DEFINITION OF BASE-LINE BLOOD-PRESSURE IN NORMOTENSIVE VOLUNTEERS

The aim of this study was to define the reproducibility and the time r equired to obtain a stable baseline level of blood pressure (BP) in no rmotensive volunteers during a phase I trial. Blood pressure was recor ded automatically (Dinamap and Marquette monitors) every 5 min during a 2-hour period and manually (Random zero device) at T20, T60 and T120 , twice at a one-week interval, under similar study conditions (6: in the morning, 7 in the afternoon) in supine position in 13 normotensive men (aged 20 to 28). The average BP was compared using a 3-way ANOVA (subject, time, week). 1 .SBP/DBP decreased significantly (p < 0.001) from one week to the other and SBP, but not DBP, decreased significant ly over time up to T7S (p < 0.001) [GRAPHICS] 2. SBP was significantly higher in the morning than in the afternoon during both weeks (p = 0. 001). The decrease in SBP with rest was only observed in the morning ( p = 0.00001). 3. Reproducibility and change over time and period did n ot significantly differ between manual and oscillometric methods. The best reproducibility of T7S was obtained with the mean of 3 automatic values (T70, T7S, T80). Conclusion : in normotensive subjects, BP decr eased from one period to the next and with rest. The baseline value of BP was obtained from T7S with the best reproducibility when baseline BP level is defined by 3 automatic values.