561 research outputs found
External validity of randomized controlled trials on Alzheimer's disease: the biases of frailty and biological aging
To date, the external validity of randomized controlled trials (RCTs) on Alzheimer's disease (AD) has been assessed only considering monodimensional variables. Nevertheless, looking at isolated and single characteristics cannot guarantee a sufficient level of appreciation of the AD patients' complexity. The only way to understand whether the two worlds (i.e., research and clinics) deal with the same type of patients is to adopt multidimensional approaches more holistically reflecting the biological age of the individual. In the present study, we compared measures of frailty/biological aging [assessed by a Frailty Index (FI)] of a sample of patients with AD resulted eligible and subsequently included in phase III RCTs compared to patients referring to the same clinical service, but not considered for inclusion. The "RCT sample" and the "real world sample" were found to be statistically similar for all the considered sociodemographic and clinical variables. Nevertheless, the "real world sample" was found to be significantly frailer compared to the "RCT sample," as indicated by higher FI scores [0.28 (SD 0.1) vs. 0.17 (SD 0.1);p < 0.001, respectively]. Moreover, when assessing the relationship between FI and age, we found that the correlation was almost null in the "RCT sample" (Spearman'sr = 0.01;p = 0.98), while it was statistically significant in the "real world sample" (r = 0.49;p = 0.02). The application of too rigid designs may result in the poor representativeness of RCT samples. It may even imply the study of a condition biologically different from that observed in the "real world." The adoption of multidimensional measures capable to capture the individual's biological age may facilitate evaluating the external validity of clinical studies, implicitly improving the interpretation of the results and their translation in the clinical arena
Nutrition and dementia: Evidence for preventive approaches?
In recent years, the possibility of favorably influencing the cognitive trajectory through
promotion of lifestyle modifications has been increasingly investigated. In particular, the relationship
between nutritional habits and cognitive health has attracted special attention. The present review
is designed to retrieve and discuss recent evidence (published over the last 3 years) coming from
randomized controlled trials (RCTs) investigating the efficacy of nutritional interventions aimed
at improving cognitive functioning and/or preventing cognitive decline in non-demented older
individuals. A systematic review of literature was conducted, leading to the identification of 11 studies
of interest. Overall, most of the nutritional interventions tested by the selected RCTs were found
to produce statistically significant cognitive benefits (defined as improved neuropsychological test
scores). Nevertheless, the clinical meaningfulness of such findings was not adequately discussed and
appears controversial. In parallel, only 2 studies investigated between-group differences concerning
incident dementia and mild cognitive impairment cases, reporting conflicting results. Results of
the present review suggest that several dietary patterns and nutritional components may constitute
promising strategies in postponing, slowing, and preventing cognitive decline. However, supporting
evidence is overall weak and further studies are needed
Sarcopenia and swallowing disorders in older people.
Aging is accompanied by several changes which may affect swallowing function. The beginning of these changes, termed presbyphagia, still captures a preserved swallowing function, although burdened by the consequences of the physiological aging process. Several stressors (including diseases and medications) can easily trigger the disruption of this (increasingly weak) equilibrium and lead to overt dysphagia. It is noteworthy that the swallowing dysfunction may be aggravated by the sarcopenic process, characterizing the so-called "sarcopenic dysphagia", potentially responsible for several health-related negative outcomes. The assessment and management of sarcopenic dysphagia largely rely on the evaluation and integrated treatment of both constituting conditions (i.e., sarcopenia and dysphagia). The management of dysphagia requires a multidimensional approach and can be designed as either compensatory (aimed at producing immediate benefit for the patient through postural adjustments, swallowing maneuvers, and diet modifications) or rehabilitative. Interestingly, some evidence suggests that resistance training traditionally applied to tackle the lower extremity in sarcopenia may be simultaneously beneficial for sarcopenic dysphagia. If these preliminary results (discussed in the present review article) will be confirmed, the systemic beneficial effects of physical exercise will be indirectly demonstrated. This will also support the need of promoting healthy lifestyle in all sarcopenic individuals (thus potentially at risk of dysphagia)
The aging process and potential interventions to extend life expectancy
Aging is commonly defined as the accumulation of diverse deleterious changes occurring in cells and tissues with advancing age that are responsible for the increased risk of disease and death. The major theories of aging are all specific of a particular cause of aging, providing useful and important insights for the understanding of age-related physiological changes. However, a global view of them is needed when debating of a process which is still obscure in some of its aspects. In this context, the search for a single cause of aging has recently been replaced by the view of aging as an extremely complex, multifactorial process. Therefore, the different theories of aging should not be considered as mutually exclusive, but complementary of others in the explanation of some or all the features of the normal aging process. To date, no convincing evidence showing the administration of existing “anti-aging” remedies can slow aging or increase longevity in humans is available. Nevertheless, several studies on animal models have shown that aging rates and life expectancy can be modified. The present review provides an overlook of the most commonly accepted theories of aging, providing current evidence of those interventions aimed at modifying the aging process
Anticipatory and pre-planned actions: A comparison between young soccer players and swimmers
The present study investigated whether a difference exists in reactive and proactive control for sport considered open or closed skills dominated. Sixteen young (11-12 years) athletes (eight soccer players and eight swimmers) were asked to be engaged into two games competitions that required either a reactive and a proactive type of control. By means of kinematic (i.e. movement time and duration) and dynamic analysis through the force platform (i.e. Anticipatory Postural Adjustments, APAs), we evaluated the level of ability and stability in reacting and anticipating actions. Results indicated that soccer players outperformed swimmers by showing higher stability and a smaller number of falls during the competition where proactive control was mainly required. Soccer players were able to reach that result by anticipating actions through well-modulated APAs. On the contrary, during the competition where reactive control was mainly required, performances were comparable between groups. Therefore, the development of specific action control is already established at 11-12 years of age and is enhanced by the training specificity
Dietary Protein and Muscle in Aging People
This Special Issue of Nutrients, entitled “Dietary Proteins and Muscle in Aging People”, welcomes the submission of manuscripts either reporting original research or reviewing the scientific literature. Manuscripts should focus on the mechanisms linking dietary protein with muscle quality and quantity. Articles presenting results from clinical trials testing protein interventions on muscle mass and function are welcome. The Special Issue aims at including articles spanning different disciplines to explore the topic of interest. Reports from basic to clinical and population research are suitable. Articles adopting a longitudinal approach or reporting data from life-long interventions/observations in the exploration of the theme will be given special consideration. Potential topics include, but are not limited to: • Description of patterns of dietary protein consumption across life • Influence of dietary protein intake on the functional status of older people • Preclinical and clinical studies describing the mechanisms through which protein intake modifies muscle mass and function • Protein/amino acid supplementation interventions against sarcopenia, cachexia, or disease conditions associated with muscle wasting in old age • Disease-specific alterations modifying the effects of dietary protein intake on skeletal muscles • Effects of the interactions of dietary protein intake and gut microbiota on skeletal muscles
Geriatric syndromes: How to treat
The survival of HIV-infected persons has been increasing over the last years, thanks to the implementation of more effective pharmacological and non-pharmacological interventions. Nevertheless, HIV-infected persons are often \u201cbiologically\u201d older than their \u201cchronological\u201d age due to multiple clinical, social, and behavioral conditions of risk. The detection in this population of specific biological features and syndromic conditions typical of advanced age has made the HIV infection an interesting research model of accelerated and accentuated aging. Given such commonalities, it is possible that \u201cbiologically aged\u201d HIV-positive persons might benefit from models of adapted and integrated care developed over the years by geriatricians for the management of their frail and complex patients. In this article, possible strategies to face the increasingly prevalent geriatric syndromes in HIV-infected persons are discussed. In particular, it is explained the importance of shifting from the traditional disease-oriented approach into models of care facilitating a multidisciplinary management of frailty
Postural adjustments to self-triggered perturbations under conditions of changes in body orientation
We studied anticipatory and compensatory postural adjustments (APAs and CPAs) associated with self-triggered postural perturbations in conditions with changes in the initial body orientation. In particular, we were testing hypotheses on adjustments in the reciprocal and coactivation commands, role of proximal vs. distal muscles, and correlations between changes in indices of APAs and CPAs. Healthy young participants stood on a board with full support or reduced support area and held a standard load in the extended arms. They released the load in a self-paced manned with a standard small-amplitude arm movement. Electromyograms of 12 muscles were recorded and used to compute reciprocal and coactivation indices between three muscle pairs on both sides of the body. The subject's body was oriented toward one of three targets: straight ahead, 60° to the left, and 60° to the right. Body orientation has stronger effects on proximal muscle pairs compared to distal muscles. It led to more consistent changes in the reciprocal command compared to the coactivation command. Indices of APAs and CPAs showed positive correlations across conditions. We conclude that the earlier suggested hierarchical relations between the reciprocal and coactivation command could be task-specific. Predominance of negative or positive correlations between APA and CPA indices could also be task-specific
An exploration on whole-body and foot-based vibrotactile sensitivity to melodic consonance
Consonance is a distinctive attribute of musical sounds, for which a psychophysical explanation has been found leading to the critical band perceptual model. Recently this model has been hypothesized to play a role also during tactile perception. In this paper the sensitivity to vibrotactile consonance was subjectively tested in musicians and non-musicians. Before the test, both such groups listened to twelve melodic intervals played with a bass guitar. After being acoustically isolated, participants were exposed to the same intervals in the form of either a whole-body or foot-based vibrotactile stimulus. On each trial they had to identify whether an interval was ascending, descending or unison. Musicians were additionally asked to label every interval using standard musical nomenclature. The intervals identification as well as their labeling was above chance, but became progressively more uncertain for decreasing consonance and when the stimuli were presented underfoot. Musicians\u2019 labeling of the stimuli was incorrect when dissonant vibrotactile intervals were presented underfoot. Compared to existing literature on auditory, tactile and multisensory perception, our results reinforce the idea that vibrotactile musical consonance plays a perceptual role in both musicians and non-musicians. Might this role be the result of a process occurring at central and/or peripheral level, involving or not activation of the auditory cortex, concurrent reception from selective somatosensory channels, correlation with residual auditory information reaching the basilar membrane through bone conduction, is a question our preliminary exploration leaves open to further research work
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