Therefore, the hemoglobin concentration may simply be a surrogate marker for poor prognosis, which indicates ESA resistance caused by inflammation, impaired iron utilization, or fluid retention in patients with CKD or congestive heart failure, rather than a therapeutic target.
Hemodilution was first described in pregnant women and is believed to be an adaptive mechanism.
During pregnancy, the maternal plasma volume expands 45% on average to meet the greater needs of the placental We hypothesize that anemia in CKD is, at least in part, also an adaptive response to the underlying state of fluid retention, cardiac dysfunction, and arteriosclerosis.
Moderate anemia results in reduced blood viscosity and blood volume, which decreases left ventricular afterload and may improve microvascular perfusion in CKD patients.
From this viewpoint, it seems reasonable that the recently published Kidney Disease Improving Global Outcomes (KDIGO) guideline further reduced the hemoglobin threshold for the initiation of ESA therapy to