title: Twenty-four-hour ambulatory BP in snoring children with obstructive sleep apnea syndrome.
abstract: BACKGROUND
  Obstructive sleep apnea syndrome (OSAS) is a known risk factor for hypertension in adults. This relationship is less clear in childhood OSAS.
  
  
  OBJECTIVE
  This study examined the relationship between OSAS and 24-h ambulatory BP (ABP), a more accurate assessment than casual BP, in children with snoring.
  
  
  METHODS
  Snoring children aged 6 to 15 years who underwent polysomnography in the sleep laboratory were recruited.
  
  
  METHODS
  Twenty-four-hour ABP monitoring was initiated a few hours before polysomnography. The children were classified into two groups: a high apnea-hypopnea index (AHI) group (obstructive AHI > 5/h), and a low-AHI group (AHI < or = 5/h). Mean sleep, wake, and 24-h systolic BP (SBP) and diastolic BP (DBP) were recorded. A child was considered a "nondipper" if his or her mean SBP and DBP did not decrease by >/= 10% during sleep.
  
  
  RESULTS
  Ninety-six children (mean age +/- SD, 9.4 +/- 2.8 years) were recruited. Forty-one children were obese. When awake, the high-AHI group children had a significantly higher SBP. When asleep, both SBP and DBP were higher in the high-AHI group. Age, body mass index (BMI) z score, and desaturation index (DI) were significant predictors for elevated sleep DBP. BMI z score was the only significant predictor for wake and sleep SBP. Sixteen children (17%) had hypertension, and all were nondippers. Obese children in the high-AHI group had a significantly higher prevalence of hypertension than obese children in the low-AHI group. This relationship was not found in nonobese children.
  
  
  CONCLUSIONS
  The current study shows that increased DI contributed to the elevation of sleep DBP elevation.
authors.affiliation: Department of Pediatrics, Kwong Wah Hospital, Waterloo Rd, Hong Kong SAR, China.
authors.forename: Lettie C K
authors.initials: LC
authors.lastname: Leung
authors.forename: Daniel K
authors.initials: DK
authors.lastname: Ng
authors.forename: Michael W
authors.initials: MW
authors.lastname: Lau
authors.forename: Chung-Hong
authors.initials: CH
authors.lastname: Chan
authors.forename: Ka-Li
authors.initials: KL
authors.lastname: Kwok
authors.forename: Pok-Yu
authors.initials: PY
authors.lastname: Chow
authors.forename: Josephine M Y
authors.initials: JM
authors.lastname: Cheung
mesh_terms: D001794:Blood Pressure / Q000502:physiology; D018660:Blood Pressure Monitoring, Ambulatory; D015992:Body Mass Index; D002648:Child; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis / Q000503:physiopathology*; D008297:Male; D009765:Obesity / Q000503:physiopathology; D010100:Oxygen / Q000097:blood; D012016:Reference Values; D012307:Risk Factors; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000503:physiopathology*; D012913:Snoring / Q000503:physiopathology*; D013223:Statistics as Topic; D014851:Wakefulness / Q000502:physiology
chemical_list: D010100:Oxygen