title: Preschool children with obstructive sleep apnea: the beginnings of elevated blood pressure?
abstract: OBJECTIVE
  In adults and older children, snoring and obstructive sleep apnea (OSA) are associated with elevated blood pressure (BP). However, BP has not been assessed in preschool children, the age of highest OSA prevalence. We aimed to assess overnight BP in preschool children with snoring and OSA using pulse transit time (PTT), an inverse continuous indicator of BP changes.
  
  
  METHODS
  Overnight polysomnography including PTT. Children were grouped according to their obstructive apnea-hypopnea index (OAHI); control (no snoring, with OAHI of one event or less per hour), primary snoring (OAHI one event or less per hour), mild OSA (OAHI greater than one event to five events per hour) and moderate-severe OSA (OAHI more than five events per hour).
  
  
  METHODS
  Pediatric sleep laboratory.
  
  
  METHODS
  There were 128 clinically referred children (aged 3-5 years) and 35 nonsnoring community control children.
  
  
  RESULTS
  PTT was averaged for each 30-sec epoch of rapid eye movement (REM) or nonrapid eye movement (NREM) sleep and normalized to each child's mean wake PTT. PTT during NREM was significantly higher than during REM sleep in all groups (P < 0.001 for all). During REM sleep, the moderate-severe OSA group had significantly lower PTT than the mild and primary snoring groups (P < 0.05 for both). This difference persisted after removal of event-related PTT changes.
  
  
  CONCLUSIONS
  Moderate-severe OSA in preschool children has a significant effect on pulse transit time during REM sleep, indicating that these young children have a higher baseline BP during this state. We propose that the REM-related elevation in BP may be the first step toward development of daytime BP abnormalities. Given that increased BP during childhood predicts hypertension in adulthood, longitudinal studies are needed to determine the effect of resolution of snoring and/or OSA at this age.
authors.affiliation: The Ritchie Centre, Monash Institute of Medical Research, Monash University, Melbourne, Victoria, Australia.
authors.forename: Lauren C
authors.initials: LC
authors.lastname: Nisbet
authors.forename: Stephanie R
authors.initials: SR
authors.lastname: Yiallourou
authors.forename: Sarah N
authors.initials: SN
authors.lastname: Biggs
authors.forename: Gillian M
authors.initials: GM
authors.lastname: Nixon
authors.forename: Margot J
authors.initials: MJ
authors.lastname: Davey
authors.forename: John A
authors.initials: JA
authors.lastname: Trinder
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Walter
authors.forename: Rosemary S C
authors.initials: RS
authors.lastname: Horne
mesh_terms: D001794:Blood Pressure / Q000502:physiology; D016022:Case-Control Studies; D002675:Child, Preschool; D005260:Female; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D006973:Hypertension / Q000209:etiology* / Q000503:physiopathology; D008297:Male; D017286:Polysomnography; D063177:Pulse Wave Analysis; D012890:Sleep / Q000502:physiology; D020181:Sleep Apnea, Obstructive / Q000150:complications* / Q000503:physiopathology; D012894:Sleep Stages / Q000502:physiology; D012913:Snoring / Q000150:complications / Q000503:physiopathology
keywords: Blood pressure; children; obstructive sleep apnea; preschool; pulse transit time; snoring
references.citation: Sleep. 2009 Oct;32(10):1265-71
references.pmid: 19848356
references.citation: Hypertension. 2008 Jan;51(1):84-91
references.pmid: 18071053
references.citation: Med Biol Eng Comput. 2000 Sep;38(5):569-74
references.pmid: 11094816
references.citation: Am J Hypertens. 1995 Jul;8(7):657-65
references.pmid: 7546488
references.citation: Hypertension. 2008 Nov;52(5):841-6
references.pmid: 18838624
references.citation: Am J Respir Crit Care Med. 1994 Dec;150(6 Pt 1):1690-6
references.pmid: 7952634
references.citation: Proc Am Thorac Soc. 2008 Feb 15;5(2):242-52
references.pmid: 18250218
references.citation: Sleep. 1992 Apr;15(2):173-84
references.pmid: 11032543
references.citation: J Med Eng Technol. 2009;33(1):79-86
references.pmid: 19116857
references.citation: J Hum Hypertens. 2002 Oct;16(10):711-7
references.pmid: 12420195
references.citation: Pediatrics. 2002 Jan;109(1):45-60
references.pmid: 11773541
references.citation: Arch Dis Child. 2003 Feb;88(2):139-42
references.pmid: 12538317
references.citation: Pediatr Nephrol. 2005 Jun;20(6):798-802
references.pmid: 15856318
references.citation: Am J Respir Crit Care Med. 2000 Aug;162(2 Pt 1):682-6
references.pmid: 10934106
references.citation: J Sleep Res. 2009 Dec;18(4):411-4
references.pmid: 19682242
references.citation: J Sleep Res. 2001 Dec;10(4):253-64
references.pmid: 11903855
references.citation: Am J Respir Crit Care Med. 2001 Jul 1;164(1):16-30
references.pmid: 11435234
references.citation: Pediatrics. 2011 Jul;128(1):e85-92
references.pmid: 21708802
references.citation: Sleep. 2007 Jul;30(7):891-7
references.pmid: 17682660
references.citation: Physiol Meas. 2001 Aug;22(3):425-32
references.pmid: 11556663
references.citation: Pediatrics. 2004 Aug;114(2 Suppl 4th Report):555-76
references.pmid: 15286277
references.citation: Chest. 2005 Mar;127(3):722-30
references.pmid: 15764750
references.citation: J Appl Physiol (1985). 2006 Jan;100(1):136-41
references.pmid: 16141378
references.citation: Eur J Appl Physiol. 2012 Jan;112(1):309-15
references.pmid: 21556814
references.citation: Pediatr Res. 2003 Apr;53(4):580-8
references.pmid: 12612196
references.citation: Sleep Med. 2012 Sep;13(8):999-1005
references.pmid: 22763016
references.citation: Sleep Med. 2012 Jun;13(6):621-31
references.pmid: 22503657
references.citation: Dtsch Med Wochenschr. 2010 Dec;135(48):2406-12
references.pmid: 21108154
references.citation: Pediatr Nephrol. 1997 Dec;11(6):707-10
references.pmid: 9438648
references.citation: Sleep Breath. 2013 May;17(2):605-13
references.pmid: 22684854
references.citation: J Pediatr. 2009 Sep;155(3):362-8.e1
references.pmid: 19540515
references.citation: Sleep Med. 2011 Oct;12(9):880-6
references.pmid: 21930428
references.citation: Am J Respir Crit Care Med. 1996 Feb;153(2):866-78
references.pmid: 8564147
references.citation: Arch Otolaryngol Head Neck Surg. 2012 Apr;138(4):398-403
references.pmid: 22508624
references.citation: Intern Med J. 2004 Jul;34(7):420-6
references.pmid: 15271177
references.citation: Am J Respir Crit Care Med. 2004 Apr 15;169(8):950-6
references.pmid: 14764433
references.citation: J Med Eng Technol. 2008 Sep-Oct;32(5):343-7
references.pmid: 18663637
references.citation: Am J Respir Crit Care Med. 1998 Apr;157(4 Pt 1):1098-103
references.pmid: 9563725
references.citation: Thorax. 2005 Jun;60(6):511-6
references.pmid: 15923253
references.citation: J Electrocardiol. 2011 Mar-Apr;44(2):201-7
references.pmid: 21353067
references.citation: J Clin Invest. 1995 Oct;96(4):1897-904
references.pmid: 7560081
references.citation: Thorax. 1999 May;54(5):452-7
references.pmid: 10212114