African American Study of Kidney Disease and Hypertension

The AASK is a multicenter, randomized, controlled clinical trial using a 2 × 3 factorial design to evaluate the effects of level of blood pressure control and type of anti-hypertensive medication on progression of chronic renal disease among African American men and women with chronic renal insufficiency caused by hypertension (hypertensive nephrosclerosis). Two levels of blood pressure control were defined in terms of mean arterial pressure (MAP = 2/3 diastolic blood pressure + 1/3 systolic blood pressure). A usual goal is defined as an MAP of 102 to 107 mm Hg, and a low goal is defined as an MAP of 92 mm Hg or less. The three antihypertensive drug regimens contained either a calcium channel blocker (amlodipine), β-blocker (metoprolol; Toprol XL), or angiotensin-converting enzyme inhibitor (ramipril) as initial therapy. Progression of renal disease was measured as the rate of decline in glomerular filtration rate (GFR).