Associations Among Serum Transferrin Levels, Markers of Malnutrition, and Mortality in Hemodialysis Patients.

Abstract

Introduction: A serum transferrin (transferrin) level below 200 mg/dL has been suggested as an indicator of malnutrition in hemodialysis (HD) patients. We investigated the relationships among transferrin levels, various markers of malnutrition, and 1-year mortality in this patient population.

Methods: We assessed transferrin, ferritin, and transferrin saturation (TSAT) five times over 1 year. We also measured baseline serum albumin, C-reactive protein (CRP), geriatric nutritional risk index (GNRI), Kt/Vurea, post-dialysis body composition (using bioimpedance analysis), and 1-year mortality.

Findings: Our study included 431 HD patients (mean age: 67 ± 11 years; median dialysis duration: 67 [35-138] months; diabetes prevalence: 45%). Patients with baseline transferrin ≥ 200 mg/dL had consistently and significantly higher transferrin concentrations throughout the study (p < 0.001). Compared to patients with baseline transferrin < 200 mg/dL (n = 285), those with baseline transferrin ≥ 200 mg/dL (n = 146) showed significantly higher serum albumin (3.7 [3.4-3.9] vs. 3.4 [3.1-3.7] g/dL), GNRI (95 [90-98] vs. 90 [85-95]), and lean tissue index (11.2 [9.5-13.3] vs. 10.3 [9.0-12.1] kg/m²). Conversely, they had significantly lower TSAT (22% ± 12% vs. 27% ± 14%), ferritin (74 ± 79 vs. 172 ± 148 ng/mL), and CRP (p < 0.01 for all). Baseline serum albumin, Kt/Vurea, and the presence of diabetes were significant determinants of having a baseline transferrin level ≥ 200 mg/dL (p < 0.05). Over the 1-year period, 45 all-cause deaths occurred among the 431 patients. Patients with baseline transferrin ≥ 200 mg/dL had a significantly higher cumulative 1-year survival rate (p < 0.05). Furthermore, baseline transferrin was a significant predictor of 1-year all-cause mortality in HD patients (hazard ratio: 0.99; p < 0.05).

Discussion: Our findings indicate that HD patients with baseline transferrin ≥ 200 mg/dL exhibit a better nutritional status than those with transferrin < 200 mg/dL. Moreover, baseline transferrin serves as a significant predictor for 1-year mortality in HD patients.