Pediatric Nephrology

, Volume 26, Issue 5, pp 775–781

The definition of daytime and nighttime influences the interpretation of ABPM in children

Original Article

DOI: 10.1007/s00467-011-1791-3

Cite this article as:
Jones, H.E. & Sinha, M.D. Pediatr Nephrol (2011) 26: 775. doi:10.1007/s00467-011-1791-3


To test if an arbitrary definition of day and night periods that differs to patient-reported awake and sleep periods leads to inaccuracies in interpretation of ambulatory blood pressure monitoring (ABPM). A single-center, retrospective review was performed comparing three different methods to classify day and night periods following a single 24-h ABPM: method A: Patient's record during monitoring; method B: 7:00 am to 11:00 pm day and 11:00 pm to 7:00 am night; method C: 8:00 am to 8:00 pm day and midnight to 6:00 am night. We included 149 studies in 149 children with a mean ± SD age of 13.0 ± 3.4 years. Reported sleep duration was 9.2 ± 1.3 h. Significant differences resulted between three methods for the means of several ambulatory BP parameters including indexed BP values during day, BP load, and nocturnal dipping status. During monitoring [median (range)], 7.5% (0.0–27.5%) readings were misclassified using method B and 0.0% (0.0–20.0%) using method C (p < 0.0001). This misclassification resulted in change of hypertension status for 11.4% (17/149) patients using method B and 9.4% (14/149) patients using method C (p = 0.70). Misclassification of measurements during ABPM can introduce significant errors in its interpretation. The clinical impact of these findings needs further evaluation in larger prospective studies.


ClassificationAmbulatory blood pressure monitoringChildrenCircadian rhythm

Copyright information

© IPNA 2011

Authors and Affiliations

  1. 1.Department of Paediatric NephrologyEvelina Children’s Hospital, Guys & St Thomas NHS Foundation TrustLondonUK