Blood pressure variability: mechanisms and clinical significance.

Studies have shown that the circadian blood pressure profile is similar in normotensive and hypertensive subjects, and that the observed increase in blood pressure variability in hypertensive patients is proportional to the increase over the normotensive baseline blood pressure, suggesting that transient blood pressure oscillations on a percentage basis are not altered by hypertension. It has also been found that although antihypertensive therapy tends to reduce mean arterial blood pressure (MAP), the tendency to oscillate around a mean pressure is modified to a lesser extent. The significance of this observation is unknown; however, this effect should possibly be considered and studied in view of the incomplete protection against cardiovascular complications that is afforded by the current management of hypertension.