[Seven-day (24-hour) ambulatory blood pressure monitoring and frequently observed day-to-day differences in the elderly].
OBJECTIVE
The goal of this study was to quantify the extent of possible day-to-day differences in 24-hour ambulatory blood pressure (ABP) monitoring results especially in association with age.


METHODS
A total of 514 community-dwelling subjects were initially recruited to participate in this study, and 450 subjects (average 58.8 years, 186 men and 264 women) had ABP monitoring for at least 6 days using an oscillometric monitor (TM-2430). We calculated the mean ABP and blood pressure (BP) dipping ratio for each day. Subjects were divided into 3 groups, 91 subjects aged from 40 to 49 years (average 41.8 years, younger group), 192 subjects from 50 to 64 years (average 57.5 years, middle-aged group), and 167 subjects over 65 years of age (average 69.5 years, elderly group). A mean ABP of >130/80 mm Hg was a criteria for hypertension (HT), and a decrease of less than 10% in BP during the night was defined as non-dipper. From the view point of day-to-day difference of ABP, 450 subjects were classified into (1) persistent normotension, masked ABP HT, intermittent ABP HT and persistent HT, and (2) persistent dipper, masked non-dipper, intermittent non-dipper and persistent non-dipper.


RESULTS
Frequency of masked and intermittent ABP HT was higher in the elderly group than the younger or middle-aged groups (47.3% vs. 27.5% or 39.6%), and the frequency of masked and intermittent non-dippers was also higher in association with age (55.0%, 59.5%, 69.7%, p<0.01).


CONCLUSIONS
Aging can affect ABP variability. ABP monitoring should be used more precisely for the better diagnosis and treatment of HT in the elderly.
Department of Medicine, Tokyo Women's Medical University, Medical Center East.
Kuniaki
K
Otsuka
D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D018660:Blood Pressure Monitoring, Ambulatory / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged