Effect of Obesity on Long-term Clinical Outcomes After Kidney Donation

Several studies have shown that renal function in patients who have donated a kidney (but
are otherwise healthy) remains stable and within normal limits. However, it is unclear how
donor nephrectomy affects patient subsets with comorbidities, an issue that becomes relevant
in the current environment where inclusion criteria are continuously becoming less stringent
and more patients are being considered as potential donors.

In the present study, the investigators plan to evaluate long-term renal function in obese
patients who have donated a kidney as part of a living donor renal transplant procedure.
The investigators have selected this group because it is at higher risk for developing
obesity-related complications such as diabetes and hypertension that may impair renal
function, it is rapidly becoming a major subgroup in the kidney donor population, and no
studies have systematically followed obese patients after kidney donation. Establishment of
an appropriate control group is of primary importance in studies examining long-term
outcomes. The investigators will also evaluate a 2-kidney control group to allow us to
compare the individual and interactive effects of obesity and kidney donation on long-term
renal function. Study participants will complete a medical questionnaire, undergo blood
pressure measurements, and provide blood and urine samples for analysis of various metabolic
parameters. Some study participants will have ambulatory blood pressure monitoring
performed which involves application of an automated blood pressure cuff for 24 hours. Some
study participants will also undergo direct measurements of GFR with iohexol.

In the proposed research, the investigators hypothesize that obesity in kidney donors
increases the likelihood of developing renal dysfunction and risk factors for CVD and may
increase the likelihood even more than in healthy controls.