Setting the limit for living kidney donation—how big is too big?

Increasingly, obese and overweight but healthy individuals are being considered for living donation, but the consequences of obesity on long-term health outcomes, including the risk of progression to end-stage kidney disease after donor nephrectomy, are relatively unknown. In this issue, Locke et al. analyzed a large cohort of living kidney donors in the United States, including 26% who were obese, and estimated the attributable and relative risk of end-stage kidney disease over time. Findings from this study challenge the current recommended thresholds for obesity that usually preclude donation, and inform communication regarding risk between clinicians and prospective donors during the donor evaluation process.