Interventions can treat, prevent iron deficiency in blood donors

Results

Dr Mast noted that, at the study’s end, all measures of iron deficiency were statistically indistinguishable in the 3 intervention arms, which were statistically different from the 2 control arms.

Between study enrollment and the donors’ final visit, the prevalence of ferritin <26 mg/L was unchanged in the control groups. But it had declined by more than 50% in the 3 intervention groups—19 mg iron, 38 mg iron, and iron status letter (P<0.0001 for all 3).

The prevalence of ferritin <12 mg/L was unchanged in the 2 control arms, but it had declined by more than 70% in the 3 intervention arms—19 mg iron (P<0.0001), 38 mg iron (P<0.01), and iron status letter (P<0.0001).

The researchers also calculated the odds ratios for iron deficiency over all donor visits. The odds for ferritin <26 or <12 mg/L decreased more than 80% in the 19 mg iron group (P<0.01 for both ferritin measurements) and the 38 mg iron group (P<0.01 for both).

The odds for ferritin <26 or <12 mg/L decreased about 50% in the iron status letter arm (P<0.01 for both).

And the odds for ferritin <12 mg/L increased about 50% in the control groups (P<0.01 for both the placebo and control letter groups). However, there was no significant difference for ferritin <26 mg/L in either control group.

Lastly, the researchers performed longitudinal modeling of hemoglobin. They found that hemoglobin increased >0.03 g/dL in the 19 mg and 38 mg iron arms (P<0.01 for both), decreasing the odds for low hemoglobin deferral about 50%.

Hemoglobin decreased >0.3 g/dL in the control groups (P<0.0001 for both the placebo and control letter groups), increasing the odds for low hemoglobin deferral about 70%.

“Interestingly, [being] in the iron status letter group did not affect hemoglobin that much in the longitudinal modeling of the donors,” Dr Mast noted.

In closing, he pointed out that the 19 mg and 38 mg iron pills were equally effective for mitigating iron deficiency and improving hemoglobin in these blood donors.

“From a physiology point of view, I think this is one of the most important results of this study,” Dr Mast said. “There’s absolutely no difference. There was no trend for 38 mg to be better than 19 in any analysis that we did.”

“There’s lots of reasons that could be happening, but I think it’s scientifically interesting and operationally interesting. And it’s important because we can tell donors—ask them to take a multivitamin with 19 mg of iron, and that will be sufficient to treat iron deficiency.”