Traditionally, diastolic blood pressure, the second or lower number, was thought to be more important. Joseph Izzo, UB professor of medicine and pharmacology, and vice chair of research for the Department of Medicine, is the primary author of the advisory, which appears in the May issue of Hypertension. The document was developed by the coordinating committee of the National High Blood Pressure Education Program, which is part of the National Heart, Lung and Blood Institute. Systolic blood pressure represents the maximum force exerted by the heart against the blood vessels during the heart's pumping phase.
Diastolic pressure is the resting pressure during the heart's relaxation phase.
Izzo said much evidence points to systolic pressure as the critical factor in determining the risk of heart disease. For example, systolic hypertension is the most prevalent risk factor in heart failure, stroke and kidney failure. It is clear that lowering systolic pressure is associated with better outcomes in cardiovascular and renal disease. Systolic hypertension interacts with other major risk factors, such as high cholesterol and diabetes, which also increase with age, to amplify the age-related risk of cardiovascular events. Isolated systolic hypertension is the most common form of hypertension and is present in about two-thirds of people over the age of 60 with diagnosed high blood pressure, he said.