ReviewThe Frailty Syndrome: Clinical measurements and basic underpinnings in humans and animals
Section snippets
Introduction—overview of the clinical implications of the Frailty Syndrome (FS)
We live in an aging society, and the most rapidly growing segment of our population are people over the age of ninety (Anon, 2011). This relatively recent explosion of large numbers of very old people living in our communities has brought to light a new and critically important health problem—the Frailty Syndrome (FS in the text). Frailty manifests as a limited capacity to maintain homeostasis and is characterized by a clinical state of age-related biological vulnerability to stressors and
Basic cellular and molecular biology of frailty/FS, or the “unknown unknowns”
There is very little solid evidence to explain how FS occurs at the level of molecules, cells and tissues and to decisively establish that it is a molecularly distinct syndrome. The expanding number of reported biomarkers associated with FS include, but are not limited to, soluble mediators of the inflammatory response including elevated cytokines and chemokines reduced IGF-I, DHEAS and leptin, hormones, fibrin turnover and fibrinolysis, free radicals, antioxidants, macro- and micro-nutrients (
Approaches to measuring frailty
There are many approaches to the measurement of frailty developed that do not include direct measures of complex processes of dysregulation. A consensus report on frailty research design by a group of Italian and American geriatricians advocated inclusion of impairments in physiological domains that include mobility, balance, muscle strength, motor processing, cognition, nutrition, and physical activity (Ferrucci et al., 2004b). A recent systematic review also suggests that frailty could be
Conclusions and recommendations: towards the “known knowns”
FS is affecting nearly a third of older adults over 90, and is of an increasing socioeconomic importance. It is very clear from the above discussion that we have preciously few animal or tissue culture models to distinguish between the current mechanistic hypotheses of frailty and that we are not particularly good at measuring it precisely and objectively in humans. To further our basic understanding of frailty/FS and to improve diagnostics and management of this condition, we propose the
Conflict of interest
The authors have no conflicts of interests.
Funding source
This review has been generously funded by the Arizona Center on Aging and in part from the NIH ADB Contract HHSN 272201100017C (NIH/NIAID N01-AI 00017) and the Bowman Endowed Professorship in Medical Research (both to J.N-Z).
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2019, Mechanisms of Ageing and DevelopmentCitation Excerpt :The concept of frailty has been developed to describe the conditions of aged people with increased vulnerability to adverse health outcomes and is considered to be associated with a major loss of capacity to maintain tissue homeostasis and regeneration. It is characterized by a state of age-related biological vulnerability to stressors and decreased physiological reserves with alterations in energy metabolism, decreased skeletal muscle mass and quality, and altered hormonal and inflammatory functions (for review see (Mohler et al., 2014)). A consensus paper defined frailty as “a medical syndrome with multiple causes and contributors that is characterized by diminished strength and endurance, and reduced physiologic function that increase an individual’s vulnerability for developing increased dependency and/or death” (Morley et al., 2013).
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These authors contributed equally to this review.