Aging health最新文献

Herpes zoster, also known as shingles, is a disease that results from the reactivation of a latent infection of the varicella zoster virus, which is usually encountered during early childhood. Aging is associated with an increased risk for herpes zoster and its complications. Boosting immunological memory is the key strategy for keeping the latent varicella zoster virus infection under control. A live attenuated virus vaccine is safe, effective and approved for use among healthy elderly adults aged 60 years or older. However, significant problems remain in the prevention of herpes zoster with the current vaccine. Future studies for improved vaccines and studies into the epidemiology of herpes zoster are required in order to address this significant public health burden.

The fastest growing segment of the US population, and that of other developed countries, is the oldest-old (aged >85 years). Many children born after the year 2000 in countries with the longest lived residents may live to see their 100th birthday. The combination of reduced mortality along with reduced fertility in developed countries is producing 'population aging', and the comorbidities associated with aging are becoming important public health issues. Age-associated obesity is one such important public health issue. Aging is associated with significant changes in body composition, including loss of skeletal muscle mass and increased visceral fat accumulation. The loss of muscle mass is accompanied by a disproportionate decline in muscle strength (up to three-times greater than the loss of mass), indicative of reduced muscle 'quality' or muscle dysfunctionality. Aging is characterized by markedly reduced physical activity and a drop in resting metabolic rate that is disproportionate to the loss of muscle mass, with a shift towards preferentially oxidizing carbohydrate at the expense of fat. A combination of these factors may act to increase muscular lipid infiltration and decrease insulin sensitivity; however, the cause and effect relationship remains undetermined. Changes in cellular energy (i.e., ATP) requirement owing to decreased ion channel activity, decreased protein synthesis or increased mitochondrial energy efficiency may underlie the decreased resting metabolic rate. Increasing energy demand through physical activity may alleviate some of the adverse metabolic changes that are associated with aging.

Driving is a complex activity that always becomes impaired at some point in older adults with degenerative dementia. Over time, disruption of the visual processing circuits of the brain that link the occipital and prefrontal regions, particularly in the right hemisphere, leads to increasing degrees of driving impairment that ultimately preclude safe driving. Neuropsychological tests of visuospatial ability, executive function and attention that tap into the integrity of these brain regions provide the clinician with important information regarding the need for a formal determination of driving competence. Enhancement of cognitive function in these domains through anti-dementia therapy and exercise may partially mitigate risk; however, all drivers with dementia must ultimately retire from driving when dementia becomes moderately severe, and often in earlier stages of the illness. Future efforts to improve screening tests for hazardous driving and to develop interventions to help prolong the time that drivers with mild dementia can continue to drive safely are needed for our increasingly aged and mobile population.

There is both popular and scientific interest in keeping the brain young and avoiding cognitive impairment and dementia. Older adults may be able to modify their cognitive health status through certain health behaviors. The aim of this review is to highlight the potential impact that cognitive activity may have on cognitive health outcomes in late life. Evidence from observational studies and randomized, controlled trials suggests that engagement in activities that are cognitively stimulating is beneficial to cognitive functioning. There are many issues and questions that need to be addressed before specific recommendations can be made at the population level or to individual patients. However, older adults should be encouraged to stay active and to try new and challenging activities in general to promote their cognitive and overall health.

Depression is a debilitating mental disorder that frequently occurs in older adults, especially in those with vascular diseases. Nutritional factors have the potential to decrease the occurrence of late-life depression but have not been adequately studied. Low folate levels, disturbed omega-3 fatty acid metabolism and obesity have been associated with depression, and may be causal factors. Longitudinal studies are urgently needed in order to examine the potential of dietary factors to prevent late-life depression.

Severe acute respiratory disease caused by respiratory virus infections in individuals aged 65 years and older and in high-risk adults, such as those with chronic cardiopulmonary disorders, is associated with increased hospitalization and mortality rates. Epidemiological studies have identified influenza virus and respiratory syncytial virus as the most frequent causes of virus-induced respiratory disease in elderly and high-risk adults. Studies in both humans and animal models have established fundamental defects in cell-mediated and humoral immune responses in aged individuals. However, it is not well understood how age specifically alters the immune response to respiratory pathogens. In this review, we will focus our discussion on the major causative agents of severe respiratory virus infections in elderly and high-risk adults and the age-associated defects in the immune response that probably contribute to the increased disease severity observed in these populations.

Asthma is an inflammatory disorder of the airway. The airway inflammation of asthma is typically an allergic inflammation characterized by cells and mediators described as a "Th2" inflammatory response. There is a growing body of evidence describing changes in the function of immune cells upon aging, a phenomenon referred to as "immunosenescence". Several studies utilizing animal models and human subjects with asthma have begun to explore age-related effects on the airway inflammation in asthma. This review explores the existing data on the presence and effects of immunosenescence or age-related changes in immune function in asthma.

The aim of this review is to present age-related changes in the bone marrow and thymus and their effects in later life. Age-related hematologic changes are marked by a decline in marrow cellularity, increased risk of myeloproliferative disorders and anemia, and a decline in adaptive immunity. The exact mechanisms that produce these changes remain undefined. For the most part, the changes in function that are a consequence of aging alone rarely have meaningful clinical consequences. However, in the face of the stresses induced by other illnesses, the decreased physiologic reserve can slow or prevent an appropriate response to the stressors.

Late-life mood disorders and cognitive aging are the most common reasons for using complementary and alternative therapies. The amount of rigorous scientific data to support the efficacy of complementary therapies in the treatment of depression or cognitive impairment is extremely limited. The areas with the most evidence for beneficial effects are exercise, herbal therapy (Hypericum perforatum), the use of fish oil, and, to a lesser extent, acupuncture and relaxation therapies. There is a need for further research involving randomized, controlled trials to investigate the efficacy of complementary and alternative therapies in the treatment of depression and cognitive impairment in late-life. This research may lead to the development of effective treatment and preventive approaches for these serious conditions.

Community-acquired pneumonia continues to have a significant impact on elderly individuals, who are affected more frequently and with more severe consequences than younger populations. As the population ages it is expected that the medical and economic impact of this disease will increase. Despite these concerns, little progress has been made in research specifically focusing on community-acquired pneumonia in the elderly. Data continue to show that a high index of suspicion, early antimicrobial therapy and appropriate medications to cover typical pathogens are extremely important in treating community-acquired pneumonia in older individuals. This review is designed to serve as an update to our previous work published in Aging Health in 2006, with specific emphasis on the most recent evidence published since that time.