Standardized thigh muscle area measured by computed axial tomography as analternate muscle mass index for nutritional assessment of hemodialysis patients

Background: Quantification of muscle mass, which represents the largest pro tein pool in the body, is important for nutritional assessment but is diffi cult to achieve with conventional methods in hemodialysis patients. Objective:We measured the cross-sectional area of the thigh occupied by mus cle by using computed tomography and compared this with other muscle mass i ndicators. Design: Thigh muscle area (TMA) was examined and correlated with creatinine production and various nutritional indexes in 163 patients undergoing hemo dialysis. Where appropriate, TMA was expressed relative to bone area in the thigh (TBA) to avoid the influence of body size. Results: TMA was highly correlated with creatinine production as measured i n the spent dialysate (r = 0.85, P < 0.001), indicating that TMA substantia lly reflects total-body muscle mass. TMA standardized for TEA was negativel y correlated with age and positively correlated with other nutritional indi cators including body weight, body mass index, serum albumin, serum transth yretin, and protein catabolic rate. Multiple regression analysis revealed t hat of these variables, age, serum albumin, and protein catabolic rate inde pendently predicted TMA standardized for TEA. By using correlations with va rious nutritional indicators, we concluded that patients with a value < 10. 0 for TMA standardized for TBA were likely to be malnourished whereas those with a value > 13.0 were likely to be well nourished. Conclusions: These results indicate that TMA standardized for TEA, measured by computed tomography, is a reliable indicator of muscle mass that could be used for nutritional assessment of hemodialysis patients.