Computed Tomography-Assessed Sarcopenia Predicts Mortality in Kidney Transplant Candidates

Abstract

Objectives: Sarcopenia is common in chronic kidney disease and associated with increased mortality. We investigated the prevalence of sarcopenia, defined as low muscle mass by the psoas muscle index, in end-stage renal disease patients on waiting lists for kidney transplant and determined its association with prognostic nutritional index, C-reactive protein-to-albumin ratio, cardiovascular events, and mortality. Materials and Methods: Our study included 162 patients with end-stage renal disease and 87 age-matched healthy controls. We calculated nutritional status as follows: prognostic nutritional index = (10 × albumin [g/dL]) + (0.005 × total lymphocyte count (×103/μL]) and C-reactive protein-to-albumin ratio. We gathered demographic and laboratory data from medical records. Results: Patients with end-stage renal disease had a mean age of 44.7 ± 14.2 years; follow-up time was 3.37 years (range, 0.35-9.60 y). Although patients with end-stage renal disease versus controls had higher prevalence of sarcopenia (16.7% vs 3.4%; P =.002) and C-reactive protein-to-albumin ratio (1.47 [range, 0.12-37.10] vs 0.74 [range, 0.21-10.20]; P <.001), prognostic nutritional index was lower (40 [range, 20.4-52.2] vs 44 [range, 36.1-53.0]; P <.001). In patients with end-stage renal disease with and without sarcopenia, prognostic nutritional index (P =.005) was lower and C-reactive protein-to-albumin ratio (P =.041) was higher in those with versus those without sarcopenia. Among 67 patients on waiting lists who received kidney transplants, those without sarcopenia had better 5-year patient survival posttransplant than those with sarcopenia (P =.001). Multivariate regression analysis showed sarcopenia and low prognostic nutritional index were independent risk factors for mortality among patients with end-stage renal disease. Conclusions: Sarcopenia was ~5 times more frequent in patients with end-stage renal disease than in healthy controls and was positively correlated with the prognostic nutritional index. Sarcopenia was an independent risk factor for mortality in patients on transplant waiting lists.