Systolic hypertension (?140 mm Hg) was associated with a greater risk (hazard ratio per unit increase in z score, 1.18) than diastolic hypertension (?90 mm Hg; hazard ratio per unit increase in z score, 1.06). The investigators found similar results with the lower threshold of hypertension (?130/80 mm Hg). (Taken from Medscape)
What does this mean? It means that both numbers have to be normal to reduce your risk of heart attacks and stroke. Your doctor can regulate it!