Population-based Trends in Obesity and Kidney Transplantation Among Patients With End-stage Kidney Disease

Abstract

Background. Obesity is a barrier to transplant, reducing access and leading to worse outcomes versus nonobese adults. Most transplant centers in the United States maintain body mass index (BMI) cutoffs to listing for kidney transplantation of 35 to 40kg/m2. There is little contemporary data on the prevalence of obesity among patients with end-stage kidney disease (ESKD) despite its impact on clinical outcomes and healthcare expenditures. Methods. We utilized data from the US Renal Data System from 2008 to 2016 to identify a prevalent cohort of 1079410 patients with ESKD. Linear regression determined trends in the proportion of patients within each category of BMI. We also evaluated geographic variation in rates of obesity and transplantation across the United States. Results. Among the 1079410 ESKD patients, the largest cohort of patients were those with obesity (n=423270; 39.2%). There were 309707 (28.7%) patients with an overweight BMI and 274683 (25.4%) with a normal BMI. The proportion of patients with obesity increased significantly from 36.8% in 2008 to 40.2% in 2016 (trend 0.28; 95% confidence interval, 0.05-0.51). There was significant geographic variation by state with rates of obesity ranging from 32.3% to 45.4% and state transplant rates among those obese patients ranging from 22.5% to 46.8%. There is a weak correlation between states with increased rates of obese ESKD patients and states with an increased obesity transplant rate as indicated with r=0.40 (P=0.003). Conclusions. Beneficiaries with obesity are now the largest and fastest growing demographic among patients with ESKD in the United States.