Circadian variations in blood pressure in health and disease: implications for patient management

Traditionally, blood pressure measurements have been performed in office settings and have provided the basis for all diagnostic and therapeutic decisions. However, the develop- ment of a clinically relevant 24-hour blood pressure monitoring system has added greatly to the ability of blood pressure values to confer additional clinical information, including prognostic value. Mechanistically, the circadian rhythm of blood pressure is mediated by a complex pro- cess as a part of the neurohormonal cascade. Pattern recognition of blood pressure peaks and troughs over a 24-hour period has led to categorization into specific subsets namely, ie, dip- pers, nondippers, extreme dippers, and reverse dippers. Cardiovascular risk is associated with certain pattern types, as has been demonstrated in large observational and prospective studies. The development of therapies for the purpose of restoring more pathological patterns to normal ones continues to grow. These include both pharmaceutical and device therapy. This article describes the development of 24-hour blood pressure monitoring systems, the identification of circadian blood pressure patterns, and the treatment strategies studied thus far which affect these newer blood pressure parameters.