Emory Investigators Find That Bariatric Surgery Could be Safe for Kidney Disease Patients

March 2012

Dr. Nicole Turgeon was lead author and Dr. John Sweeney senior author of the largest study of its kind to focus on the impact of kidney function on patients' health following weight-loss surgery. Published online March 1, 2012, by the Journal of the American Society of Nephrology, "The Impact of Renal Function on Outcomes of Bariatric Surgery" suggests that obese chronic kidney disease patients who undergo surgery to achieve weight loss do not face a particularly dangerous rate of complications as a result.

Using the American College of Surgeons National Surgical Quality Improvement Program Participant Use File, Drs. Turgeon, Sweeney, and their co-authors analyzed information from 27,736 patients who underwent weight-loss surgery between 2006 and 2008. Before surgery, 34 (0.12%) patients were undergoing long-term dialysis. Among those not undergoing dialysis, 20,806 patients (75.0%) had a normal estimated glomerular filtration rate (GFR) or stage 1 chronic kidney disease (CKD), 5011 (18.07%) had stage 2 CKD, 1734 (6.25%) had stage 3 CKD, 94 (0.34%) had stage 4 CKD, and 91 (0.33%) had stage 5 CKD. In an unadjusted analysis, CKD stage was directly associated with complication rate, ranging from 4.6% for those with stage 1 CKD or normal estimated GFR to 9.9% for those with stage 5 CKD (test for trend, P,0.001). Multivariable logistic regression demonstrated that CKD stage predicts higher complication rates (odds ratio for each higher CKD stage, 1.30) after adjustment for diabetes and hypertension. Although patients with higher CKD stage had higher complication rates, the absolute incidence of complications remained 10%.

In view of the data demonstrating higher risks of bariatric surgery among patients with worse renal function, the researchers emphasized that further study is needed to establish whether the potential benefits outweigh the risks in this population. However, they also note, the upside of such a surgical intervention could be tremendous, as obesity can be an impediment to a patient's ability to undergo a lifesaving kidney transplant.

"This work provides strong evidence that it is safe to proceed with bariatric surgery in kidney failure patients who suffer from obesity," says Dr. Sweeney.