Sleep disorders and endothelial dysfunction in children with sickle cell anemia

Objective: We sought to assess sleep characteristics in children with sickle cell anemia (SCA) to investigate the possible association between sleep-related disorders and parameters of endothelial function. Methods: Sleep Disturbance Scale for Children (SDSC) and endothelial function variables (flow-mediated dilatation using brachial artery ultrasound, cytokines) were compared in children with SCA and healthy children aged 6e18 years. Results: Flow-mediated dilation (FMD) median (IQR) values were 10.1 (6.4; 14) vs 16.9 (12; 26.4), in the SCA and comparison groups (p = 0.001), respectively. Associations were found between difficulty initiating and maintaining sleep as well as IL-12p70 (rs = 0.3, p = 0.03) and IL-1b (rs = 0.4, p = 0.01); disorders of excessive sleepiness and TNF-a (rs = 0.3, p = 0.02), IL-6 (rs = 0.3, p = 0.03), e IL-17A (rs = 0.3, p = 0.04), and disorders of arousal with IL-6 (rs = 0.3, p = 0.04). Regarding SDSC subscales, the score for sleep breathing disorders was higher in the SCA group than in the comparison group [6.7 (3.4) vs. 5.2 (2.7), p = 0.04]. Sleep breathing disorders, disorders of excessive sleepiness and sleep hyperhidrosis scores were also higher among those SCA patients who were using hydroxyurea than those with SCA who were not using hydroxyurea [7.4 (3.9) vs. 5.9 (2.9); p = 0.026; 7.5 (3.5) vs. 6.9 (3); p = 0.028; 4.3 (3.1) vs. 3.9 (2.6); p = 0.044, respectively]. Conclusion: The SCA group presented higher sleep-disordered breathing scores and lower FMD values. Patients with SCA using hydroxyurea exhibited a higher frequency of scores on SDSC subscales. A positive correlation was found between SDSC subscales and cytokines. (c) 2018 Elsevier B.V. All rights reserved.