pubmed-article:16296696 | pubmed:abstractText | It has been recognized for some time that blood pressure is highly variable over a 24-h period. A number of studies have demonstrated that the extent and severity of target-organ damage associated with hypertension can be correlated more closely with blood pressure values monitored continuously for 24 h than with individual values recorded sphygmomanometrically. A great deal of interest is focused on whether absolute values of diastolic or systolic blood pressure, values during the day or night, or the rate of change of blood pressure such as the rapid increase that occurs in the early morning are more or less important factors contributing to the mortality and morbidity associated with hypertension. Work from our own unit provides evidence of the importance of two features in the variability of blood pressure. Blood pressure decreases during the night, but remains higher in hypertensive patients than in normotensive subjects. The mean nighttime blood pressure was shown to correlate with hypertension-related target-organ damage almost as closely as the mean daytime blood pressure. Using 24-h blood pressure monitoring, we have shown that the higher the mean 24-h blood pressure, the greater the extent and severity of target-organ involvement. In addition, for patients with comparable mean 24-h blood pressure values, larger degrees of blood pressure variability throughout the monitoring period were associated with more target-organ damage. Taking the available evidence into account, it is probably important that treatments used for hypertension should provide control of blood pressure for a full 24-h period confirmed by ambulatory blood pressure monitoring. | lld:pubmed |