Neurological disorders are a large and heterogeneous field of research that can be tackled through a variety of approaches, ranging from epidemiology to molecular biology, through clinical, ...biostatistical, and laboratory experiments ....
Sarcopenia encompasses the loss of muscle mass and strength/function during aging. Several methods are available for the estimation of muscle or lean body mass. Popular assessment tools include body ...imaging techniques (e.g., magnetic resonance imaging, computed tomography, dual X-ray absorptiometry, ultrasonography), bioelectric impedance analysis, anthropometric parameters (e.g., calf circumference, mid-arm muscle circumference), and biochemical markers (total or partial body potassium, serum and urinary creatinine, deuterated creatine dilution method). The heterogeneity of the populations to be evaluated as well as the setting in which sarcopenia is investigated impacts the definition of “gold standard” assessment techniques. The aim of this article is to critically review available methods for muscle mass estimation, highlighting strengths and weaknesses of each of them as well as their proposed field of application.
Frailty is a clinical state characterized by a decrease of an individual's homeostatic reserves and is responsible for enhanced vulnerability to endogenous and/or exogenous stressors. Such a ...condition of extreme vulnerability exposes individuals to an increased risk of negative health-related outcomes. Multiple operational definitions of frailty are available in the literature, but none can be indicated as a gold standard. Frailty should be considered a condition of major interest for public health and become the lever for reshaping the obsolete health care systems currently unable to adequately address the clinical needs of aging populations.
Abstract
Background
Multimorbidity and frailty are complex syndromes characteristics of aging. We reviewed the literature and provided pooled estimations of any evidence regarding (a) the coexistence ...of frailty and multimorbidity and (b) their association.
Methods
We searched PubMed and Web of Science for relevant articles up to September 2017. Pooled estimates were obtained through random effect models and Mantel–Haenszel weighting. Homogeneity (I2), risk of bias, and publication bias were assessed. PROSPERO registration: 57890.
Results
A total of 48 studies involving 78,122 participants were selected, and 25 studies were included in one or more meta-analyses. Forty-five studies were cross-sectional and 3 longitudinal, with the majority of them including community-dwelling participants (n = 35). Forty-three studies presented a moderate risk of bias and five a low risk. Most of the articles defined multimorbidity as having two or more diseases and frailty according to the Cardiovascular Health Study criteria. In meta-analyses, the prevalence of multimorbidity in frail individual was 72% (95% confidence interval = 63%–81%; I2 = 91.3%), and the prevalence of frailty among multimorbid individuals was 16% (95% confidence interval = 12%–21%; I2 = 96.5%). Multimorbidity was associated with frailty in pooled analyses (odds ratio = 2.27; 95% confidence interval = 1.97–2.62; I2 = 47.7%). The three longitudinal studies suggest a bidirectional association between multimorbidity and frailty.
Conclusions
Frailty and multimorbidity are two related conditions in older adults. Most frail individuals are also multimorbid, but fewer multimorbid ones also present frailty. Our findings are not conclusive regarding the causal association between the two conditions. Further longitudinal and well-designed studies may help to untangle the relationship between frailty and multimorbidity.
Aging is a complex and multifactorial process resulting, at least partly, from the generation and accrual of damage in the setting of reduced resilience ....
The identification of cost-effective interventions that improve the health status and prevent disability in old age is one of the most important public health challenges. Regular physical activity is ...the only intervention that has consistently been shown to improve functional health and energy balance and to reduce the risk of cardiovascular disease, stroke, diabetes, several cancers, depression and falls. In advanced age, physical activity is also effective at mitigating sarcopenia, restoring robustness, and preventing/delaying the development of disability. On the other hand, physical inactivity is recognized as one of the leading causes of several chronic degenerative diseases and is also a major contributing factor to sarcopenia and functional disability. This compelling evidence has prompted the World Health Organization to recommend engaging in regular physical activity throughout one’s life course. The present review summarizes the available evidence in support of physical activity as a remedy against physical frailty and sarcopenia. The relevant pathways through which the benefits of physical activity are conveyed are also discussed.
Skeletal muscle aging is associated with a significant loss of skeletal muscle strength and power (i.e., dynapenia), muscle mass and quality of life, a phenomenon known as sarcopenia. This condition ...affects nearly one-third of the older population and is one of the main factors leading to negative health outcomes in geriatric patients. Notwithstanding the exact mechanisms responsible for sarcopenia are not fully understood, mitochondria have emerged as one of the central regulators of sarcopenia. In fact, there is a wide consensus on the assumption that the loss of mitochondrial integrity in myocytes is the main factor leading to muscle degeneration. Mitochondria are also key players in senescence. It has been largely proven that the modulation of mitochondrial functions can induce the death of senescent cells and that removal of senescent cells improves musculoskeletal health, quality, and function. In this review, the crosstalk among mitochondria, cellular senescence, and sarcopenia will be discussed with the aim to elucidate the role that the musculoskeletal cellular senescence may play in the onset of sarcopenia through the mediation of mitochondria.
Sarcopenia, the age-dependent loss of muscle mass and function, is a common condition among older adults, and is associated with several adverse health outcomes. Owing to the impact of sarcopenia on ...quality of life, disability and mortality, a greater awareness is necessary in order to correctly identify the condition both in community and geriatric settings. Research on sarcopenia prevention and treatment is developing quickly, but many questions are still unanswered. The core of the sarcopenia condition involves quantitative and qualitative losses of skeletal muscle. These two dimensions should therefore be considered when designing and testing preventive and therapeutic interventions. The recently released operationalization of sarcopenia by the Foundation for the National Institutes of Health (FNIH) Sarcopenia Project allows for the framing of an objective, standardized, and clinically relevant condition, which should facilitate its translation into the clinical arena as well as its adoption by public health and regulatory agencies. Such a conceptualization might eventually encourage key stakeholders to combine their efforts in approaching the sarcopenia condition. Bearing these considerations in mind, the “Sarcopenia and Physical fRailty IN older people: multi-componenT Treatment strategies” project has operationalized a specific condition, named physical frailty and sarcopenia (PF&S), characterized by the combination of low physical performance (based on the Short Physical Performance Battery) and low muscle mass (according to the FNIH cut-points). A randomized controlled trial will be conducted to evaluate the efficacy of a multi-component intervention for preventing mobility disability and other adverse health outcomes in older adults with PF&S.
Sarcopenia, the age-related loss of muscle mass and function, imposes a dramatic burden on individuals and society. The development of preventive and therapeutic strategies against sarcopenia is ...therefore perceived as an urgent need by health professionals and has instigated intensive research on the pathophysiology of this syndrome. The pathogenesis of sarcopenia is multifaceted and encompasses lifestyle habits, systemic factors (e.g., chronic inflammation and hormonal alterations), local environment perturbations (e.g., vascular dysfunction), and intramuscular specific processes. In this scenario, derangements in skeletal myocyte mitochondrial function are recognized as major factors contributing to the age-dependent muscle degeneration. In this review, we summarize prominent findings and controversial issues on the contribution of specific mitochondrial processes – including oxidative stress, quality control mechanisms and apoptotic signaling – on the development of sarcopenia. Extramuscular alterations accompanying the aging process with a potential impact on myocyte mitochondrial function are also discussed. We conclude with presenting methodological and safety considerations for the design of clinical trials targeting mitochondrial dysfunction to treat sarcopenia. Special emphasis is placed on the importance of monitoring the effects of an intervention on muscle mitochondrial function and identifying the optimal target population for the trial.
This article is part of a Directed Issue entitled: Molecular basis of muscle wasting.
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