The influence of recipient body mass on the outcome of cadaver kidney transplants.

Abstract

Background. It is well known that a cadaver kidney transplant from an aged donor will result in lower graft survival. However, such marginal kidneys should not be easily given up, and it is important to explore ways to make the best use of them. Against this background, the present study was carried out to examine the relationship between recipient body mass and cadaver kidney transplant outcome. Methods. All 63 cadaver kidney transplant recipients at our institutions were studied. These patients were divided into two groups according to the age of the donor: group A (under age 60 years; n = 48) and group B (age 60 years and over; n = 15). Each of the groups was subdivided into two groups according to the mean body mass index (BMI) and body surface area (BSA) values, and the effects of BMI and BSA on graft survival were also studied. Results. There was no correlation between BMI and lowest serum creatinine (nadir S-Cr) in group A, but there was a positive correlation in group B. Similarly, there was a positive correlation between BSA and nadir S-Cr only in group B. In group A, there was no difference in graft survival between the recipients with a smaller BMI (BMI < 21.0) and larger BMI (BMI ≧ 21.0) or BSA. However, in group B, the 5-year graft survival of the recipients with a smaller BMI was 60.0%, and it was significantly better than that of the recipients with a larger BMI. Similarly, the 5-year graft survival of the recipients with a smaller BSA (BSA < 1.54 m(2)) was 62.5%, which was also significantly better than that of the recipients with a larger BSA (BSA ≧ 1.54 m(2)). Conclusions. In the recipients whose donor was aged 60 and over, recipient BMI and BSA affected posttransplant kidney function and graft survival. These results strongly suggest that the lower graft survival due to an aged donor can be improved if a recipient with a smaller body size can be selected.