Arterial Stiffness and Blood Pressure Variability

Epidemiological evidence has indicated that the risk of cardiovascular complications associated with hypertension may not only depend on the magnitude of blood pressure elevation per se but also on the presence of increased blood pressure variability. Although the neurogenic influences to the peripheral vasculature and the heart are major determinants of blood pressure fluctuations (in particular in the short term), evidence has also been provided that the degree of blood pressure variability is directly related to stiffness of large arteries, known to be a strong and independent predictor of cardiovascular risk. This chapter is aimed at reviewing: (1) current definitions, mechanisms, and clinical significance of BPV; (2) the evidence on the relationship of arterial stiffness with different components of BPV (i.e., short-term, mid-term, and long-term BPV); (3) the potential mechanisms underlying the association of arterial stiffness with BPV (i.e., the relative role of alterations in carotid baroreflex and arterial mechanical properties); (4) in its final part, the chapter will review a still controversial question regarding the possible reverse causality between arterial stiffness and BPV, i.e., whether greater BPV is not only the consequence of increased arterial stiffness but also a contributor to increased arterial stiffness.