Frailty as a Clinically Relevant Measure of Human Aging

Abstract

potential stressors with decreased physiological reserve owing to aging, has long been considered a geriatric syndrome. Research interest in frailty has increased following observations of vast inter-individual heterogeneities in accumulating deficits or functional impairments among functional or biological parameters with the progression of chronological aging. In the last three decades, researchers have attempted to capture frailty in various ways, from operational definitions to counting percentages of deficits arising owing to human aging. Although their methods of determining or quantifying frailty differ, studies have shown correlations between frailty spectrums defined by phenotype definition or deficit accumulation. The clinical relevance of frailty as an aging phenotype has been validated with respect to multiple aspects. By incorporating age-related parameters that are also interconnected to form complex systems of human physiology, the burden of frailty in individuals reflects a systemic disturbance in response to various stressors. Population-based longitudinal studies have assessed the ability of the frailty index in predicting mortality, an unequivocal outcome indicator of human aging. Similarly, studies on patients with medical or surgical conditions have reported the superiority of the frailty spectrum in predicting adverse health outcomes compared with conventional measures. As a dynamic aging marker that responds to structured interventions, frailty is gradually becoming a cornerstone of geriatric medicine to deliver patient-centered management. With recent advances in clinical and biological knowledge on frailty, the Annals of Geriatric Medicine and Research planned a special issue covering this geriatric syndrome from multifaceted aspects of biology, clinical medicine, and public health. In this issue, Ji et al. discussed frailty starting from molecular biology and demonstrated the validity of the frailty index as a measure of human aging compared to omics-based epigenetic clocks and biomarkers. Kwak discussed delirium, a geriatric giant and an imCommentary pISSN 2508-4798 eISSN 2508-4909 Ann Geriatr Med Res 2021;25(3):139-140 https://doi.org/10.4235/agmr.21.0106