Is subjective global assessment a reliable measure of nutritional status in hemodialysis?

OBJECTIVE: Subjective global assessment (SGA) is recommended in US and European guidelines for the nutritional assessment of patients with end-stage renal failure (ESRF). SGA identifies patient groups with abnormal nutritional parameters, but may fail to identify patients with malnutrition as identified by other techniques, such as total body nitrogen. We sought to compare SGA with a composite nutritional score.
METHODS: HD patients were assessed by SGA, anthropometry, 3-day food diary, serum albumin, Kt/V urea, and normalized protein catabolic rate (nPCR). A composite nutritional score was derived from SGA, body mass index, percent of reference weight, triceps skinfold, midarm muscle circumference, and serum albumin.
RESULTS: In 72 HD patients an abnormal SGA identified a patient group with reduced midarm circumference, midarm muscle circumference and serum creatinine and an increased composite nutritional score. However, overlap of nutritional scores was considerable between the normal and abnormal SGA groups, suggesting that SGA misclassified a large number of subjects. Serum albumin correlated with C-reactive protein (r = -0.473, P <.0001), not nutritional status. The composite nutritional score correlated with all of its components except for serum albumin.
CONCLUSIONS: SGA may not reliably identify hemodialysis patients with abnormal nutrition. Serum albumin is related to inflammation and not to nutrition status.