Evaluation of the Malnutrition-Inflammation Score in Kidney Transplant Recipients

Background: Chronic protein-energy wasting, termed malnutrition-inflammation complex syndrome, is frequent in patients with chronic kidney disease and is associated with anemia, morbidity, and mortality in patients on maintenance dialysis therapy. The Malnutrition-Inflammation Score (MIS) recently has been developed and validated in dialysis patients. Study Design: Observational cross-sectional study. Setting & Participants: 993 prevalent kidney transplant recipients. Predictor: MIS computed from change in body weight, dietary intake, gastrointestinal symptoms, functional capacity, comorbid conditions, decreased fat store/Systemic Global Assessment, signs of muscle wasting/Systemic Global Assessment, body mass index, serum albumin level, and serum transferrin level. Outcomes: Markers of inflammation and malnutrition, including serum C-reactive protein, interleukin 6, tumor necrosis factor alpha, serum leptin, prealbumin, body mass index, and abdominal circumference. The relationship was modeled by using structural equation models. Results: Mean age was 51 +/- 13 years, 57% were men, and 21% had diabetes. Median time from transplant was 72 months. MIS significantly correlated with abdominal circumference (r = -0.144), serum C-reactive protein level (r = 0.094), serum interleukin 6 level (r = 0.231), and serum tumor necrosis factor alpha level (r = 0.102; P < 0.01 for all). A structural equation model with 2 latent variables (malnutrition and inflammation factor) showed good fit to the observed data. Limitations: Single-center study, lack of information about vascular access, presence of nonfunctioning kidney transplant, relatively high refusal rate. Conclusions: Our results confirm that MIS reflects both energy-protein wasting and inflammation in kidney transplant recipients. This simple instrument appears to be a useful tool to assess the presence of protein-energy wasting in this patient population. Am J Kidney Dis 56:102-111. (C) 2010 by the National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.