Obesity and renal transplant outcome: A report of the North American Pediatric Renal Transplant Cooperative Study

Objective. Obesity is increasing in the end-stage renal disease population. Studies that have evaluated the effect of obesity on transplant outcomes in adults have yielded varying results. This issue has received little attention in the pediatric population. Methods. We performed a retrospective study of the effect of obesity on pediatric renal transplant outcomes using the North American Pediatric Renal Transplant Cooperative Study database. Registry data from 1987 through 2002 on 6658 children aged 2 to 17 years were analyzed. Obesity was defined by a BMI>95th percentile for age. Results. Overall, 9.7% were obese with an increase noted in recent years (12.4% after 1995 vs 8% before 1995). Obese children were significantly younger and shorter and had been on dialysis for a longer time than nonobese children. There was no significant difference in the overall patient and allograft survival between the 2 groups. However, obese children aged 6 to 12 years had higher risk for death than nonobese patients (adjusted relative risk: 3.65 for living donor; adjusted relative risk: 2.94 for cadaver), and death was more likely as a result of cardiopulmonary disease (27% in obese vs 17% in nonobese). Overall, graft loss as a result of thrombosis was more common in obese as compared with nonobese (19% vs 10%). Conclusions. Obesity is an increasing problem in children who present for transplantation and may have an adverse effect on allograft and patient survival.