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

Trial Summary

The impact of obesity on long-term renal function and cardiovascular disease risk factors in patients who donated a Kidney at the UCSF.

Eligibility

All patients who underwent donor nephrectomy at UCSF more than 5 years ago (1967-2004). 

Detailed Description

Live donor kidney transplantation is generally considered the best choice for transplant recipients.  This is primarily due to the recognition that live donor kidneys function better and last longer than kidneys from cadaveric donors, the introduction of less invasive techniques for donor nephrectomy, the long waiting times for cadaveric transplantation, and broadening of the pool of eligible donors.

Although several retrospective studies have shown that kidney donation is associated with very low rates of short-term morbidity and mortality, the data examining long-term outcomes are much less complete.  This is particularly true of donor groups with medical co-morbidities which are now being utilized with greater frequency.

One such patient group is the overweight donor.  There is substantial evidence that overweight patients are more susceptible to the development of renal disease either as a direct result of their weight or as a consequence of their obesity-related co-morbidities.  In addition, it appears that even mild renal dysfunction can increase the risk of developing cardiovascular disease (CVD), an important concern in this population.

Despite these findings, very little is known about the long-term outcomes in overweight kidney donors.  In the proposed research, we 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.

The study groups will consist of patients who donated a kidney at UCSF between 1967-2004.  The 2-kidney control groups will comprise of all potential kidney donors during this period who passed initial medical screening tests but were found to be ABO- or cross-match incompatible.  The following specific aims will be pursued:

Primary Objective

Examine the effects of kidney donation and obesity on long-term renal function.  Study and control subjects will undergo a medical interview, physical exam, blood and urine collections, and direct measurement of renal function using iohexol. 

Examine the effects of kidney donation and obesity on the development of hypertension and other CVD risk factors.  All study subjects will be screened for the presence of CVD risk factors with the following tests:  clinic and 24-hour blood pressure monitoring, evaluation for metabolic syndrome, measurements of serum lipids, fasting glucose and insulin, homocysteine, and cystatin

We believe that these studies will provide important information regarding a donor subpopulation that is being encountered more frequently and will allow better selection and long-term management of this group.

Control Population

The following groups will serve as the control for this study.
 
A. The 1-Kidney control group will consist of the  normal weight donors as internal controls for the overweight donor groups

B.   The 2-kidney control group will consist of prospective donors evaluated at UCSF between 1967-2004 who were found to be eligible for donation on the basis of a medical screening evaluation, but then were excluded due to unrelated medical reasons.

Final eligibility is determined by the health professionals conducting the trial and the protocol approved by the Committee on Human Resources (CHR) at the University of California, San Francisco (UCSF). The Patient Consent Form for this trial is available upon request.

For More Information