Lee Jung Hie, Parker Kathy P, Ansari Fari P, Bliwise Donald L
Department of Psychiatry, Kangwon National University College of Medicine, Chunchon, Kangwon-do, South Korea.
Sleep Med. 2006 Dec;7(8):646-8. doi: 10.1016/j.sleep.2006.01.007. Epub 2006 Jun 5.
Hemodialysis (HD) is associated with restless legs syndrome (RLS) and periodic leg movements in sleep (PLMS), but the mechanisms underlying these relationships remain unclear. African-American HD patients have been reported previously to have a reduced likelihood of RLS. Alterations in iron metabolism, known to be a risk factor for idiopathic forms of RLS, could represent the basis for these racial differences.
In secondary data analyses from a previously published study, we examined raw and log-transformed values for plasma ferritin and polysomnographically recorded PLMS in Caucasian and African-American HD patients.
African-American (n=36) HD patients had higher ferritin and lower PLMS than Caucasians (n=10). However, within the African-American population, ferritin levels were unrelated to PLMS.
These results are compatible with previously reported racial differences in RLS to the extent that PLMS were less common in the African-American population. However, they suggest that if a differential genetic vulnerability underlies those racial differences, it may not manifest as a deficiency in iron metabolism, at least within the constraints of the marker of iron stores used here (e.g. serum ferritin) and in the specific population studied (hemodialysis). Future studies with larger, more representative samples of African-Americans and Caucasians will be required to replicate such differences.
