African Americans at increased risk of kidney failure caused by hypertension

Regardless of demographics, African American patients with hypertensive nephrosclerosis have a higher rate of developing end stage renal disease (ESRD) than dying prematurely, according to a study appearing in an upcoming issue of the Journal of the American Society of Nephrology (JASN). Earlier studies showed patients of all races with Chronic Kidney Disease (CKD) were at greater risk of dying prematurely from cardiovascular disease (CVD) than reaching ESRD.

Hypertensive nephrosclerosis (also called Hypertensive Chronic Kidney Disease) is a common kidney disorder in which the smallest arteries in the kidneys, called the arterioles, are damaged. This type of damage can be benign, which means it occurs over a period of years. While it often does not lead to kidney failure, in some patients this form of kidney disease progresses very quickly and the patient develops kidney failure. Hypertensive nephrosclerosis accounts for about 1/3 of new cases of kidney failure in African-Americans.

Tahira Palmer Alves MD, MPH (University of Texas Health Science Center at San Antonio), senior author Julia Lewis, MD (Vanderbilt University, Nashville) and colleagues studied participants from the African American Study of Kidney Disease and Hypertension (AASK) trial and cohort phase. The AASK trial had 1094 participants enrolled, 764 (70%) of whom completed the trial phase without an event and 691 of those (90%), subsequently enrolled in the cohort phase.

"The results may provide new insights into the relationship between high blood pressure and kidney disease in African Americans, as well as some of the reported racial differences in the rates and outcomes of ESRD," explains Dr. Alves.

African Americans are at increased risk of kidney failure caused by hypertension. The African American Study of Kidney Disease and Hypertension (AASK) Cohort Study was created to identify risk factors for progressive kidney disease in African Americans with hypertensive chronic kidney disease in the setting of recommended antihypertensive therapy. Dr. Alves noted that AASK allowed the medical community to gain a greater understanding of the types of serious health outcomes (ESRD, CVD events, and mortality) that afflict African-Americans with nondiabetic hypertensive nephrosclerosis.

In an accompanying editorial, Linda F. Fried, MD (VA Pittsburgh Healthcare System, Pittsburgh) explained that the study "suggests that the risk for death before dialysis is not uniform. Whether this should have an impact on clinical care is not yet clear. Although it could affect the focus on preparing for dialysis or transplantation evaluation, we would need to improve our risk prediction on an individual level before this could be initiated."

ASN leads the fight against kidney disease by highlighting complex areas of interest and controversy, such as addressing profound health care disparities, its leading legislative priority for 2010. ASN believes Congress and the National Institutes of Health (NIH) can play a significant role in addressing disparities, by increasing funding and support of minority investigators and providing additional aid to investigators who study disparities in treatment of Americans with kidney disease.