Recovery Time After Hemodialysis Is Associated with Hemoglobin Concentration

Background: Prolong recovery time is associated with impaired quality of life, hospitalization, and mortality in hemodialysis patients. Anemia, an important complication of ESKD, also contributes to fatigue, poorer quality of life, and increased morbidity and mortality. The relationship of recovery time with anemia management in hemodialysis patients is not known. Methods: We enrolled 81 ESKD patients (n=81, 55% female) on hemodialysis for ≥6 months. Recovery time was assessed using a validated single-item question, “How many hours do you typically need to recover from a dialysis session?” Results: Mean hemoglobin (Hb) was 11.2 ± 1.5 g/dl, hematocrit (HCT) 35.1 ± 4.3%, ferritin 626.1 ± 341.4 ng/mL, and transferrin saturation (TSAT) 36.6 ± 15.0%. The median recovery time was 3.0 hrs (IQR 2.0 – 6.0). Values for recovery time were log transformed to reduce data skewness and to conform to normality. In Pearson correlation analysis, recovery time was positively associated with Hb (r = 0.31, P = 0.005), hematocrit (r = 0.30, P = 0.007), and TSAT (r = 0.28, P = 0.025). In linear regression analysis recovery time was significantly associated with Hb (b 0.20 [95% CI: 0.06-0.33], P=0.005) and TSAT (b 0.02 [95% CI: 0.00-0.04], P=0.03). Using recommended cut points for the treatment of anemia (<10.0, 10.0-11.5, 11.5-13.0, and >13.0 g/dl) as per current guidelines, Hb levels of >13.0 g/dl was associated with higher recovery time than those with lower values (P <0.01 for all 4 comparisons). Age- and sex-adjusted multinomial logistic regression analysis of independent variable recovery time (hours) categorized as per the Dialysis Outcomes and Practice Patterns Study (<2, 2-6, 7-12, >12 hrs) show that 1 g/dl increase in Hb was associated with 2.6 times increase in the relative odds of being in >12 hrs category vs. reference category of <2 hrs. Conclusion: Hemodialysis patients with Hb >13 g/dL had significantly longer recovery time, suggesting that higher Hb levels—possibly from ESA or iron therapy—may prolong recovery time. These findings highlight the need to balance between anemia correction and functional outcomes. Clinical trials are warranted to define safe Hb targets that minimize symptoms and recovery time while reducing cardiovascular risk. Mechanisms underlying prolonged recovery time at higher Hb levels should be further explored.