Sarcopenia is an independent predictor of mortality in patients with liver cirrhosis. However, evidence has emerged that skeletal muscles mediate their protective effect against sarcopenia by secreting myokines. Therefore, we investigated whether irisin was associated with sarcopenia in patients with liver cirrhosis. This was an observational cross-sectional study of data collected from 187 cirrhotic patients. Sarcopenia was defined by computed tomography (CT) scans using specific cutoffs of the 3rd lumbar vertebra skeletal muscle index (L3 SMI). Morning irisin levels were obtained in all patients. Of the 187 patients, sarcopenia was noted in 73 (39%). Irisin concentrations were lower in sarcopenic patients (32.40 pg/ml [interquartile range (IQR): 18.70, 121.26], p < 0.001) than in nonsarcopenic patients. There was a weak correlation between L3 SMI and irisin levels (r = 0.516, p < 0.001). Multivariable regression analysis including L3 SMI, body mass index (BMI), very-low-density lipoprotein (VLDL)-cholesterol, aspartate aminotransferase (AST), adiponectin, and irisin levels showed that L3 SMI (odds ratio [OR] = 0.915, p = 0.023), adiponectin levels (OR = 1.074, p = 0.014), irisin levels (OR = 0.993, p < 0.001) and BMI (OR = 0.456, p = 0.004) were independently associated with sarcopenia. Irisin levels are associated with sarcopenia in patients with liver cirrhosis. This paper addresses a gap in the literature and facilitates the future transition into clinical treatment.

Granulomatosis with polyangiitis (GPA) is a small-vessel vasculitis that is highly associated with anti-neutrophil cytoplasmic antibodies. GPA carries an increased risk of organ infarction, but renal infarction is rare. We herein describe a case of multiple renal infarctions caused by GPA. A 66-year-old man presented with hearing loss, nasal discharge, fatigue, and weight loss for several months. Cross-sectional contrast-enhanced computed tomography images revealed multiple low-attenuation areas in both kidneys. He subsequently developed fever and impaired renal function. Blood serum was positive for cytoplasmic anti-neutrophil cytoplasmic antibody and a renal biopsy showed granulomatous necrotizing vasculitis. He was diagnosed with GPA and treated with high-dose corticosteroids, plasma exchange, and cyclophosphamide. The patient ultimately entered clinical remission.