Loss of skeletal muscle mass affects the incidence of minimal hepatic encephalopathy: a case control study

Background Sarcopenia is a syndrome characterized by progressive and systemic decreases in skeletal muscle mass and muscle strength. The influence or prognosis of various liver diseases in this condition have been widely investigated, but little is known about whether sarcopenia and/or muscle mass loss are related to minimal hepatic encephalopathy (MHE). Methods To clarify the relationship between MHE and sarcopenia and/or muscle mass loss in patients with liver cirrhosis. Methods Ninety-nine patients with liver cirrhosis were enrolled. MHE was diagnosed by a neuropsychiatric test. Skeletal mass index (SMI) and Psoas muscle index (PMI) were calculated by dividing skeletal muscle area and psoas muscle area at the third lumbar vertebra by the square of height in meters, respectively, to evaluate muscle volume. Results This study enrolled 99 patients (61 males, 38 females). MHE was detected in 48 cases (48.5%) and sarcopenia in 6 cases (6.1%). Patients were divided into two groups, with or without MHE. Comparing groups, no significant differences were seen in serum ammonia concentration or rate of sarcopenia. SMI was smaller in patients with MHE (46.4 cm(2)/m(2)) than in those without (51.2 cm(2)/m(2), P = 0.027). Similarly, PMI was smaller in patients with MHE (4.24 cm(2)/m(2)) than in those without (5.53 cm(2)/m(2), P = 0.003). Skeletal muscle volume, which is represented by SMI or PMI was a predictive factor related to MHE (SMI >= 50 cm(2)/m(2); odds ratio 0.300, P = 0.002, PMI >= 4.3 cm(2)/m(2); odds ratio 0.192, P = 0.001). Conclusions Muscle mass loss was related to minimal hepatic encephalopathy, although sarcopenia was not. Measurement of muscle mass loss might be useful to predict MHE.