Ambulatory blood pressure, blood pressure variability and the prevalence of carotid artery alteration: the Ohasama study.
OBJECTIVE
To investigate the association between ambulatory blood pressure (BP) variables (level, short-term variability, circadian variation and morning pressor surge) and carotid artery alteration in a general population.


METHODS
We measured ambulatory BP every 30 min in 775 participants (mean age 66.2 +/- 6.2 years, 68.8% women) from the Japanese general population. Short-term BP variability during the daytime and night-time were estimated as within-subject standard deviation of daytime and night-time BP, respectively. Circadian BP variation was calculated as the percentage decline in nocturnal BP. Morning pressor surge was defined as morning BP minus pre-waking BP. The extent of carotid artery alteration was evaluated as the average of common carotid intima-media thickness (IMT) and the presence of focal carotid plaque.


RESULTS
Daytime and night-time BP values were more closely associated with carotid artery alteration than casual BP. With mutual adjustment for daytime and night-time BP, the latter (P < 0.0001) was more closely associated with IMT, which represents diffuse arterial thickening and arteriosclerosis, than daytime BP (P = 0.2). Night-time systolic BP variability was positively associated with carotid plaque (focal atherosclerotic lesions) independently of possible confounding factors, including night-time systolic BP (P = 0.01). A diminished nocturnal decline in systolic BP was associated with a greater IMT after adjustment for confounding factors (P = 0.03). A morning pressor surge was not associated with carotid artery alteration.


CONCLUSIONS
Ambulatory BP levels and BP variability were closely associated with carotid artery alteration, suggesting that these parameters are independent risk factors or predictors of carotid artery alteration.
Shintani
Yoriko
Y
Department of Clinical Pharmacology, Tohoku University Hospital, Sendai, Aoba-ku, Japan.
Kikuya
Masahiro
M
Hara
Azusa
A
Ohkubo
Takayoshi
T
Metoki
Hirohito
H
Asayama
Kei
K
Inoue
Ryusuke
R
Obara
Taku
T
Aono
Yoko
Y
Hashimoto
Takanao
T
Hashimoto
Junichiro
J
Totsune
Kazuhito
K
Hoshi
Haruhisa
H
Satoh
Hiroshi
H
Imai
Yutaka
Y
D000368:Aged; D001794:Blood Pressure; D002339:Carotid Arteries / Q000000981:diagnostic imaging / Q000502:physiology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography