P1468: sleep disordered breathing in sickle cell disease: relation to pulmonary hypertension and stroke

Background: Sleep disordered breathing (SDB) is a common underdiagnosed sequela of sickle cell disease (SCD) characterized by daytime sleepiness, behavioral changes, and cognitive deficits. Nocturnal desaturations have also been linked to the frequency of vaso-occlusive crises (VOCs), acute chest syndrome (ACS), cardiac abnormalities, central nervous system (CNS) events, and nocturnal enuresis. Aims: To determine the frequency of SDB in patients with SCD and its association with SCD-related complications. Methods: Thirty children and adolescents with SCD were evaluated using overnight polysomnography after completing the modified STOP-Bang questionnaire. Transcranial doppler (TCD) and echocardiography with assessment of tricuspid regurge velocity (TRV) were performed. Data of SCD, and related complications were collected from the patients’ records. Results: The median age of the studied cohort was 10.2 years (range 6-17 years), with male: female ratio 1.7:1. Six patients (20%) had high-risk for obstructive sleep apnea (OSA), nine (30%) had intermediate risk, and fifteen (50%) at low risk. Sleep apnea, defined as respiratory disturbance index (RDI) > 1 event/hour, was found in 18/30 (60%) of patients (14 males and 4 females). Patients with RDI > 5 (moderate to severe OSA) had significantly higher TRV (p = 0.007) and left MCA flow velocity (p = 0.049) when compared to those with RDI < 5. Although right MCA flow velocity was higher in the moderate to severe OSA group, this did not reach statistical significance (p = 0.054). Other variables including BMI-SDS (0.07), presence of cardiac dysfunction (p = 0.26), history of stroke (p = 0.17), or presence of nocturnal enuresis (p = 0.33) were comparable between both groups. Patients with RDI > 5 were at higher risk of OSA according to the modified STOP-Bang questionnaire (p = 0.02). RDI positively correlated with TRV (r = 0.53, p = 0.003), right MCA flow velocity (r = 0.45, p = 0.013) and left MCA flow velocity (r = 0.55, p = 0.002), while it showed negative correlation with BMI-SDS (r = -0.48, p = 0.008). Summary/Conclusion: Sleep apnea is a common problem in patients with SCD associated with risks of pulmonary hypertension and alterations in cerebral blood flow which highlights the need for early diagnosis and management.