Dr. Deidra Crews of The Johns Hopkins University and colleagues wondered whether racial differences in inflammation might explain the survival paradox among dialysis patients.
The investigators tracked 554 white and 262 African-American dialysis patients from 81 clinics for an average of three years, but a range of four months to 9.5 years.
The study found:
-- After five years, 34 percent of African-Americans died, compared with 56 percent of whites, as expected.
-- A survival advantage for African-Americans only existed among patients with high levels of inflammation.
-- In comparisons of patients with lower levels of inflammation, African-American and white patients survived for similar lengths of time.
It's not clear why inflammation was linked to survivability, but the study authors said inflammation in whites may be caused mostly by heart disease while in African-Americans it may be due to other causes that have less detrimental effects on survival.
"Our findings challenge the long-held notion that African-Americans do better than whites on dialysis," Crews said in a statement. "If we can determine, and somehow modify the impact of inflammation, we may be able to improve survival for all patients treated with dialysis."
The study was published in the Journal of the American Society Nephrology.