ABPM Induced Alarm Reaction: A Possible Cause of Overestimation of Daytime Blood Pressure Values Reduced By Treatment with Beta-Blockers.
BACKGROUND
Alarm reaction to clinical blood pressure (BP) measurement, defined white-coat effect (WCE), can cause overestimation of true BP values.


OBJECTIVE
To assess whether ambulatory blood pressure monitoring (ABPM) can similarly affect BP values during the initial hours of recording.


METHODS
In 420 ABPMs selected for a first systolic BP (SBP) reading at least 10 mmHg higher than the mean daytime SBP, we calculated mean diurnal and 24 h SBP with and without the exclusion of the two first hours of recording defined as the WCE window (WCEw). We also calculated the magnitude and duration of WCE. These analyses were also performed separately in patients off anti-hypertensive treatment (n = 156), and on treatment with and without the inclusion of beta-blockers (respectively n = 113 and 151).


RESULTS
Exclusion of WCEw period reduced mean diurnal and 24 h SBP respectively from 135 ± 0.5 to 133 ± 0.5 (p < 0.01) and from 131 ± 0.5 to 130 ± 0.5 (p < 0.02). As a result the percentage of patients diagnosed as having diurnal or 24 h hypertension was reduced respectively from 48 to 40 % and from 52 to 47 %. The magnitude of WCEw was similar in both genders but the duration was longer in females (66 ± 2 vs. 56 ± 2 min, p < 0.01). Treatment with beta-blockers was associated with a shorter duration of WCE in both genders but this effect was statistically significant only in males.


CONCLUSIONS
In some patients ABPM is not free from WCE. WCE may affect the overall estimation of BP profile and is longer but less blunted by beta-blockers in females than in males.
Division of Internal Medicine, Poveri Infermi Hospital, Loc. San Bernardino, 4, 17073, Ceva, CN, Italy. fre1988s@gmail.com.
Francesco
F
Salvo
Department of Internal Medicine and Hypertension Center, S. Giuseppe Hospital, Via San Vittore, 12, 20123, Milan, Italy.
Chiara
C
Lonati
Division of Internal Medicine, Poveri Infermi Hospital, Loc. San Bernardino, 4, 17073, Ceva, CN, Italy.
Monica
M
Albano
Division of Internal Medicine, Poveri Infermi Hospital, Loc. San Bernardino, 4, 17073, Ceva, CN, Italy.
Paolo
P
Fogliacco
Division of Internal Medicine, Poveri Infermi Hospital, Loc. San Bernardino, 4, 17073, Ceva, CN, Italy.
Andrea Riccardo
AR
Errani
Division of Internal Medicine, Poveri Infermi Hospital, Loc. San Bernardino, 4, 17073, Ceva, CN, Italy.
Cinzia
C
Vallo
Division of Internal Medicine, Poveri Infermi Hospital, Loc. San Bernardino, 4, 17073, Ceva, CN, Italy.
Michele
M
Berardi
Division of Internal Medicine, Poveri Infermi Hospital, Loc. San Bernardino, 4, 17073, Ceva, CN, Italy.
Vito
V
Meinero
Division of Internal Medicine, Poveri Infermi Hospital, Loc. San Bernardino, 4, 17073, Ceva, CN, Italy.
Carlo Lorenzo
CL
Muzzulini
Center of Clinical Physiology and Hypertension, Policlinico Hospital, University of Milan, Via Francesco Sforza, 25, 20122, Milan, Italy.
Alberto
A
Morganti
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use*; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001794:Blood Pressure / Q000187:drug effects*; D018660:Blood Pressure Monitoring, Ambulatory; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D013997:Time Factors; D016896:Treatment Outcome; D059466:White Coat Hypertension / Q000175:diagnosis / Q000188:drug therapy* / Q000503:physiopathology / Q000523:psychology
D000319:Adrenergic beta-Antagonists; D000959:Antihypertensive Agents
Alarm reaction; Ambulatory blood pressure monitoring; Beta-blockers; White-coat effect