Skeletal muscle mass in patients with end-stage liver disease: Not only muscle size but especially muscle quality matters in relation to physical fitness

Abstract

Background: Physical fitness is an important modifiable factor related to quality of life. Sarcopenia and myosteatosis are associated with morbidity and mortality in patients with end-stage liver disease (ESLD). However, their relationship with physical fitness has not been established yet. Therefore, the main purpose of this study was to investigate the association between both low skeletal muscle index (SMI) and myosteatosis with physical fitness in patients with ESLD.

Methods: In this retrospective cross-sectional cohort study, a cohort of patients with ESLD who were evaluated for liver transplantation (LT) was included. Physical fitness was reflected by cardiorespiratory fitness (CRF) and skeletal muscle strength, as measured by the 6-min walking distance (6MWD) and handgrip strength (HGS), respectively. Both were included in routine LT evaluation. Skeletal Muscle Index (SMI) and Muscle Radiation Attenuation (MRA) were evaluated based on the routine abdominal computed tomography. Linear and logistic regression analyses were performed.

Results: Out of the 130 patients 94 (72%) were male, mean age was 56 ± 11 years. Myosteatosis was significantly associated with low 6MWD as percentage of predicted (β = -12.815 (CI -24.608 to -1.022, p-value 0.034)) as well as with low absolute 6MWD (<250 m) (OR 3.405 (CI 1.134-10.220, p-value 0.029)). No association was found between SMI and/or myosteatosis with HGS, or between SMI and 6MWD.

Conclusion: In contrast to SMI, myosteatosis is associated with low CRF. Neither low SMI nor myosteatosis was associated with skeletal muscle strength. Therefore physical exercise training might be especially beneficial for LT candidates with myosteatosis.

Keywords: 6-Min walking distance; End-stage liver disease; Liver transplantation; Myosteatosis; Sarcopenia.