Multiple blood donations associated with iron deficiency in patients with restless legs syndrome.

OBJECTIVE: To describe a series of patients with restless legs syndrome (RLS) and iron deficiency with and without anemia related to repeated blood donations.

PATIENTS AND METHODS: Study patients were identified by asking consecutive patients with RLS seen at the Mayo Clinic in Rochester, Minn, from February 1 to December 31, 2001, whether they donated blood. All patients who fulfilled the International Restless Legs Syndrome Study Group criteria for RLS, had donated blood a minimum of 3 times a year the preceding 3 years, and had iron deficiency (serum ferritin concentration <20 microg/L) were included in the study.

RESULTS: Eight patients met the study criteria. The mean +/- SD serum ferritin concentration was 8.1 +/- 3.5 microg/L, and 4 patients had anemia. In 6 of the 8 patients, RLS began at about the same time of or after blood donation. Patients had donated blood for 4.2 +/- 13 times a year (range, 3-6 times a year) for 15.2 +/- 83 years (range, 5-25 years). Hemoglobin concentrations were 12.8 +/- 1.8 g/dL (range, 10.6-15.5 g/dL). In 2 patients, RLS essentially resolved with correction of iron stores alone, and medications for RLS were successfully discontinued in 2 other patients.

CONCLUSIONS: Repeated blood donation is associated with induction or perpetuation of RLS due to iron deficiency with or without coexisting anemia. Potential blood donors should be questioned about RLS, and donation should not be allowed until the serum ferritin concentration has been measured and iron stores replenished if necessary.