Association of Pre-End-Stage Renal Disease Hemoglobin with Early Dialysis Outcomes

Abstract

Background: Incident hemodialysis patients have a high mortality risk within the first months after dialysis initiation. Pre-end-stage renal disease (ESRD) factors like anemia management may impact early post-ESRD outcomes. Therefore, we evaluated the impact of pre-ESRD hemoglobin (Hgb) and pre-ESRD Hgb slope on post-ESRD mortality and hospitalization outcomes. Methods: The study included 31,472 veterans transitioning to ESRD. Using Cox and negative binomial regression models, we evaluated the association of pre-ESRD Hgb and Hgb slope with 12-month post-ESRD all-cause and cardiovascular mortality and hospitalization rates using 4 levels of hierarchical multivariable adjustment, including erythropoietin use and kidney decline in slope models. Results: The cohort was 2% female, 30% African-American, and on average 68 ± 11 years old. Compared to Hgb 10–< 11 g/dL, both low (< 10 g/dL) and high (≥12 g/dL) levels were associated with higher all-cause mortality after full adjustment (HR 1.25 [95% CI 1.15–1.35] and 1.09 [95% CI 1.02–1.18], respectively). Similarly, Hgb exhibited a U-shaped association with CV mortality, while only lower Hgb was associated with a higher hospitalization rate. Neither an annual pre-ESRD decline in Hgb nor increase was associated with higher post-ESRD mortality risk after adjustment for kidney decline. However, we observed a modest J-shaped association between pre-ESRD Hgb slope and post-ESRD hospitalization rate. Conclusions: Lower and higher pre-ESRD Hgb levels are associated with a higher risk of early post-ESRD mortality, while there was no association between the pre-ESRD slope and mortality. An increase in pre-ESRD Hgb slope was associated with higher risk of post-ESRD hospitalization. Additional studies aimed at anemia management prior to ESRD transition are warranted.