Subjective global assessment of nutritional status is strongly associated with mortality in chronic dialysis patients

The subjective global assessment of nutritional status (SGA) is used to assess the nutritional status of chronic dialysis patients, but longitudinal data in relation to mortality risk are lacking.

Our objective was to study the long-term and time-dependent associations of the SGA with mortality risk in chronic dialysis patients.

In a prospective, longitudinal, observational, multicenter study of incident dialysis patients, the 7-point SGA [7 = normal nutritional status; 1 = severe protein-energy wasting (PEW)] was assessed 3 and 6 mo after the start of dialysis and subsequently every 6 mo during 7 y of follow-up. With Cox regression analysis, we calculated hazard ratios (HRs) of the baseline and time-dependent SGA measurements, adjusted for age, sex, treatment modality, primary kidney diseases, and comorbidity.

In total, 1601 patients were included [mean (+/-SD) age: 59 +/- 15 y; 61% men; 23% with moderate PEW (SGA(4-5)), and 5% with severe PEW (SGA(1-3))]. There was a dose-dependent trend of the 7-point SGA with mortality. Compared with a normal nutritional status at baseline, SGA(4-5) (HR: 1.6; 95% CI: 1.3, 1.9) and SGA(1-3) (HR: 2.1; 95% CI: 1.5, 2.8) were associated with an increase in 7-y mortality. Time-dependently, these associations were stronger: SGA(4-5) (HR: 2.1; 95% CI: 1.7, 2.5) and SGA(1-3) (HR: 5.0; 95% CI: 3.8, 6.5).

In dialysis patients, PEW at baseline assessed with SGA was associated with a 2-fold increased mortality risk in 7 y of follow-up. Time-dependently, this association was even stronger, which indicated that PEW was associated with a remarkably high risk of short-term mortality. These data imply that the 7-point SGA may validly distinguish different degrees of PEW associated with increasing risks of mortality.