 |
|
|
| |
Racial Disparity in Kidney Disease At Hopkins:
Sharp Racial Disparities in Kidney Trouble and End-Stage Disease in HIV+ Cohort
|
| |
| |
15th Conference on Retroviruses and Opportunistic Infections
February 3-6, 2008
Boston
(Poster online at http://www.retroconference.org/2008/PDFs/972.pdf.)
Mark Mascolini
While 39% of blacks with CKD (CKD) in the Johns Hopkins HIV cohort saw their kidney function deteriorate to end-stage renal disease (ESRD), only 3% of whites with CKD in the cohort endured the same fate from 1990 through 2004 [1]. An array of factors analyzed by Gregory Lukas and Hopkins colleagues probably contributes to this stark disparity.
The Hopkins team analyzed kidney function and other variables in all non-Hispanic African-American or white members of the cohort. No one had ESRD or stage 5 CKD when entering the cohort. The investigators estimated glomerular filtration rate (GFR) by the 4-variable modification of diet and renal disease (MDRD) equation. They defined CKD as a GFR below 60 mL/min/1.73 m(2) for more than 90 days and ESRD as the start of renal replacement therapy.
The cohort had a median age of 38 years. Two thirds were men, 78% were African American, and 47% were injecting drug users (IDUs). Lucas did not specify what proportions of blacks and whites were IDUs, though injecting drugs often correlates with failing health and fitful health care that may contribute to kidney problems. Indeed, IDUs had a 73% greater risk of a new CKD diagnosis than non-IDUs (adjusted incidence rate ratio [AIRR] 1.73, 95% confidence interval [CI] 1.25 to 2.41).
Overall incidence of CKD measured 11.2 cases per 1000 person-years in this cohort. Although being African American raised the risk of newly diagnosed chronic kidney trouble 65% (AIRR 1.65), that difference from whites straddled the line of statistical significance (95% CI 1.00 to 2.71).
Four other factors independently affected the risk of a new CKD diagnosis:
· Women had a 50% higher risk than men (AIRR 1.50, 95% CI 1.08 to 2.07).
· People 45 to 55 years old had a 45% higher risk than younger counterparts (AIRR 1.45, 95% CI 1.01 to 2.09), and people over 55 had more than triple the risk (AIRR 3.47, 95% CI 2.07 to 5.81).
· Compared with people who had more than 300 CD4s, those counting fewer than 100 had a 68% higher risk (AIRR 1.68, 95% CI 1.09 to 2.60).
· Compared with people who entered the cohort before 1996, those who entered in 2002 or later had half the risk (AIRR 0.49, 95% CI 0.30 to 0.79).
Blacks had twice the risk of progression to CKD as whites (hazard ratio 1.9, 95% CI 1.2 to 2.8, P = 0.002). Comparing African Americans and whites with CKD, the Hopkins investigators found blacks significantly younger (median 41 versus 46 years, P = 0.04) and at a decidedly more dangerous CD4 count (median 122 versus 239, P = 0.04). Notably, treatment with a protease inhibitor or nonnucleoside proved significantly more common among whites than blacks with CKD (71% versus 41%, P = 0.009). Compared with whites, African Americans with CKD had significantly worse serum creatinine, GFR, 24-hour urine protein excretion, and serum albumin (see poster).
The downward GFR slope was six times steeper in blacks than whites (-9.2 versus -1.5 mL/min/1.73m(2) per year), a highly significant difference (P < 0.001). While 99 blacks with CKD (39%) ended up with ESRD, only 1 white (3%) did (P < 0.001). Those numbers meant blacks with chronic kidney trouble had nearly an 18 times higher risk of ESRD than whites (hazard ratio 17.7, 95% CI 2.8 to 127.0, P < 0.001).
Reference
1. Lucas G, Lau B, Atta M, et al. CKD incidence and progression to ESRD in HIV-infected individuals: a tale of 2 races. 15th Conference on Retroviruses and Opportunistic Infections. February 3-6, 2008. Boston. Abstract 972.
|
| |
|
|
|
|
|
