Periodic limb movement in sleep and sickle cell disease: a neglected association?

High frequency of periodic limb movements in sleep (PLMS) has been described among children with sickle cell disease (SCD), but there is little information about PLMS among adults with SCD. We aim to determine the frequency of PLMS among adults with SCD and to identify possible associations with iron status and haemolytic parameters. We analysed polysomnography on 99 adults: 74 with sickle cell anaemia (HbSS), 19 with HbSC (double heterozygosis HbS and HbC) and 6 with HbS-beta thalassaemia. Laboratory data were collected close to the time of the polysomnography examination. The prevalence of PLMS > 5/h was 70% and of PLMS > 15/h 36%, in the total group of patients. No differences were observed regarding gender, use of hydroxyurea and iron parameters. Logistic regression showed an association between PLMS > 15/h and hemolytic parameters: absolute reticulocyte count (p = 0.03) and unconjugated bilirubin (p = 0.01). Our data suggest that PLMS may be associated with manifestations of greater severity in SCD.