Ethnicity Affects CKD Progression
MONTREAL—Caucasians with CKD have a significantly lower rate of renal function decline than Oriental Asians (OA) and South Asians (SA) with CKD, a new analysis revealed. The study, however, also showed that Caucasians with CKD have a higher rate of all-cause mortality.
Adeera Levin, MD, Professor of Medicine at the University of British Columbia, Vancouver, led the study. Nephrology fellow Sean Barbour, MD, was the first author.
The researchers, who presented findings at the Canadian Society of Nephrology's 2010 annual meeting, analyzed data from a British Columbia database of all individuals referred to a nephrologist between January 1, 2000 and June 30, 2006. They included 3,444 patients with pre-dialysis CKD—based on criteria that included an estimated glomerular filtration rate (eGFR) below 60 mL/min/1.73 m2—with available self-reported race and complete laboratory data. The study cohort was 76% Caucasian, 11.5% OA, and 12.2% SA.
The three groups had some significant differences in baseline characteristics. For example, the OA group had a lower eGFR than the other groups and the SA patients were significantly younger. Caucasians experienced a 2.11 mL/min/1.73 m2 decline in eGFR from baseline during the study; by comparison, the OA and SA groups had declines of 2.93 and 3.56 mL/min/1.73 m2, respectively.
In addition, the death rate among Caucasians prior to the initiation of renal replacement therapy was significantly higher than the SA and OA groups (44 vs. 23 and 31 deaths per 1,000 patient-years, respectively). Mortality rates after initiation of dialysis were comparable.
After adjusting for initiation of dialysis, eGFR, comorbidities, laboratory abnormalities, and use of ACE inhibitors, angiotensin receptor blockers, vitamin D supplements, and statins, the OA group had 31% reduced odds of death and CKD progression compared with Caucasians; the SA group had 20% reduced odds.
Furthermore, the researchers' analysis of cumulative incidence curves revealed Caucasians have a lower probability of initiating dialysis than those of OA or SA ethnicity, but a higher risk of death before starting dialysis.
Laura Plantingna, ScM, Assistant Adjunct Professor of Medicine at the University of California, San Francisco, who has co-authored studies on the prevalence of CKD in the United States, praised the Canadian researchers for conducting the pioneering work. “Differences in CKD progression and mortality between Caucasians and Asian groups have never been looked at in the U.S.,” she told Renal & Urology News.
Study findings also were published online recently in Nephrology Dialysis Transplantation.