Roux-en-Y gastric bypass compared with aggressive diet and exercise therapy for morbidly obese patients awaiting renal transplant: a decision analysis.

BACKGROUND: The optimal management of morbidly obese patients awaiting renal transplant is controversial and unknown. The objective of this study was to compare the impact of Roux-en-Y gastric bypass (RYGB) versus diet and exercise on the survival of morbidly obese patients with end-stage renal disease awaiting renal transplant.
METHODS: A decision analytic Markov state transition model was designed to simulate the life of morbidly obese patients with end-stage renal disease awaiting transplant. Life expectancy after RYGB and after 1 and 2 years of diet and exercise was estimated and compared in the framework of 2 clinical scenarios in which patients above a body mass index (BMI) of 35 kg/m(2) or above a BMI of 40 kg/m(2) were ineligible for transplantation, reflecting the BMI restrictions of many transplant centers. In addition to base case analysis (45 kg/m(2) BMI preintervention), sensitivity analysis of initial BMI was completed. Markov model parameters were extracted from the literature.
RESULTS: RYGB improved survival compared with diet and exercise. Patients who underwent RYGB received transplants sooner and in higher frequency. Using 40 kg/m(2) as the upper limit for transplant eligibility, base case patients who underwent RYGB gained 5.4 years of life, whereas patients who underwent 1 and 2 years of diet and exercise gained 1.5 and 2.8 years of life, respectively. Using 35 kg/m(2) as the upper limit, RYGB base case patients gained 5.3 years of life, whereas patients who underwent 1 and 2 years of diet and exercise gained .7 and 1.5 years of life, respectively.
CONCLUSIONS: In morbidly obese patients with end-stage renal disease, RYGB may be more effective than optimistic weight loss outcomes after diet and exercise, thereby improving access to renal transplantation.