Clinical global assessment of nutritional status as predictor of mortality in chronic kidney disease patients

BACKGROUND: The value of subjective global assessment (SGA) as nutritional assessor of protein-energy wasting (PEW(SGA)) in chronic kidney disease (CKD) patients depends on its mortality predictive capacity. We investigated associations of PEW(SGA) with markers of nutritional status and all-cause mortality in CKD patients. METHODS: In 1031 (732 CKD1-5 non-dialysis and 299 dialysis) patients, SGA and body (BMI), lean (LBMI) and fat (FBMI) body mass indices, % handgrip strength (% HGS), serum albumin, and high sensitivity C-reactive protein (hsCRP) were examined at baseline. The five-year all-cause mortality predictive strength of baseline PEW(SGA) and during follow-up were investigated. RESULTS: PEW(SGA) was present in 2% of CKD1-2, 16% of CKD3-4, 31% of CKD5 non-dialysis and 44% of dialysis patients. Patients with PEW(SGA) (n = 320; 31%) had higher hsCRP and lower BMI, LBMI, FBMI, %HGS and serum albumin. But, using receiver operating characteristics-derived cutoffs, these markers could not classify (by kappa statistic) or explain variations of (by multinomial logistic regression analysis) presence of PEW(SGA). In generalized linear models, SGA independently predicted mortality after adjustments of multiple confounders (RR: 1.17; 95% CI: 1.11–1.23). Among 323 CKD5 patients who were re-assessed after median 12.6 months, 222 (69%) remained well-nourished, 37 (11%) developed PEW(SGA) de novo, 40 (12%) improved while 24 (8%) remained with PEW(SGA). The latter independently predicted mortality (RR: 1.29; 95% CI: 1.13–1.46). CONCLUSIONS: SGA, a valid assessor of nutritional status, is an independent predictor of all-cause mortality both in CKD non-dialysis and dialysis patients that outperforms non-composite nutritional markers as prognosticator.