[Effect of sleep on blood pressure]

Seventeen normotensive subjects have their blood pressure recorded each 10 mn, at home, from 7 pm to 9 am, by Spacelabs 5200, and undergo polygraphic, recording of EEG, activity of the mylohyoid muscle and horizontal oculogram allowing in this way to specify the different sleeping stages. The analysis method using increasing rates of SBP, DBP and HR according to different sleeping stages, has showed following results: 1--the pre sleep period (one hour before sleep) is marked by a decrease in blood pressures, with SBP changing sooner than DBP. HR is the variable which fluctuates the most. 2--during the sleeping period, no correlation has been noticed between different sleeping stages and the variations of SBP, DBP and HR. 3--the wakening period is characterized by a concomitant increase of the 3 variables, however this increase occurs indifferently depending on the subjects, before, during or after wakening. Furthermore the rising slope of blood pressure is markedly greater, in absolute value, than the blood pressure fall before sleep.

The organization of sleep does not seem to have a determining influence on nocturnal blood pressure evolution.