Asia has currently one of the largest concentrations of aging persons in the world.This trend is expected to continue due to increasing longevity and continued fertility reductions in its member countries.Asian countries need to start planning for these future demographic changes by formulating evidence-based policies to address aging.A workshop on healthy aging in Asia was recently organized by the International Life Sciences Institute Southeast Asia (ILSI SEA) Region in Singapore 1 .The goal was to discuss aging-related issues in the region and identify ways to address these issues through scientific research.Policy issues that were identified include: difficulty in translating scientific findings into policy initiatives, lack of government financial resources to support agingresearch, food insecurity among Asian elderly, and diverse ethnic populations that necessitate tailored interventions to address specific health problems.Better quality of health rather than increased longevity was seen as an important goal to strive for.Health issues identified include: maintaining autonomy and independence in a developing country context, developing fitness standards for Asians, examining how Asian populations transition into disability, and identifying health pathways in developing countries, among others.Multi-disciplinary and collaborative research is the best approach to address these issues.Future actions include the establishment of a regional consortium or collaborative network to guide the research agenda that can support aging policies as well as the exploitation of existing opportunities for public-private partnerships.
Steroid hormones are lipophilic, low-molecular weight organic compounds all of which are derived from cholesterol.They are primarily synthesized by steroidogenic glands such as gonads (ovary and testis), the adrenal gland and, during pregnancy, by the placental trophoblasts.Limited steroid synthesis also takes place in the brain.Steroid hormones are crucial for the proper functioning of the body.They mediate a wide variety of vital physiological functions, ranging from maintaining normal reproductive function and secondary sexual characteristics, to regulating virtually every metabolic process in the body.Like many age-related endocrine disorders, aging also progressively impacts the tissue-specific synthesis and secretion of steroid hormones.The goal of this review is to summarize the effects of aging on steroid hormone synthesis and secretion by the adrenal gland and gonads of both human and experimental animal models, to describe the potential involvement of excessive oxidative stress in mediating age-related alterations in steroidogenesis, and to discuss the possible underlying mechanisms involved.
The term immunosenescence is used to describe the decreased function of the immune system with age, and al- so to describe the phenotypic alterations in immune cells and cytokines that develop with age. The most dramatic pheno- typic change is seen in the T cell compartment, where the percentage of cells with an effector memory phenotype increas- es, and the number and diversity of naive cells decrease. In particular, large, often oligoclonal accumulations of CD28- CD8+ T cells develop. This hallmark change is largely attributable to CMV infection; the accumulating cells are the enormous "inflationary" virus-specific T cell population that are responding to this lifelong, smouldering, subclinical in- fection. In many populations, at least 80% of the elderly carry CMV, so CMV-driven changes in old age were easily as- cribed to aging per se. There is broad agreement that CMV drives this characteristic phenotype of the aged immune sys- tem. There is also considerable evidence that the size of the CD8+CD28- population can be used to describe an "immune risk phenotype" which correlates with an increased inflammatory milieu ("inflammaging"), which may be a predictor of all cause mortality. However, the evidence that CMV contributes causally to the functional failings of the immune system in old age, rather than innocently providing a convenient biomarker, is much less convincing. This important question needs to be addressed with studies including enough CMV seronegative individuals to provide statistically valid data.
The elderly are susceptible to infection with the bacterial pathogen Mycobacterium tuberculosis, and to the de- velopment of active TB disease. In this review we utilize experimental data from animal models to discuss the concept that age-associated changes in immune function are a critical parameter that contributes to the increased susceptibility of the elderly to M. tuberculosis infection.
The immune system plays an important role in the defence against various threats to health, such as pathogens, cancer cells or modified-self proteins.With aging there is a decrease in the immune response, called immunosenescence, concomitantly with the increase in some age-related diseases such as infections, autoimmune disorders, chronic inflammatory diseases and cancer.The immune response is traditionally divided between innate and adaptive immune responses.Accumulating evidence suggests that immunosenescence is not only restricted to the adaptive but also affects the innate immune system.Assessment of innate immune system functions revealed that it is also susceptible to age-related dysregulation.Furthermore, it is becoming clear that the sustained function of innate cells is indispensable for the adequate functioning of the adaptive immune response.This review will describe the changes in the innate immune response with aging and the recent discoveries, which may shed new light on its contribution to immunosenescence.
Vaccinations are powerful tools to help prevent/minimize the consequences of infections. Currently available vaccines are protecting only part of the human population because of the age-related decrease in immune functions. Vac- cination against Streptococcus pneumoniae and influenza are strongly recommended in children under 2 years of age and individuals over 65 years of age to protect them from infection. However, although commercially available vaccines against these infectious diseases provide protection and ensure lasting immunological memory in children and adults, they are much less effective in elderly individuals. The mechanisms for the reduced response of the elderly to pneumococcal and influenza vaccines are discussed in this review from the perspective of deficiencies seen in B cell function with age.
Multiple recent population-based studies document the rising prevalence of lung disease caused by the envi- ronmentally ubiquitous nontuberculous mycobacteria (NTM), particularly among older women. The reasons for this changing epidemiology are unclear, and the specific predisposing conditions and pathophysiologic mechanisms underly- ing the development of NTM lung disease among affected individuals are poorly understood. Progress in our understand- ing of this disease has been hampered by the lack of animal models for NTM lung disease. Various systemic immune de- fects, structural lung diseases, and a constellation of factors among a subset of post-menopausal women with a distinct body morphotype have all been evaluated among affected individuals, yet the majority of NTM lung disease remains in- completely explained. This review summarizes the available literature describing NTM as an emerging pathogen particu- larly among the aging population, including the changing epidemiology, clinical features of NTM lung disease, and pro- posed pathophysiologic mechanisms underlying disease susceptibility and manifestations particularly among the elderly. The rising prevalence of NTM lung disease and significant gaps in our understanding and tools for study highlight this disease as an important subject of further research.
Advanced age is associated with a decline in immune fitness commonly referred as “immune senescence”. Despite considerable advances in the medical field, infections continue to seriously compromise quality of life of the elderly. Indeed, infectious diseases such as tuberculosis, pneumonia and influenza remain amongst the 10 leading causes of mortality amongst the elderly in the US. Given that the World Health Organization predicts that by 2050, 2 billion people will be at least 60 years of age (http://www.who.int/ageing/ en/), there is an urgent need to better understand the causes and consequences of immune senescence. The articles in this special issue of Open Longevity Sciences provide an excellent overview of the age-related changes in both the adaptive and the innate branches of the immune system, as well as the impact of these on the host response to infectious agents. This issue also examines the impact of neuroendocrine changes on immune senescence and reviews the current field of immune restorative approaches in the elderly.
Major changes in social welfare, economic conditions and medical knowledge over the last 60 years have produced a demographic shift in the population.More individuals are living longer, and in a decade there will be more people over 65 than infants under 5 for the first time in history.Taking the analysis beyond mere numbers reveals that older individuals are now physically more active than their forebears and travel more widely.This provides a greater opportunity for encountering infectious agents which could present a considerable problem.Older individuals are more susceptible to infection and do not respond as well as younger people to vaccination because of an age related decline in immunity, a state which has been termed immunosenesence.This decline is not uniform and some older individuals show a greater decline in their immune response than others.In this review we have sought to consider who are the 'at risk' individuals, how they might best be treated and when.
Dampened humoral immune responses and increased propensity for autoimmune and inflammatory diseases are hallmarks of aging.Here, we summarize recent progress in understanding how aging affects humoral immunity, focusing on the discovery of a phenotypically and functionally unique B cell subset in aged mice, its potential role in immunosenescence, and its relationship to increased inflammation and autoimmunity.
Several lines of evidence suggest that ovarian steroids modulate immune function in women.Women are at higher risk of autoimmune disease than men; generate more robust humoral responses to vaccination than men; and plasma cytokine levels and the immune response to certain vaccines change throughout the menstrual cycle.Aging is accompanied by a decline in immunity referred to as "immune senescence" that significantly contributes to increased morbidity and mortality in the elderly.Aging is also associated with menopause, one of the most dramatic age-related physiological changes in women.Given the strong evidence for sex differences in immune function between pre-menopausal adult women and men, it has been suggested that the loss of ovarian steroids associated with menopause might contribute to decreased immune function in post-menopausal women.However, we do not yet fully understand the interplay between ovarian and immune senescence.In this article, we review studies that have investigated the impact of menopause and hormone therapy on changes in immune function.
Higher morbidity and mortality following infections, particularly influenza, is observed in the elderly population. Because of this, people over 65 years old are often targeted for preventive immunization. Many vaccines, however, are not as effective in generating protective antibodies in older individuals. CD4+ T cells, through their B cell helper functions, play a central role in the humoral response. Aging has deleterious effects on the immune system, and understanding how aging impairs CD4+ T cell functions is of critical importance to design new immunization and treatment strategies targeted to the elderly population. In this paper, we review some of the qualitative and quantitative changes in the CD4+ T cell compartment that arise with aging. We also summarize the age-related intrinsic defects that impact naïve, memory and regulatory CD4+ T cell functions.
With advances in global health care, ageing populations are expected to grow worldwide throughout the 21 st century.Increased lifespan is a testament to modern medical and social practices, but also presents a growing challenge to a system with limited resources.Elderly populations present specific concerns related to preventative health practices, especially vaccination.Although the power of vaccination is unquestionable in controlling infectious disease, immunosenescence can lead to reduced immune responses following immunization in the elderly, and increased morbidity and mortality.Further complicating this issue, some vaccines themselves may pose a substantial safety risk in the elderly when compared to younger counterparts.Though any health care intervention must balance risk and reward, safety and immunogenicity are often poorly characterized in older populations.This review explores several domestic and travel vaccines, examining what is known concerning efficacy and safety in the elderly, and considers future alternatives.
Avoiding and negotiating obstacles is a common cause of falling in the elderly. There is also evidence that under dual-task conditions, which requires a high level of attention, is associated with an elevated risk of falls in older adults. To better understand the role of dual-tasking in the disturbance of postural control when subjects are faced with obstacles, we used a simple quantification method to assess postural control after obstacle clearance. Sixty healthy elderly volunteers (aged 66-85 years) were tested for their postural stabilization on a force platform under the five follow- ing conditions: i) simple walking, ii) and over an obstacle, and iii to v) and over the obstacle under dual or triple-task conditions, the secondary task being either motor or cognitive for the dual-task and a combination of both for the triple-task. Postural control was assessed by determining both the distance covered by the cen- ter of pressure (COP) and the root-mean-square of the medio-lateral COP displacement. Only the latter differed signifi- cantly between conditions. In the walking plus stepping conditions, the motor and cognitive secondary tasks led to opposite effects, the motor task perturbed whereas the cognitive task improved postural control. These findings highlight the adverse effects of performing a secondary motor task while under challenging conditions, and con- firm the appropriate prioritization of postural control over a cognitive task in cognitively unimpaired older subjects. These results also indicate that this near ecological approach may be useful for fall risk investigations in the elderly.
The need to prevent falls and related injuries among seniors is a significant public health issue in Canada and all nations where an aging demographic puts higher numbers at risk. In British Columbia (BC), falls are the leading cause of injury-related hospitalization and death among seniors. Seniors are BC's fastest growing age group, with one in four reaching the age of 65 or older by 2036. To address this costly and complex problem, a sustained collaboration has occurred over the past 20 years among fall prevention leaders within government, the health system, academia and local communities. This article summarizes key elements of a coordinated, province-wide public health approach to reduce falls and related injuries among those aged 65 years and older in BC. Historical records of the interventions are recorded in two influential reports that have also helped to galvanize this province-wide collaborative effort. Outcomes include a signifi- cant reduction in fall-related hospitalization and death rates, with a parallel growth in fall prevention programs and serv- ices for those at risk. This article concludes with a summary of the key developments in the evolution of fall prevention activities in the province over the past two decades and how the sustained, collaborative efforts have resulted in BC emerging as an example of success in the formation of comprehensive networks and the integration of evidence-based fall prevention into health service delivery for seniors. However, more needs to be done to ensure integrated and sustained results.
Objective: This study aims to describe how patients perceive the threat of falls in hospitals, to identify patient characteristics that are associated with greater or lesser perceptions of the threat of falls, and to examine whether there is a discord between the risk that patients perceive in general and the risk that they perceive for themselves personally. Method: A cross-sectional survey amongst geriatric rehabilitation inpatients in Brisbane, Australia, was implemented. The first component of the survey dealt with the 'general' nature of in-hospital falls and falls related risks while the second component of the survey was directed at identifying whether the patient held the same belief for themselves. Results: A total of 21 out of 125 participants (17%) indicated that they felt that they were at risk of falling during their hospitalisation and 28 (22%) felt that they would injure themselves if they were to fall. Self-perceived risk of falls was as- sociated with decreasing age and lower cognitive function (Functional Independence Measure Cognitive score). A major- ity of patients felt that falls most commonly occur in the bathroom (n=67 (54%)) and that if they were to fall, they would fall in the bathroom (n=56 (45%)). Discussion: Patients generally do not think they are at risk of falling while in hospital and this may contribute to poor ad- herence to falls prevention strategies. It is possible that raising patient perception of the risk of falls and injury from falls in hospitals may help improve adherence to falls prevention strategies in this setting.
Unintentional falls among persons aged 65 years and older are an important public health issue, associated with significant mortality and morbidity. About one third of older adults fall annually and, although many fall outcomes are minor, between 10% and 20% cause serious injuries such as traumatic brain injury, contusions, and fractures. Therefore the U.S. Centers for Disease Control and Prevention (CDC) is working to prevent injuries and fatalities due to older adult falls. The public health approach to older adult falls focuses on prevention and is based on scientific rigor. Its steps in- clude defining the problem, identifying causes, developing and testing interventions, and then implementing effective ap- proaches on a large scale. We highlight current CDC activities that map onto each step of the public health model and close by providing future directions for older adult fall prevention, including improved surveillance, support for program implementation, and enhanced partnership building.
