Autonomic cardiovascular tests in children with obstructive sleep apnea syndrome.
OBJECTIVE
The aim of our study was to investigate cardiovascular autonomic activity during wakefulness, using cardiovascular tests, in a population of children with OSAS.


METHODS
Prospective study.


METHODS
Sleep unit of an academic center.


METHODS
We included 25 children (mean age 10.2 +/- 2.3 years) undergoing a diagnostic assessment for OSAS, and 25 age-matched healthy control subjects. All subjects underwent an overnight polysomnography and autonomic cardiovascular tests using parts of the Ewing test battery, which is a physiological test used for the assessment of autonomic function (head-up tilt test, Valsalva maneuver, deep breathing test).


RESULTS
Eighteen of 25 children with OSAS (11 males, mean age 9.4 +/- 1.7 years) concluded the study. OSAS patients had higher systolic blood pressure, diastolic blood pressure, baseline heart rate, the 30:15 index (which represents the RR interval at the 15th and 30th beats during the head up tilt test), and delta diastolic and systolic blood pressure during the head-up tilt test, while the heart rate variability during the deep breathing test was lower, compared with controls. A positive correlation between systolic and diastolic blood pressure and the apnea-hypopnea index (AHI), and negative between AHI and both the 30:15 index and Valsalva ratio, were found. Stepwise linear regression analysis detected a negative correlation between AHI and the 30:15 index and Valsalva ratio, a positive correlation between overnight mean oxygen saturation and delta heart rate, and between AHI and delta systolic blood pressure.


CONCLUSIONS
Our data point to an increase in basal sympathetic activity during wakefulness and to an impaired reaction to several physiological stimuli, which is dependent on the severity of OSAS.
Pediatric Department, "La Sapienza" University, II Faculty, Medicine, Rome, Italy.
Marilisa
M
Montesano
Silvia
S
Miano
Maria Chiara
MC
Paolino
Anna Claudia
AC
Massolo
Filomena
F
Ianniello
Martina
M
Forlani
Maria Pia
MP
Villa
D000293:Adolescent; D000704:Analysis of Variance; D001341:Autonomic Nervous System / Q000503:physiopathology*; D001794:Blood Pressure; D002319:Cardiovascular System / Q000503:physiopathology*; D002648:Child; D015331:Cohort Studies; D004562:Electrocardiography / Q000379:methods / Q000706:statistics & numerical data; D004569:Electroencephalography / Q000379:methods / Q000706:statistics & numerical data; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D017286:Polysomnography / Q000379:methods / Q000706:statistics & numerical data; D011446:Prospective Studies; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology*; D018667:Tilt-Table Test / Q000379:methods / Q000706:statistics & numerical data; D014636:Valsalva Maneuver; D014851:Wakefulness