Arm lean mass determined by dual-energy X-ray absorptiometry is superior to characterize skeletal muscle and predict sarcopenia-related mortality in cirrhosis

Abstract

Sarcopenia worsens survival in patients with advanced liver disease including cirrhosis. In this study, we aimed to characterize skeletal muscle status by dual-energy X-ray absorptiometry (DXA) in patients with cirrhosis and examine the association between different skeletal muscle compartments and mortality. We included 231 men and 84 women (Child A, B, and C) with cirrhosis and 315 healthy matched controls (231 men and 84 women). Body composition was assessed with DXA. Appendicular skeletal muscle index (ASMI), arms index (AI), and legs index (LI) were calculated by normalizing lean mass to height squared. Low ASMI was defined as ASMI < 7.0 kg/m² in men and <5.5 kg/m² in women. Biochemical and hemodynamic data were recorded for cirrhotic patients and mortality data retrieved from registers. Low ASMI was more prevalent in both men (49%) and women (43%) with cirrhosis compared with healthy men (8%) and women (5%) (P < 0.001). ASMI and LI were lowest in Child B, whereas AI decreased gradually with advancing Child class. ASMI was inversely associated with mortality in men [HR = 0.74 (0.59-0.93), P < 0.01], and this was mainly driven by AI [HR = 0.37 (0.18-0.71), P < 0.01]. AI showed closer association than ASMI or LI to both the severity of liver disease and to mortality, which may be due to increasing prevalence of leg edema with disease progression in this population. Determination of arm lean mass may add information on survival in patients with cirrhosis.NEW & NOTEWORTHY Sarcopenia increases mortality in patients with end-stage liver disease. We show that arm lean mass determined by dual-energy X-ray absorptiometry is a better marker than the traditional appendicular skeletal muscle mass when predicting sarcopenia-related mortality in patients with cirrhosis of different severity. The findings add to the dispute about the optimal method for repeated assessments of skeletal muscle status in patients with cirrhosis and may have implications for clinical decision making.

Keywords: arm lean mass; cirrhosis; dual-energy X-ray absorptiometry; mortality; sarcopenia.