Donation‐induced iron depletion is significantly associated with low hemoglobin at subsequent donations

Abstract

Background: Blood donation is associated with a loss of hemoglobin (Hb)-bound iron. Hb levels recover relatively fast by using stored iron. However, it takes more time to replenish iron stores, potentially resulting in iron deficiency.Study design: Hb and ferritin levels were measured in 5056 new, first-time, and repeat whole blood donors. We investigated whether increasing numbers of donations are associated with lower ferritin levels. Furthermore, we tested whether low ferritin levels are associated with low-Hb deferral at the subsequent donation attempt by performing logistic regression adjusted for age and stratified by sex. Results: Whereas mean Hb levels are relatively stable, ferritin levels significantly decrease with increasing numbers of donations and were approximately 50% lower for donors with >50 donations compared with those with 2-10 donations. Despite the poor correlation of ferritin and Hb levels, cross-sectional, iron-deficient donors (ferritin <15 ng/ml) had 21.8 (8.5-55.6) higher odds in men, 10.1 (6.1-16.5) in premenopausal women, and 11.7 (5.2-26.4) in postmenopausal women for Hb deferral at a subsequent visit.Discussion: To conclude, repeated donations may induce iron deficiency, which corresponds with an over tenfold increased risk of having insufficiently restored Hb levels at a subsequent donation attempt. Longer donation intervals and/or higher dietary or supplemental iron intake are warranted to prevent accumulated iron depletion and subsequent low-Hb deferral in whole blood donors.

A computational model for prediction of ferritin and haemoglobin levels in blood donors

“…When ferritin levels are to be maintained above this threshold, donors should donate at lower donation frequencies than currently allowed in most countries, including the Netherlands. This result echoes findings that a donation interval of 56 days is insufficient time for the donor to replete the iron loss through donation, and that iron deficiency in high‐frequency donors is common 33–38 . Maintaining a threshold of 15 ng/ml for ferritin levels would imply mean donation frequencies of 1.9 per year for women and 4.1 per year for men.…”

Ferritin Trajectories over Repeated Whole Blood Donations: Results from the FIND+ Study

“…Based on previous studies showing a high prevalence of iron deficiency in repeat donors, and relatively long recovery of iron stores, this finding might not be very surprising [1,5,9,24]. While Hb levels may remain stable over consecutive donations, iron stores continue to be depleted, which remains unnoticed when ferritin levels are not measured [13,14]; however, previous findings were either based on single measurements rather than repeated measurements [13] or based on Hb levels rather than ferritin levels, which is a better indicator of iron status [25]. To our knowledge, the present study was the first study in which we followed donors with repeated ferritin measurements over time, thus enabling us to look into the shape of the ferritin trajectories over time, and whether or not these differ between individual donors.…”

“…A major strength of the study is that ferritin levels were measured retrospectively at every donation over two years; this allowed for detecting trajectories of iron stores among donors, presenting both inter-and intra-individual differences in ferritin levels over repeated donations, and this enabled showing that low ferritin not only predicts subsequent low Hb but also iron deficiency through repeated measurements [13]. Yet, our study suffered from a limited sample size, due to which we were not able to provide any information on whether the identified subpopulations differed in their risk to develop low pre-donation hemoglobin levels.…”

“…The prevalence of iron deficiency in repeat donors, even in those with normal Hb levels, is remarkably high [8][9][10][11][12]. In addition, once donors have become iron-deficient, their risk of subsequent Hb deferral is over tenfold increased [13]. Several investigations have assessed appropriate methods for lowering the rates of Hb deferrals, among which a recent study assessed changes in Hb levels through repeated donations to identify donors at risk for quick declines in Hb levels [14].…”

Iron status of blood donors

“…This suggests plasma ferritin of 25.4 ng/ml represents a physiological point below, which there is exhaustion of available iron stores signaled by rising sTfR and declining hemoglobin. Consistently, a study of 5056 Dutch donors found that those with plasma ferritin less than 15 ng/ml had 21.8 (male), 10.1 (premenopausal female), or 11.7 (postmenopausal woman) higher odds for low hemoglobin deferral at a subsequent donation attempt when compared with donors with plasma ferritin greater than 30 ng/ml [64 ▪ ]. REDS-III investigators examined recovery of erythropoietin, reticulocytes, total body iron, RBC iron, storage iron, and hepcidin using samples collected from 193 donor at baseline donation and during 24-week follow-up.…”