Periodic limb movements during sleep (PLMS) are commonly described in children with Sickle Cell Disease (SCD), however the relevance of such events in sleep disturbance or complaint of daytime fatigue remain questionable. It has been known that the dopaminergic neurotransmission has a modulator role in pain perception. Since PLMS have been suggested to be a potential biological marker of dopaminergic mechanisms, this study aimed to assess PLMS in adults with SCD and its correlations with clinical and sleep parameters.
Seventy adults with SCD (50% females, matched for age and body mass index), underwent Brief Pain Inventory, overnight polysomnogram and laboratorial tests for hemoglobin, reticulocytes, ferritin, transferin saturation, haptoglobin, fetal hemoglobin, lactate dehydrogenase (LDH), and bilirrubins.
The mean PLMS index was higher in females (16.5±10.7/h vs. 8.7±8.2/h, p< 0.05), with 88.6% of the females having increased PLMS index (≥ 15/h) in comparison to males (22.6), p<0.01. Total arousal index and PLMS arousal index were increased in females with PLMS ≥ 15/h compared to those with PLMS < 5/h (p<0.05, both), but not in males. Females also exhibited correlation of increased PLMS index and clinical parameters such as pain score (rS =0.71), indirect bilirrubin (rS =0.42) and LDH (rS =0.38), p<0.01 in all. An interaction effect of the non-use of hydroxyurea treatment in PLMS abnormality was also observed (p<0.05).
Elevated PLMS were more common in females with SCD than in males and correlated with pain symptoms and hematological parameters of hemolysis. Hydroxyurea treatment showed a protective effect against the PLMS index increase.
Supported by AFIP, CEPID-FAPESP 98/14303-3, and CAPES/SUS.
No relevant conflicts of interest to declare.
Asterisk with author names denotes non-ASH members.