UC Irvine

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.