Quételet's index predicts outcome in cadaveric kidney transplantation

Objective: To determine the association of body composition, as estimated by Quételet's index (weight in kilograms divided by height in meters squared), with patient and graft survival in cadaveric kidney transplantation.

Design: Cohort analytic study.

Setting: 131 US transplant centers.

Patients: 16,110 adult male and 10,447 adult female recipients of cadaver kidneys between October 1987 and December 1991.

Main Outcome Measures: The relative risks of death and graft failure by Quételet's index category stratified by sex, and adjusted for recipient age, race, diabetes, previous transplantation, pretransplant blood transfusions, peak panel reactive antibody, cold ischemia time, functional status, donor age, sex, and race, and HLA antigen mismatch.

Results: There was a U-shaped relation between the relative risk of death and Quételet's index in men that was not present in women. There was an increased rate of graft loss with increasing Quételet's index in both sexes. A Quételet's index of more than 33 kg per m2 was associated with a 38% and 28% increase in the rate of graft failure in men and women, respectively. Age modified the effect of Quételet's index on graft loss in men. The associations between Quételet's index and outcomes were not influenced by race or diabetes. Results were similar when an alternative index of body composition uncorrelated with height (Benn's index) was used.

Conclusions: Body composition is an important determinant of premature death and graft loss after kidney transplantation, particularly among men. Whether the increased risks are directly attributable to body composition, or to other related factors, such as drug disposition or adherence to therapy, is unknown. Considerations should be given to nutritional interventions, including dietary modification and exercise, before cadaveric kidney transplantation.