Subtypes of physical frailty: Latent class analysis and associations with clinical characteristics and outcomes

Li-Kuo Liu, Chao-Yu Guo, Wei-Ju Lee, Liang-Yu Chen, An-Chun Hwang, Ming-Hsien Lin, Li-Ning Peng, Liang-Kung Chen, Kung-Yee Liang
2017 Scientific Reports  
Frailty is a well-recognized geriatric syndrome with various definitions and conceptual frameworks. This study aimed to use latent class analysis to discover potential subtypes of pre-frail and frail older people. Data from the I-Lan Longitudinal Aging Study (ILAS), a community-based cohort study was used for analysis. Latent class analysis was applied to characterize classes or subgroups with different frailty phenotypes among ILAS participants targeting older adults aged 65 and above, capable
more » ... of completing a 6-meter walk, without severe major or life threatening diseases, and not institutionalized. Latent class analysis identified three distinct subgroups with different frailty phenotypes: non-mobilitytype (weight loss and exhaustion), mobility-type frailty (slowness and weakness), and low physical activity. Comparing these groups with the robust group, people with mobility-type frailty had poorer body composition, worse bone health, poorer cognitive function, lower survival (hazard ratio: 6.82, p = 0.019), and poorer overall health outcomes (hazard ratio: 1.67, p = 0.040). People in the nonmobility-type group had poorer bone health and more metabolic serum abnormalities. In conclusion, mobility-type frailty was a better predictor of adverse outcomes. However, further investigation is needed to evaluate how these phenotypic subgroups may help in predicting prognosis or in developing interventions. Frailty, a well-recognized geriatric syndrome that is characterized by loss of function and physiologic reserve, highlights the vulnerability older adults 1,2 . Several studies have shown that frailty may effectively predict adverse health outcomes and mortality 3,4 . A theoretical dynamic model that integrates biomedical and psychosocial perspectives has been proposed to evaluate frailty progression 5 . Though all frail elderly may share a final common pathway of functional decline due to dysregulated homeostasis of multiple organ systems 6 , the clinical presentations of frailty may differ greatly. Previous studies have proposed various operational definitions and conceptual frameworks of frailty; however, despite different definitions in different study populations, the prevalence of frailty did not vary greatly 2,7 . Moreover, it is likely that no single operational definition of frailty will satisfy all experts, and previous studies failed to reach a consensus regarding the definition of frailty of clinical uses 8 . Due to the complex physiopathological process, multifaceted etiology, and diverse clinical phenotype of frailty, current studies categorize frailty into different functional domains, such as physical frailty, cognitive frailty, and social frailty 9,10 . Although there are no universal criteria for assessing frailty, proper assessment of physical frailty and timely intervention may reduce subsequent disability, hospitalizations and mortality 11,12 . Instead of keeping creating new frailty criteria, we tried to focus on a more clearly defined and well-accepted term: "physical frailty". Physical frailty has recently garnered extensive research interest, based on five phenotypic criteria proposed by Fried, et al. from the Cardiovascular Health Study (CHS) 13 : weakness; slowness; low level of physical activity; weight loss;
doi:10.1038/srep46417 pmid:28397814 pmcid:PMC5387710 fatcat:ntgq5vr4vjfarlp4o45mcd3uhy