Abnormal circadian blood pressure regulation in children born preterm.
OBJECTIVE
To assess a possible relationship between prematurity and casual blood pressure (BP) by means of 24-hour ambulatory BP monitoring (ABPM).


METHODS
ABPM was performed in 41 children aged 5 to 17 years who were born prematurely with (n = 11) or without intrauterine growth restriction, and in 27 matched children who were born at term with a birth weight appropriate for gestational age.


RESULTS
Although BP did not differ between the preterm group and control subjects during the daytime, nocturnal standardized systolic BP was elevated (P < .05) and a lack of nocturnal decrease was more prevalent in the preterm children compared with the control subjects (73% versus 41%, P = .01). The difference was caused by a marked increase of nighttime systolic BP in the light-for-date children (1.17 +/- 0.61 standard deviation scores; P < .01), although preterm children with appropriate weight (0.33 +/- 1.00) were not different from control subjects (0.09 +/- 0.73). Nighttime BP standard deviation scores were closely correlated with standardized heart rate, compatible with a role of sympathetic hyperactivation.


CONCLUSIONS
Subtle abnormalities of BP regulation, indicated by a selective increase of nocturnal systolic BP, are present during childhood in subjects born prematurely, and are prominent in those with intrauterine growth restriction.
Bayrakci
Umut Selda
US
Division of Pediatric Nephrology, University Hospital for Pediatric and Adolescent Medicine, Hacettepe University, Ankara, Turkey. ukavak@yahoo.com
Schaefer
Franz
F
Duzova
Ali
A
Yigit
Sule
S
Bakkaloglu
Aysin
A
D000293:Adolescent; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002940:Circadian Rhythm; D005317:Fetal Growth Retardation / Q000503:physiopathology*; D006706:Homeostasis; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007236:Infant, Small for Gestational Age; D016014:Linear Models; D016555:Matched-Pair Analysis; D012016:Reference Values; D018709:Statistics, Nonparametric