Frailty

Frailty is a multidimensional and dynamic condition characterized by declines in reserve and function across multiple physiological systems, such that the ability to cope with everyday or acute stressors becomes compromised. ^[1] The course of frailty is characterised by a decline in functioning across multiple physiological systems accompanied by increased vulnerability to stressors, placing a person at increased risk of adverse outcomes. ^[2] The decline in skeletal muscle mass and function, also known as sarcopenia, is key in the development of physical frailty. ^[3]

The biological mechanisms of frailty and sarcopenia are multifactorial and complex, ranging from DNA damage, proteostasis impairment and epigenetic changes to mitochondrial dysfunction and cellular senescence. ^[3] Inflammageing, a condition of elevated blood inflammatory markers common in older individuals, is a risk factor for frailty, and mechanistic hypotheses propose that inflammation contributes to frailty by inhibiting growth factors and increasing catabolism. ^[4] Frailty is a dynamic and reversible geriatric syndrome, and reasonable preventive interventions can restore the elderly to an independent life. ^[5]

Despite efforts over three decades, agreement on a standard instrument to identify frailty has not yet been achieved. ^[2] Frailty has commonly been operationalised through a physical phenotype and through broader multidimensional approaches, with several tools such as the Fried frailty phenotype and the Rockwood Clinical Frailty Scale used to classify patients. ^{[6] [7]} In community-dwelling older persons the overall weighted prevalence of frailty was 10.7%, being 9.9% for physical frailty and 13.6% for the broad phenotype, and was higher in women (9.6%) than in men (5.2%). ^[6] Frailty is a significant risk factor for falls in older adults, with a combined relative risk of 1.48 (95% CI 1.27-1.73) compared with those without frailty. ^[8] Grip strength is a key component of the frailty phenotype, and weaker grip strength in later life is associated with disability, morbidity, and mortality ^[9]. Gait speed is an important measure of functional ability that has been widely used in older adults as an indicator of frailty

Having frailty places a person at increased risk of adverse outcomes including falls, hospitalisation and mortality, with a clear pattern of increased health-care costs and use. ^[2] First-line therapy for the management of frailty should include a multi-component physical activity programme with a resistance-based training component, while pharmacological treatment as presently available is not recommended. ^[11] Protein or caloric supplementation is recommended when weight loss or undernutrition are present, and a comprehensive care plan should also address polypharmacy and treatable causes of weight loss and exhaustion. ^[11] Progressive resistance training is indispensable for maintaining or improving functional capacity in older adults, particularly those with frailty, sarcopenia or osteoporosis ^[12].