Reverse epidemiology and the obesity paradox for patients with chronic kidney disease: a Markov decision model

Background: Obesity has been associated with both increased progression of chronic kidney disease (CKD) as well as with a paradoxical improvement in survival among end-stage renal disease patients undergoing hemodialysis. As such, the optimal weight management strategy for obese CKD patients remains unclear. Objective: To estimate the outcomes of obese, CKD stage 3b patients after 3 weight loss interventions, including medical weight management, sleeve gastrectomy (SG), and Roux-en-Y gastric bypass (RYGB), were followed to determine which strategy optimizes long-term survival. Setting: University hospital, Aurora, Colorado. Methods: A decision analytic Markov state transition model was created to simulate the life of 30,000 obese patients with CKD stage 3b, as they progressed to end-stage renal disease, transplantation, and death. Life expectancy after conservative medical weight management, RYGB, and SG were estimated. Base case patients were defined as being 50 years old and having a preintervention BMI of 40 kg/m². Sensitivity analysis of initial BMI was performed. All Markov parameters were extracted from literature review. Results: RYGB and SG were associated with improved survival for patients with preintervention body mass index of >38 kg/m². Compared with conservative weight management, base case patients who underwent RYGB gained 10.6 months of life, and gained 8.3 months of life after SG. Conclusions: Balancing progression of CKD with improved survival on end-stage renal disease for obese patients requires selective use of weight management strategies. RYGB and SG improved survival for CKD patients with Class II and III obesity, but not for patients with Class I obesity. As such, aggressive weight loss interventions should be reserved for patients with Class II and III obesity, while more conservative methods should be offered to those with Class I obesity.