Continuous blood pressure variation: Hidden adaptability

Abstract

Although the literature on blood pressure is dominated by its role as an indicator of cardiovascular health, the fundamental nature of blood pressure as a biological phenomenon has come into sharper focus over the past 30-40 years due to the increasing use of ambulatory blood pressure monitors in medical practice, which has uncovered an enormous amount of diurnal variation. The concept of allostasis was first coined to describe the adaptive variation in blood pressure and its diversity of stable states. It is apparent that blood pressure continuously responds to the ambient conditions of everyday life, increasing and decreasing as needed. However, the definition of what is sufficient variation remains elusive due to methodological issues involving subjective reporting and intrinsic individual and population differences in behavior and physiological processes. This chapter examines the methodological issues and discusses the behavioral and physiological processes that impact diurnal blood pressure adaptability. The focus is on what happens to blood pressure over the course of a day, although some specific hidden cardiovascular adaptations to the menstrual cycle, having children, and standing up are also divulged.