Serial monitoring of nutritional status in Chinese peritoneal dialysis patients by Subjective Global Assessment and comprehensive Malnutrition Inflammation Score

Abstract

The Malnutrition Inflammation Score (MIS) has been proposed for the assessment of nutritional status in peritoneal dialysis (PD) patients. The MIS and the Subjective Global Assessment (SGA) for serial monitoring of nutritional status in PD patients were compared. The change in the MIS and SGA overall score of 59 PD patients (28 male) over 12 months was studied. Clinical factors relating to the discrepancy between the two instruments were explored. The average patient age was 55.8+/-9.7 years. Thirty of the 59 patients (50.8%) had exact agreement in the changed MIS and SGA scores. Cohen's kappa score was 0.274, indicating a modest degree of agreement. For the detection of deterioration in nutritional status and using the MIS as the reference measure, the SGA had a sensitivity of 61.9% and specificity of 86.8%; serum ferritin level was substantially higher in the ones whose SGA did not detect a deterioration in nutrition (1464.1+/-873.3 vs 800.5+/-561.6 pmol/L, P=0.046). For the detection of improvement in nutritional status, the SGA had a sensitivity of 45.8% and specificity of 82.9%; patients whose SGA did not detect an improvement in nutrition were dialyzed longer (53.8+/-35.3 vs 27.6+/-18.9 months, P=0.038), had higher total iron binding capacity (TIBC) (45.6+/-5.5 vs 38.2+/-8.1 micromol/L, P=0.015), had higher total Kt/V (2.02+/-0.36 vs 1.75+/-0.23, P=0.048) and higher normalized protein nitrogen appearance (1.16+/-0.25 vs 0.95+/-0.23 g/kg per day, P=0.048). The longitudinal changes in the MIS and SGA score have modest agreement with each other. However, PD patients with a longer duration of dialysis, higher serum ferritin, TIBC, total Kt/V or normalized protein nitrogen appearance tend to have discrepancies between the longitudinal changes in the MIS and SGA overall score.