Treatment of hypertension based on measurement of blood pressure variability: lessons from animal studies.
Blood pressure variability, a quantitative index for the spontaneous variation in blood pressure, has been proposed as a risk factor for end-organ damage and to determine the efficacy of hypertension treatment. Animal studies indicate that blood pressure variability is as important as blood pressure level in determining end-organ damage, and that high blood pressure variability is associated with end-organ damage, including myocardial lesions, aortic hypertrophy, vascular remodeling and renal damage. Although the organ damage induced by high blood pressure variability was similar to that induced by hypertension, comparative studies in sinoaortic-denervated and spontaneously hypertensive rats revealed that aortic hypertrophy is a sensitive index of high blood pressure variability, and left ventricular hypertrophy is a sensitive index of high blood pressure level. The possible mechanisms for high blood pressure variability-induced end-organ damage include: direct endothelial lesions, renin-angiotensin system activation, inflammation initiation and cardiomyocyte apoptosis augmentation. Blood pressure variability reduction contributes importantly to the organ-protective effect of some antihypertensive drugs. Although animal studies suggest some advantages in blood pressure variability measurements, clinical trials are necessary before the widespread use of blood pressure variability as a predictor of hypertensive organ damage and a new strategy for the treatment of hypertension.