONCLUSION

Maintaining or increasing PA levels may attenuate age-associated physical performance decline.

Temporal dynamics of cognitive performance and anxiety across older adulthood

Cognitive decline and anxiety symptoms commonly co-occur in later life, but the temporal order of changes on these two attributes is unclear. Specifically, it is unknown if greater anxiety leads to subsequent declines in cognitive performance or if worse cognitive performance leads to increased anxiety. In this study, we sought to elucidate the temporal dynamics between anxiety symptoms and cognitive performance across old age-that is, the extent to which level and change in one variable influence subsequent changes in a second variable. We examined data from 721 nondemented participants from the Swedish Adoption/Twin Study of Aging. Participants completed as many as eight assessments of cognitive performance and anxiety over a 26-year period. Bivariate dual-change score models were fit to examine the dynamic association between anxiety and cognitive performance. Bidirectional associations between anxiety and cognitive performance were found among measures of processing speed, attention, and memory but not visuospatial abilities. Higher anxiety was associated with greater declines in processing speed over the duration of 6 years and worsening attention over a span of 3 years. The reverse direction was also significant in that slower processing speed, worse attention, and poorer nonverbal and working memory performance were associated with larger increases in anxiety 3 years later. These findings highlight that in cognitively intact older adults, the association between anxiety and worse cognitive performance is bidirectional and complex. (PsycINFO Database Record

Dissociating Normal Aging from Alzheimer's Disease: A View from Cognitive Neuroscience

Both normal aging and Alzheimer's disease (AD) are associated with changes in cognition, grey and white matter volume, white matter integrity, neural activation, functional connectivity, and neurotransmission. Obviously, all of these changes are more pronounced in AD and proceed faster providing the basis for an AD diagnosis. Since these differences are quantitative, however, it was hypothesized that AD might simply reflect an accelerated aging process. The present article highlights the different neurocognitive changes associated with normal aging and AD and shows that, next to quantitative differences, there are multiple qualitative differences as well. These differences comprise different neurocognitive dissociations as different cognitive deficit profiles, different weights of grey and white matter atrophy, and different gradients of structural decline. These qualitative differences clearly indicate that AD cannot be simply described as accelerated aging process but on the contrary represents a solid entity.

[The special requirements of old age in terms of dying]

It is expected that the rising average life expectancy will leave ever more people with chronic progressive diseases of the body and brain. This then means not only having to deal with increasingly longer periods of care, but also possibly distinct neurocognitive disorders in the years prior to death and dying. The aim of this study is to report epidemiological data on the causes of death, as well as on the places of death. In addition, the attitudes and behaviour towards death and dying, as well as the different places of death will be discussed. Expecting support in the process of dying, as well as factors that have a more conducive effect on the internal processing of dying, are mentioned. At the same time, the attitudes and behaviours in respect of the accompaniment of dying people, which can be seen in the staff in clinical inpatient facilities, are addressed. Personal intense grappling with dying and death actually has a positive effect on these behaviours and attitudes. Finally, the contribution turns to the question of to what extent the theory of compression of morbidity may be perceived as valid, especially in view of the rising average life expectancy. It is emphasised that chronic diseases, even when no functional loss is present, place not only great demands on the patient, but also on the care system and financial resources. Furthermore, it is demonstrated that frailty can often cause mental disorders. Specific requirements with a view to the care of people with dementia are given.

Factors associated with ADL/IADL disability in community dwelling older adults in the Irish longitudinal study on ageing (TILDA)

PURPOSE

To identify the factors associated with disability across many domains using a large powered sample in the activities of daily living (ADL) and instrumental activities of daily living (IADL).

METHODS

Those aged ≥65 years from the Irish longitudinal study on ageing (TILDA) were included in this cross sectional analysis. Three logistic regression models were used to examine the relationships between 25 health, psychological and sociodemographic variables and difficulties in ADL, IADL and ADL/IADL combined.

RESULTS

The proportion of those reporting combined ADL/IADL difficulties was 18%. More individuals reported difficulty with ADLs (13%) than IADLS (11%). The main model showed that after age, the top three factors associated with difficulty in ADL/IADL combined were pain, taking five or more medications and depression. After age, the factors with the highest impact on ADL disability were pain, taking five or more medications and body mass index (BMI); the factors with the highest impact on IADL were being separated or divorced, living with others (non-spouse) and self-rated memory.

CONCLUSIONS

Awareness of sociodemographics and early interventions for pain and cognitive deficits could reduce ADL/IADL disability and promote successful ageing. Identification of variables that influence ADL/IADLs can be used to inform policy and practice. Implications for rehabilitation After age, pain and taking five or more medications were the strongest factors associated with difficulty in ADL/IADL combined and ADL alone. Practice therefore needs to be cognizant that it is not the disease label but the symptoms of a disease that affect ADL and IADL activities. Given the strong influence of pain on difficulties with ADL and IADL, there is a need for early interventions from a multidisciplinary perspective for pain reduction, control, and self-management. These interventions should include development of pain-coping strategies and exercises to maintain mobility. After age, being separated/divorced or living with non-spouse others are the strongest factors associated with IADL difficulties. Awareness of these social factors can be used to inform support mechanisms, such as development of community services and suitable housing for those with these changing sociodemographics. Unsurprisingly, cognitive impairments were strongly associated with IADL difficulties. Simple cognitive screening assessments could be used for early detection of cognitive changes. In order to maintain optimal cognitive functioning, rehabilitation professionals should facilitate older adults' engagement in activities that are cognitively demanding and socially interactive.

The NEIL Memory Research Unit: psychosocial, biological, physiological and lifestyle factors associated with healthy ageing: study protocol

Background

Population ageing is a global phenomenon that has characterised demographic trends during the 20th and 21st century. The rapid growth in the proportion of older adults in the population, and resultant increase in the incidence of age-related cognitive decline, dementia and Alzheimer’s disease, brings significant social, economic and healthcare challenges. Decline in cognitive abilities represents the most profound threat to active and healthy ageing. Current evidence suggests that a significant proportion of cases of age-related cognitive decline and dementia may be preventable through the modification of risk factors including education, depressive symptomology, physical activity, social engagement and participation in cognitively stimulating activities. The NEIL Memory Research Unit cohort study was established to investigate factors related to brain health and the maintenance of cognitive function.

Methods

A cohort of 1000 normally ageing adults aged 50 years and over are being recruited to participate in comprehensive assessments at baseline, and at follow-up once every 2 years. The assessment protocol comprises a comprehensive neuropsychological battery, some basic physical measures, psychosocial scales, questionnaire measures related to a range of health, lifestyle and behavioural factors, and a measure of resting state activity using electroencephalography (EEG).

Discussion

The NEIL Memory Research Unit cohort study will address key questions about brain health and cognitive ageing in the population aged 50+, with a particular emphasis on the influence of potentially modifiable factors on cognitive outcomes. Analyses will be conducted with a focus on factors involved in the maintenance of cognitive function among older adults, and therefore will have the potential to contribute significant knowledge related to key questions within the field of cognitive ageing, and to inform the development of public health interventions aimed at preventing cognitive decline and promoting active and healthy ageing.

Sharing data in the global alzheimer's association interactive network

The Global Alzheimer's Association Interactive Network (GAAIN) aims to be a shared network of research data, analysis tools, and computational resources for studying the causes of Alzheimer's disease. Central to its design are policies that honor data ownership, prevent unauthorized data distribution, and respect the boundaries of contributing institutions. The results of data queries are displayed in graphs and summary tables, which protects data ownership while providing sufficient information to view trends in aggregated data and discover new data sets. In this article we report on our progress in sharing data through the integration of geographically-separated and independently-operated Alzheimer's disease research studies around the world.

Ascertainment bias in dementias: a secondary to tertiary centre analysis in Central Italy and conceptual review

BACKGROUND AND AIMS

Ascertainment bias (AB) indicates a bias of an evaluation centre in estimating the prevalence/incidence of a disease due to the specific expertise of the centre. The aim of our study was to evaluate classification of different types of dementia in new cases appearing in secondary and tertiary centres, in order to evidence possible occurrence of AB in the various (secondary to tertiary) dementia centres.

METHODS

To assess the mechanism of AB, the rates of new cases of the different forms of dementia reported by different centres were compared. The centres involved in the study were 11 hospital-based centres including a tertiary centre, located in the University Department of Clinical Neurology. The tertiary centre is endowed with state-of-the-art diagnostic facilities and its scientific production is prominently focused on dementia with Lewy bodies (DLB) thus suggesting the possible occurrence of a bias. Four main categories of dementia were identified: Alzheimer's disease (AD), DLB, fronto-temporal dementia (FTD), vascular dementia (VaD), with other forms in a category apart. The classification rate of new cases of dementia in the tertiary centre was compared with rates reported by secondary centres and rates of recoding were calculated during a follow-up of 2 years.

RESULTS

The study classified 2,042 newly diagnosed cases of dementia in a population of 1,370,000 inhabitants of which 315,000 were older than 65. AD was categorized in 48-52 % of cases, DLB in 25-28 %, FTD in 2-4 % and VaD in 17-28 %. During the 2-year follow-up the diagnosis was re-classified in 40 patients (3 %). The rate of recoding was 5 % in the tertiary centre, 2-8 % in referrals from secondary to tertiary centre, 2-10 % in recodings performed in secondary centres and addressed to tertiary centre. Recoding or percentages of new cases of AD or DLB were not different in the comparison between secondary or between secondary and tertiary centres. FTD and VaD were instead significantly recoded.

CONCLUSION

The results of the study suggest that in a homogeneous area, AB is not interfering with diagnosis of AD or DLB.

Review of selected databases of longitudinal aging studies

One of the recommendations of the 2010 Leon Thal Symposium, organized to develop strategies to prevent Alzheimer's disease, was to build a global database of longitudinal aging studies. Although several databases of longitudinal aging studies exist, none of these are comprehensive or complete. In this article, we review selected databases of longitudinal aging studies. We also make recommendations on future steps to create a comprehensive database. Additionally, we discuss issues related to data harmonization.

The Longitudinal Urban Cohort Ageing Study (LUCAS): study protocol and participation in the first decade

Background

We present concept, study protocol and selected baseline data of the Longitudinal Urban Cohort Ageing Study (LUCAS) in Germany. LUCAS is a long-running cohort study of community-dwelling seniors complemented by specific studies of geriatric patients or diseases. Aims were to (1) Describe individual ageing trajectories in a metropolitan setting, documenting changes in functional status, the onset of frailty, disability and need of care; (2) Find determinants of healthy ageing; (3) Assess long-term effects of specific health promotion interventions; (4) Produce results for health care planning for fit, pre-frail, frail and disabled elderly persons; (5) Set up a framework for embedded studies to investigate various hypotheses in specific subgroups of elderly.

Methods/Design

In 2000, twenty-one general practitioners (GPs) were recruited in the Hamburg metropolitan area; they generated lists of all their patients 60 years and older. Persons not terminally ill, without daily need of assistance or professional care were eligible. Of these, n = 3,326 (48 %) agreed to participate and completed a small (baseline) and an extensive health questionnaire (wave 1). In 2007/2008, a re-recruitment took place including 2,012 participants: 743 men, 1,269 women (647 deaths, 197 losses, 470 declined further participation). In 2009/2010 n = 1,627 returned the questionnaire (90 deaths, 47 losses, 248 declined further participation) resulting in a good participation rate over ten years with limited and quantified dropouts. Presently, follow-up data from 2007/2008 (wave 2) and 2009/2010 (wave 3) are available. Data wave 4 is due in 2011/2012, and the project will be continued until 2013. Information on survival and need of nursing care was collected continuously and cross-checked against official records. We used Fisher’s exact test and t-tests. The study served repeatedly to evaluate health promotion interventions and concepts.

Discussion

LUCAS shows that a cohort study of older persons is feasible and can maintain a good participation rate over ten years, even when extensive self-reported health data are collected repeatedly through self-filled questionnaires. Evidently individual health developments of elderly persons can be tracked quantifying simultaneously behaviour, co-morbidity, functional competence and their changes. In future, we expect to generate results of significance about the five study aims listed above.

Pathways to aging: the mitochondrion at the intersection of biological and psychosocial sciences

Compelling evidence suggests that both biological and psychosocial factors impact the process of aging. However, our understanding of the dynamic interplay among biological and psychosocial factors across the life course is still fragmentary. For example, it needs to be established how the interaction of individual factors (e.g., genetic and epigenetic endowment and personality), behavioral factors (e.g., physical activity, diet, and stress management), and psychosocial experiences (e.g., social support, well-being, socioeconomic status, and marriage) in perinatal, childhood, and adulthood influence health across the aging continuum. This paper aims to outline potential intersection points serving as an interface between biological and psychosocial factors, with an emphasis on the mitochondrion. Mitochondria are cellular organelles which play a critical role in cellular senescence. Both chronic exposure to psychosocial stress and genetic-based mitochondrial dysfunction have strikingly similar biological consequences; both predispose individuals to adverse age-related health disorders and early mortality. Exploring the interactive nature of the factors resulting in pathways to normal healthy aging, as well as those leading to morbidity and early mortality, will continue to enhance our ability to translate research into effective practices that can be implemented throughout the life course to optimise the aging process.

Immunological hurdles of ageing: indispensable research of the human model

Census reports of many countries indicate continuing trends for the graying of their populations. For the United States alone, persons aged ≥65 years are projected to comprise over 20% of the population by the year 2050. In view of the special medical needs of elders, scientific investigation into the biological aspects of ageing is key towards the improvement of geriatric care for the coming decades. This special issue of Ageing Research Reviews focuses on advances in research on the immunology of human ageing. Herein are nine articles about the age-related alterations in both the innate and adaptive arms of the immune system, and about continuing hurdles in vaccinology. These articles point to a common theme that the immunological milieu in old age is substantially different from that seen in the young. This suggests that new development and/or innovation of immune-based clinical interventions for the elderly may need to be customized for their age group, rather than the mere adoption of therapies that have been designed for and/or tested for younger persons.