The relationship between extracellular water-to-body water ratio and sarcopenia according to the newly revised Asian Working Group for Sarcopenia: 2019 Consensus Update

Abstract

Objective: The purpose of this study was to evaluate the association between sarcopenia and extracellular water-to-total body water ratio (ECW/TBW), one of the results of bioimpedance that can be easily measured in communities, following the recent revision of the Asian Working Group for Sarcopenia.

Methods: This study data were extracted from the baseline data of Namgaram-2. Among the surveyed subjects, 885 persons aged 60 years or older were selected as study subjects. All surveys were conducted on a one-on-one interview basis; blood tests, physical function evaluations (hand grip strength, short physical performance battery; SPPB), and dual-energy X-ray absorptiometry (DEXA) and bioimpedance were also conducted. The Asian Working Group's revised definition of sarcopenia was applied. ECW/TBW was one of the results of bioimpedance this study.

Results: A high ECW/TBW was 1.63 times higher in the low grip strength group than in the robust group (P = 0.017) and was 2.13 times higher in the low SPPB group compared to the robust group (P < 0.001). ECW/TBW higher than 0.391 was 2.17 times more likely to occur in sarcopenic patients compared to the robust group (P < 0.001). In addition, ECW/TBW lower than 0.391 was 3.65 times more likely to occur in severely sarcopenic patients compared to the robust group (P = 0.002).

Conclusion: The ECW/TBW may be one of the valid research tools to evaluate the strength and physical performance of the elderly. In addition, it is expected to be one of the effective indicators for tracking physical function under newly revised sarcopenia criteria.

Keywords: Extracellular water; Muscle strength; Physical performance; Sarcopenia.