title: Reproducibility of nocturnal blood pressure assessed by self-measurement of blood pressure at home.
abstract: To assess the reproducibility of nocturnal blood pressure (BP) during sleep as measured using a self-measurement device at home, we obtained repeated nocturnal home BP at 0200 h and quality of sleep assessment from a diary in 556 subjects (71% women, 62.4+/-11.1 years) in the general population. We used an Omron device (HEM-747IC-N, Omron Healthcare Co., Ltd., Kyoto, Japan), with which the time and frequency of monitoring can be preset and the readings stored. The mean+/-SD of the difference between test-retest BP measurements was 0.7+/-15.1 mmHg systolic and 0.2+/-9.7 mmHg diastolic with a mean interval of 5.9 days. The absolute differences were greater than 10 mmHg in 261 (46.9%) subjects for systolic and 145 (26.0%) subjects for diastolic. There was no evidence of regression to the mean in nocturnal measurements over at least three nights (n=390, p>0.22). The differences (the first minus the second measurement) were large in subjects who experienced sleep disturbance only in the first (n=64, 2.3+/-13.6 mmHg and 1.6+/-9.6 mmHg for systolic and diastolic, respectively) or second sessions (n=56, -4.1+/-16.4 mmHg and -2.5+/-11.4 mmHg) compared with the subjects without sleep disturbance (n=66, 1.5+/-17.8 mmHg and 0.8+/-10.3 mmHg) and those with sleep disturbance (n=370, 0.9+/-14.5 mmHg and 0.2+/-9.3 mmHg) in both sessions. In conclusion, the reproducibility of single nocturnal BP as assessed using a self-measurement device at home was not good, especially for subjects who experienced different quality of sleep in each session. To evaluate nocturnal BP using a self-measurement device, estimation of quality of sleep is indispensable.
authors.affiliation: Department of Planning for Drug Development and Clinical Evaluation, Tohoku University Graduate School of Pharmaceutical Sciences and Medicine, Sendai, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Hosohata
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kikuya
authors.forename: Takayoshi
authors.initials: T
authors.lastname: Ohkubo
authors.forename: Hirohito
authors.initials: H
authors.lastname: Metoki
authors.forename: Kei
authors.initials: K
authors.lastname: Asayama
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Inoue
authors.forename: Taku
authors.initials: T
authors.lastname: Obara
authors.forename: Junichiro
authors.initials: J
authors.lastname: Hashimoto
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Totsune
authors.forename: Haruhisa
authors.initials: H
authors.lastname: Hoshi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Satoh
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Imai
mesh_terms: D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory / Q000295:instrumentation / Q000592:standards*; D015924:Blood Pressure Monitors / Q000592:standards*; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D015203:Reproducibility of Results; D012890:Sleep / Q000502:physiology; D012893:Sleep Wake Disorders