Obstructive sleep apnea may be associated with an increased risk of pulmonary hypertension and alterations in cerebral blood flow in pediatric patients with sickle cell disease (SCD), according to a recent study published in the Annals of Hematology.

For this single-center cross-sectional study, the authors recruited 30 children and adolescents with an established SCD diagnosis and separated them into 2 age groups: 6 to 13 years and 13 to 18 years. All participants were in their steady state, defined as the absence of an acute painful crisis or any changes due to therapy.

A thorough evaluation was performed with special emphasis on anthropometric measurements (weight, height, body mass index, and neck circumference), neurological and cardiac examination, laboratory testing, and transfusion index. The patients also completed a STOP-Bang questionnaire, which is a modified version of a commonly used adult clinical prediction tool for stratifying the risk of obstructive sleep apnea.

The study authors evaluated pulmonary pressure by measuring tricuspid regurgitant jet velocity via transthoracic doppler echocardiography. Transcranial doppler was used to evaluate the risk of stroke by analyzing the mean blood flow velocities of the middle cerebral arteries on both sides of the brain.

Read more about SCD comorbidities

In addition, the patients underwent polysomnography, an overnight multiparametric sleep study test using a sleep monitor to record snoring, abdominal and thoracic respiratory effort, nasal cannula flow, body position, oxygen saturation, heart rate, peripheral capillary oxygen saturation, and single-channel electroencephalography.

According to the results, the STOP-Bang questionnaire classified 9 patients (30%) as intermediate risk and 6 patients (20%) as high risk for sleep apnea. Sleep apnea, defined as an apnea-hypopnea index (AHI) of more than 1 event per hour, was detected in 18 patients, while children with an AHI of more than 5 (moderate to severe obstructive sleep apnea) had significantly higher tricuspid regurgitation velocity and left middle cerebral artery mean blood flow velocity than those with an AHI of less than 5. According to the modified STOP-Bang questionnaire, children with an AHI over 5 were at a higher risk of obstructive sleep apnea.

AHI positively correlated with tricuspid regurgitation velocity, right middle cerebral artery flow velocity, and left middle cerebral artery blood flow velocity and negatively correlated with standardized body mass index.

“The high frequency of [obstructive sleep apnea] in the studied cohort with SCD and its association with increasing risk of [pulmonary hypertension] and [transcranial duplex changes] highlights the importance of early detection and management of [obstructive sleep apnea] in children with SCD,” Tantawy and colleagues wrote.

Sleep-disordered breathing is a common underdiagnosed consequence of SCD that has been associated with an increased frequency of vaso-occlusive crises.


Tantawy A, El-Sherif N, Makkeyah S, et al. Sleep disordered breathing and its relation to stroke and pulmonary hypertension in children with sickle cell disease: a single-center cross-sectional study. Ann Hematol. Published online January 16, 2023. doi:10.1007/s00277-023-05099-4