¹William J Von Liebig Transplant Center, Mayo Clinic College of Medicine, Rochester, Minnesota, USA

Correspondence: MD Stegall, William J Von Liebig Transplant Center, Rochester, MN 55904, USA. E-mail: stegall.mark@mayo.edu

Received 28 November 2005; Revised 19 April 2006; Accepted 20 June 2006; Published online 6 September 2006.

Abstract

The link between obesity and renal disease is unclear, and there is no consensus as to whether obese individuals are at increased risk for kidney disease after living kidney donation if they otherwise meet acceptance criteria. We retrospectively studied time-zero (implantation) biopsies in 49 obese (body mass index (BMI) 30 kg/m²) and 41 non-obese (BMI<30 kg/m²) renal donors that met acceptance criteria. We found that our obese donor population had higher systolic blood pressure (P<0.001 vs non-obese) and higher absolute iothalamate clearance (P=0.001 vs non-obese) before donation. The obese donors had larger glomerular planar surface area compared to non-obese controls (P=0.017), and this parameter correlated with patient weight and urinary microalbumin excretion. Detailed examination of the biopsies revealed that although most histologic findings were similar between groups, the obese donors had more tubular dilation (P=0.01), but less tubular vacuolization (P=0.02) than the non-obese controls. There was also a trend toward more arterial hyalinosis in the obese patients than controls (P=0.08). From these data, our studies detected subtle differences in donor organs obtained from obese compared to non-obese individuals. Further studies should be carried out to quantify the long-term impact of these findings.