104,893 research outputs found
Anorexia of Aging: Metabolic Changes and Biomarker Discovery
No full textAnna Picca,1 Riccardo Calvani,1 Hélio José Coelho-Júnior,2 Francesco Landi,1,2 Emanuele Marzetti1,2 1Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, Rome, Italy; 2Department of Geriatrics and Orthopedics, Università Cattolica Del Sacro Cuore, Rome, ItalyCorrespondence: Riccardo Calvani, Fondazione Policlinico Universitario “Agostino Gemelli” IRCCS, Largo A. Gemelli 8, Rome, 00168, Italy, Tel +39-06-3015-5559, Fax +39-06-3051911, Email [email protected]: The age-associated decrease in appetite and food intake is referred to as “anorexia of aging”. Older adults with anorexia show changes in the quantity/quality of energy supplied to the organism which eventually may cause a mismatch between ingested calories and physiological energy demands. Therefore, a state of malnutrition and impaired metabolism may ensue which renders older people more vulnerable to stressors and more prone to incur negative health outcomes. These latter cover a wide range of conditions including sarcopenia, low engagement in physical activity, and more severe consequences such as disability, loss of independence, hospitalization, nursing home placement, and mortality. Malnutrition has been recognized by the European Society of Clinical Nutrition (ESPEN) among the chief risk factors for the development of frailty. Frailty refers to a state of increased vulnerability to stressors stemming from reduced physiologic reserve, and according to ESPEN, is also nutrition-based. Alike frailty, anorexia is highly prevalent among older adults, and its multifactorial nature includes metabolic changes that develop in older age and possibly underly the condition. Circulating factors, including hormones (eg, cholecystokinin, ghrelin, leptin, and inflammatory and microbial mediators of gut dysbiosis), have been proposed as biomarkers for this condition to support early identification and develop personalized nutritional interventions. Additional studies are needed to untangle the interrelationship between gut microbiota and appetite regulation in older adults operating through brain–gut crosstalk. Furthermore, the contribution of the genetic background to appetite regulation and specific nutritional needs warrants investigation. Here, we provide an overview on anorexia of aging in the context of age-related metabolic changes. A special focus is placed on candidate biomarkers that may be used to assist in the early identification of anorexia of aging and in the development of personalized nutritional counseling.Keywords: frailty, geroscience, inflammation, muscle, nutrition, sarcopeni
Prescription of resistance training for sarcopenic older adults: Does it require specific attention?
No full textSarcopenia is an age-related neuromuscular disease characterized by substantial muscle atrophy, dynapenia and/or loss of physical function. Sarcopenia progression increases the risk for numerous negative events, including falls, disability, hospitalization, nursing home placement, and death. As such, this condition is recognized as an important topic in gerontology and geriatrics. The best approach to counteract the development and progression of sarcopenia is actively debated. Resistance training (RT) has received special attention in this context, owing to the large number of studies showing its ability to produce significant improvements in sarcopenia-related parameters. Recommendations to guide RT prescription for older adults with different conditions, including people who have traits of sarcopenia, have been published. Some authors have argued that RT guidelines for older adults are similar to one another, which may indicate that the presence of sarcopenia does not require specific physical exercise programs. However, older people with sarcopenia might present with peculiar physical, biomechanical, physiological, and psychosocial characteristics that, in our view, are not taken into adequate consideration in existing exercise guidelines. Here, we present evidence to support the view that RT prescription for older adults with sarcopenia is complex, multifactorial, and still needs more evidence
Acute Effects of Low-and High-Speed Resistance Exercise on Cognitive Function in Frail Older Nursing-Home Residents: A Randomized Crossover Study
No full textAim. The present study investigated the acute effects of low-and high-speed resistance exercise on the cognitive function of frail older women living in nursing home. Materials and Methods. Ten institutionalized frail older women were recruited. Rey Auditory Verbal Learning Test and Stroop test were performed before, immediately after, 1 h after, and 24 h after the end of the experimental session. Participants randomly performed low-and high-speed resistance exercise and a control session. Exercise sessions were composed of 4 resistance exercises with 4-8 sets of 4-10 repetitions at moderate intensity. Results. Results indicated that the performance of Rey Auditory Verbal Learning Test was similarly increased immediately after both low-and high-speed resistance exercises. However, only improvements elicited by low-speed resistance exercise remained significant 1 h after the end of the exercise session. No acute effects of resistance exercise were observed on Stroop performance. Conclusion. Our findings indicated that both low-and high-speed resistance exercises acutely increased episodic memory in frail older women, whereas no changes on Stroop were observed
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
If my muscle could talk: Myokines as a biomarker of frailty
No full textFrailty is a potentially reversible state of increased vulnerability to negative health-related outcomes that occurs as a result of multisystem biological impairment and environmental aspects. Given the relevance of this condition in both clinics and research, biomarkers of frailty have been actively sought after. Although several candidate biomarkers of frailty have been identified, none of them has yet been incorporated in the assessment or monitoring of the condition. Over the last years, increasing research interest has been focused on myokines, a set of cytokines, small proteins and proteoglycan peptides that are synthetized, expressed and released by skeletal myocytes in response to muscular contractions. Myokines may act in autocrine, paracrine, and endocrine manner and regulate several processes associated with physical frailty, including muscle wasting, dynapenia, and slowness. This review discusses the rationale to support the use of myokines as biomarkers of frailty in older adults
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Mammalian Target of Rapamycin (mTOR) Signaling at the Crossroad of Muscle Fiber Fate in Sarcopenia
No full textThe mammalian target of rapamycin (mTOR) is a major regulator of skeletal myocyte viability. The signaling pathways triggered by mTOR vary according to the type of endogenous and exogenous factors (e.g., redox balance, nutrient availability, physical activity) as well as organismal age. Here, we provide an overview of mTOR signaling in skeletal muscle, with a special focus on the role played by mTOR in the development of sarcopenia. Intervention strategies targeting mTOR in sarcopenia (e.g., supplementation of plant extracts, hormones, inorganic ions, calorie restriction, and exercise) have also been discussed
Biomarkers shared by frailty and sarcopenia in older adults: A systematic review and meta-analysis
No full textBackground: Physical frailty and sarcopenia show extensive clinical similarities. Whether biomarkers exist that are shared by the two conditions is presently unclear. Methods: We conducted a systematic review and meta-analysis of cross-sectional and longitudinal studies that investigated the association of frailty and/or sarcopenia with biomarkers as a primary or secondary outcome in adults aged 60 years and older. Only studies published in English that defined frailty using a validated scale and/or questionnaire and diagnosed sarcopenia according to the presence of muscle atrophy plus dynapenia or low physical function were included. Studies were identified from a systematic search of MEDLINE and SCOPUS databases from inception through August 2020. The quality of reporting of each study was assessed by using the Quality Assessment Tool for Observational Cohort, Cross-Sectional and Case-Control studies of the National Institute of Health. A meta-analysis was conducted when at least three studies investigated the same biomarker in both frailty and sarcopenia. Pooled effect size was calculated based on standard mean differences and random-effect models. Sensitivity analysis was performed based on age and the setting where the study was conducted. Results: Eighty studies (58 on frailty and 22 on sarcopenia) met the inclusion criteria and were included in the qualitative analysis. Studies on frailty included 33,160 community-dwellers, hospitalized, or institutionalized older adults (60–88 years) from 21 countries. Studies on sarcopenia involved 4904 community-living and institutionalized older adults (68–87.6 years) from 9 countries. Several metabolic, inflammatory, and hematologic markers were found to be shared between the two conditions. Albumin and hemoglobin were negatively associated with both frailty and sarcopenia. Interleukin 6 was associated with frailty and sarcopenia only in people aged < 75. Community-dwelling older adults with frailty and sarcopenia had higher levels of tumor necrosis factor alpha compared with their robust and non-sarcopenic counterparts. Conclusions: A set of metabolic, hematologic, and inflammatory biomarkers was found to be shared by frailty and sarcopenia. These findings fill a knowledge gap in the quest of biomarkers for these conditions and provide a rationale for biomarker selection in studies on frailty and sarcopenia
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