Recipient body size and cadaveric renal allograft survival

Transplantation of renal allografts inadequate to meet recipient metabolic demands has been hypothesized to be one cause of chronic allograft failure. This cohort study examined the relationship of each of three measures of recipient body size and one measure of recipient metabolic rate to the rate of allograft failure among 239 recipients of cadaveric renal allografts between 1985 and 1990. All subjects were followed until allograft failure, death, or December 31, 1992, whichever occurred first. Using multivariate Cox proportional hazards analysis, all measures of recipient size and metabolic rate were found to be strong and statistically significant predictors of allograft survival adjusted for other predictors of allograft survival including allograft rejection, delayed allograft function, recipient race, prior renal transplantation, and donor age. The adjusted relative risk (RR) of allograft failure for a 15-kg increase in recipient body weight was 1.47, P < 0.0001 (95% confidence interval (CI), 1.21-1.78); adjusted RR for a 10-U increase in recipient body mass index was 2.34, P < 0.0001 (95% CI, 1.53-3.58); adjusted RR for a 0.5 m2 increase in recipient body surface area was 2.34, P < 0.001 (95% CI, 1.40-3.91); and adjusted RR for a 250 Kcal increase in metabolic rate was 1.49, P < 0.01 (95% CI, 1.17-1.89). These results are consistent with prior research indicating that a renal tissue supply-demand mismatch may accelerate failure of renal allografts. Alternative explanations of this relationship between recipient body size and allograft survival include inadequate immunosuppressive medication administration among recipients with a larger body size. Additional research is warranted to examine more fully the relationship between recipient body size and allograft survival.