Blood pressure variability and arterial stiffness parameters derived from ambulatory blood pressure monitoring.

Multiple blood pressure (BP) measurements allow an evaluation of BP variability and BP‑derived arterial stiffness indices. Periodic variations in BP are well known, from beat‑to‑beat BP readings in intra‑arterial measurement to seasonal variations in BP. Diurnal BP variation has been investigated in relation to its prognostic value. People with night‑to‑day BP ratio of 1 or higher, that is, those with a higher nocturnal than daytime BP, were older than those with normal dipping status at baseline and had a greater risk of cardiovascular mortality and morbidity. Short‑term BP variability was evaluated using an intraindividual standard deviation or average real variability without any assumption of a periodic fluctuation. The ambulatory arterial stiffness index (AASI), which is derived from ambulatory BP monitoring, is a surrogate measure of arterial stiffness. An increased short‑term BP variability and the AASI have been linked to target organ damage and poor prognosis, while short‑term BP variability added only 1% or less to the prediction of a cardiovascular event. Although strict BP control at any time of the day is essential, studies are required to clarify how much additional benefit is derived from a treatment considering BP variability or the AASI in patients with hypertension.