Objectives: In this study, we aimed to examine the possible association between liver fibrosis and loss of skeletal muscle mass (SM) in community-dwelling older adults with no history of liver diseases.
Methods: A total of 2,028 older adults (mean age, 69.8 ± 5.2 years) who had not received any treatment for liver diseases and had participated in a comprehensive health survey for community residents in Wakayama, Japan were included in this study. We carried out bioelectrical impedance analysis to estimate the SM of the whole body including the arms, legs, and trunk of the subjects. Liver fibrosis was evaluated by calculating the Fib4 index based on the subject's age, AST level, ALT level, and platelet counts.
Results: The subjects were divided into three groups according to cutoff values of the Fib4 index (low: <1.30, medium: 1.30-2.66, high: ≥2.67). The SM index (kg/m2) was the lowest among subjects in the high-Fib4-index category, followed by the medium- and low-Fib4-index categories. This dose-response reduction in the SM index was more pronounced among individuals with lower blood albumin level (low nutrition) and in those with more sedentary behavior (physical inactivity). Among the selected 262 subjects who underwent SM measurement twice with an interval of 3 years, the subjects with a high Fib4 index showed greater reduction in the SM index than those with medium and low Fib4 indices. Multiple regression analysis revealed that the Fib4 index was significantly associated with the SM index, independent of age, sex, albumin level, sedentary behavior, diabetes mellitus, alcohol intake, and smoking status.
Conclusions: The present findings suggest that the potential progression of liver fibrosis is associated with the excessive loss of SM among apparently healthy older adults without any treatment for liver diseases.
Keywords: liver fibrosis; Fib4 index; general population; older adults; skeletal muscle mass.