Plasma levels of the pro-inflammatory protein S100A12 (EN-RAGE) are associated with muscle and fat mass in hemodialysis patients: a cross-sectional study

BACKGROUND Malnutrition is highly prevalent and contributes to mortality in hemodialysis (HD) patients. Although the receptor for advanced glycation end products (RAGE) system also contributes to the morbidity and mortality of these patients, the role that the RAGE system plays in determining nutritional status is currently unknown. METHODS A cross-sectional study examining 79 HD patients was performed. The plasma concentrations of the soluble RAGE (sRAGE) and S100A12 (also known as EN-RAGE) were studied to evaluate their association with nutritional status, which was assessed by measuring the mid-thigh muscle mass and subcutaneous fat mass with computed tomography. RESULTS Plasma S100A12 concentrations were shown to be significantly and negatively correlated with muscle mass and with fat mass (r = -0.237, P < 0.05 and r = -0.261, P < 0.05, respectively). In contrast, sRAGE was not shown to significantly correlate with either of these factors. Multiple regression analyses demonstrated that S100A12 is a significant independent predictor of both muscle mass and fat mass (P < 0.01 and P < 0.05, respectively). CONCLUSIONS Our findings suggest that plasma S100A12 levels could play an important role in determining muscle mass and fat mass in HD patients. TRIAL REGISTRATION Study number; UMIN000012341.