Heterogeneity of Aging: Individual Risk Factors, Mechanisms, Patient Priorities, and Outcomes

The Power of a Complex Systems Perspective to Elucidate Aging

It is becoming highly accepted that aging, age-related diseases, and geriatric healthcare can move forward if reductionist research is complemented by integrative research uniting knowledge on specific aging mechanisms, multiple biomedical, social, psychological, lifestyle, and environmental factors and their interactions. In this special issue, we present exciting papers that illustrate how complexity science theory and practice can be applied to aging research and provide a better understanding and quantification of healthy aging and vulnerability to disease. Recent insights on biomarkers, clocks of aging, frailty, and resilience are covered and studied in interaction with a dynamic multiscale perspective. The editorial and closing viewpoint guide you through basic principles of gerontological complexity science and shed light on new research horizons, including innovative systems-based interventions.

Breathlessness, Frailty, and Sarcopenia in Older Adults

BACKGROUND

Breathlessness shares aging mechanisms with frailty and sarcopenia.

RESEARCH QUESTION

Are frailty and sarcopenia associated with breathlessness itself?

STUDY DESIGN AND METHODS

We analyzed data from a population-based, prospective cohort study of 780 community-dwelling older adults. Breathlessness was defined using the modified Medical Research Council dyspnea scale (≥ 2 points) and the COPD Assessment Test (≥ 10 points). Frailty was defined by frailty index (FI); frailty phenotype; and fatigue, resistance, ambulation, illness, and weight loss (FRAIL) questionnaire results. Sarcopenia was defined by the Asian Working Group for Sarcopenia 2019. Sarcopenia phenotype score quantified the number of criteria met. The associations of frailty and sarcopenia with breathlessness were evaluated by logistic regression analyses. Adjusted ORs (aORs) were calculated, accounting for age, sex, chronic airway disease, smoking status, BMI, lung functions, socioeconomic status (living alone, income, education), comorbid conditions (hypertension, diabetes, malignancy, myocardial infarction, heart failure), and other geriatric contributors (cognitive dysfunction, depression, malnutrition, polypharmacy, fall history in the past year). Institutionalization-free survival was compared by log-rank test.

RESULTS

The prevalence of frailty was higher in the breathlessness group compared with the group without breathlessness (42.6% vs 10.5% by FI, 26.1% vs 8.9% by frailty phenotype, and 23.0% vs 4.2% by FRAIL questionnaire) and sarcopenia (38.3% vs 26.9%), with P < .01 for all comparisons. The multivariable logistic regression analyses showed that frailty (FI [aOR, 9.29], FRAIL questionnaire [aOR, 5.21], and frailty phenotype [aOR, 3.09]) and sarcopenia phenotype score (2 [aOR, 2.00] and 3 [aOR, 2.04] compared with 0) were associated with breathlessness. The cumulative incidence of institutionalization-free survival was higher in the breathlessness group than its counterparts (P = .02).

INTERPRETATION

The findings suggest that frailty and sarcopenia strongly contribute to breathlessness in community-dwelling older adults. Measuring sarcopenia and frailty in older adults may offer opportunities to prevent age-related breathlessness.

Circadian Rhythm of Distal Skin Temperature in Healthy Older and Young Women and Its Relationship with Sleep-Wake Rhythm and Environmental Factors under Natural Living Conditions

Little is known about the healthy aging of the circadian timing system under natural living conditions. This study explores changes in the circadian rhythm of distal skin temperature (DST) with aging and relates these changes to sleep-wake timing and environmental influences. DST, sleep-wake timing, 24-h light exposure, and physical activity were measured and averaged over seven consecutive days using temperature sensors, actigraphy with a light meter, and sleep diaries in 35 healthy older women (60-79 years) and 30 young women (20-34 years). Circadian rhythm characteristics, describing strength (amplitude) and timing (acrophase) of the DST rhythm, were calculated using cosinor analysis. The older adults displayed an 18-19% smaller amplitude and a 66-73 min earlier acrophase (peak time) for DST rhythm than the young adults, indicating a weaker and phase-advanced DST rhythm. The phase advance for DST was not due to an earlier evening increase, but to a shorter nocturnal plateau period. Daytime light exposure inversely affected strength (amplitude) but not phasing of the DST rhythm in older adults. The DST rhythm was 3.5 times more advanced than the sleep-wake rhythm, showing an altered phase relationship (phase angle) between both rhythms with aging. The phase angle was more heterogeneous among older adults, showing differential aging. The phase advance for DST rhythm and the altered and heterogeneous phase relationship between DST and sleep-wake rhythms were not related to ambient light exposure and the physical activity of older adults. This suggests that healthy aging of the circadian system might be due to endogenous mechanisms such as an internal rearrangement rather than external influences.

Variation in mesenchymal KITL/SCF and IGF1 expression in middle age underlies steady-state hematopoietic stem cell aging

ABSTRACT

Intrinsic molecular programs and extrinsic factors including proinflammatory molecules are understood to regulate hematopoietic aging. This is based on foundational studies using genetic perturbation to evaluate causality. However, individual organisms exhibit natural variation in the hematopoietic aging phenotypes and the molecular basis of this heterogeneity is poorly understood. Here, we generated individual single-cell transcriptomic profiles of hematopoietic and nonhematopoietic cell types in 5 young adult and 9 middle-aged C57BL/6J female mice, providing a web-accessible transcriptomic resource for the field. Among all assessed cell types, hematopoietic stem cells (HSCs) exhibited the greatest phenotypic variation in expansion among individual middle-aged mice. We computationally pooled samples to define modules representing the molecular signatures of middle-aged HSCs and interrogated, which extrinsic regulatory cell types and factors would predict the variance in these signatures between individual middle-aged mice. Decline in signaling mediated by adiponectin, kit ligand (KITL) and insulin-like growth factor 1 (IGF1) from mesenchymal stromal cells (MSCs) was predicted to have the greatest transcriptional impact on middle-aged HSCs, as opposed to signaling mediated by endothelial cells or mature hematopoietic cell types. In individual middle-aged mice, lower expression of Kitl and Igf1 in MSCs was highly correlated with reduced lymphoid lineage commitment of HSCs and increased signatures of differentiation-inactive HSCs. These signatures were independent of expression of aging-associated proinflammatory cytokines including interleukin-1β (IL-1β), IL-6, tumor necrosis factor α and RANTES. In sum, we find that Kitl and Igf1 expression are coregulated and variable between individual mice at the middle age and expression of these factors is predictive of HSC activation and lymphoid commitment independently of inflammation.

Aging promotes metabolic dysfunction-associated steatotic liver disease by inducing ferroptotic stress

Susceptibility to the biological consequences of aging varies among organs and individuals. We analyzed hepatocyte transcriptomes of healthy young and aged male mice to generate an aging hepatocyte gene signature, used it to deconvolute transcriptomic data from humans and mice with metabolic dysfunction-associated liver disease, validated findings with functional studies in mice and applied the signature to transcriptomic data from other organs to determine whether aging-sensitive degenerative mechanisms are conserved. We discovered that the signature enriches in diseased livers in parallel with degeneration. It is also enriched in failing human hearts, diseased kidneys and pancreatic islets from individuals with diabetes. The signature includes genes that control ferroptosis. Aged mice develop more hepatocyte ferroptosis and liver degeneration than young mice when fed diets that induce metabolic stress. Inhibiting ferroptosis shifts the liver transcriptome of old mice toward that of young mice and reverses aging-exacerbated liver damage, identifying ferroptosis as a tractable, conserved mechanism for aging-related tissue degeneration.

Protocol for the San Diego Nathan Shock Center Clinical Cohort: a new resource for studies of human aging

INTRODUCTION

While it is well recognised that aging is a heterogeneous process, our understanding of the determinants of biological aging and its heterogeneity remains unclear. The San Diego Nathan Shock Center (SD-NSC) Clinical Cohort aims to establish a resource of biospecimens and extensive donor clinical data such as physical, cognitive and sensory function to support other studies that aim to explore the heterogeneity of normal human aging and its biological underpinnings.

METHODS AND ANALYSIS

The SD-NSC Clinical Cohort is composed of 80 individuals across the adult human lifespan. Strict inclusion and exclusion criteria are implemented to minimise extrinsic factors that may impede the study of normal aging. Across three visits, participants undergo extensive phenotyping for collection of physical performance, body composition, cognitive function, sensory ability, mental health and haematological data. During these visits, we also collected biospecimens including plasma, platelets, peripheral blood mononuclear cells and fibroblasts for banking and future studies on aging.

ETHICS AND DISSEMINATION

Ethics approval from the UC San Diego School of Medicine Institutional Review Board (IRB #201 141 SHOCK Center Clinical Cohort, PI: Molina) was obtained on 11 November 2020. Written informed consent is obtained from all participants after objectives and procedures of the study have been fully explained. Congruent with the goal of establishing a core resource, biological samples and clinical data are made available to the research community through the SD-NSC.

Prognosticating the outcome of intensive care in older patients-a narrative review

Prognosis determines major decisions regarding treatment for critically ill patients. Statistical models have been developed to predict the probability of survival and other outcomes of intensive care. Although they were trained on the characteristics of large patient cohorts, they often do not represent very old patients (age ≥ 80 years) appropriately. Moreover, the heterogeneity within this particular group impairs the utility of statistical predictions for informing decision-making in very old individuals. In addition to these methodological problems, the diversity of cultural attitudes, available resources as well as variations of legal and professional norms limit the generalisability of prediction models, especially in patients with complex multi-morbidity and pre-existing functional impairments. Thus, current approaches to prognosticating outcomes in very old patients are imperfect and can generate substantial uncertainty about optimal trajectories of critical care in the individual. This article presents the state of the art and new approaches to predicting outcomes of intensive care for these patients. Special emphasis has been given to the integration of predictions into the decision-making for individual patients. This requires quantification of prognostic uncertainty and a careful alignment of decisions with the preferences of patients, who might prioritise functional outcomes over survival. Since the performance of outcome predictions for the individual patient may improve over time, time-limited trials in intensive care may be an appropriate way to increase the confidence in decisions about life-sustaining treatment.

Aging precisely: Precision medicine through the lens of an older adult

Precision medicine presents an opportunity to use novel, data-driven strategies to improve patient care. The field of precision medicine has undergone many advancements over the past few years. It has moved beyond incorporation of individualized genetic risk into medical decision-making to include multiple other factors such as unique social, demographic, behavioral, and clinical characteristics. Geriatric medicine stands to benefit heavily from the integration of precision medicine into its standard practices. Older adults, compared with other populations, have high clinical and biological heterogeneity that can alter the risks and benefits of different approaches to patient care. These factors have not been routinely considered previously by geriatricians. Yet, geriatricians' ability to address older adults' baseline heterogeneity is increasingly recognized as a cornerstone of delivering quality care in a geriatric medical practice. Given the shared focus of individualized decision-making, precision medicine is a natural fit for geriatric medicine. This manuscript provides, via cases and discussion, examples that illustrate how precision medicine can improve the care of our older patients today. We will share specific and existing tools and evidence, and review the existing multilevel barriers to further incorporate and implement these tools into clinical practice. We propose methods to address these barriers and to help realize the full potential of precision medicine for the care of older adults. We conclude with a brief discussion of potential future directions of research of precision medicine in the care of older adults.

Continuous Glucose Monitoring in Older Adults: What We Know and What We Have Yet to Learn

OBJECTIVE

To assess the growing use of continuous glucose monitoring (CGM) systems by older adults and explore additional areas integration that could benefit adults with frailty.

BACKGROUND

The use of CGM devices has expanded rapidly in the last decade. This has been supported by substantial data showing significant benefit in glycemic metrics: hemoglobin A1c improvements, less hypoglycemia, and improved quality of life. However, sub-populations, such as older persons, exist where available data are limited. Furthermore, frail older adults represent a heterogeneous population with their own unique challenges to the management of diabetes. This group has some of the poorest outcomes related to the sequela of diabetes. For example, hypoglycemia resulting in significant morbidity and mortality is more frequent in older person with diabetes than in younger persons with diabetes.

METHOD

We present a concise literature review on CGM use in the older adult as well as expand upon glycemic and nonglycemic benefits of CGM for patients, caregivers, and providers. Retrospective analysis of inpatient glycemic data of 16,935 older adults with Type 2 diabetes mellitus at Atrium Health Wake Forest Baptist indicated those with fraility managed with insulin or sulfonylurea had the highest rates of delirium (4.8%), hypoglycemia (3.5%), cardiovascular complications (20.2%) and ED visits/hospitalizatoins (49%). In addition, we address special consideration of specific situations including inpatient, palliative and long term care settings.

CONCLUSION

This review article summarizes the available data for CGM use in older adults, discusses the benefits and obstacles with CGM use in this population, and identifies areas of future research needed for improved delivery of care to older persons with diabetes.

Reevaluation of the protein requirement in Chinese elderly adults without sarcopenia with the indicator amino acid oxidation technique

It is now generally believed that elderly may have slightly higher dietary protein requirements than those of the young-middle-aged adults. We have previously conducted related studies by the indicator amino acid oxidation (IAAO) technique, but more research data are needed to revise the protein requirements of the elderly. The main objective was to reevaluate the dietary protein requirements of healthy Chinese adults (65-80 years) without sarcopenia by using the IAAO technique. Nine healthy adult men and seven healthy adult women participated in the study, with protein intakes ranging from 0·1 to 1·8 g/(kg·d). Diets that delivered energy at a 1·5 resting energy expenditure were isocaloric. The amounts of phenylalanine and tyrosine needed to remain constant for each protein dosage. By applying a nonlinear mixed-effects model analysis on the F13CO2 data, which revealed a breakpoint in F13CO2 in response to graded protein intakes, the mean protein requirement was calculated. The mean estimated average requirement (EAR) for healthy elderly Chinese adults without sarcopenia was determined to be 0·94 g/(kg·d). The protein recommended nutrient intake (RNI) determined using various derivation approaches ranged from 1·13 to 1·36 g/(kg·d). The EAR for Chinese adults without sarcopenia aged 65-80 years in this study is 6·8 % higher than the current recommended EAR (0·88 g/(kg·d)). The RNI derived using various derivation approaches are all greater than the current RNI (0·98 g/(kg·d)). This trial was registered with the Chinese clinical trial registry as ChiCTR2200061382.

Physiological phenotypes have optimal values relevant to healthy aging: sweet spots deduced from the Canadian Longitudinal Study on Aging

Previous observations on a group of exceptionally healthy "Super-Seniors" showed a lower variance of multiple physiological measures relevant for health than did a less healthy group of the same age. The finding was interpreted as the healthier individuals having physiological measurement values closer to an optimal level, or "sweet spot." Here, we tested the generalizability of the sweet-spot hypothesis in a larger community sample, comparing differences in the variance between healthier and less healthy groups. We apply this method to the Canadian Longitudinal Study on Aging (CLSA) comprehensive cohort of 30,097 participants aged 45 to 85 years with deep phenotype data. Data from both sexes and four age ranges were analyzed. Five instruments were used to represent different aspects of health, physical, and cognitive functioning. We tested 231 phenotypic measures for lower variance in the most healthy vs. least healthy quartile of each sex and age group, as classified by the five instruments. Segmented regression was used to determine sex-specific optimal values. One hundred forty-two physiological measures (61%) showed lower variance in the healthiest than in the least healthy group, in at least one sex and age group. The difference in variance was most significant for hemoglobin A1c and was also significant for many body composition measurements, but not for bone mineral density. Ninety-four phenotypes showed a nonmonotonic relationship with health, consistent with the idea of a sweet spot; for these, we determined optimal values and 95% confidence intervals that were generally narrower than the ranges of current clinical reference intervals. These findings for sweet spot discovery validate the proposed approach for identifying traits important for healthy aging.

Intrinsic capacity trajectories and socioeconomic inequalities in health: the contributions of wealth, education, gender, and ethnicity

BACKGROUND

Life-long health inequalities exert enduring impacts and are governed by social determinants crucial for achieving healthy aging. A fundamental aspect of healthy aging, intrinsic capacity, is the primary focus of this study. Our objective is to evaluate the social inequalities connected with the trajectories of intrinsic capacity, shedding light on the impacts of socioeconomic position, gender, and ethnicity.

METHODS

Our dynamic cohort study was rooted in three waves (2009, 2014, 2017) of the World Health Organization's Study on Global AGEing and Adult Health in Mexico. We incorporated a nationally representative sample comprising 2722 older Mexican adults aged 50 years and over. Baseline measurements of socioeconomic position, gender, and ethnicity acted as the exposure variables. We evaluated intrinsic capacity across five domains: cognition, psychological, sensory, vitality, and locomotion. The Relative Index of Inequality and Slope Index of Inequality were used to quantify socioeconomic disparities.

RESULTS

We discerned three distinct intrinsic capacity trajectories: steep decline, moderate decline, and slight increase. Significant disparities based on wealth, educational level, gender, and ethnicity were observed. Older adults with higher wealth and education typically exhibited a trajectory of moderate decrease or slight increase in intrinsic capacity. In stark contrast, women and indigenous individuals were more likely to experience a steeply declining trajectory.

CONCLUSIONS

These findings underscore the pressing need to address social determinants, minimize gender and ethnic discrimination to ensure equal access to resources and opportunities across the lifespan. It is imperative for policies and interventions to prioritize these social determinants in order to promote healthy aging and alleviate health disparities. This approach will ensure that specific demographic groups receive customized support to sustain their intrinsic capacity during their elder years.

Endothelial Senescence: From Macro- to Micro-Vasculature and Its Implications on Cardiovascular Health

Endothelial cells line at the most inner layer of blood vessels. They act to control hemostasis, arterial tone/reactivity, wound healing, tissue oxygen, and nutrient supply. With age, endothelial cells become senescent, characterized by reduced regeneration capacity, inflammation, and abnormal secretory profile. Endothelial senescence represents one of the earliest features of arterial ageing and contributes to many age-related diseases. Compared to those in arteries and veins, endothelial cells of the microcirculation exhibit a greater extent of heterogeneity. Microcirculatory endothelial senescence leads to a declined capillary density, reduced angiogenic potentials, decreased blood flow, impaired barrier properties, and hypoperfusion in a tissue or organ-dependent manner. The heterogeneous phenotypes of microvascular endothelial cells in a particular vascular bed and across different tissues remain largely unknown. Accordingly, the mechanisms underlying macro- and micro-vascular endothelial senescence vary in different pathophysiological conditions, thus offering specific target(s) for therapeutic development of senolytic drugs.

Impact of driving cessation on health-related quality of life trajectories

BACKGROUND

Trajectories of health-related quality of life (HRQoL) after driving cessation (DC) are thought to decline steeply, but for some, HRQoL may improve after DC. Our objective is to examine trajectories of HRQoL for individuals before and after DC. We hypothesize that for urban drivers, volunteers and those who access alternative transportation participants' health may remain unchanged or improve.

METHODS

This study uses data from the AAA Longitudinal Research on Aging Drivers (LongROAD) study, a prospective cohort of 2,990 older drivers (ages 65-79 at enrollment). The LongROAD study is a five-year multisite study and data collection ended October 31, 2022. Participants were recruited using a convenience sample from the health centers roster. The number of participants approached were 40,806 with 7.3% enrolling in the study. Sixty-one participants stopped driving permanently by year five and had data before and after DC. The PROMIS®-29 Adult Profile was utilized and includes: 1) Depression, 2) Anxiety, 3) Ability to Participate in Social Roles and Activities, 4) Physical Function, 5) Fatigue, 6) Pain Interference, 7) Sleep Disturbance, and 8) Numeric Pain Rating Scale. Adjusted (age, education and gender) individual growth models with 2989 participants with up to six observations from baseline to year 5 in the models (ranging from n = 15,041 to 15,300) were utilized.

RESULTS

Ability to participate in social roles and activities after DC improved overall. For those who volunteered, social roles and activities declined not supporting our hypothesis. For those who accessed alternative transportation, fatigue had an initial large increase immediately following DC thus not supporting our hypothesis. Urban residents had worse function and more symptoms after DC compared to rural residents (not supporting our hypothesis) except for social roles and activities that declined steeply (supporting our hypothesis).

CONCLUSIONS

Educating older adults that utilizing alternative transportation may cause initial fatigue after DC is recommended. Accessing alternative transportation to maintain social roles and activities is paramount for rural older adults after DC especially for older adults who like to volunteer.

The trajectory of very old critically ill patients

The demographic shift, together with financial constraint, justify a re-evaluation of the trajectory of care of very old critically ill patients (VIP), defined as older than 80 years. We must avoid over- as well as under-utilisation of critical care interventions in this patient group and ensure the inclusion of health care professionals, the patient and their caregivers in the decision process. This new integrative approach mobilises expertise at each step of the process beginning prior to intensive care unit (ICU) admission and extending to long-term follow-up. In this review, several international experts have contributed to provide recommendations that can be universally applied. Our aim is to define a minimum core dataset of information to be shared and discussed prior to ICU admission and to facilitate the shared-decision-making process with the patient and their caregivers, throughout the patient journey. Documentation of uncertainty may contribute to a tailored level of care and ultimately to discussions around possible limitations of life sustaining treatments. The goal of ICU care is not only to avoid death, but more importantly to maintain an acceptable quality of life and functional autonomy after hospital discharge. Societal consideration is important to highlight, together with alternatives to ICU admission. We discuss challenges for the future and potential areas of research. In summary, this review provides a state-of-the-art current overview and aims to outline future directions to address the challenges in the treatment of VIP.

Metabolomics to Study Human Aging: A Review

In the last years, with the increase in the average life expectancy, the world's population is progressively aging, which entails social, health and economic problems. In this sense, the need to better understand the physiology of the aging process becomes an urgent need. Since the study of aging in humans is challenging, cellular and animal models are widely used as alternatives. Omics, namely metabolomics, have emerged in the study of aging, with the aim of biomarker discovering, which may help to uncomplicate this complex process. This paper aims to summarize different models used for aging studies with their advantages and limitations. Also, this review gathers the published articles referring to biomarkers of aging already discovered using metabolomics approaches, comparing the results obtained in the different studies. Finally, the most frequently used senescence biomarkers are described, along with their importance in understanding aging.

Physical Resilience as a Predictor of Lifespan and Late-Life Health in Genetically Heterogeneous Mice

Dynamic measures of resilience-the ability to resist and recover from a challenge-may be informative of the rate of aging before overt manifestations such as chronic disease, disability, and frailty. From this perspective mid-life resilience may predict longevity and late-life health. To test this hypothesis, we developed simple, reproducible, clinically relevant challenges, and outcome measures of physical resilience that revealed differences between and within age groups of genetically heterogeneous mice, and then examined associations between mid-life resilience and both lifespan and late-life measures of physiological function. We demonstrate that time to recovery from isoflurane anesthesia and weight change following a regimen of chemotherapy significantly differed among young, middle-aged, and older mice, and were more variable in older mice. Females that recovered faster than the median time from anesthesia (more resilient) at 12 months of age lived 8% longer than their counterparts, while more resilient males in mid-life exhibited better cardiac (fractional shortening and left ventricular volumes) and metabolic (glucose tolerance) function at 24 months of age. Moreover, female mice with less than the median weight loss at Day 3 of the cisplatin challenge lived 8% longer than those that lost more weight. In contrast, females who had more weight loss between Days 15 and 20 were relatively protected against early death. These data suggest that measures of physical resilience in mid-life may provide information about individual differences in aging, lifespan, and key parameters of late-life health.

Exploring Successful Cognitive Aging: Insights Regarding Brain Structure, Function, and Demographics

In the realm of cognitive science, the phenomenon of "successful cognitive aging" stands as a hallmark of individuals who exhibit cognitive abilities surpassing those of their age-matched counterparts. However, it is paramount to underscore a significant gap in the current research, which is marked by a paucity of comprehensive inquiries that deploy substantial sample sizes to methodically investigate the cerebral biomarkers and contributory elements underpinning this cognitive success. It is within this context that our present study emerges, harnessing data derived from the UK Biobank. In this study, a highly selective cohort of 1060 individuals aged 65 and above was meticulously curated from a larger pool of 17,072 subjects. The selection process was guided by their striking cognitive resilience, ascertained via rigorous evaluation encompassing both generic and specific cognitive assessments, compared to their peers within the same age stratum. Notably, the cognitive abilities of the chosen participants closely aligned with the cognitive acumen commonly observed in middle-aged individuals. Our study leveraged a comprehensive array of neuroimaging-derived metrics, obtained from three Tesla MRI scans (T1-weighted images, dMRI, and resting-state fMRI). The metrics included image-derived phenotypes (IDPs) that addressed grey matter morphology, the strength of brain network connectivity, and the microstructural attributes of white matter. Statistical analyses were performed employing ANOVA, Mann-Whitney U tests, and chi-square tests to evaluate the distinctive aspects of IDPs pertinent to the domain of successful cognitive aging. Furthermore, these analyses aimed to elucidate lifestyle practices that potentially underpin the maintenance of cognitive acumen throughout the aging process. Our findings unveiled a robust and compelling association between heightened cognitive aptitude and the integrity of white matter structures within the brain. Furthermore, individuals who exhibited successful cognitive aging demonstrated markedly enhanced activity in the cerebral regions responsible for auditory perception, voluntary motor control, memory retention, and emotional regulation. These advantageous cognitive attributes were mirrored in the health-related lifestyle choices of the surveyed cohort, characterized by elevated educational attainment, a lower incidence of smoking, and a penchant for moderate alcohol consumption. Moreover, they displayed superior grip strength and enhanced walking speeds. Collectively, these findings furnish valuable insights into the multifaceted determinants of successful cognitive aging, encompassing both neurobiological constituents and lifestyle practices. Such comprehensive comprehension significantly contributes to the broader discourse on aging, thereby establishing a solid foundation for the formulation of targeted interventions aimed at fostering cognitive well-being among aging populations.

Spatial and single-cell profiling of the metabolome, transcriptome and epigenome of the aging mouse liver

Tissues within an organism and even cell types within a tissue can age with different velocities. However, it is unclear whether cells of one type experience different aging trajectories within a tissue depending on their spatial location. Here, we used spatial transcriptomics in combination with single-cell ATAC-seq and RNA-seq, lipidomics and functional assays to address how cells in the male murine liver are affected by age-related changes in the microenvironment. Integration of the datasets revealed zonation-specific and age-related changes in metabolic states, the epigenome and transcriptome. The epigenome changed in a zonation-dependent manner and functionally, periportal hepatocytes were characterized by decreased mitochondrial fitness, whereas pericentral hepatocytes accumulated large lipid droplets. Together, we provide evidence that changing microenvironments within a tissue exert strong influences on their resident cells that can shape epigenetic, metabolic and phenotypic outputs.

OMICmAge: An integrative multi-omics approach to quantify biological age with electronic medical records

Biological aging is a multifactorial process involving complex interactions of cellular and biochemical processes that is reflected in omic profiles. Using common clinical laboratory measures in ~30,000 individuals from the MGB-Biobank, we developed a robust, predictive biological aging phenotype, EMRAge, that balances clinical biomarkers with overall mortality risk and can be broadly recapitulated across EMRs. We then applied elastic-net regression to model EMRAge with DNA-methylation (DNAm) and multiple omics, generating DNAmEMRAge and OMICmAge, respectively. Both biomarkers demonstrated strong associations with chronic diseases and mortality that outperform current biomarkers across our discovery (MGB-ABC, n=3,451) and validation (TruDiagnostic, n=12,666) cohorts. Through the use of epigenetic biomarker proxies, OMICmAge has the unique advantage of expanding the predictive search space to include epigenomic, proteomic, metabolomic, and clinical data while distilling this in a measure with DNAm alone, providing opportunities to identify clinically-relevant interconnections central to the aging process.

Systematic review of research barriers, facilitators, and stakeholders in long-term care and geriatric settings, and a conceptual mapping framework to build research capacity

BACKGROUND

Older adults are underrepresented in research. Heterogeneity of research processes in this population, specifically in long-term care (LTC) and geriatric acute care (GAC), is not well described and may impede the design, planning, and conduct of research. In this study, we identified, quantified, and mapped stakeholders, research stages, and transversal themes of research processes, to develop a mapping framework to improve research capacity by better characterizing this heterogeneity.

METHODS

Multicomponent mixed methods study. An environmental scan was used to initiate a preliminary framework. We conducted a systematic literature search on processes, barriers, and methods for clinical research in GAC and LTC to extract and update stakeholders, research stages, and themes. Importance and interactions of elements were synthesized via heatmaps by number of articles, mentions, and content intersections.

RESULTS

For our initial framework and environmental scan, we surveyed 24 stakeholders. Of 9277 records, 68 articles were included in our systematic review and allowed us to identify 12 stakeholders, 13 research stages, 17 transversal themes (either barriers, facilitators, general themes, or recommendations), and 1868 intersections. Differences in relative importance between LTC and GAC emerged for stakeholders (staff, managers vs. caregivers, ethics committees), and for research stages (funding, facility recruitment vs. ethics, individual recruitment). Crucial themes according to specific stakeholders were collaboration for the research team; communication, trust, and human resources for managers; heterogeneity for patients and residents. A heatmap framework synthesizing vital stakeholders and themes per research stage was generated.

CONCLUSIONS

We identified and quantified the interactions between stakeholders, stages, and themes to characterize heterogeneity in LTC and GAC research. Our framework may serve as a blueprint to co-construct and improve each stage of the research process.

Determinants of Vaccine Hesitancy among Home Health Care Service Recipients in Saudi Arabia

BACKGROUND

Vaccine hesitancy has been identified by the World Health Organization (WHO) as a major worldwide health threat. Home Health Care (HHC) service recipients represent a vulnerable group and were prioritized to receive coronavirus disease (COVID-19) vaccination during the national vaccine campaigns in Saudi Arabia. We aimed to investigate the most frequent reasons for vaccine hesitancy among home health care recipients in Saudi Arabia.

METHODS

This cross-sectional survey was conducted among home health care (HHC) service recipients in Saudi Arabia from February 2022 to September 2022. The behavioral and social drivers (BeSD) model developed by the WHO was used to understand the factors affecting vaccination decision making in our cohort.

RESULTS

Of the 426 HHC service recipients enrolled in the study, a third were hesitant to complete the COVID-19 vaccination series. The most prevalent reported reason for COVID-19 vaccine refusal was concerns about the vaccine side effects (41.6%). Factors independently associated with COVID-19 vaccination hesitancy were: having chronic conditions (odds ratio [OR] = 2.59; 95% confidence interval [CI] = 1.33-5.05, p = 0.005), previous COVID-19 diagnosis (OR = 0.48; 95% CI: 0.28-0.82, p = 0.008), ease of getting the COVID-19 vaccine by themselves (OR = 0.49; 95% CI: 0.28-0.89, p = 0.018), belief in the importance of COVID-19 vaccine in protecting their health (OR = 0.60; 95% CI: 0.38-0.96, p = 0.032), and confidence in the safety of COVID-19 vaccination (OR = 0.38; 95% CI: 0.21-0.69, p = 0.001).

CONCLUSION

Only one-third of the study participants were hesitant to complete the series of COVID-19 vaccination. Understanding the factors underpinning vaccine hesitancy among this group would help healthcare workers and policymakers in developing personalized health awareness campaigns aimed at improving vaccine acceptance levels.

Substitution of self-reported measures for objectively assessed grip strength and slow walk in the Physical Frailty Phenotype: ramifications for validity

BACKGROUND

Frailty assessment promises to identify older adults at risk for adverse consequences following stressors and target interventions to improve health outcomes. The Physical Frailty Phenotype (PFP) is a widely-studied, well validated assessment but incorporates performance-based slow walk and grip strength criteria that challenge its use in some clinical settings. Variants replacing performance-based elements with self-reported proxies have been proposed. Our study evaluated whether commonly available disability self-reports could be substituted for the performance-based criteria in the PFP while still identifying as "frail" the same subpopulations of individuals.

METHODS

Parallel analyses were conducted in 3393 female and 2495 male Cardiovascular Health Study, Round 2 participants assessed in 1989-90. Candidate self-reported proxies for the phenotype's "slowness" and "weakness" criteria were evaluated for comparable prevalence and agreement by mode of measurement. For best-performing candidates: Frailty status (3 + positive criteria out of 5) was compared for prevalence and agreement between the PFP and mostly self-reported versions. Personal characteristics were compared between those adjudicated as frail by (a) only a self-reported version; (b) only the PFP; (c) both, using bivariable analyses and multinomial logistic regression.

RESULTS

Self-reported difficulty walking ½ mile was selected as a proxy for the phenotype's slowness criterion. Two self-reported weakness proxies were examined: difficulty transferring from a bed or chair or gripping with hands, and difficulty as just defined or in lifting a 10-pound bag. Prevalences matched to within 4% between self-reported and performance-based criteria in the whole sample, but in all cases the self-reported prevalence for women exceeded that for men by 11% or more. Cross-modal agreement was moderate, with by-criterion and frailty-wide Kappa statistics of 0.55-0.60 in all cases. Frail subgroups (a), (b), (c) were independently discriminated (p < 0.05) by race, BMI, and depression in women; by age in men; and by self-reported health for both.

CONCLUSIONS

Commonly used self-reported disability items cannot be assumed to stand in for performance-based criteria in the PFP. We found subpopulations identified as frail by resultant phenotypes versus the original phenotype to systematically differ. Work to develop self-reported proxies that more closely replicate their objective phenotypic counterparts than standard disability self-reports is needed.

Introduction to the Special Issue: Toward a Lifespan Prevention Science - A Focus on Middle and Late Adulthood

The interdisciplinary field of prevention science was founded on the premise of a lifespan developmental model. Prevention scientists have developed a strong set of tools and intervention technologies for understanding and potentially modifying risk and protective factors through early adulthood. However, there is a demographic imperative to apply prevention science principles to health issues in middle and late adulthood. The articles in this special issue utilize a variety of methods to investigate important scientific questions about how theories, methodologies, and interventions applied in the science of prevention can be usefully integrated into the study of health and wellness in middle and late adulthood. More specifically, contributions (1) highlight current empirical research that draws on lifespan developmental science to address the unique prevention and intervention needs in middle and late adulthood, (2) illustrate the opportunities and challenges of a lifespan approach to prevention science with special attention to middle and late adulthood, and (3) identify additional areas that prevention science can contribute to advancements in middle and late adulthood. These articles provide a glimpse into the challenges and opportunities at the intersection of prevention science and gerontology. As a field, we have much room to grow in leveraging innovative tools, approaches, and efforts to best support older adults' physical, mental, and social health, particularly for diverse and under-served populations.

Advancements in Anti-Aging Treatment Development

Aging is a complex and multifactorial process resulting, at least partly, from the generation and accrual of damage in the setting of reduced resilience [...].

Can Three-Dimensional Multiple Object Tracking Training Be Used to Improve Simulated Driving Performance? A Pilot Study in Young and Older Adults

Driving ability has been shown to be dependent on perceptual-cognitive abilities such as visual attention and speed of processing. There is mixed evidence suggesting that training these abilities may improve aspects of driving performance. This preliminary study investigated the feasibility of training three-dimensional multiple object tracking (3D-MOT)-a dynamic, speeded tracking task soliciting selective, sustained and divided attention as well as speed of processing-to improve measures of simulated driving performance in older and younger adults. A sample of 20 young adults (23-33 years old) and 14 older adults (65-76 years old) were randomly assigned to either a 3D-MOT training group or an active control group trained on a perceptual discrimination task as well as 2048. Participants were tested on a driving scenario with skill-testing events previously identified as optimal for cross-sectional comparisons of driving ability. Results replicated previously identified differences in driving behaviour between age groups. A possible trend was observed for the 3D-MOT trained group, especially younger adults, to increase the distance at which they applied their maximum amount of braking in response to dangerous events. This measure was associated with less extreme braking during events, implying that these drivers may have been making more controlled stops. Limitations of sample size and task realism notwithstanding, the present experiment offers preliminary evidence that 3D-MOT training might transfer to driving performance through quicker detection of or reaction to dangerous events and provides a rationale for replication with a larger sample size.

Skeletal muscle mitochondrial interactome remodeling is linked to functional decline in aged female mice

Genomic, transcriptomic and proteomic approaches have been used to gain insight into molecular underpinnings of aging in laboratory animals and in humans. However, protein function in biological systems is under complex regulation and includes factors besides abundance levels, such as modifications, localization, conformation and protein-protein interactions. By making use of quantitative chemical cross-linking technologies, we show that changes in the muscle mitochondrial interactome contribute to mitochondrial functional decline in aging in female mice. Specifically, we identify age-related changes in protein cross-links relating to assembly of electron transport system complexes I and IV, activity of glutamate dehydrogenase, and coenzyme-A binding in fatty acid β-oxidation and tricarboxylic acid cycle enzymes. These changes show a remarkable correlation with complex I respiration differences within the same young-old animal pairs. Each observed cross-link can serve as a protein conformational or protein-protein interaction probe in future studies, which will provide further molecular insights into commonly observed age-related phenotypic differences. Therefore, this data set could become a valuable resource for additional in-depth molecular studies that are needed to better understand complex age-related molecular changes.

Dental Students' Positive and Negative Views on Aging at an Undergraduate Course at the University of British Columbia, Canada

Background

Different views of aging exist, including ageism as the stereotyped idea about older adults in general. The objective of this study was to perform an initial exploration on how third-year undergraduate dental students at the University of British Columbia (UBC), Vancouver, Canada self-perceived themselves at ages 65, 75, or 85 years old.

Methods

For a period of 10 years, and using a cross-sectional design, third-year undergraduate dental students were asked to envision themselves at 65, 75, or 85 years old in a brief 150-word written essay. We employed a thematic analysis of the textual data via a coding process as suggested. The main themes were identified and displayed in a table with their respective categories of information. NVivo® 12 (QSR International) software was used for data analysis.

Results

Between 2010 and 2020, a total of 519 students enrolled in the UBC undergraduate dental program; 425 essays were collected. Initial coding and thematic analysis led to the identification of four main themes and eight categories; themes included "Ups and Downs," "Financial Sustainability," while categories focused on "Trade-offs," and "Camaraderie," for example. Different levels of ageism were also apparent when students saw themselves experiencing isolation and forgetfulness regardless of the selected age and the academic year. For other students, they anticipate aging would be healthy, joyful, and productive.

Conclusion

Ageism was present when students imagined themselves at three different older ages, but so were more realistic views of an aging. Further studies are warranted to unravel the impact of geriatric education in tackling stereotypes and ageism.

Associations of the skin, oral and gut microbiome with aging, frailty and infection risk reservoirs in older adults

Older adults represent a vulnerable population with elevated risk for numerous morbidities. To explore the association of the microbiome with aging and age-related susceptibilities including frailty and infectious disease risk, we conducted a longitudinal study of the skin, oral, and gut microbiota in 47 community- or skilled nursing facility-dwelling older adults vs. younger adults. We found that microbiome changes were not associated with chronological age so much as frailty: we identified prominent changes in microbiome features associated with susceptibility to pathogen colonization and disease risk, including diversity, stability, heterogeneity, and biogeographic determinism, which were moreover associated with a loss of Cutibacterium (C.) acnes in the skin microbiome. Strikingly, the skin microbiota were also the primary reservoir for antimicrobial resistance, clinically important pathobionts, and nosocomial strains, suggesting a potential role particularly for the skin microbiome in disease risk and dissemination of multidrug resistant pathogens.

The impact of glycaemic load on cognitive performance: A meta-analysis and guiding principles for future research

The effect of breakfast glycaemic load (GL) on cognition was systematically examined. Randomised and non-randomised controlled trials were identified using PubMed, Scopus, and Cochrane Library (up to May 2022). 15 studies involving adults (aged 20 - 80 years) were included. Studies had a low risk, or some concerns, of bias. A random-effects meta-analysis model revealed no effect of GL on cognition up to 119 min post-consumption. However, after 120 min, immediate episodic memory scores were better following a low-GL compared to a high-GL (SMD = 0.16, 95% confidence interval [CI] = -0.00 to 0.32, p = 0.05, I2 = 5%). Subgroup analyses indicated that the benefit was greater in younger adults (<35 years) and those with better GT. A qualitative synthesis of 16 studies involving children and adolescents (aged 5 - 17 years) suggested that a low-GL breakfast may also benefit episodic memory and attention after 120 min. Methodological practises were identified which could explain a failure to detect benefits in some studies. Consequently, guiding principles were developed to optimise future study design.

Targeting senescent cells for a healthier longevity: the roadmap for an era of global aging

Aging is a natural but relentless process of physiological decline, leading to physical frailty, reduced ability to respond to physical stresses (resilience) and, ultimately, organismal death. Cellular senescence, a self-defensive mechanism activated in response to intrinsic stimuli and/or exogenous stress, is one of the central hallmarks of aging. Senescent cells cease to proliferate, while remaining metabolically active and secreting numerous extracellular factors, a feature known as the senescence-associated secretory phenotype. Senescence is physiologically important for embryonic development, tissue repair, and wound healing, and prevents carcinogenesis. However, chronic accumulation of persisting senescent cells contributes to a host of pathologies including age-related morbidities. By paracrine and endocrine mechanisms, senescent cells can induce inflammation locally and systemically, thereby causing tissue dysfunction, and organ degeneration. Agents including those targeting damaging components of the senescence-associated secretory phenotype or inducing apoptosis of senescent cells exhibit remarkable benefits in both preclinical models and early clinical trials for geriatric conditions. Here we summarize features of senescent cells and outline strategies holding the potential to be developed as clinical interventions. In the long run, there is an increasing demand for safe, effective, and clinically translatable senotherapeutics to address healthcare needs in current settings of global aging.

How Age and Gender Affect the Opinions of Computing Students Regarding Computer Usage and Design Needs

This study aimed to understand the perceptions of young computing science students about women and older people with regard to their computer literacy and how this may affect the design of computer-based systems. Based on photos, participants were asked how likely they thought the person depicted would be to use desktop computers, laptops and smartphones, and how much expertise they thought they would have with each technology. Furthermore, in order to see what impact this could have on systems being developed, we asked what design aspects would be important for the depicted person and whether they thought an adapted technology would be required. This study is based on an existing questionnaire, which was translated into German and extended to explore what impact this may have on system design. The results draw on 200 questionnaires from students in the first year of their Information and Communications Technology (ICT) studies at an Austrian university of applied sciences. Quantitative methods were used to determine if the perceptions varied significantly based on the age and gender of the people depicted. Qualitative analysis was used to evaluate the design aspects mentioned. The results show that there are biases against both older people and women with respect to their perceived expertise with computers. This is also reflected in the design aspects thought to be important for the different cohorts. This is crucial as future systems will be designed by the participants, and these biases may influence whether future systems meet the needs and wishes of all groups or increase the digital divide.

Health and Quality of Life Outcomes of Driving Cessation for Older People are More Complex Than We Thought

OBJECTIVES

This study examined whether there are meaningful subgroups of older past drivers who experience better health and quality of life outcomes, and the factors that may contribute to such outcomes.

METHODS

Data from 127 people aged 56-89 years who were past drivers in a New Zealand longitudinal study of aging was used in cluster analysis.

RESULTS

Older past drivers experienced a range of outcomes regarding health and quality of life following driving cessation that clustered into five subgroups, ranging from people with robust outcomes to those with vulnerable health and quality of life. The subgroups were distinguished by economic position, social support, and volunteering.

CONCLUSIONS

Using methodology to address issues associated with use of aggregated data, there were subgroups of older past drivers who had better health and wellbeing outcomes following driving cessation than the literature has indicated. Further research is needed to identify the characteristics of those who experience better outcomes, including the role of health, the impact of voluntary and involuntary cessation, and the impact of time to cessation, including self-regulation.

CLINICAL IMPLICATIONS

Older people who stop driving can have positive health and wellbeing outcomes, particularly if they can access social support and volunteering activities.

Longitudinal phenotypic aging metrics in the Baltimore Longitudinal Study of Aging

To define metrics of phenotypic aging, it is essential to identify biological and environmental factors that influence the pace of aging. Previous attempts to develop aging metrics were hampered by cross-sectional designs and/or focused on younger populations. In the Baltimore Longitudinal Study of Aging (BLSA), we collected longitudinally across the adult age range a comprehensive list of phenotypes within four domains (body composition, energetics, homeostatic mechanisms and neurodegeneration/neuroplasticity) and functional outcomes. We integrated individual deviations from population trajectories into a global longitudinal phenotypic metric of aging and demonstrate that accelerated longitudinal phenotypic aging is associated with faster physical and cognitive decline, faster accumulation of multimorbidity and shorter survival. These associations are more robust compared with the use of phenotypic and epigenetic measurements at a single time point. Estimation of these metrics required repeated measures of multiple phenotypes over time but may uniquely facilitate the identification of mechanisms driving phenotypic aging and subsequent age-related functional decline.

Multicomponent intervention to prevent mobility disability in frail older adults: randomised controlled trial (SPRINTT project)

OBJECTIVE

To determine whether a multicomponent intervention based on physical activity with technological support and nutritional counselling prevents mobility disability in older adults with physical frailty and sarcopenia.

DESIGN

Evaluator blinded, randomised controlled trial.

SETTING

16 clinical sites across 11 European countries, January 2016 to 31 October 2019.

PARTICIPANTS

1519 community dwelling men and women aged 70 years or older with physical frailty and sarcopenia, operationalised as the co-occurrence of low functional status, defined as a short physical performance battery (SPPB) score of 3 to 9, low appendicular lean mass, and ability to independently walk 400 m. 760 participants were randomised to a multicomponent intervention and 759 received education on healthy ageing (controls).

INTERVENTIONS

The multicomponent intervention comprised moderate intensity physical activity twice weekly at a centre and up to four times weekly at home. Actimetry data were used to tailor the intervention. Participants also received personalised nutritional counselling. Control participants received education on healthy ageing once a month. Interventions and follow-up lasted for up to 36 months.

MAIN OUTCOME MEASURES

The primary outcome was mobility disability (inability to independently walk 400 m in <15 minutes). Persistent mobility disability (inability to walk 400 m on two consecutive occasions) and changes from baseline to 24 and 36 months in physical performance, muscle strength, and appendicular lean mass were analysed as pre-planned secondary outcomes. Primary comparisons were conducted in participants with baseline SPPB scores of 3-7 (n=1205). Those with SPPB scores of 8 or 9 (n=314) were analysed separately for exploratory purposes.

RESULTS

Mean age of the 1519 participants (1088 women) was 78.9 (standard deviation 5.8) years. The average follow-up was 26.4 (SD 9.5) months. Among participants with SPPB scores of 3-7, mobility disability occurred in 283/605 (46.8%) assigned to the multicomponent intervention and 316/600 (52.7%) controls (hazard ratio 0.78, 95% confidence interval 0.67 to 0.92; P=0.005). Persistent mobility disability occurred in 127/605 (21.0%) participants assigned to the multicomponent intervention and 150/600 (25.0%) controls (0.79, 0.62 to 1.01; P=0.06). The between group difference in SPPB score was 0.8 points (95% confidence interval 0.5 to 1.1 points; P<0.001) and 1.0 point (95% confidence interval 0.5 to 1.6 points; P<0.001) in favour of the multicomponent intervention at 24 and 36 months, respectively. The decline in handgrip strength at 24 months was smaller in women assigned to the multicomponent intervention than to control (0.9 kg, 95% confidence interval 0.1 to 1.6 kg; P=0.028). Women in the multicomponent intervention arm lost 0.24 kg and 0.49 kg less appendicular lean mass than controls at 24 months (95% confidence interval 0.10 to 0.39 kg; P<0.001) and 36 months (0.26 to 0.73 kg; P<0.001), respectively. Serious adverse events occurred in 237/605 (39.2%) participants assigned to the multicomponent intervention and 216/600 (36.0%) controls (risk ratio 1.09, 95% confidence interval 0.94 to 1.26). In participants with SPPB scores of 8 or 9, mobility disability occurred in 46/155 (29.7%) in the multicomponent intervention and 38/159 (23.9%) controls (hazard ratio 1.25, 95% confidence interval 0.79 to 1.95; P=0.34).

CONCLUSIONS

A multicomponent intervention was associated with a reduction in the incidence of mobility disability in older adults with physical frailty and sarcopenia and SPPB scores of 3-7. Physical frailty and sarcopenia may be targeted to preserve mobility in vulnerable older people.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02582138.

Multimodal Diagnostic Approaches to Advance Precision Medicine in Sarcopenia and Frailty

Sarcopenia, defined as the loss of muscle mass, strength, and function with aging, is a geriatric syndrome with important implications for patients and healthcare systems. Sarcopenia increases the risk of clinical decompensation when faced with physiological stressors and increases vulnerability, termed frailty. Sarcopenia develops due to inflammatory, hormonal, and myocellular changes in response to physiological and pathological aging, which promote progressive gains in fat mass and loss of lean mass and muscle strength. Progression of these pathophysiological changes can lead to sarcopenic obesity and physical frailty. These syndromes independently increase the risk of adverse patient outcomes including hospitalizations, long-term care placement, mortality, and decreased quality of life. This risk increases substantially when these syndromes co-exist. While there is evidence suggesting that the progression of sarcopenia, sarcopenic obesity, and frailty can be slowed or reversed, the adoption of broad-based screening or interventions has been slow to implement. Factors contributing to slow implementation include the lack of cost-effective, timely bedside diagnostics and interventions that target fundamental biological processes. This paper describes how clinical, radiographic, and biological data can be used to evaluate older adults with sarcopenia and sarcopenic obesity and to further the understanding of the mechanisms leading to declines in physical function and frailty.

Timed up and go test predicts mortality in older adults in Peru: a population-based cohort study

Background

While there is evidence about stablished risk factors (e.g., raised blood pressure) and higher mortality risk in older population, less has been explored about other functional parameters like the Timed Up and Go test and the Gait Speed in older people at low- and middle-income countries. We aimed to study these mobility tests as predictors of mortality in a population of older people in Peru.

Methods

Population-based prospective cohort study (2013–2020). Random sampling of people aged 60+ years in a community of Lima, Peru. Geriatricians conducted all clinical evaluations and laboratory tests were conducted in the local hospital. Participants were sought in the national vital registration system, and we collated cause (ICD-10) and date of death. We conducted a nested forward multivariate Cox proportional hazard model to identify all potential predictors of all-cause, communicable and non-communicable diseases mortality.

Results

At baseline, there were 501 older people (mean age 70.6 and 62.8% were women), complete follow-up information was available from 427 people. Mean follow-up time was 46.5 months (SD = 25.3). In multivariate models, the Timed Up and Go test was associated with higher risk of all-cause mortality (HR = 1.05; 95% CI: 1.02–1.09). For cause-specific mortality, history of heart disease (HR = 2.25; 95% CI: 1.07–4.76) and age in years (HR = 1.05; 95% CI: 1.01–1.09) were predictors of non-communicable diseases mortality.

Conclusions

In addition to established risk factors for mortality in older population, the Timed Up and Go test, a functional parameter, raised as a relevant predictor of all-cause mortality.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12877-022-02749-6.

Sex Differences in the Relation Between Frailty and Endothelial Dysfunction in Old Mice

Vascular endothelial function declines with age on average, but there is high variability in the magnitude of this decline within populations. Measurements of frailty, known as frailty index (FI), can be used as surrogates for biological age, but it is unknown if frailty relates to the age-related decline in vascular function. To examine this relation, we studied young (4-9 months) and old (23-32 months) C57BL6 mice of both sexes. We found that FI was greater in old compared with young mice, but did not differ between old male and female mice. Middle cerebral artery (MCA) and mesenteric artery endothelium-dependent dilation (EDD) also did not differ between old male and female mice; however, there were sex differences in the relations between FI and EDD. For the MCA, FI was inversely related to EDD among old female mice, but not old male mice. In contrast, for the mesenteric artery, FI was inversely related to EDD among old male mice, but not old female mice. A higher FI was related to a greater improvement in EDD with the superoxide scavenger TEMPOL in the MCAs for old female mice and in the mesenteric arteries for old male mice. FI related to mesenteric artery gene expression negatively for extracellular superoxide dismutase (Sod3) and positively for interleukin-1β (Il1b). In summary, we found that the relation between frailty and endothelial function is dependent on sex and the artery examined. Arterial oxidative stress and pro-inflammatory signaling are potential mediators of the relations of frailty and endothelial function.

Roadmap to 2030 for Drug Evaluation in Older Adults

Changes that accompany older age can alter the pharmacokinetics (PK), pharmacodynamics (PD), and likelihood of adverse effects (AEs) of a drug. However, older adults, especially the oldest or those with multiple chronic health conditions, polypharmacy, or frailty, are often under-represented in clinical trials of new drugs. Deficits in the current conduct of clinical evaluation of drugs for older adults and potential steps to fill those knowledge gaps are presented in this communication. The most important step is to increase clinical trial enrollment of older adults who are representative of the target treatment population. Unnecessary eligibility criteria should be eliminated. Physical and financial barriers to participation should be removed. Incentives could be created for inclusion of older adults. Enrollment goals should be established based on intended treatment indications, prevalence of the condition, and feasibility. Relevant clinical pharmacology data need to be obtained early enough to guide dosing and reduce risk for participation of older adults. Relevant PK and PD data as well as patient-centered outcomes should be measured during trials. Trial data should be analyzed for differences in PK, PD, effectiveness, and safety arising from differences in age or from the presence of conditions common in older adults. Postmarket evaluations with real-world evidence and drug labeling updates throughout the product lifecycle reflecting new knowledge are also needed. A comprehensive plan is needed to ensure adequate evaluation of the safety and effectiveness of drugs in older adults.

Strategies for Targeting Senescent Cells in Human Disease

Cellular senescence represents a distinct cell fate characterized by replicative arrest in response to a host of extrinsic and intrinsic stresses. Senescence provides programming during development and wound healing, while limiting tumorigenesis. However, pathologic accumulation of senescent cells is implicated in a range of diseases and age-associated morbidities across organ systems. Senescent cells produce distinct paracrine and endocrine signals, causing local tissue dysfunction and exerting deleterious systemic effects. Senescent cell removal by apoptosis-inducing "senolytic" agents or therapies that inhibit the senescence-associated secretory phenotype, SASP inhibitors, have demonstrated benefit in both pre-clinical and clinical models of geriatric decline and chronic diseases, suggesting senescent cells represent a pharmacologic target for alleviating effects of fundamental aging processes. However, senescent cell populations are heterogeneous in form, function, tissue distribution, and even differ among species, possibly explaining issues of bench-to-bedside translation in current clinical trials. Here, we review features of senescent cells and strategies for targeting them, including immunologic approaches, as well as key intracellular signaling pathways. Additionally, we survey current senolytic therapies in human trials. Collectively, there is demand for research to develop targeted senotherapeutics that address the needs of the aging and chronically-ill.