Stability of polysomnography for one year and longer in children with sickle cell disease.
OBJECTIVE
Serious morbidity may be linked to sleep disordered breathing (SDB) among children with sickle cell disease (SCD). We investigated the stability of polysomnography (PSG) results among children not having acute complications of SCD.


METHODS
Two PSGs were performed on a subsample of 63 children 4 to 18 years of age from the Sleep and Asthma Cohort Study. All had Hb SS or HbSβ(0) disease. Two PSGs were compared for 45 subjects. Excluded from comparison were 18 children who had begun transfusions or hydroxyurea, had an adenotonsillectomy between the PSGs, or had a pain crisis or the acute chest syndrome within 3 months of the second PSG. Sleep disordered breathing was identified using 2 thresholds for the apnea hypopnea index (AHI): ≥ 2 or ≥ 5 respiratory events per hour.


RESULTS
Ages were 12.3 yrs ± 4.0, BMI, 18.2 ± 3.2. Interval between PSGs was 581 ± 119 days (19.1 ± 3.9 months). Ten of 45 changed from ≥ 2 events per hour to < 2; 3 of 45 from < 2 to ≥ 2; 7 of 45 had ≥ 2 on both nights. Six of 45 changed from ≥ 5 to < 5, 2 of 45 from < 5 to ≥ 5, and 1 had ≥ 5 on both nights (McNemar χ(2), p = 0.09, and p = 0.29).


CONCLUSIONS
In the absence of acute SCD complications, overnight PSG usually remains stable or improves over a 12- to 30-month period. Only 6.7% subjects, or fewer, had AHI on a subsequent PSG that would re-classify the child as having SDB not identified in the earlier PSG.
Case Western Reserve University School of Medicine, Cleveland, OH, USA.
Jonathan E
JE
Mullin
Benjamin P
BP
Cooper
Fenella J
FJ
Kirkham
Carol L
CL
Rosen
Robert C
RC
Strunk
Michael R
MR
DeBaun
Susan
S
Redline
James S
JS
Kemp
D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000150:complications / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D017286:Polysomnography; D011446:Prospective Studies; D012890:Sleep / Q000502:physiology; D012891:Sleep Apnea Syndromes / Q000209:etiology* / Q000503:physiopathology; D013997:Time Factors