Design and statistical aspects of the African American Study of Kidney Disease and Hypertension (AASK)

Area of Science:

• Nephrology
• Cardiology
• Clinical Trials

Background:

• Hypertensive kidney disease disproportionately affects African Americans.
• Effective management strategies are crucial to slow disease progression and prevent end-stage renal disease.

Purpose of the Study:

• To compare the effectiveness of three anti-hypertensive drug regimens (ACE inhibitor, calcium channel blocker, beta-blocker) on hypertensive kidney disease progression.
• To assess the impact of two blood pressure control levels on the rate of decline in kidney function.

Main Methods:

• A multicenter, randomized clinical trial involving African-American adults with hypertensive kidney disease and GFR 20-65 ml/min/1.73 m(2).
• Participants were assigned to initial therapy with ramipril, amlodipine, or metoprolol, targeting either a lower mean arterial pressure (
• Renal function was primarily assessed by the rate of change in glomerular filtration rate (GFR) using (125)I-iothalamate clearance.

Main Results:

• The study aimed to determine which drug regimens and blood pressure targets best preserve kidney function.
• Primary outcome: rate of change in GFR.
• Secondary outcomes included a composite of 50% GFR reduction, end-stage renal disease, or death.

Conclusions:

• The AASK trial provides critical data on managing hypertensive kidney disease in a high-risk population.
• Findings inform clinical guidelines for anti-hypertensive therapy and blood pressure targets to protect kidney health.
• Results contribute to understanding long-term renal outcomes in African Americans with hypertension and kidney disease.