title: The definition of daytime and nighttime influences the interpretation of ABPM in children.
abstract: 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.
authors.affiliation: Department of Paediatric Nephrology, Evelina Children's Hospital, London, SE1 7EH, UK.
authors.forename: Helen E
authors.initials: HE
authors.lastname: Jones
authors.forename: Manish D
authors.initials: MD
authors.lastname: Sinha
mesh_terms: D000293:Adolescent; D018660:Blood Pressure Monitoring, Ambulatory / Q000379:methods*; D002648:Child; D002940:Circadian Rhythm / Q000502:physiology*; D006801:Humans; D006973:Hypertension / Q000175:diagnosis* / Q000503:physiopathology; D012189:Retrospective Studies; D057566:Self Report / Q000592:standards*; D012890:Sleep / Q000502:physiology; D013995:Time