New Anthropometric and Biochemical Models for Estimating Appendicular Skeletal Muscle Mass in Male Patients with Cirrhosis

ABSTRACT Background The use of easily accessible methods to estimate skeletal muscle mass (SM) in patients with cirrhosis is often limited by the presence of edema and ascites, precluding a reliable diagnosis of sarcopenia. Objective To design predictive models using variables derived from anthropometric and/or biochemical measures to estimate SM; and to validate their applicability in diagnosing sarcopenia in patients with cirrhosis. Design Anthropometric and biochmeical data were obtained from 124 adult (aged 18–76 years) male patients with cirrhosis who also underwent dual-energy X-ray absorptiometry (DXA) and handgrip strength (HGS) assessments to identify low SM and diagnose sarcopenia using reference cutoff values. Univariate analyses for variable selection were applied to generate predictive decision tree models for low SM. Model accuracy for the prediction of low SM and sarcopenia (when associated with HGS) was tested by comparison with reference cutoff values (appendicular SM index, obtained by DXA) and clinical sarcopenia diagnoses. The prognostic value of the models for the prediction of sarcopenia and mortality at 104 weeks of follow up was further tested using Kaplan–Meier graphics and Cox models. Results The models with anthropometric variables, alone and combined with biochemical variables, showed good accuracy (0.89 [0.83; 0.94] and 0.90 [0.84;0.95], respectively) and sensitivity (0.72 [0.56; 0.85] and 0.74 [0.59; 0.86], respectively) and excellent specificity (0.96 [0.90; 0.99] and 0.97 [0.92; 0.99], respectively) in predicting SM . Both models showed excellent accuracy (0.94 [0.89; 0.98], good sensitivity (0.68 [0.45; 0.86]) and excellent specificity (1.00 [0.96; 1.00]) in prediction sarcopenia. The models predicted mortality in patients with sarcopenia, with death liklihood six-fold greater relative to patients not predicted to have sarcopenia. Conclusions Our simple and inexpensive models provide a practical and safe approach to diagnosing sarcopenia patients with cirrhosis along with an estimate of their mortality risk when other reference methods are unavailable.