Iron deficiency in blood donors: the REDS-II Donor Iron Status Evaluation (RISE) study

Abstract

Background: Blood donors are at risk of iron deficiency. We evaluated the effects of blood donation intensity on iron and hemoglobin (Hb) in a prospective study.

Study design and methods: Four cohorts of frequent and first-time or reactivated (FT/RA) blood donors (no donation in 2 years), female and male, totaling 2425, were characterized and followed as they donated blood frequently. At enrollment and the final visit, ferritin, soluble transferrin receptor (sTfR), and Hb were determined. Models to predict iron deficiency and Hb deferral were developed. Iron depletion was defined at two levels: iron deficiency erythropoiesis (IDE) [log(sTfR/ferritin) ≥ 2.07] and absent iron stores (AIS; ferritin < 12 ng/mL).

Results: Among returning female FT and RA donors, 20 and 51% had AIS and IDE at their final visit, respectively; corresponding proportions for males were 8 and 20%. Among female frequent donors who returned, 27 and 62% had AIS and IDE, respectively, while corresponding proportions for males were 18 and 47%. Predictors of IDE and/or AIS included a higher frequency of blood donation in the past 2 years, a shorter interdonation interval, and being female and young; conversely, taking iron supplements reduced the risk of iron depletion. Predictors of Hb deferral included female sex, black race, and a shorter interdonation interval.

Conclusions: There is a high prevalence of iron depletion in frequent blood donors. Increasing the interdonation interval would reduce the prevalence of iron depletion and Hb deferral. Alternatively, replacement with iron supplements may allow frequent donation without the adverse outcome of iron depletion.

Conflict of interest statement

The remaining authors declare that they have no conflicts of interest relevant to the manuscript.

© 2011 American Association of Blood Banks.

Figures

Figure 1. Adjusted odds ratios and 95% confidence intervals for hemoglobin deferral overall and for females alone by weeks since last red cell donation

ORs are based on reference group of donation intervals ≥ 26 weeks. Squares correspond to mean ORs for all return donations; Bars represent 95% CI. Diamonds represent mean ORs for female donations (no 95% CI presented). There were insufficient male deferrals to analyze by week.

Figure 2. Adjusted odds ratios and 95% confidence intervals for absent iron stores (AIS) overall and for females alone by weeks since last red cell donation

ORs are based on reference group of donation intervals ≥ 26 weeks. Squares correspond to mean ORs for all donations; Bars represent 95% CI. Diamonds represent mean ORs for female donations (no 95% CI presented). There were insufficient male observations with AIS to analyze by week.

Figure 3

Panels A–C: The proportion of donors with indicated laboratory results at enrollment and final visits, by gender and donation category. Donors are accepted for donation based on fingerstick hemoglobin measurements which are not always concordant with venous hemoglobin. There were 1,334 enrolled RISE donors for whom data at enrollment and at the final visit were available. Panel A: Proportion of donors with absent iron stores (AIS, defined by ferritin < 12ng/mL). Panel B: Proportion of donors with iron deficient erythropoiesis (IDE, defined as log[sTfR/ferritin] ≥2.07). Panel C: Proportion of donors with venous hemoglobin < 12.5 g/dL.

Figure 3

Panels A–C: The proportion of donors with indicated laboratory results at enrollment and final visits, by gender and donation category. Donors are accepted for donation based on fingerstick hemoglobin measurements which are not always concordant with venous hemoglobin. There were 1,334 enrolled RISE donors for whom data at enrollment and at the final visit were available. Panel A: Proportion of donors with absent iron stores (AIS, defined by ferritin < 12ng/mL). Panel B: Proportion of donors with iron deficient erythropoiesis (IDE, defined as log[sTfR/ferritin] ≥2.07). Panel C: Proportion of donors with venous hemoglobin < 12.5 g/dL.

Figure 3

Panels A–C: The proportion of donors with indicated laboratory results at enrollment and final visits, by gender and donation category. Donors are accepted for donation based on fingerstick hemoglobin measurements which are not always concordant with venous hemoglobin. There were 1,334 enrolled RISE donors for whom data at enrollment and at the final visit were available. Panel A: Proportion of donors with absent iron stores (AIS, defined by ferritin < 12ng/mL). Panel B: Proportion of donors with iron deficient erythropoiesis (IDE, defined as log[sTfR/ferritin] ≥2.07). Panel C: Proportion of donors with venous hemoglobin < 12.5 g/dL.