Iron status and restless legs syndrome in the elderly

The relationship between iron status and the restless legs syndrome (RLS) was examined in 18 elderly patients with RLS and in 18 matched control subjects. A rating scale with a maximum score of 10 was used to assess the severity of RLS symptoms. Serum ferritin levels were reduced in the RLS patients compared with control subjects (median 33 micrograms/l vs. 59 micrograms/l, p < 0.01, Wilcoxon signed rank test); serum iron, vitamin B12 and folate levels and haemoglobin levels did not differ between the two groups. Serum ferritin levels were inversely correlated with the severity of RLS symptoms (Spearman's rho -0.53, p < 0.05). Fifteen patients with RLS were treated with ferrous sulphate for 2 months. RLS severity score improved by a median value of 4 points in six patients with an initial ferritin < or = 18 micrograms/l, by 3 points in four patients with ferritin > 18 micrograms/l, < or = 45 micrograms/l and by 1 point in five patients with ferritin > 45 micrograms/l, < 100 micrograms/l. Iron deficiency, with or without anaemia, is an important contributor to the development of RLS in elderly patients, and iron supplements can produce a significant reduction in symptoms.