ST. LOUIS -- Black and Hispanic kidney donors are significantly more likely than white donors to develop hypertension, diabetes and chronic kidney disease, according to new Saint Louis University research published in the August 19, 2010 issue of the New England Journal of Medicine.
"We've long known that diabetes and hypertension disproportionately affect blacks and Hispanics. Our research found that these racial disparities also exist among living kidney donors, post donation," said Krista Lentine, M.D., associate professor of internal medicine and lead researcher at Saint Louis University School of Medicine. "Increased attention to health outcomes among demographically diverse kidney donors is needed."
Researchers say that while these findings should not be used to discourage anyone from donating on the basis of race and ethnicity alone, these factors should be taken into consideration when counseling potential donors about their future health risks.
Live Kidney Donation Disparities
Given the significant organ shortage, many patients with end-stage renal disease rely on living donor kidney transplantation. According to Lentine, in 2006, approximately 27,000 live donor kidney transplants were reported worldwide, and live donors supplied nearly 40 percent of kidney transplants in the U.S.
The need for live kidney donors is greatest among blacks, who are significantly more likely to develop end-stage renal disease, yet have less access to kidney transplants. Researchers say that blacks are less likely to identify a potential donor and their potential donors are more likely to have health conditions at evaluation that limit their ability to donate.
About the Research
Researchers used insurance claims from a private insurance provider, linked with identifiers from the Organ Procurement and Transplantation Network, to examine variations in the risk of post-donation medical diagnoses according to race.
All potential kidney donors undergo an evaluation that focuses on excluding patients with medical abnormalities at the time of assessment. After kidney donation, researchers found that in comparison to white donors, black donors were 52 percent more likely to be diagnosed with hypertension Hispanic donors also were 36 percent more likely than white donors to be diagnosed with hypertension. Additionally, black and Hispanic donors were more than two times as likely as white donors to be diagnosed with chronic kidney disease and to have drug-treated diabetes. Relative patterns were similar to those in the general population.
While normal pre-donation medical evaluation increases the overall likelihood of long-term good health for donors, Lentine says these screenings alone cannot be expected to eliminate the impact of epidemiologic risk factors for disease over time, such as aging and race.
"We are not proposing any change to donor selection policy based on these data," Lentine said. "However, these findings show that we need a national policy for longer donor follow up, as opposed to the current two-year mandated tracking, so that we can capture and monitor the outcomes of donors from all sociodemographic groups."
Understanding the Risks of Post-Donation Hypertension and Diabetes
According to Lentine, more studies are needed to understand the consequences of post-donation diabetes and hypertension on the overall health of the donors. In the general population, hypertension and diabetes are typically associated with increased risk of end-organ complications. However, because kidney donors often receive closer surveillance and early intervention, the implications may be milder in this group.
Even if the risk of serious end-organ damage is small with good care, better understanding of the risk for hypertension and diabetes is relevant to counseling donors on possible financial risks from future prescriptions, medical treatment and associated insurance premiums.
"All donors should be committed to long-term medical follow up so that any health conditions that arise over time can be recognized and treated," Lentine said.
Co-authors of the study include Lentine, Mark A Schnitzler, Ph.D., and Huiling Xiao, M.S., from the Center for Outcomes Researcher at Saint Louis University School of Medicine; Georges Saab, M.D., and Daniel C. Brennan, M.D., from Washington University School of Medicine in St. Louis; Paolo R. Salvalaggio, M.D., Ph.D., and Connie L Davis, M.D., from University of Washington in Seattle; David Axelrod, M.D., from Dartmouth - Hitchcock Medical Center; from Kevin C Abbott, M.D., M.P.H, from Walter Reed Army Medical Center.
The study was funded in part by grants from the National Institute of Diabetes and Digestive and Kidney Diseases.
Established in 1836, Saint Louis University School of Medicine has the distinction of awarding the first medical degree west of the Mississippi River. The school educates physicians and biomedical scientists, conducts medical research, and provides health care on a local, national and international level. Research at the school seeks new cures and treatments in five key areas: cancer, infectious disease, liver disease, aging and brain disease and heart/lung disease.