Preface

摘要

The demographic shift of the average age of the population worldwide mandates that careful attention be paid to the nutritional and health needs of all segments of our older adult population. Well-defined changes in body composition occur with advancing age. Characteristic of this change is the expanding pool of subcutaneous and visceral adipose tissue and the age-associated decline in skeletal muscle mass and function, sarcopenia. Sarcopenia has been linked to declines in physical function, loss of independence and mortality. In addition, dysregula-tion of host defense mechanisms and cellular senescence, all accumulate with advancing age. The functional declines associated with these changes are mediating factors that contribute to the syndrome of frailty with advancing age. Frailty has been defined as a geriatric syndrome that is characterized by a reduction in physiologic reserve required for an individual to respond to endogenous and exogenous stressors. Using a discrete definition of frailty that includes: sedentariness, involuntary weight loss, fatigue, poor muscle strength and slow gait speed, 'frailty' has been associated with increased disability, postsurgical complications and increased mortality. Despite the strong associations between frailty and subsequent poor outcomes, limited attention to this common geriatric condition has been paid in clinical settings. While multiple syndromes overlap with and are likely contributors to frailty, several lines of evidence suggest that 'frailty' is a distinct phenotype that has important clinical significance in the care and treatment of older adults.