The aging-disease dichotomy: true or false?

Geroscience: just another name or is there more to it?

The widespread use of the name 'geroscience' in the science of aging is sometimes met with a wary attitude by biogerontologists other than its inventors. Here, we provide an overview of its origin and evolution to assess what exactly it is and to discuss its theoretical and biological relationship to earlier movements of anti-aging medicine and biogerontology more generally. Geroscience posits that targeting aging may offer a cost-effective approach to improve late-life health in humans, and because aging is malleable in model organisms and what regulates this is sufficiently understood, the time is ripe for moving forward to translational and clinical research. The geroscience agenda has rebranded imagery of past traditions, yet the claim that therapies for human aging are ready or within the imminent future is contestable and on brand with tradition, even if biogerontology has made great progress in the past decades.

Biological aging of two innate behaviors of Drosophila melanogaster: Escape climbing versus courtship learning and memory

Motor and cognitive aging can severely affect life quality of elderly people and burden health care systems. In search for diagnostic behavioral biomarkers, it has been suggested that walking speed can predict forms of cognitive decline, but in humans, it remains challenging to separate the effects of biological aging and lifestyle. We examined a possible association of motor and cognitive decline in Drosophila, a genetic model organism of healthy aging. Long term courtship memory is present in young male flies but absent already during mid life (4-8 weeks). By contrast, courtship learning index and short term memory (STM) are surprisingly robust and remain stable through mid (4-8 weeks) and healthy late life (>8 weeks), until courtship performance collapses suddenly at ~4.5 days prior to death. By contrast, climbing speed declines gradually during late life (>8 weeks). The collapse of courtship performance and short term memory close to the end of life occur later and progress with a different time course than the gradual late life decline in climbing speed. Thus, during healthy aging in male Drosophila, climbing and courtship motor behaviors decline differentially. Moreover, cognitive and motor performances decline at different time courses. Differential behavioral decline during aging may indicate different underlying causes, or alternatively, a common cause but different thresholds for defects in different behaviors.

Melatonin to Rescue the Aged Heart: Antiarrhythmic and Antioxidant Benefits

Aging comes with gradual loss of functions that increase the vulnerability to disease, senescence, and death. The mechanisms underlying these processes are linked to a prolonged imbalance between damage and repair. Damaging mechanisms include oxidative stress, mitochondrial dysfunction, chronodisruption, inflammation, and telomere attrition, as well as genetic and epigenetic alterations. Several endogenous tissue repairing mechanisms also decrease. These alterations associated with aging affect the entire organism. The most devastating manifestations involve the cardiovascular system and may lead to lethal cardiac arrhythmias. Together with structural remodeling, electrophysiological and intercellular communication alterations during aging predispose to arrhythmic events. Despite the knowledge on repairing mechanisms in the cardiovascular system, effective antiaging strategies able to reduce the risk of arrhythmias are still missing. Melatonin is a promising therapeutic candidate due to its pleiotropic actions. This indoleamine regulates chronobiology and endocrine physiology. Of relevance, melatonin is an antiaging, antioxidant, antiapoptotic, antiarrhythmic, immunomodulatory, and antiproliferative molecule. This review focuses on the protective effects of melatonin on age-induced cardiac functional and structural alterations, potentially becoming a new fountain of youth for the heart.

Method and Computer System for Dialog Optimization of Aging Biomarker Panels for Biological Age Assessment

A concept, method, algorithm, and computer system (CS) of step-by-step dialog optimization of biomarker (BM) panels for assessing human biological age (BA) according to a number of universal criteria based on incomplete and noisy data have been developed. This system provides the ability to automatically build BM panels for BA assessment and to increase the accuracy of BA determination while reducing the number of measured BMs. The optimization criteria are as follows: high correlation of BMs with chronological age (CA); minimum size of BM panels, obtained by rejecting highly cross-correlated BMs; high accuracy of BA assessment; high accuracy of BA/CA dependency interpolation; absence of outliers in BM values, which reduce the BA assessment accuracy; rejection of panels resulting in a high standard deviation for the BA-CA difference; and possible additional criteria entered by the researcher according to the task specifics. The CS input consists of data on physiological, biochemical, and other BMs that change with age. The CS output is a panel of BMs optimized according to the specified optimization criteria. The CS is user-friendly. It allows the user to add optimization criteria that the researcher considers to be important or to remove criteria that the user considers incorrect. The CS may be used in solving practical problems of anti-aging medicine, such as the treatment and prevention of age-related chronic non-infectious diseases representing the main causes of death. The authors' point of view on the role and place of BA diagnostics in this area is discussed.

Systematic causality mapping of factors leading to accidental falls of older adults

Introduction

According to WHO’s statistical evidence, accidental falls are the second leading causes of death worldwide. This systematic literature review and meta-analysis aims to provide a holistic view of risk factors and unfold the missing or less addressed but crucial factors that lead to accidental falls of the older adults. It also intends to profile the risk factors at different levels, which helps exhibit the level of consistency relationship between various risk factors and falls.

Study design

Systematic literature review.

Methods

A systematic review on the risk factors leading to accidental falls of older adults by retrieving English journal papers published starting from 1980 was conducted on April 2018. A method of literature synthesis and causal mapping was adopted to aggregate those fall-leading factors into macro variables and a coherent causal tracing network was thereby built, which can reflect not only the causal relationship of various macro variables but also the “consistency of agreement” between macro variables and falls of the older adults.

Results

A hypothesized causal relationship diagram of 19 aggregated macro variables and their 31 causal relationship suggested by the observational evidences is demonstrated. The consistency relationship between macro variables and elderly accidental fall are summarized and demonstrated. Our analysis reveals that “Time”, “Season” and “Weather” are three less-studied factors in the literature. In our comprehensive analysis, our study also indicates neglected countries and senior populations such as Africa and Oceania, which requires more attention from the research community and global funding agencies. It is found that major quantitative tools focus on the traditional statistical analysis.

Conclusion

With the accelerated aging and increase of longevity worldwide, national and regional policies, and public health programs to provide adequate care services for the older people are crucially needed in both industrialized and developing countries. Evidences identified in the research are valuable inputs for policy design and decision makers of different stakeholders and prevention design of risk factors for falls in the older adults. The categorization of research methods in different literature also suggests that more quantitative approaches including simulation, optimization in operational research, and maybe machine learning are needed to enrich the research paradigm. We suggest researchers to consider using our presented causal map and the way of building it and explore the possibility of extending this framework to uncover more research topics in health-related research.

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Find less addressed but important fall-leading factors for the older adults.

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Apply a systematic causal mapping method for synthetizing known factors.

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Profile fall-leading factors in the older adults at different levels.

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Identify the level of consistency for those relationships of risk factors to fall.

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Build a framework containing all causal relationships of key fall-causing factors.

Untangling Aging Using Dynamic, Organism-Level Phenotypic Networks

Research on aging requires the ability to measure aging, and therein lies a challenge: it is impossible to measure every molecular, cellular, and physiological change that develops over time, but it is difficult to prioritize phenotypes for measurement because it is unclear which biological changes should be considered aspects of aging and, further, which species and environments exhibit "real aging." Here, I propose a strategy to address this challenge: rather than classify phenotypes as "real aging" or not, conceptualize aging as the set of all age-dependent phenotypes and appreciate that this set and its underlying mechanisms may vary by population. Use automated phenotyping technologies to measure as many age-dependent phenotypes as possible within individuals over time, prioritizing organism-level (i.e., physiological) phenotypes in order to enrich for health relevance. Use those high-dimensional phenotypic data to construct dynamic networks that allow aging to be studied with unprecedented sophistication and rigor.

Understanding the knowledge, attitudes and beliefs of community-dwelling older adults and their carers about the modification of oral medicines: A qualitative interview study to inform healthcare professional practice

BACKGROUND

Oral medicines are commonly modified (e.g. tablets split/crushed) to meet the dosing and swallowing requirements of older adults. However, there is limited research investigating the opinions of community-dwelling patients and carers about medicine modification.

OBJECTIVES

The aim of this study was to investigate the views of community-dwelling older adults and their carers about oral medicine modification.

METHODS

Semi-structured, face-to-face interviews were conducted with community-dwelling older adults and carers of older adults who experienced difficulty swallowing medicines, or who required medicines to be modified. Participants were recruited from purposively selected community pharmacies using a combination of purposive, convenience and snowball sampling. Interviews were audio-recorded, transcribed verbatim and analysed thematically. The Francis method governed when data saturation had been reached.

RESULTS

Twenty-six interviews (13 patients, 13 carers) were conducted (76.9% female, median length 11 min (IQR 8-16 min)). Four themes emerged from the data: variation in medical needs and preferences; balancing acceptance and resignation; healthcare professional engagement and; opportunities for optimising formulation suitability. The heterogeneity of medical conditions experienced by community-dwelling older adults resulted in a variety of modifications being required. Patients and carers are accepting of their medications and formulations. However, when challenges arise, they tend to feel resigned to coping within the constraints of the current medication regimen, resulting in a lack of focused communication with healthcare professionals. Thus, healthcare professionals were unaware of their difficulties and unable to offer advice or solutions.

CONCLUSION

Healthcare professionals must engage proactively with this group. Whilst a holistic approach to medication management is ideal, the disadvantage is that no single healthcare professional may identify this as their responsibility. Whilst the input and expertise of all healthcare professionals will be required, as medication experts, the pharmacy profession should take ownership and become the champion of, and for, the patient.

Nutrient sensing pathways as therapeutic targets for healthy ageing

INTRODUCTION

In the present paper, the authors have discussed anti-aging strategies which aim to slow the aging process and to delay the onset of age-related diseases, focusing on nutrient sensing pathways (NSPs) as therapeutic targets. Indeed, several studies have already demonstrated that both in animal models and humans, dietary interventions might have a positive impact on the aging process through the modulation of these pathways. Areas covered: Achieving healthy aging is the main challenge of the twenty-first century because lifespan is increasing, but not in tandem with good health. The authors have illustrated different approaches that can act on NSPs, modulating the rate of the aging process. Expert opinion: Humanity's lasting dream is to reverse or, at least, postpone aging. In recent years, increasing attention has been devoted to anti-aging therapies. The subject is very popular among the general public, whose imagination runs wild with all the possible tools to delay aging and to gain immortality. Some approaches discussed in the present review should be able to substantially slow down the aging process, extending our productive, youthful lives, without frailty.

Exploring the power of yeast to model aging and age-related neurodegenerative disorders

Aging is a multifactorial process determined by molecular, cellular and systemic factors and it is well established that advancing age is a leading risk factor for several neurodegenerative diseases. In fact, the close association of aging and neurodegenerative disorders has placed aging as the greatest social and economic challenge of the 21st century, and age-related diseases have also become a key priority for countries worldwide. The growing need to better understand both aging and neurodegenerative processes has led to the development of simple eukaryotic models amenable for mechanistic studies. Saccharomyces cerevisiae has proven to be an unprecedented experimental model to study the fundamental aspects of aging and to decipher the intricacies of neurodegenerative disorders greatly because the molecular mechanisms underlying these processes are evolutionarily conserved from yeast to human. Moreover, yeast offers several methodological advantages allowing a rapid and relatively easy way of establishing gene-protein-function associations. Here we review different aging theories, common cellular pathways driving aging and neurodegenerative diseases and discuss the major contributions of yeast to the state-of-art knowledge in both research fields.

Classifying aging as a disease in the context of ICD-11

Aging is a complex continuous multifactorial process leading to loss of function and crystalizing into the many age-related diseases. Here, we explore the arguments for classifying aging as a disease in the context of the upcoming World Health Organization's 11th International Statistical Classification of Diseases and Related Health Problems (ICD-11), expected to be finalized in 2018. We hypothesize that classifying aging as a disease with a "non-garbage" set of codes will result in new approaches and business models for addressing aging as a treatable condition, which will lead to both economic and healthcare benefits for all stakeholders. Actionable classification of aging as a disease may lead to more efficient allocation of resources by enabling funding bodies and other stakeholders to use quality-adjusted life years (QALYs) and healthy-years equivalent (HYE) as metrics when evaluating both research and clinical programs. We propose forming a Task Force to interface the WHO in order to develop a multidisciplinary framework for classifying aging as a disease with multiple disease codes facilitating for therapeutic interventions and preventative strategies.

Educational inequalities in aging-related declines in fluid cognition and the onset of cognitive pathology

BACKGROUND

Education has been robustly associated with cognitive reserve and dementia, but not with the rate of cognitive aging, resulting in some confusion about the mechanisms of cognitive aging. This study uses longitudinal data to differentiate between trajectories indicative of healthy versus pathological cognitive aging.

METHODS

Participants included 9,401 Health and Retirement Study respondents aged 55 and older who completed cognitive testing regularly over 17.3 years until most recently in 2012. Individual-specific random change-point modeling was used to identify age of incident pathological decline; acceleration is interpreted as indicating likely onset of pathological decline when it is significant and negative.

RESULTS

These methods detect incident dementia diagnoses with specificity/sensitivity of 89.3%/44.3%, 5.6 years prior to diagnosis. Each year of education was associated with 0.09 (95% CI, 0.087-0.096; P<0.001) standard deviation higher baseline cognition and delayed onset of cognitive pathology (HR, 0.98; 95% CI, 0.96-0.99; P=0.006).

CONCLUSION

Longitudinal random change-point modeling was able to reliably identify incident dementia. Accounting for incident cognitive pathology, we find that education predicts cognitive capability and delayed onset pathological declines.

Defining aging in cyborgs: a bio-techno-social definition of aging

Initially the aim of this article was to discuss and define aging at the intersection point between biology and sociology. However, recent biomedical and technological advances are changing the discourse on aging, and against this background the author of this article argues that current definitions of aging should be improved. The author emphasizes that there is a need to update current definitions of aging, or to formulate new multidisciplinary ones. The author suggests that (besides biology, psychology and sociology) the technological discipline should be included in the integrative gerontology model. Finally, in this article a new definition of aging is put forward. According to the author of this article, human bio-techno-social aging is characterized by: (a) a time-bound process of change including, (b) both reversible and irreversible biological processes, (c) social processes forming an irreversible chain of events, and (d) an increasing use of technological artifacts whose purpose is to support or replace damaged biological functions; and/or an increasing use of technological artifacts whose purpose is to facilitate or enable interaction.

What is an anti-aging treatment?

Key objectives of biogerontology are to understand the biology of aging and to translate scientific insight into interventions that improve late-life health - or anti-aging treatments. In this context, when considering the problem of how to effect translational research, it is useful to have a clear, consensus view on what exactly constitutes an anti-aging treatment. This essay critically assesses the understanding of this concept common among biogerontologists, and proposes a new definition. A current conception of anti-aging treatment imagines a primary cause of aging that is causally upstream of, and the cause of, all age-related pathology. Intervening in this aging process thus protects against the totality of age-related diseases. However, this underlying aging process remains an abstraction. By contrast, what is demonstrable is that interventions in model organisms can improve late-life health and extend lifespan. Furthermore, a safe deduction is that treatments that extend lifespan do so by reducing age-related pathology, both florid and subtle. What is currently identifiable about aging (i.e. senescence) is that it is a very complex disease syndrome, likely involving a number of biological mechanisms. Treatments that substantially extend lifespan must suppress multiple pathologies that otherwise limit lifespan, but whether they suppress the entire aging process remains undemonstrated. A more pragmatic and realistic definition of anti-aging treatment is any preventative approach to reduce late-life pathology, based on the understanding that senescence is a disease syndrome. This definition would encompass preventative approaches aimed at both broad and narrow spectra of age-related pathologies. Its adoption would facilitate translation, since it would shift the emphasis to medical practice, particularly the introduction of preventative approaches. Narrow spectrum anti-aging treatments (e.g. the cardiovascular polypill) could establish a practice that eventually extends to broader spectrum anti-aging treatments (e.g. dietary restriction mimetics).

Biochemical markers of aging for longitudinal studies in humans

Much progress has been made in the past decades in unraveling the mechanisms that are responsible for aging. The discovery that particular gene mutations in experimental species such as yeast, flies, and nematodes are associated with longevity has led to many important insights into pathways that regulate aging processes. However, extrapolating laboratory findings in experimental species to knowledge that is valid for the complexity of human physiology remains a major challenge. Apart from the restricted experimental possibilities, studying aging in humans is further complicated by the development of various age-related diseases. The availability of a set of biomarkers that really reflect underlying aging processes would be of much value in disentangling age-associated pathology from specific aging mechanisms. In this review, we survey the literature to identify promising biochemical markers of aging, with a particular focus on using them in longitudinal studies of aging in humans that entail repeated measurements on easily obtainable material, such as blood samples. Our search strategy was a 2-pronged approach, one focused on general mechanisms of aging and one including studies on clinical biomarkers of age-related diseases.

The dynamic relationship between physical function and cognition in longitudinal aging cohorts

On average, older people remember less and walk more slowly than do younger persons. Some researchers argue that this is due in part to a common biologic process underlying age-related declines in both physical and cognitive functioning. Only recently have longitudinal data become available for analyzing this claim. We conducted a systematic review of English-language research published between 2000 and 2011 to evaluate the relations between rates of change in physical and cognitive functioning in older cohorts. Physical functioning was assessed using objective measures: walking speed, grip strength, chair rise time, flamingo stand time, and summary measures of physical functioning. Cognition was measured using mental state examinations, fluid cognition, and diagnosis of impairment. Results depended on measurement type: Change in grip strength was more strongly correlated with mental state, while change in walking speed was more strongly correlated with change in fluid cognition. Examining physical and cognitive functioning can help clinicians and researchers to better identify individuals and groups that are aging differently and at different rates. In future research, investigators should consider the importance of identifying different patterns and rates of decline, examine relations between more diverse types of measures, and analyze the order in which age-related declines occur.

Association of a Modified Physiologic Index with mortality and incident disability: the Health, Aging, and Body Composition study

BACKGROUND

Indexes constructed from components may identify individuals who age well across systems. We studied the associations of a Modified Physiologic Index (systolic blood pressure, forced vital capacity, Digit Symbol Substitution Test score, serum cystatin-C, serum fasting glucose) with mortality and incident disability.

METHODS

Data are from the Health, Aging, and Body Composition study on 2,737 persons (51.2% women, 40.3% black) aged 70-79 years at baseline and followed on average 9.3 (2.9) years. Components were graded 0 (healthiest), 1 (middle), or 2 (unhealthiest) by tertile or clinical cutpoints and summed to calculate a continuous index score (range 0-10). We used multivariate Cox proportional hazards regression to calculate risk of death or disability and determined accuracy predicting death using the area under the curve.

RESULTS

Mortality was 19% greater per index unit (p < .05). Those with highest index scores (scores 7-10) had 3.53-fold greater mortality than those with lowest scores (scores 0-2). The unadjusted index (c-statistic = 0.656, 95% CI 0.636-0.677, p < .0001) predicted death better than age (c-statistic = 0.591, 95% CI 0.568-0.613, p < .0001; for comparison, p < .0001). The index attenuated the age association with mortality by 33%. A model including age and the index did not predict death better than the index alone (c-statistic = 0.671). Prediction was improved with the addition of other markers of health (c-statistic = 0.710, 95% CI 0.689-0.730). The index was associated with incident disability (adjusted hazard ratio per index unit = 1.04, 95% CI 1.01-1.07).

CONCLUSIONS

A simple index of available physiologic measurements was associated with mortality and incident disability and may prove useful for identifying persons who age well across systems.

An evaluation of analytical approaches for understanding change in cognition in the context of aging and health

OBJECTIVES

In this article, we discuss the importance of studying the relationship between health and cognitive function, and some of the methods with which this relationship has been studied.

METHODS

We consider the challenges involved, in particular operationalization of the health construct and causal inference in the context of observational data. We contrast the approaches taken, and review the questions addressed: whether health and cognition are associated, whether changes in health are associated with changes in cognition, and the degree of interdependency among their respective trajectories.

RESULTS

A variety of approaches for understanding the association between cognition and health in aging individuals have been used. Much of the literature on cognitive change and health has relied on methods that are based at least in part on the reorganization of between-person differences (e.g., cross-lag analysis) rather than relying more fully on analysis of within-person change and joint analysis of individual differences in within-person change in cognition and health.

DISCUSSION

We make the case for focusing on the interdependency between within-person changes in health and cognition and suggest methods that would support this.

Tragedy and delight: the ethics of decelerated ageing

Biogerontology is sometimes viewed as similar to other forms of biomedical research in that it seeks to understand and treat a pathological process. Yet the prospect of treating ageing is extraordinary in terms of the profound changes to the human condition that would result. Recent advances in biogerontology allow a clearer view of the ethical issues and dilemmas that confront humanity with respect to treating ageing. For example, they imply that organismal senescence is a disease process with a broad spectrum of pathological consequences in late life (causing or exascerbating cardiovascular disease, cancer, neurodegenerative disease and many others). Moreover, in laboratory animals, it is possible to decelerate ageing, extend healthy adulthood and reduce the age-incidence of a broad spectrum of ageing-related diseases. This is accompanied by an overall extension of lifespan, sometimes of a large magnitude. Discussions of the ethics of treating ageing sometimes involve hand-wringing about detrimental consequences (e.g. to society) of marked life extension which, arguably, would be a form of enhancement technology. Yet given the great improvements in health that decelerated ageing could provide, it would seem that the only possible ethical course is to pursue it energetically. Thus, decelerated ageing has an element of tragic inevitability: its benefits to health compel us to pursue it, despite the transformation of human society, and even human nature, that this could entail.

Revisiting the biomedicalization of aging: clinical trends and ethical challenges

Developments in the realms of medical innovation and geriatric clinical intervention impact our understanding of the nature of late life, the possibilities for health in advanced age, medical decision making, and family responsibility in ways that could not have been predicted 15 years ago. This essay begins to map new forms of biomedicalization in the U.S. and to underscore their emergence in a new ethical field. We suggest that a new kind of ethical knowledge is emerging through "routine" clinical care, and we offer examples from the following interventions: cardiac procedures, kidney dialysis, and kidney transplant. This new ethical knowledge is characterized by the difficulty of saying "no" to life-extending interventions, regardless of age. We explore the intensification of the biomedicalization of old age through a discussion of three features of the new ethical field: (a) the ways in which routine medical care overshadows choice; (b) the transformation of the technological imperative to a moral imperative; and (c) the coupling of hope with the normalization and routinization of life-extending interventions. We argue that societal expectations about longevity and standard medical care come together today in a shifting ethics of normalcy, with unexplored socio-cultural ramifications.

Ageing, repetitive genomes and DNA damage

The mitochondrial production of reactive oxygen species is inversely proportional to longevity in animals. A key question now is, which molecules, among those that are oxidized, affect the lifespan of the organism most significantly?