Better Survival in African Americans with Non-Dialysis-Dependent CKD

As in dialysis patients, African Americans with advanced non-dialysis-dependent CKD (NDD-CKD) have higher survival than white patients, reports a study in the Clinical Journal of the American Society of Nephrology.

The study included two groups of men with moderate or advanced NDD-CKD: 298 African Americans and 945 white patients seen at one Veterans Affairs center. The outcomes of mortality and ESRD were compared at a median follow-up of 2.8 years.

African Americans with NDD-CKD had significantly lower crude mortality, unadjusted hazard ratio 0.75. However, the difference became nonsignificant on sequential adjustment for differences in baseline variables—particularly case-mix characteristics. African Americans with cardiovascular disease had the highest mortality.

African Americans also had a higher crude incidence of ESRD, unadjusted hazard ratio 1.64. Again, the difference became nonsignificant on adjusted analysis. Mixed effects models showed no significant racial difference in the slope of the estimated glomerular filtration rate.

Thus differences in clinical characteristics appear to account for the lower mortality in African American men with NDD-CKD, compared to white men. The fact that African Americans are more likely to die in the earlier stages of CKD may lead to selection of a group with less comorbidity and better survival later in the disease process. The apparent increase in ESRD risk may reflect the reduction in late-stage CKD mortality, rather than faster CKD progression [Kovesdy CP, Anderson JE, Derose SF, Kalantar-Zadeh K: Outcomes associated with race in males with non-dialysis dependent CKD. Clin J Am Soc Nephrol 2009; 4:973–978].