Baseline blood pressure in healthy normotensive volunteers

The aim of this study was to define the reproducibility and the time required to obtain a stable baseline level of blood pressure (BP) in normotensive volunteers during a phase I trial. Blood pressure was recorded 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 significantly over time up to T75 (p < 0.001): [table: see text] 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 not significantly differ between manual and oscillometric methods. The best reproducibility of T75 was obtained with the mean of 3 automatic values (T70, T75, T80).in normotensive subjects, BP decreased from one period to the next and with rest. The baseline value of BP was obtained from T75 with the best reproducibility when baseline BP level is defined by 3 automatic values.