A comparison of awake-sleep blood pressure variation between normotensive Japanese-American and Caucasian women in Hawaii.
OBJECTIVE
To compare awake-sleep ambulatory blood pressure variation between Japanese-American and Caucasian women in Hawaii, specifically determining whether Japanese-Americans have reduced dipping of blood pressure during sleep, as is found in comparisons of Japanese and US samples.


METHODS
Normotensive school teachers from East Hawaii who were either of Japanese-American (n = 70) or Caucasian (n = 48) ethnicity were recruited. They wore an ambulatory blood pressure monitor (Spacelabs 90207) that took measurements every 15 min during waking hours and every 30 min during sleep for a 24-h period on a normal workday. All subjects provided demographic information and underwent a series of anthropometric measurements the day before monitoring. Japanese-American subjects also answered questionnaires relating to cultural identity and migration history.


RESULTS
The Japanese-American women had significantly higher mean diastolic (P < 0.01) blood pressure during sleep. These ethnic differences in sleep blood pressure persisted when analyses controlled for age, body mass index, and the waist-hip circumference ratio. There were also significant differences in the proportion by which blood pressure dipped from waking to sleeping, with the Japanese-American women dipping significantly less than the Caucasian women (P < 0.05 systolic, P < 0.001 diastolic).


CONCLUSIONS
Normotensive Japanese-American women have higher sleep pressure, and a smaller awake-sleep dip, in pressure than Caucasian women. The relative elevation of blood pressure in Japanese-American women during sleep, but not at other times of the day, is similar to the pattern seen among Japanese women in Japan.
Brown
Daniel E
DE
Department of Anthropology, University of Hawaii at Hilo, Hilo, Hawaii 96720, USA. dbrown@hawaii.edu
James
Gary D
GD
Aki
Sue L
SL
Mills
Phoebe S
PS
Etrata
Michaelyn B
MB
D000328:Adult; D001213:Asian; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory; D005260:Female; D006801:Humans; D008875:Middle Aged; D012016:Reference Values; D012890:Sleep / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology*; D044465:White People