"Our study demonstrated a striking and unexpected degree of ESRD among HIV-infected persons of black race," comments Dr. Andy I. Choi of San Francisco General Hospital and University of California, San Francisco. "On the other hand, among white patients with HIV, rates of ESRD were far lower than among blacks and HIV did not confer an increased risk of ESRD. We can think of few other risk factors for ESRD that are modified to this extent by race."
The researchers analyzed Veterans Administration (VA) health data on more than 2 million veterans who underwent kidney function tests during 2000-01. Follow-up data to 2004 were used to identify patients who developed ESRD: permanent loss of kidney function requiring dialysis or kidney transplantation.
The study was designed to evaluate HIV as a risk factor for ESRD. About 15,000 of the veterans in the study had HIV—a rate of 0.8 percent. Fifty-four percent of the HIV-positive veterans were African American.
For white patients, HIV did not increase ESRD risk. Risk was approximately doubled for white patients with diabetes, which is the main risk factor for ESRD. In contrast, for African Americans, HIV was associated with a sharply increased risk of ESRD—twice as high as for African-American patients without HIV or diabetes. For African-Americans with diabetes, ESRD risk was also two times higher when compared to this group. (For both blacks and whites, ESRD risk was somewhat higher when both HIV and diabetes was present, compared to diabetes alone.)
After adjustment for other factors, the risk of ESRD for black patients with HIV was six times higher than for whites with HIV. For African Americans, HIV was about as strong a risk factor for ESRD as diabetes.
Kidney disease is a growing problem among patients with HIV. The number of HIV-infected patients with ESRD has increased markedly in recent years. "While we know that HIV infection can cause kidney disease, few studies have quantified the risk of ESRD associated with HIV," says Dr. Choi. The new results show an unexpected racial difference in the ESRD risk associated with HIV. "The chances of a black person with HIV developing ESRD are similar to those of a black person with diabetes," says Dr. Choi. "For reasons that are unclear, white patients with HIV are much less likely than black patients with HIV to develop ESRD."
The researchers hope their study will draw attention to the magnitude and extent of kidney disease in the HIV-infected population. "The findings highlight the importance of efforts to improve the management of kidney disease among black patients with HIV infection," adds Dr. Choi. "The pronounced race-dependence of HIV as a risk factor for ESRD also suggests that HIV may serve as a model for understanding racial differences in progression of kidney disease."