Changes with age in the distribution of a frailty index

Models of human mortality include a factor that summarises intrinsic differences in individual rates of ageing, commonly called frailty. Frailty also describes a clinical syndrome of apparent vulnerability. In a representative, cross-sectional, Canadian survey (n = 66,589) we calculated a frailty index as the mean accumulation of deficits and previously showed it to increase exponentially with age. Here, its density function exhibited a monotonic change in shape, being least skewed at the oldest ages. Although the shape gradually changed, the frailty index was well fitted by a gamma distribution. Of note, the variation coefficient, initially high, decreased from middle age on. Being able to quantify frailty means that health risks can be summarised at both the individual and group levels.     

The relationship between oral health and nutrition in older people

The oral health of older people is changing with reducing numbers of people relying on complete dentures for function, and retaining some natural teeth. Despite this there are substantial numbers of older people whose ability to chew foods is compromised by their oral health status, either because they have few or no natural teeth. This alteration results in individuals selecting a diet that they can chew in comfort. Such diets are low in fruits and vegetables intake with associated reduction in both non-starch polysaccharide and micronutrient intakes. There is also a trend for reduced dietary intake overall. Salivary flow and function may have an impact in relation to the ability to chew and swallow. Whilst there are few differences in salivary function in fit healthy unmedicated subjects, disease resulting in reduced salivary flow and particularly polypharmacy, with xerostomia as a side effect, are likely to have a role in older people. This paper explores the relationships between oral health status and food's choice and discusses the potential consequences for the individual of such dietary change.     

Body movements during night sleep in healthy elderly subjects and their relationships with sleep stages

In order to enlighten the profile of body movements during sleep at old age, the night sleep of twelve elderly subjects was polygraphically investigated; seven young healthy subjects were the control group. Significantly less body movements during sleep were found in the elderly compared to young subjects, meaning that the decrease in the number of body movements observed from infancy to childhood up to adulthood also continues at later ages. Differently from young adult, whose sleep body movements mainly occur in stage REM, no specific sleep state and/or stage was preferentially associated with the occurrence of body movements in the elderly. These data may point to an age-related modification in the interaction between motor cortex control and subcortical circuits. Furthermore, when body movements occur in elderly individuals, they are significantly more often followed in the next 60 s by a sleep stage change or by a spontaneous behavioural awakening. This might reflect a peculiar inability of elderly subjects to sustain stable states, and could also suggest that body movements may act as a co-factor in a process, comprising other physiological changes, leading to state shifts.     

Metallothionein isoforms (I+II and III) and interleukin-6 in the hippocampus of old rats: may their concomitant increments lead to neurodegeneration?

Metallothionein (MT)-III isoform is a brain metal-binding protein that, like the MT-I + II isoform, binds zinc with high affinity. In the young-adult age, MT-III isoform increases during transient stress while MT-I + II isoform decreases, suggesting compensatory phenomena between the two isoforms and a protective role of MT-III against oxidative damage. This role may be questioned during ageing, because the stress-like condition is chronic in ageing due to high persistent levels of interleukin-6. In the present study, high expression of MT-III and MT-I + II genes (examined by RT-PCR and in situ hybridisation) was found in the hippocampus of old rats. These results indicate that a large amount of free zinc ions can be sequestered by MT isoforms, leading to impaired zinc-dependent functions in the ageing brain. In addition, zinc (tested with the Timm's method) was found to be low in mossy fibres from the old hippocampus. As this method tests bound and unbound zinc, we also investigated free zinc ion bioavailability based on the ratio active thymulin/total thymulin. We found that zinc ion bioavailability was low in old rats, together with increased interleukin-6 mRNA, high expression of both MT isoforms and reduced number of synapses whose function is zinc-dependent, in the old hippocampus. The results indicate that concomitant increments of both MT isoforms may provoke detrimental synergistic effects leading to reduced free zinc ion bioavailability for synapses. As a consequence, compensatory phenomena between MT isoforms may not occur in the old hippocampus due to chronic stress-like condition elicited by high persistent levels of interleukin-6.     

Old and alone: barriers to healthy eating in older men living on their own

Ageing is associated with reduced energy intake and loss of appetite. Older men tend to have poorer dietary intakes including consumption of fewer fruits and vegetables in comparison to older women. Living and eating alone further diminishes food consumption and dietary quality. The aim of the present study was to explore food choice and energy intake in older men living alone using both quantitative and qualitative methods. 39 older men were interviewed and completed questionnaires on health, food choice, dietary patterns and appetite. Few men managed to consume recommended levels of energy, essential trace elements or vitamins A and D. Age and BMI failed to predict patterns of intake, but men with good cooking skills reported better physical health and higher intake of vegetables. However, cooking skills were negatively correlated with energy intake. Men who managed to consume at least 4 portions of fruits and vegetables each day had significantly higher vitamin C levels, a greater percentage of energy as protein and generally more adequate diets. Interviews revealed that poor cooking skills and low motivation to change eating habits may constitute barriers to improving energy intake, healthy eating and appetite in older men (193).     

Oxidative inactivation of CD45 protein tyrosine phosphatase may contribute to T lymphocyte dysfunction in the elderly

The decline in T lymphocyte function during ageing has been linked to changes in intracellular signalling pathways. Oxidative damage has long been thought to be involved in the ageing process and we investigated a link between ageing, oxidation and T cell signalling focusing on the membrane phosphatase CD45. We investigated the relative sensitivity of CD45 to oxidative inactivation and then compared the phosphatase activity of CD45 in blood lymphocytes from elderly and young volunteers and related this to intracellular levels of the antioxidant glutathione. The CD45 phosphatase was particularly sensitive to oxidative inactivation compared to total Jurkat T cell PTP activity. The IC50 with H(2)O(2) was 3 mM for CD45 at which concentration there was a minimal decrease in global PTP activity. In normal peripheral blood CD4(+) T cells the IC50 was much lower at 54 microM. In a group of elderly healthy individuals, whose T cell responses to mitogen were depressed, PB lymphocyte CD45 phosphatase activity was decreased by about 60% compared to young controls. There was no difference in intracellular levels of glutathione. The loss of CD45 activity in lymphocytes from the elderly may underlie poor T cell function associated with ageing. The relative sensitivity of CD45 to oxidative damage may result from its location in the plasma membrane, where it might be more accessible to extracellular oxidants.     

Age-related effects on induction of DNA strand breaks by intermittent exposure to electromagnetic fields

Several studies indicating a decline of DNA repair efficiency with age raise the question, if senescence per se leads to a higher susceptibility to DNA damage upon environmental exposures. Cultured fibroblasts of six healthy donors of different age exposed to intermittent ELF-EMF (50 Hz sinus, 1 mT) for 1-24 h exhibited different basal DNA strand break levels correlating with age. The cells revealed a maximum response at 15-19 h of exposure. This response was clearly more pronounced in cells from older donors, which could point to an age-related decrease of DNA repair efficiency of ELF-EMF induced DNA strand breaks.     

IL-10 and TNF-alpha polymorphisms in a sample of Sicilian patients affected by tuberculosis: implication for ageing and life span expectancy

Human longevity seems to be directly correlated with optimal functioning of the immune system, suggesting that some genetic determinants of longevity might reside in those polymorphisms for the immune system genes that regulate immune responses, in particular cytokine gene polymorphisms. In fact, modification of cytokine network is a constant report in studies on age related modification of immune response. Moreover cytokine polymorphisms studies are indicating their involvement in the reshaping of cytokines network as an integral part of the scenario related to a successful ageing. A particular role might be attributed to the influence of cytokine polymorphisms on the efficiency of immune response against infectious diseases that have been the principal selection in oldest old. Here are reported data on the evaluation of the frequency of the functional polymorphisms at genes coding for TNF-alpha (-308G-->A) and IL-10 (-1082G-->A), analysed by ARMS-PCR, in a group of Sicilian patients affected by chronic lung tuberculosis (TBC) compared to that from a group of healthy individuals living in the same region. Data obtained demonstrated a reduction of -308GG TNF homozygous individuals in TBC affected subject group. In the same group a reduction of IL-10 -1082A/* carriers was found. Our results seem to suggest that multiple genetic traits may affect the capacity to cope with an infectious agents and this might predispose to an overt disease. Moreover these data are in agreement with previous reports suggesting that a balanced interaction among pro- and anti-inflammatory molecules it is a key point for conditioning the life span expectancy.     

Study of phagocytosis of senescent erythrocytes in young and elderly individuals

There is a decrease in the percentage contribution of a heavy density fraction of red blood cells to whole blood with increasing age. The aim of this study was to investigate in the young and elderly the interaction between monocytes and different erythrocyte suspensions: senescent red blood cells, erythrocytes stored with or without serum, and desialylated red blood cells. The results obtained with senescent red blood cells and erythrocytes stored with serum show the involvement of autologous IgG in the selective removal of erythrocytes. These values were higher in elderly individuals, indicating that this process increases with age. Our observation suggest that desialylation is not involved in the increased removal of erythrocytes observed in elderly individuals. Received: 3 October 2002 / Accepted: 11 December 2002 Correspondence to C. Biondi     

Marginality among older injectors in today's illicit drug culture: assessing the impact of ageing

Aims  As conceptualized by Robert Park in 1928, the 'marginal man' occupies simultaneously an intermediate point between two distinct cultures that embody some level of contradictory normative expectations, behaviors and beliefs. This paper explores the influence of ageing and social change on the creation of marginality among injection drug users over age 50 who have been chronic heroin users since their youth.
Design  Our data are drawn from in-depth interviews with 40 (28 male and 12 female) not-in-drug-treatment, active injecting drug users between the ages of 18 and 68.
Setting  Our sample was recruited using street outreach as part of a larger, community-based study conducted from a converted storefront in a high crime, economically depressed neighborhood on the west side of Chicago.
Findings  As they aged, and under the pressures of social change, the older users whom we studied moved from center positioning in the illicit drug culture of their youth to the margins of a differing drug culture of today where they participate largely unseen by others. Nostalgic for the 'Old School' mores of the past, and unable to transcend or assimilate fully into the cultural practices and norms of the 'New', they respond to their predicament by embracing 'poise' in the face of loneliness, stress and fear of victimization.
Conclusions  Our respondents' experiences draw attention to the need to refine the field's theoretical and practical understandings of what it means to be marginal and its consequences for older drug users and people in general. The results also point to what happens when society changes but some of its members do not.