Patients with kidney failure who undergo regular hemodialysis need a permanent site of access to veins and arteries for the exchange of fluids during dialysis. These arteriovenous access sites can be created with the patient's own vessels (native fistulae) or with synthetic grafts. Elevated lipoprotein(a) [Lp(a)] may be a risk factor for arteriovenous access complications due to blood clots and other problems among both black and white hemodialysis patients, according to recent findings from the Choices for Healthy Outcomes in Caring for ESRD (CHOICE) study. The study was supported in part by the Agency for Healthcare Research and Quality (HS08365).
The metabolic abnormalities associated with kidney failure often result in elevated levels of Lp(a), which are significantly higher among blacks than among whites, explains lead author Brad C. Astor, Ph.D., of Johns Hopkins University. Dr. Astor and his colleagues analyzed the intervention-free survival of the first arteriovenous access among 215 white and 112 black hemodialysis patients participating in the CHOICE study, a national multicenter study (81 dialysis clinics) begun in 1995 to investigate treatment choice, dose, and outcomes of dialysis care.
The researchers found that median levels of Lp(a) protein were higher among blacks than whites (81.0 vs. 37.5 nmol/L). The rate of access interventions needed to rectify complications did not vary by race but was much higher in those with synthetic grafts vs. native fistulae (1.0 vs. 0.5 interventions per access-year) and in patients with kidney failure primarily due to diabetes vs. other causes (0.9 vs. 0.6). However, blacks in the highest race-specific Lp(a) quartile (greater than 145 nmol/L) had a significantly higher rate of arteriovenous access interventions than other blacks (1.4 vs. 0.7), but no similar association was found for white patients.
More details are in "Race-specific association of lipoprotein(a) with vascular access interventions in hemodialysis patients: The CHOICE study," by Dr. Astor, Joseph A. Eustace, M.D., Michael J. Klag, M.D., and others, in Kidney International 61, pp. 1115-1123, 2002.