Gerontology

<b><i>Background:</i></b> Most older adults prefer to age in place, and supporting older adults to remain in their own homes and communities is also favored by policy makers. Technology can play a role in staying independent, active and healthy. However, the use of technology varies considerably among older adults. Previous research indicates that current models of technology acceptance are missing essential predictors specific to community-dwelling older adults. Furthermore, in situ research within the specific context of aging in place is scarce, while this type of research is needed to better understand how and why community-dwelling older adults are using technology. <b><i>Objective:</i></b> To explore which factors influence the level of use of various types of technology by older adults who are aging in place and to describe these factors in a comprehensive model. <b><i>Methods:</i></b> A qualitative explorative field study was set up, involving home visits to 53 community-dwelling older adults, aged 68-95, living in the Netherlands. Purposive sampling was used to include participants with different health statuses, living arrangements, and levels of technology experience. During each home visit: (1) background information on the participants' chronic conditions, major life events, frailty, cognitive functioning, subjective health, ownership and use of technology was gathered, and (2) a semistructured interview was conducted regarding reasons for the level of use of technology. The study was designed to include various types of technology that could support activities of daily living, personal health or safety, mobility, communication, physical activity, personal development, and leisure activities. Thematic analysis was employed to analyze interview transcripts. <b><i>Results:</i></b> The level of technology use in the context of aging in place is influenced by six major themes: challenges in the domain of independent living; behavioral options; personal thoughts on technology use; influence of the social network; influence of organizations, and the role of the physical environment. <b><i>Conclusion:</i></b> Older adults' perceptions and use of technology are embedded in their personal, social, and physical context. Awareness of these psychological and contextual factors is needed in order to facilitate aging in place through the use of technology. A conceptual model covering these factors is presented.

<i>Background:</i> It is generally accepted that depression can be associated with significant cognitive deficits and that depression can be comorbid with dementia. <i>Objective:</i> This review seeks to go further and ask whether depression earlier in life can be a risk factor for subsequent dementia or for cognitive decline. <i>Methods:</i> A review was made of the epidemiological evidence from case-control and prospective studies that depression is a risk factor. The literature was also reviewed in relation to six hypotheses that might explain an association: (1) depression treatments are a risk factor for dementia, (2) dementia and depression share common risk factors, (3) depression is a prodrome of dementia, (4) depression is an early reaction to cognitive decline, (5) depression affects the threshold for manifesting dementia, and (6) depression is a causal factor in dementia. <i>Results:</i> A meta-analysis found that depression was associated with an increased risk of subsequent dementia in both case-control studies (95% CI for relative risk: 1.16–3.50) and prospective studies (95% CI: 1.08–3.20). There was little support for hypotheses 1 and 2. The other hypotheses have limited support, but warrant further research. <i>Conclusion: </i>There is sufficient evidence to take seriously the possibility that depression is a risk factor for dementia and cognitive decline. Further work is needed to examine depression as a prodrome of vascular dementia, depression as an early reaction to perceived cognitive decline, the effects of depression on the threshold for manifesting dementia, and depression as a source of hippocampal damage through a glucocorticoid cascade.

The association of obesity, insulin resistance, and chronic low-grade inflammation has been evident for several years by now. Since obesity, insulin resistance, and inflammation all are related to aging as well, the mechanisms underlying this association are of critical importance for gerontology. Although several molecular and cellular mechanisms by which inflammatory events decrease the sensitivity to insulin in obese patients have recently been elucidated, the pathogenesis of obesity-induced insulin resistance is still obscure in many aspects. This review aims at giving a general view on the known mechanisms and summarizing the recent progress. Research currently focuses on adipose tissue inflammation as predominantly driven by adipose tissue macrophages, but also related alterations in other organs (liver, muscle, pancreas) have to be considered. Moreover, novel approaches for treatment and prevention of insulin resistance and type 2 diabetes by targeting obesity-induced inflammatory processes are discussed here.

<i>Background:</i> Participating in regular physical activity is an important part of healthy aging. There is an increased risk for inactivity associated with aging and the risk becomes greater for adults who have a chronic disease. However, there is limited information on current physical activity levels for older adults and even less for those with chronic diseases. <i>Objective:</i> Our primary objective was to determine the proportion of older adults who achieved a recommended amount of weekly physical activity (≥1,000 kcal/week). The secondary objectives were to identify variables associated with meeting guideline leisure-time physical activity (LTPA), and to describe the type of physical activities that respondents reported across different chronic diseases. <i>Methods:</i> In this study we used the Canadian Community Health Survey Cycle 1.1 (2000/2001) to report LTPA for adults aged 65 years and older. This was a population-based self-report telephone survey. We used univariate logistic regression to provide odds ratios to determine differences in activity and the likelihood of meeting guideline recommendations. <i>Results:</i> For adults over 65 years of age with no chronic diseases, 30% reported meeting guideline LTPA, while only 23% met the recommendations if they had one or more chronic diseases. Factors associated with achieving the guideline amount of physical activity included a higher level of education, higherincome and moderate alcohol consumption. Likelihood for not achieving the recommended level of LTPA included low BMI, pain and the presence of mobility and dexterity problems. Walking, gardening and home exercises were the three most frequent types of reported physical activities. <i>Conclusion:</i> This study provides the most recent evidence to suggest that older Canadians are not active enough and this is accentuated if a chronic disease is present. It is important to develop community-based programs to facilitate LTPA, in particular for older people with a chronic disease.

The Atherosclerosis Risk in Communities Study administered cognitive function tests to more than 14,000 middle-aged adults in 1990–1992. The battery included the Delayed Word Recall test, the Digit Symbol Subtest of the Wechsler Adult Intelligence Scale-Revised, and the Controlled Oral Word Association (Word Fluency) test. Test performance was correlated positively with education level, negatively with age, was better in women than in men, and better in managers/professionals compared with other occupations. After controlling for these factors, race and community, the findings most consistent for both sexes were that Delayed Word Recall was negatively associated with depressive symptoms, diabetes, and fibrinogen level; the Digit Symbol Subtest was associated with marital status, negatively associated with depressive symptoms, smoking status, fibrinogen level, and carotid intima-media thickness, and positively associated with alcohol drinking and FEV₁; and the Word Fluency test was positively associated with marital status, alcohol drinking, sports participation, and FEV₁. Most of these cross-sectional results were in the predicted direction and have biologic plausibility, but mean differences between extreme categories were small (generally on the order of 0.1 to 0.2 of a standard deviation). Longitudinal study is warranted to evaluate whether small differences in middle-age lead to larger, clinically meaningful deficits with aging.

It is now well recognized that the body temperature of older men and women is lower than that of younger people and that their tolerance of thermal extremes is more limited. The regulation of body temperature does not depend on a single organ, but rather involves almost all the systems of the body, i.e. systems not exclusively dedicated to thermoregulatory functions such as the cardiovascular and respiratory systems. Since these deteriorate naturally with advancing age, the decrement in their functions resonates throughout all the bodily processes, including those that control body temperature. To the extent that the age-related changes in some of these, e.g. in the musculoskeletal system, can be slowed, or even prevented, by certain measures, e.g. fitness training, so can the decrements in thermoregulatory functions. Some deficits, however, are unavoidable, e.g. structural skin changes and metabolic alterations. These impact directly on the ability of the elderly to maintain thermal homeostasis, particularly when challenged by ambient thermal extremes. Since the maintenance of a relatively stable, optimal core temperature is one of the body’s most important activities, its very survival can be threatened by these disorders. The present article describes the principal, age-associated changes in physiological functions that could affect the ability of seniors to maintain their body temperature when exposed to hot or cold environments.

Comparative study has been made histologically and micrometrically on the senile changes of the kidney between Caucasians and Japanese. In both races, weight loss of the kidney, decrease in number of the parenchymal cells and tendency to increase in size of the cells were considered to be main characteristics of the senile changes, but in the process of the senile changes some differences were noticed between the two races. The race differences may be partly due to the difference in the process of sclerotic changes of the intrarenal arteries. These differences have been discussed with special consideration to the nutritional conditions of the two races.

<i>Background:</i> Sarcopenia, the age-related loss of muscle mass and function, represents a relevant public health issue due to its high prevalence and detrimental consequences. While the exact mechanisms underlying the pathogenesis of sarcopenia are not clear, growing experimental evidence indicates that progressive myonuclear elimination over the course of aging via an apoptosis-like process may represent a converging mechanism through which muscle atrophy and loss of physical function develop. Notably, the proapoptotic environment taking place in aged muscle appears amenable to interventions. <i>Objective:</i> We aimed at providing (1) an overview of signaling pathways of apoptosis relevant to sarcopenia, and (2) a review of the literature supporting myocyte apoptosis as a target for interventions against muscle aging. <i>Methods:</i> We summarized findings from studies focused on skeletal myocyte apoptosis as a mechanism in the development of sarcopenia and reports supporting myonuclear apoptosis as a target for interventions against age-related muscle loss. <i>Results:</i> Advanced age is associated with increased signaling through extrinsic and intrinsic apoptotic pathways in skeletal myocytes. In contrast, downregulation of myocyte apoptosis through calorie restriction, exercise training, hormonal supplementation, drugs (e.g. angiotensin-converting enzyme inhibitors, acetaminophen, antimyostatin antibodies), nutraceuticals or genetic interventions (e.g. PGC-1α overexpression) is linked with preservation of muscle integrity and improved physical performance in late life. Preliminary data also indicate that skeletal myocyte apoptotic signaling may be downregulated by compounds, such as resveratrol, with calorie restriction-mimicking properties. Whether exercise mimetics exert a similar effect has not yet been investigated. <i>Conclusions:</i> Available evidence suggests that targeting myonuclear apoptosis might provide novel and effective therapeutic tools to combat sarcopenia. Further research is required to definitely establish if downregulating myonuclear apoptosis is effective in maintaining muscle mass and function in late life, identify the most relevant apoptotic pathway(s) to target, and determine the optimal timing for intervening.

Receptor activator of nuclear factor κB (RANK) and its ligand (RANKL) have originally been described for their key roles in bone metabolism and the immune system. Subsequently, it has been shown that the RANKL-RANK system is critical in the formation of mammary epithelia in lactating females and the thermoregulation of the central nervous system. RANKL and RANK are under the tight control of the female sex hormones estradiol and progesterone. A reduction of the circulating female sex hormones leading to an increase in RANKL-RANK signaling is the leading cause of osteoporosis in postmenopausal women. Denosumab, a human monoclonal anti-RANKL antibody, has been approved for the treatment of postmenopausal osteoporosis, where it is showing great promise. In addition, RANKL-RANK signaling also plays a critical role in other bone pathologies, bone metastasis or hormone-driven breast cancer. This review will highlight some of the functions of RANKL-RANK in bone turnover, the immune system and brain with a focus on the regulatory role of the female sex hormones.