Sarc-frailty: towards an integrated view of ageing

Sarcopenia and frailty have both been related to adverse events in ageing, but have long been studied in parallel. The purpose of this study was to provide a better depiction of ageing by taking the advantages of both entities.

2532 participants were enrolled from the National Health and Nutrition Examination Survey 1999-2002. A new diagnostic entity, sarc-frailty, was established by merging the diagnostic elements of both sarcopenia and frailty.

Cox proportional hazard models, Kaplan-Meier curve, and receiver operating characteristic (ROC) curve analysis were utilized to compare the hazard ratios and predictive power in relation to mortality of sarcopenia, frailty, and sarc-frailty. Two different classification strategies, categorical and scoring, were used as alternative assessment methods.

The median follow-up duration was 67.49 months, and no participants were lost to follow-up. ROC analysis revealed the highest area under curves (AUC) in sarc-frailty by both categorical and scoring classification (AUC = 0.660, p value <0.001 and AUC = 0.697, p value <0.001, respectively), indicating the best predictive ability in relation to mortality. Kaplan-Meier analysis also demonstrated the shortest overall survival for sarc-frailty with both classifications (p value both <0.001). In addition, hazard ratios (HRs) of sarc-frailty with both classifications were higher than their counterparts for sarcopenia and frailty (HR = 12.599, 95 % CI = 7.780 to 20.403, p < 0.001 by categorical method, and HR = 20.121, 95 % CI = 8.101 to 49.973, p < 0.001 by scoring classification). Moreover, the scoring classification revealed a more delicate hierarchical structure of mortality levels than the categorical classification.

Sarc-frailty had a better predictive ability in relation to mortality. Considering that ageing well is a holistic health-care issue, our new entity, along with the scoring method, provides clinicians with more effective tools in geriatric assessment.