Reverse geroscience: how does exposure to early diseases accelerate the age-related decline in health?

Associations of seven measures of biological age acceleration with frailty and all-cause mortality among adult survivors of childhood cancer in the St. Jude Lifetime Cohort

Survivors of childhood cancer may experience accelerated biological aging, resulting in premature frailty and death. We used seven measures of biological age in the St. Jude Lifetime (SJLIFE) Cohort to compare biological age acceleration between the SJLIFE Cohort and the third United States National Health and Nutrition Examination Survey controls, explore trajectories of biological age according to cancer treatment and type, and test associations of biological age acceleration with frailty and death (mean follow-up of 26.5 years) among survivors. Survivors of cancer aged 5% faster per year and measured, on average, 0.6-6.44 years biologically older compared to controls and 5-16 years biologically older compared to age-matched individuals at the population level. Survivors treated with hematopoietic cell transplant and vinca alkaloid chemotherapy evidenced the fastest trajectories of biological aging. Biologically, older and faster-aging survivors consistently and robustly had a higher risk of frailty and died earlier than those with slower biological aging, suggesting a potential opportunity to intervene on excess aging.

Age-Accelerated Increase of White Matter Hyperintensity Volumes Is Exacerbated by Heavy Alcohol Use in People Living With HIV

BACKGROUND

Antiretroviral treatment has enabled people living with HIV infection to have a near-normal life span. With longevity comes opportunities for engaging in risky behavior, including initiation of excessive drinking. Given that both HIV infection and alcohol use disorder (AUD) can disrupt brain white matter integrity, we questioned whether HIV infection, even if successfully treated, or AUD alone results in signs of accelerated white matter aging and whether HIV+AUD comorbidity further accelerates brain aging.

METHODS

Longitudinal magnetic resonance imaging-FLAIR data were acquired over a 15-year period from 179 control individuals, 204 participants with AUD, 70 participants with HIV, and 75 participants with comorbid HIV+AUD. White matter hyperintensity (WMH) volumes were quantified and localized, and their functional relevance was examined with cognitive and motor testing.

RESULTS

The 3 diagnostic groups each had larger WMH volumes than the control group. Although all 4 groups exhibited accelerating volume increases with aging, only the HIV groups showed faster WMH enlargement than control individuals; the comorbid group showed faster acceleration than the HIV-only group. Sex and HIV infection length, but not viral suppression status, moderated acceleration. Correlations emerged between WMH volumes and attention/working memory and executive function scores of the AUD and HIV groups and between WMH volumes and motor skills in the 3 diagnostic groups.

CONCLUSIONS

Even treated HIV can show accelerated aging, possibly from treatment sequelae or legacy effects, and notably from AUD comorbidity. WMH volumes may be especially relevant for tracking HIV and AUD brain health because each condition is associated with liability for hypertensive processes, for which WMHs are considered a marker.

Combining remaining life expectancy and time to death as a measure of old-age dependency related to health care needs

Public concern about the rising number of older dependent citizens is still based mainly on standard population aging indicators. This includes the old-age dependency ratio (OADR), which divides the state pension age population by the working age population. However, the OADR counts neither the dependent elderly nor those who provide for them. This paper builds on previous research to propose several alternative indicators, including the health care (HC) need-adjusted real elderly dependency ratio and the HC need-adjusted dependent population-to-tax rate. These indicators consider improvements in old-age survival and time to death in order to better define the health care needs of the dependent old-age population and to better approximate their financial burden. We define the old-age population dependent on health care as those above the age at which remaining life expectancy is 15 years or less and are expected to die within 5 years. We use data from the US to illustrate differences between the proposed new and standard measures. Results show that, as a share of the total population, the old-age population dependent on health care has virtually not changed since 1950. Moreover, increases in GDP and state tax revenue have outstripped population aging almost continuously since 1970, irrespective of the indicator used, and they are expected to continue to do so during the coming decade. The demand for health care services is therefore not being fueled by population aging but instead by other factors such as progress in medical knowledge and technology, costs of hospitalization, and the increasing use of long-term care facilities.

Study design and methods for the pilot study of muscadine grape extract supplement to improve fatigue among older adult cancer survivors (FOCUS) trial

INTRODUCTION

Fatigue is a prevalent symptom among both cancer survivors and older adults. Negative consequences of fatigue include increased sedentary behavior, decreased physical activity and function, and lower quality of life. Few pharmacologic interventions improve fatigue. Our preclinical and clinical data show promising effects of a muscadine grape extract supplement (MGES) on oxidative stress, mitochondrial bioenergetics, the microbiome, and the symptom of fatigue. This pilot study seeks to translate these observations to cancer survivorship by testing the preliminary effect of MGE supplementation on older adult cancer survivors with self-reported fatigue.

MATERIALS AND METHODS

We designed a double-blinded placebo-controlled pilot study to evaluate preliminary efficacy of MGE supplementation versus placebo on fatigue among older adult cancer survivors (aged ≥65 years) who report baseline fatigue. Sixty-four participants will be enrolled and randomized 1:1 to twice daily MGES (four tablets twice daily) versus placebo for 12 weeks. The primary outcome is change in Patient-Reported Outcomes Measurement Information System (PROMIS) Fatigue score from baseline to 12 weeks. Secondary outcomes are change in self-reported physical function, physical fitness (6-min walk test), self-reported physical activity, global quality of life (QOL), and the Fried frailty index. Correlative biomarker assays will assess changes in 8-hydroxy-2 deoxyguanosine, peripheral blood mitochondrial function, inflammatory markers, and the gut microbiome.

DISCUSSION

This pilot study builds on preclinical and clinical observations to estimate effects of MGE supplementation on fatigue, physical function, QOL, and biologic correlates in older adult cancer survivors. Trial registration #: CT.govNCT04495751; IND 152908.

Is an MRI-derived anatomical measure of dementia risk also a measure of brain aging?

Machine learning methods have been applied to estimate measures of brain aging from neuroimages. However, only rarely have these measures been examined in the context of biologic age. Here, we investigated associations of an MRI-based measure of dementia risk, the Alzheimer's disease pattern similarity (AD-PS) scores, with measures used to calculate biological age. Participants were those from visit 5 of the Atherosclerosis Risk in Communities Study with cognitive status adjudication, proteomic data, and AD-PS scores available. The AD-PS score estimation is based on previously reported machine learning methods. We evaluated associations of the AD-PS score with all-cause mortality. Sensitivity analyses using only cognitively normal (CN) individuals were performed treating CNS-related causes of death as competing risk. AD-PS score was examined in association with 32 proteins measured, using a Somalogic platform, previously reported to be associated with age. Finally, associations with a deficit accumulation index (DAI) based on a count of 38 health conditions were investigated. All analyses were adjusted for age, race, sex, education, smoking, hypertension, and diabetes. The AD-PS score was significantly associated with all-cause mortality and with levels of 9 of the 32 proteins. Growth/differentiation factor 15 (GDF-15) and pleiotrophin remained significant after accounting for multiple-testing and when restricting the analysis to CN participants. A linear regression model showed a significant association between DAI and AD-PS scores overall. While the AD-PS scores were created as a measure of dementia risk, our analyses suggest that they could also be capturing brain aging.

Aging Accelerates Postural Instability in HIV Infection: Contributing Sensory Biomarkers

People living with HIV infection (PWH) who are adequately treated pharmacologically are now likely to have a near normal life span. Along with this benefit of the aging HIV population are potential physical problems attendant to aging, including postural stability. Whether aging with HIV accelerates age-related liability for postural instability and what sensory factors contribute to imbalance were examined in 227 PWH and 137 people living without HIV (PWoH), age 25 to 75 years. A mixed cross-sectional/longitudinal design revealed steeper aging trajectories of the PWH than PWoH in sway path length, measured as center-of-pressure micro-displacements with a force platform while a person attempted to stand still. Sway paths were disproportionately longer for PWH than PWoH when tested with eyes closed than open. Multiple regression identified objective measures of sensory perception as unique predictors of sway path length, whereas age, sway path length, and self-reports of falls were predictors of standing on one leg, a common measure of ataxia. Knowledge about sensory signs and symptoms of imbalance in postural stability with and without visual information may serve as modifiable risk factors for averting instability and liability for falls in the aging HIV population.

Physiological Systems in Promoting Frailty

Frailty is a complex syndrome affecting a growing sector of the global population as medical developments have advanced human mortality rates across the world. Our current understanding of frailty is derived from studies conducted in the laboratory as well as the clinic, which have generated largely phenotypic information. Far fewer studies have uncovered biological underpinnings driving the onset and progression of frailty, but the stage is set to advance the field with preclinical and clinical assessment tools, multiomics approaches together with physiological and biochemical methodologies. In this article, we provide comprehensive coverage of topics regarding frailty assessment, preclinical models, interventions, and challenges as well as clinical frameworks and prevalence. We also identify central biological mechanisms that may be at play including mitochondrial dysfunction, epigenetic alterations, and oxidative stress that in turn, affect metabolism, stress responses, and endocrine and neuromuscular systems. We review the role of metabolic syndrome, insulin resistance and visceral obesity, focusing on glucose homeostasis, adenosine monophosphate-activated protein kinase (AMPK), mammalian target of rapamycin (mTOR), and nicotinamide adenine dinucleotide (NAD+ ) as critical players influencing the age-related loss of health. We further focus on how immunometabolic dysfunction associates with oxidative stress in promoting sarcopenia, a key contributor to slowness, weakness, and fatigue. We explore the biological mechanisms involved in stem cell exhaustion that affect regeneration and may contribute to the frailty-associated decline in resilience and adaptation to stress. Together, an overview of the interplay of aging biology with genetic, lifestyle, and environmental factors that contribute to frailty, as well as potential therapeutic targets to lower risk and slow the progression of ongoing disease is covered. © 2022 American Physiological Society. Compr Physiol 12:1-46, 2022.

Integrating Environment and Aging Research: Opportunities for Synergy and Acceleration

Despite significant overlaps in mission, the fields of environmental health sciences and aging biology are just beginning to intersect. It is increasingly clear that genetics alone does not predict an individual’s neurological aging and sensitivity to disease. Accordingly, aging neuroscience is a growing area of mutual interest within environmental health sciences. The impetus for this review came from a workshop hosted by the National Academies of Sciences, Engineering, and Medicine in June of 2020, which focused on integrating the science of aging and environmental health research. It is critical to bridge disciplines with multidisciplinary collaborations across toxicology, comparative biology, epidemiology to understand the impacts of environmental toxicant exposures and age-related outcomes. This scoping review aims to highlight overlaps and gaps in existing knowledge and identify essential research initiatives. It begins with an overview of aging biology and biomarkers, followed by examples of synergy with environmental health sciences. New areas for synergistic research and policy development are also discussed. Technological advances including next-generation sequencing and other-omics tools now offer new opportunities, including exposomic research, to integrate aging biomarkers into environmental health assessments and bridge disciplinary gaps. This is necessary to advance a more complete mechanistic understanding of how life-time exposures to toxicants and other physical and social stressors alter biological aging. New cumulative risk frameworks in environmental health sciences acknowledge that exposures and other external stressors can accumulate across the life course and the advancement of new biomarkers of exposure and response grounded in aging biology can support increased understanding of population vulnerability. Identifying the role of environmental stressors, broadly defined, on aging biology and neuroscience can similarly advance opportunities for intervention and translational research. Several areas of growing research interest include expanding exposomics and use of multi-omics, the microbiome as a mediator of environmental stressors, toxicant mixtures and neurobiology, and the role of structural and historical marginalization and racism in shaping persistent disparities in population aging and outcomes. Integrated foundational and translational aging biology research in environmental health sciences is needed to improve policy, reduce disparities, and enhance the quality of life for older individuals.

Moving geroscience from the bench to clinical care and health policy

Geriatricians and others must embrace the emerging field of geroscience. Until recently geroscience research was pursued in laboratory animals, but now this field requires specialized expertise in the care of vulnerable older patients with multiple chronic diseases and geriatric syndromes, the population likely to benefit the most from emerging therapies. While chronological aging measures the inevitable passage of clock time that occurs equally for everyone, biological aging varies among individuals, and importantly, it is modifiable. Advances in our understanding of biological aging, the discovery of strategies for modifying its rate, and an appreciation of aging as a shared risk factor for chronic diseases have jointly led to the Geroscience Hypothesis. This hypothesis states that interventions modifying aging biology can slow its progression-resulting in the delay or prevention of the onset of multiple diseases and disorders. Here we wish to report on the Third Geroscience Summit held at National Institutes of Health on November 4-5, 2019, which highlighted the importance of engaging other disciplines including clinicians. Involvement by scientists with expertise in clinical trials, health outcomes research, behavioral and social sciences, health policy, and economics is urgently needed to translate geroscience discoveries from the bench to clinical care and health policy. Adding to the urgency of broadening this geroscience coalition is the emergence of biological aging as one the most important modifiable factors of COVID-19, combined with the inability of our society to once again recognize and confront aging as a priority and opportunity when facing these types of public health emergencies.

Immunity to acute virus infections with advanced age

New infections in general, and new viral infections amongst them, represent a serious challenge to an older organism. This review discusses the age-related alterations in responsiveness to infection from the standpoint of virus:host relationship and the host physiological whole-organism and specific immune response to the virus. Changes with age in the innate and adaptive immune system homeostasis and function are reviewed briefly. This is followed by a review of specific alterations and defects in the response of older organisms (chiefly mice and humans) to acute (particularly emerging and re-emerging) viral infections, with a very brief summary of the response to latent persistent infections. Finally, we provide a brief summary of the perspectives for possible interventions to enhance antiviral immunity.

Premature Aging in Young Cancer Survivors

Advances in early detection, treatment, and supportive care have resulted in an estimated 16 million cancer survivors who are alive in the United States today. Outcomes have notably improved for children with cancer as well as young adults with hematologic malignancies due, in part, to the intensification of cancer treatment, including the use of hematopoietic cell transplantation. Emerging evidence suggests that these cancer survivors are at risk for premature aging, manifesting as early onset of chronic health conditions and a higher risk of mortality compared with the general population. Although the pathophysiology of premature aging in these survivors has not been fully elucidated, emerging concepts in aging research could help shed light on this phenomenon. Longitudinal studies are needed to better characterize aging in these survivors, setting the stage for much-needed interventions to halt the trajectory of accelerated aging. These efforts will be enhanced through collaborations between translational researchers, clinical oncologists, primary care providers, geriatricians, patient caretakers, and other stakeholders committed to improving the lives of the growing population of survivors.

A longitudinal study of the stability, variability, and interdependencies among late-differentiated T and NK cell subsets in older adults

The stability and variability of older adults' late-differentiated peripheral blood T and natural killer (NK) cells over time remains incompletely quantified or understood. We examined the variability and change over time in T and NK cell subsets in a longitudinal sample of older adults; the effects of sex, cytomegalovirus (CMV) serostatus, and chronic disease severity on immune levels and trajectories; and interdependencies among T and NK cell subsets. Older adults (N = 149, age 64-94 years, 42% male) provided blood every 6 months for 2.5 years (up to 5 waves) to evaluate late-differentiated CD8 T cells (CD28-, CD57+) and CD56dimNK cells (CD57+, NKG2C+, FcɛRIγ-). In multilevel models, most of the variance in immune subsets reflected stable differences between people. However, CD56dimNK cell subsets (CD57+ and FcɛRIγ-) also increased with age, whereas T cell subsets did not. Independent of age, all subsets examined were higher in CMV-positive older adults. Men had higher levels of CD56dim CD57+ than women. Chronic disease was not associated with any immune subset investigated. T and NK cell subsets correlated within each cell type, but interdependencies differed by CMV serostatus. Our results suggest the accumulation of these stable cell populations may be driven less by chronological aging, even less by chronic disease severity, and more by CMV, which may differentially skew T and NK cell differentiation.

Adult vaccination as part of a healthy lifestyle: moving from medical intervention to health promotion

As the global population ages, there is concern about the effect of an increased proportion of older individuals on the economic sustainability of healthcare systems and the social effects of an older society. Health authorities and advocacy groups in countries at the forefront of this trend are now developing strategies to ameliorate the social and financial effects of an ageing population. There is broad agreement that for both society and for the individuals, it is important to ensure that increasing lifespans are matched with increased "healthspans" - the number of years spent in good health. There is also growing consensus that vaccination is one of the tools that can play an important role in improving adult health - though currently vaccination coverage is often poor. This review focuses on two issues that consistently appear to be associated with under-vaccination: the low awareness of risk (and potential consequences) for vaccine-preventable diseases and a poor understanding of the value of improved vaccination coverage for adults. We suggest that understanding of vaccination as a health-promoting activity, rather than a medical intervention designed to prevent the spread of a specific pathogen - is a crucial step to improve vaccination uptake among adults (see Supplementary video abstract ). Key messages As populations age globally, we are seeing an increasing burden of vaccine-preventable disease in adults. Adult vaccination against some common diseases has been shown to dramatically improve health and quality of life for older people. Despite the attested benefits, vaccination coverage is almost always poor in adults, even in countries where access is free at point of care. In this article, we discuss what appears to a neglected issue in adult vaccination, that of personal autonomy. We argue that adult vaccination will only be successful if it respects individual autonomy and that this requires treating the choice to vaccinate as a public health issue akin to smoking cessation, exercise and healthy diet.

Multimorbidity and functional impairment-bidirectional interplay, synergistic effects and common pathways

This review discusses the interplay between multimorbidity (i.e. co-occurrence of more than one chronic health condition in an individual) and functional impairment (i.e. limitations in mobility, strength or cognition that may eventually hamper a person's ability to perform everyday tasks). On the one hand, diseases belonging to common patterns of multimorbidity may interact, curtailing compensatory mechanisms and resulting in physical and cognitive decline. On the other hand, physical and cognitive impairment impact the severity and burden of multimorbidity, contributing to the establishment of a vicious circle. The circle may be further exacerbated by people's reduced ability to cope with treatment and care burden and physicians' fragmented view of health problems, which cause suboptimal use of health services and reduced quality of life and survival. Thus, the synergistic effects of medical diagnoses and functional status in adults, particularly older adults, emerge as central to assessing their health and care needs. Furthermore, common pathways seem to underlie multimorbidity, functional impairment and their interplay. For example, older age, obesity, involuntary weight loss and sedentarism can accelerate damage accumulation in organs and physiological systems by fostering inflammatory status. Inappropriate use or overuse of specific medications and drug-drug and drug-disease interactions also contribute to the bidirectional association between multimorbidity and functional impairment. Additionally, psychosocial factors such as low socioeconomic status and the direct or indirect effects of negative life events, weak social networks and an external locus of control may underlie the complex interactions between multimorbidity, functional decline and negative outcomes. Identifying modifiable risk factors and pathways common to multimorbidity and functional impairment could aid in the design of interventions to delay, prevent or alleviate age-related health deterioration; this review provides an overview of knowledge gaps and future directions.

The telomere world and aging: Analytical challenges and future perspectives

Telomeres, the terminal nucleoprotein structures of eukaryotic chromosomes, play pleiotropic functions in cellular and organismal aging. Telomere length (TL) varies throughout life due to the influence of genetic factors and to a complex balancing between "shortening" and "elongation" signals. Telomerase, the only enzyme that can elongate a telomeric DNA chain, and telomeric repeat-containing RNA (TERRA), a long non-coding RNA involved in looping maintenance, play key roles in TL during life. Despite recent advances in the knowledge of TL, TERRA and telomerase activity (TA) biology and their measurement techniques, the experimental and theoretical issues involved raise a number of problems that should carefully be considered by researchers approaching the "telomere world". The increasing use of such parameters - hailed as promising clinically relevant biomarkers - has failed to be paralleled by the development of automated and standardized measurement technology. Consequently, associating given TL values to specific pathological conditions involves on the one hand technological issues and on the other clinical-biological issues related to the planning of clinically relevant association studies. Addressing these issues would help avoid major biases in association studies involving TL and a number of outcomes, especially those focusing on psychological and bio-behavioral variables. The main challenge in telomere research is the development of accurate and reliable measurement methods to achieve simple and sensitive TL, TERRA, and TA detection. The discovery of the localization of telomeres and TERRA in cellular and extracellular compartments had added an additional layer of complexity to the measurement of these age-related biomarkers. Since combined analysis of TL, TERRA and TA may well provide more exhaustive clinical information than a single parameter, we feel it is important for researchers in the various fields to become familiar with their most common measurement techniques and to be aware of the respective merits and drawbacks of these approaches.

Nrf2: Molecular and epigenetic regulation during aging

Increase in life-span is commonly related with age-related diseases and with gradual loss of genomic, proteomic and metabolic integrity. Nrf2 (Nuclear factor-erythroid 2-p45 derived factor 2) controls the expression of genes whose products include antioxidant proteins, detoxifying enzymes, drug transporters and numerous cytoprotective proteins. Several experimental approaches have evaluated the potential regulation of the transcription factor Nrf2 to enhance the expression of genes that contend against accumulative oxidative stress and promote healthy aging. Negative regulators of Nrf2 that act preventing it´s binding to DNA-responsive elements, have been identified in young and adult animal models. However, it is not clearly established if Nrf2 decreased activity in several models of aging results from disruption of that regulation. In this review, we present a compilation of evidences showing that changes in the levels or activity of Keap1 (Kelch-like ECH associated protein 1), GSK-3β (glycogen synthase kinase-3), Bach1, p53, Hrd1 (E3 ubiquitin ligase) and miRNAs might impact on Nrf2 activity during elderly. We conclude that understanding Nrf2 regulatory mechanisms is essential to develop a rational strategy to prevent the loss of cellular protection response during aging.

Aging in a Relativistic Biological Space-Time

Here we present a theoretical and mathematical perspective on the process of aging. We extend the concepts of physical space and time to an abstract, mathematically-defined space, which we associate with a concept of “biological space-time” in which biological dynamics may be represented. We hypothesize that biological dynamics, represented as trajectories in biological space-time, may be used to model and study different rates of biological aging. As a consequence of this hypothesis, we show how dilation or contraction of time analogous to relativistic corrections of physical time resulting from accelerated or decelerated biological dynamics may be used to study precipitous or protracted aging. We show specific examples of how these principles may be used to model different rates of aging, with an emphasis on cancer in aging. We discuss how this theory may be tested or falsified, as well as novel concepts and implications of this theory that may improve our interpretation of biological aging.

Aging Research: Collaborations Forge a Promising Future

The National Institute on Aging (NIA), one of 27 institutes and centers at the National Institutes of Health (NIH), was founded in 1974 to conduct and support research on aging and the health and well-being of older people. The Institute's interests span the fundamental processes that contribute to aging and their impact on systems; diseases and conditions for which aging is a risk factor; and interventions that may prevent, delay, or treat these conditions or otherwise contribute to an extension of healthy, active years of life. Multiple fruitful research collaborations within and outside the federal government, spanning the breadth of the Institute's research activities, have marked NIA's growth over the past 40 years, as well as its current areas of ongoing research. This article discusses several highlights of these collaborations, including the Health and Retirement Study, geroscience research, falls injury prevention in elderly adults, and implementation of the National Plan to Address Alzheimer's Disease, from the perspective of past accomplishments and trends for the future.