The Longitudinal Associations of Sarcopenia Definitions with Functional Deterioration: a Comparative Study

Probable sarcopenia is a predictor of functional limitation in older adults. However, whether standard thresholds recommended by guides, or population-specific thresholds better predict impairment in functionality is an issue that needs to be enlightened. We aimed to study the associations of probable sarcopenia identified by the use of EWGSOP2 and population-specific thresholds with deterioration in functionality at follow-up and give prevalences of probable sarcopenia with different thresholds in older outpatients admitted to a tertiary health center. In this retrospective, longitudinal follow-up study, we assessed handgrip strength (HGS) at the admission with a Jamar hand-dynamometer and diagnosed probable sarcopenia with standard and population-specific thresholds, i.e., 27 kg/16 kg, and 35 kg/20 kg in males/females, respectively. We evaluated activities of daily living (ADL) and instrumental ADL (IADL), with Katz and Lawton scales, at the admission and follow-up. To study whether probable sarcopenia was a predictor of impaired functionality, we defined two models for Cox regression analysis. We performed adjustments for age, sex, and nutritional status (assessed by Mini-Nutritional Assessment-Short Form) in Model 1 and defined Model 2 by adding low gait speed and frailty to the variables in Model 1. Among a total of 1970 patients, 195 had follow-up of median 560 days. The mean age was 75.5 ± 5.5, and 142 (72.8