Renovasculopathies of hypertension and the rise of blood pressure with age in blacks and whites.

Blood pressure increases with age in all US population groups that have been studies, but does so faster in African Americans. Evidence from extensive microscopic renal vascular studies at autopsy supports the view that blood pressure increases with age because of progressive fibroplasia of renal interlobular arteries and arterioles that leads to incrementally escalating renal ischemia. This process precedes the development of hypertension and progresses, on average, faster in African Americans compared with whites. The etiology for fibroplasia of the renal vasculature and the reasons for its faster progression in African Americans remains unknown.