Study evaluates why blacks do not successfully donate kidneys

May 8 2007

In one of the first studies of its kind, researchers from Wake Forest University School of Medicine explored why blacks are less likely than other races to become living kidney donors, and the reasons are obesity and failure to complete the donor evaluation.

"Obesity is a growing problem in the African-American community, particularly among women, and this reflects what we found in the study," said Amber Reeves-Daniel, D.O., an instructor in internal medicine-nephrology. "The other issue is the social reasons for non-donation, including failure to complete the donor evaluation process. This issue is just not well understood."

Reeves-Daniel reported the results at the 2007 American Transplant Congress in San Francisco.

Donor questionnaires and charts for 541 disqualified potential donors were reviewed. The disqualified donors were all identified by documented information, race, gender and cause of donor exclusion. In some cases, disqualified donors had more than one reason for exclusion.

About 30 percent of blacks were excluded because of obesity, compared to 16.6 percent of whites. Obesity was defined by body mass index (BMI) greater than or equal to 32 kg/m. Twelve percent of blacks were excluded because they didn't complete the evaluation process, compared to 1.8 percent of whites. For whites, the biggest reason for exclusion was kidney stones, at 7.3 percent, compared to 1.5 percent in blacks.

"Further study of these differences may improve our understanding of the causes of low rates of living kidney donation among African-Americans, particularly regarding the social reasons," said Reeves-Daniel. "Is it lack of trust in the medical community, financial inability to get to doctor's appointments for tests, concerns with work and child care, or perhaps some other issue?"

The researchers also examined reasons for non-donation between men and women. They found that more women than men did not donate because of reduced renal function, at 7.9 percent and 0.9 percent, respectively. Also, more women (6.4 percent) than men (1.8 percent) were excluded due to not completing the process.

"I did find this kind of surprising because more women successfully donate than men, at a rate of 58 percent versus 42 percent," said Reeves-Daniel.

"We hope all of these results will help with understanding so we can recruit successful donors in the future."