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Medline ® Abstracts for References 61,62

of 'Evaluation of suspected obstructive sleep apnea in children'

61
TI
Sleep-disordered breathing does not affect nocturnal dipping, as assessed by pulse transit time, in preschool children: evidence for early intervention to prevent adverse cardiovascular effects?
AU
Nisbet LC, Nixon GM, Yiallourou SR, Biggs SN, Davey MJ, Trinder J, Walter LM, Horne RS
SO
Sleep Med. 2014;15(4):464. Epub 2014 Feb 10.
 
OBJECTIVE: Sleep-disordered breathing (SDB) is associated with reduced nocturnal dipping of blood pressure (BP) and sleep disruption in adults, and these features confer an increased risk of cardiovascular events. As SDB prevalence in children peaks during the preschool years, we investigated nocturnal dipping and sleep fragmentation in preschool children with SDB.
METHODS: Children (3-5 years; n=163) grouped by obstructive apnoea hypopnoea index (OAHI): control, no snoring history and OAHI≤1 event/h; primary snoring, OAHI≤1 event/h; mild SDB,>1-≤5 events/h; moderate-severe SDB,>5 events/h. Pulse transit time (PTT), an inverse continuous indicator of BP changes, and heart rate (HR) during total sleep time and the first period of rapid eye movement (REM), non-REM (NREM)1/2 and NREM3/4 sleep were expressed as percentage change from wake before sleep onset. The sleep fragmentation index (SFI) was calculated as the number of sleep stage transitions or awakenings per hour of sleep.
RESULTS: There were no group differences in the change in PTT or HR from wake to total sleep time or to individual sleep stages or in the proportion of children in the quartile with the smallest change in PTT during total sleep. Children with moderate-severe SDB had higher SFI than primary snoring (PS) or mild SDB groups (p<0.05 for both) and controls (p=0.07).
CONCLUSIONS: In contrast to adults, nocturnal dipping is preserved in young children with SDB, despite increased sleep fragmentation. As there is evidence that nocturnal dipping is similarly preserved at the school age, childhood may pose a window of opportunity for resolution of SDB when the cardiovascular effects are less marked.
AD
The Ritchie Centre, Monash Institute of Medical Research, Monash University, Melbourne, Victoria, Australia.
PMID
62
TI
Nocturnal dipping is preserved in children with sleep disordered breathing regardless of its severity.
AU
Horne RS, Yang JS, Walter LM, Richardson HL, O'Driscoll DM, Foster AM, Wong S, Ng ML, Bashir F, Patterson R, Jolley D, Walker AM, Anderson V, Davey MJ, Nixon GM
SO
Pediatr Pulmonol. 2013;48(11):1127. Epub 2013 Jun 29.
 
OBJECTIVE: Sleep disordered breathing (SDB) in adults has been associated with a loss of nocturnal dipping in blood pressure (BP) and heart rate, however, there have been limited studies in children. We measured BP non-invasively and continuously overnight in 105 children aged 7-12 with a range of severities of SDB and 36 non-snoring controls to examine nocturnal dipping profiles.
STUDY DESIGN: Children with SDB were divided into three severity groups according to their obstructive apnea hypopnea index. Nocturnal dipping profiles across sleep stages were described both as a proportion of children exhibiting a≥10% fall in systolic arterial pressure (SAP) and heart rate (HR) from wake to sleep and according to SAP sleep/SAP wake ratio as extreme dippers (ratio ≤ 0.8), dippers (ratio < 0.8 and≤0.9), non-dippers (ratio < 0.9 and≤1.0), and reverse dippers (ratio > 1.0).
RESULTS: The mean fall in BP between wakeand NREM 1/2, SWS, and REM sleep was not different between the groups and there were no differences between the dipping profiles of children in each group.
CONCLUSIONS: SDB did not alter nocturnal dipping patterns of BP and HR compared to controls, a finding which may suggest that these young children have not been exposed to the effects of SDB long enough or that SDB severity was not great enough to affect nocturnal dipping profiles. However, further studies are required to determine if the elevated BP previously reported in this group of children will have long-term effects on the cardiovascular system.
AD
The Ritchie Centre, Monash Institute of Medical Research, Monash University, Melbourne, Australia.
PMID