Restless legs syndrome in blood donors

Restless legs syndrome (RLS) may be a cause of significant sleep disturbance. In a Swedish survey, the prevalence of RLS has been estimated to be 5.8% among men and 11.4% among women. Blood donation may result in iron deficiency, which is hypothesized to be one substantial cause of RLS.

Nine hundred and forty-six (618 men, 328 women) consecutive blood donors aged 18-64 years, who attended a blood donation unit in mid-Sweden, answered a questionnaire that included questions about sleep habits. Frequency of blood donation was recorded and intake of iron tablets was assessed. Red blood cell distribution width (RDW) was also recorded. The value of RDW increases in relation to iron deficiency.

RLS affected 14.7% of male and 24.7% of female blood donors. The mean intake of iron among the blood donors after each blood donation was only 781 mg, although the recommended intake is 2000 mg. Among the women, 7.4% presented an RDW of >14.5%, which strongly indicates iron deficiency. In this group of women, 37.5% were affected by RLS. The female RLS-sufferers were more affected than the female non-RLS subjects by problems initiating sleep (P=0.006 maintaining sleep (P<0.0001) and were also less refreshed upon awakening (P<0.001).

This study showed that RLS was common among female blood donors. Women with RLS were more iron-deficient than those without and were affected by impaired sleep.