Ascertainment of Iron Depletion and Deficiency in Blood Donors Through Screening Questions for Pica and Restless Legs Syndrome.

Abstract

2283 Background: Pica and restless legs syndrome (RLS) are associated with iron depletion and deficiency. Pica refers to the compulsive craving for and persistent consumption of non-nutritive substances. Pagophagia, the pathological consumption of ice, is a specific pica strongly associated with iron deficiency. RLS is a neurological movement disorder characterized by uncomfortable sensations in the lower extremities, with a compelling urge to move the extremities to relieve the discomfort. Primary RLS is a central nervous system disorder; however, secondary RLS may be caused or exacerbated by iron deficiency. The purpose of this study was to prospectively assess the prevalence of pica and RLS in blood donors presenting to a hospital-based donor center, to correlate the findings with donor hemoglobin and iron levels, and to study the effects of oral iron replacement on the resolution of symptoms. Methods: During a 39-month period, 1236 blood donors deferred for fingerstick hemoglobin <12.5 g/dL and 400 non-deferred “control” donors underwent health screening and laboratory testing (CBC, ferritin, iron, transferrin). Iron deficiency was defined as a ferritin level below the institutional reference range of 9 mcg/L in females and 18 mcg/L in males. Iron depletion was defined as a ferritin of 9 – 19 mcg/L in females and 18 – 29 mcg/L in males. Pica and RLS were assessed by direct questioning. Deferred donors and iron-deficient control donors were given ferrous sulfate 325 mg daily for 60 days. Reassessments were performed and additional iron tablets dispensed at subsequent visits. Results: Pica was reported in 11% of donors with iron depletion/deficiency, compared with 4% of iron-replete donors (p<0.0001). The prevalence of pica rose to 21% in females with ferritin <9 mcg/L. Pagophagia (ice pica) was most common and was often of extraordinary intensity, with characteristics of an addiction. Donors with pagophagia given iron reported a marked reduction in the desire to eat ice by day 5–8 of therapy, with disappearance of symptoms by day 10–14. RLS was reported in 16% of subjects with iron depletion/deficiency compared with 11% of iron-replete donors (p=0.012). Iron replacement generally resulted in improvement of RLS symptoms, however, at least 4–6 weeks of iron therapy was necessary. The positive predictive values of pica and RLS in iron deficient/depleted blood donors were 73% and 58%, respectively. Conclusion: The presence of pica is highly predictive of iron depletion/deficiency in blood donors; however, RLS lacks a strong correlation in this population. Screening questions for pica, in particular pagophagia, may be useful in the ascertainment of iron depletion and deficiency in blood donors and may identify those who would benefit from oral iron therapy. Disclosures: No relevant conflicts of interest to declare.

Restless legs syndrome, pica, and iron status in blood donors

“…This apparent sex difference may be real (albeit unexplained) or may derive from the presence of relatively sparse outcomes in a multivariable logistic model or potentially represent a differential in accuracy of information elicited from male and female RISE donors. In any case, this mixed result, while unexplained, is consistent with the only other report of which we are aware that has measured iron status and assessed pica in blood donors, which also found an association between pica and iron status in females but not in male donors . Neither our study nor the earlier one on pica in blood donors reports a higher cooccurrence of pica and RLS than would be expected by chance.…”

“…As detailed elsewhere and shown in Table , these results occurred in donor cohorts with a high prevalence of iron depletion (near or surpassing 50% prevalence of IDE in three of the four cohorts) and recent donation intensity that is considerably higher than the “average” donor. Although several‐fold higher than reported figures for weekly (5%) or “medically significant” (2.7%) RLS symptoms in a recent report drawn from the general population, RLS prevalence between 9 and 20% is consistent with other studies in blood donor populations . In RISE, as in these earlier studies, RLS prevalence nearly twice that of the general population in a cohort enriched for iron deficiency (e.g., blood donors) does not require that such an association holds at the individual level or that it is necessarily causative.…”

“…Blood donors represent a population suitable for further delineating the potentially causative associations of iron deficiency to both RLS and pica and to examine for the first time the potential interrelationship between these two clinical conditions. Previous studies, although reporting prevalence of RLS and pica that were much higher among blood donors, failed to find or examine for a relationship to donation intensity. We therefore examined self‐reported RLS‐like symptoms and pica behaviors among repeat (RPT) blood donors at the conclusion of the Retrovirus Epidemiology Donor Study‐II (REDS‐II) Iron Status Evaluation Study (RISE) and probed for associations between iron status and RLS and pica.…”

The strategies to reduce iron deficiency in blood donors randomized trial: design, enrolment and early retention

“…This eligibility criterion prevents donation by those with significant anaemia, but does not prevent donation by those with iron deficiency in the absence of anaemia. The recognition and prevention of iron deficiency in donors are important, because even in the absence of significant anaemia, it is associated with fatigue, decreased exercise capacity, pica, and restless legs syndrome . In addition, studies performed in young women have shown that iron deficiency is associated with decreased cognitive performance over a broad range of cognitive tasks, and longitudinal studies of teenagers have shown that iron status during adolescence is associated with micro‐ and macro‐neuroanatomical variations in early adulthood .…”

Iron deficiency in blood donors: a national cross‐sectional study

“…ID has also been associated with adverse pregnancy outcomes including low birthweight, preterm delivery, and anemia and risk of transfusion at delivery . Finally, some, although not all, studies have reported associations between blood donation–induced ID and restless leg syndrome.…”