Impact of hydroxyurea on pediatric sleep in sickle cell disease Open Access

1. Hydroxyurea use in kids with sickle cell disease is linked to higher sleep oxygen levels but not fewer sleep disturbances like OSA.

2. Despite therapy, children with SCD still face poor sleep quality and oxygen drops—causes remain unclear.

Children with sickle cell disease (SCD) have a higher prevalence of sleep disturbances than the general population. Disease modifying therapies such as hydroxyurea aim to reduce SCD complications. The impact of disease modifying therapies on SCD sleep remains unclear. We hypothesized that hydroxyurea would increase nocturnal oxygen saturation, improve sleep quality, and decrease degree of obstructive sleep apnea (OSA). This retrospective cohort included 425 children with SCD aged 1 to 18 years who underwent 662 polysomnograms (PSGs) between 2013 and 2023. Children were group by therapy status (no therapy vs. Hydroxyurea). Sleep data were abstracted from PSGs and clinical metadata collected. At first PSG, oxygen saturation levels were significantly higher during REM and NREM sleep in the hydroxyurea group (p < 0.001). Multivariable regression showed hydroxyurea was independently associated with higher NREM (β = 1.88, p = 0.001) and REM (β = 1.69, p = 0.005) oxygen saturation nadir. AHI and other parameters did not differ between groups. Among 135 children with repeat PSGs, modeling demonstrated lower baseline SpO₂ (difference: –0.93, p = 0.027) in the hydroxyurea group with no other significant differences. Hospitalization rates for asthma, vaso-occlusive episodes, and acute chest were not associated with changes in PSG parameters over time. Children with SCD on hydroxyurea demonstrated higher oxygen saturation during sleep but persistent abnormalities including OSA, oxygen desaturations, and decreased sleep efficiency. Underlying factors for persistent sleep abnormalities remain undetermined.