Treating the Obese Dialysis Patient: Challenges and Paradoxes

Obesity and Kidney Transplantation-How to Evaluate, What to Do, and Outcomes

Obesity is a growing issue that is spreading worldwide; its prevalence is ever increasing in patients with end-stage renal disease and represents a potential barrier to transplantation. The lack of unanimous guidelines exacerbates the current disparity in treatment, which can affect outcomes, leading to a significantly longer time on the waiting list. Multidisciplinary and multimodal management (encompassing several healthcare professionals such as nephrologists, transplant physicians and surgeons, primary care providers, and nurses) is of paramount importance for the optimal management of this patient population in a continuum from waitlisting to transplantation. Development of this guideline followed a standardized protocol for evidence review. In this review, we report on our clinical experience in transplantation of obese patients; strategies to manage this condition, including bariatric surgery, suitable timing for transplantation among this patient population, and clinical experience in robotic sleeve gastrectomy; and simultaneous robotic kidney transplantation to achieve optimal outcomes.

Comparable kidney transplant outcomes in selected patients with a body mass index ≥ 40: A personalized medicine approach to recipient selection

INTRODUCTION

Many kidney transplant (KT) centers decline patients with a body mass index (BMI) ≥40 kg/m2 . This study's aim was to evaluate KT outcomes according to recipient BMI.

METHODS

We performed a single-center, retrospective review of adult KTs comparing BMI ≥40 patients (n = 84, BMI = 42 ± 2 kg/m2 ) to a matched BMI < 40 cohort (n = 84, BMI = 28 ± 5 kg/m2 ). Patients were matched for age, gender, race, diabetes, and donor type.

RESULTS

BMI ≥40 patients were on dialysis longer (5.2 ± 3.2 years vs. 4.1 ± 3.5 years, p = .03) and received lower kidney donor profile index (KDPI) kidneys (40 ± 25% vs. 53 ± 26%, p = .003). There were no significant differences in prevalence of delayed graft function, reoperations, readmissions, wound complications, patient survival, or renal function at 1 year. Long-term graft survival was higher for BMI ≥40 patients, including after adjusting for KDPI (BMI ≥40: aHR = 1.79, 95% CI = 1.09-2.9). BMI ≥40 patients had similar BMI change in the first year post-transplant (delta BMI: BMI ≥ 40 +.9 ± 3.3 vs. BMI < 40 +1.1 ± 3.2, p = .59).

CONCLUSIONS

Overall outcomes after KT were comparable in BMI ≥40 patients compared to a matched cohort with lower BMI with improved long-term graft survival in obese patients. BMI-based exclusion criteria for KT should be reexamined in favor of a more individualized approach.

Dialysis of the Obese Patient: Meeting Needs for a Growing Epidemic

Increasing population obesity and associated metabolic consequences has led to increased number of obese patients with chronic kidney disease and end-stage renal disease. While obesity is associated with increased cardiovascular morbidity and mortality, obese dialysis patients present a seeming paradox for survival benefit, given other acute intervening illnesses for those on dialysis with loss of lean body mass overtime. Challenges remain in providing adequate renal replacement options and therapy for this growing segment of obese patients on dialysis which are discussed in this article.

Impact of obesity on dialysis and transplant and its management

Obesity is increasing to unprecedented levels, including in the end-stage kidney disease population, where upwards of 60% of kidney transplant patients are overweight or obese. Obesity poses additional challenges to the care of the dialysis patient, including difficulties in creating vascular access and inserting Tenckhoff catheters, higher rates of catheter malfunction and peritonitis, the need for longer and/or more frequent dialysis (or peritoneal dialysis [PD] exchanges) to achieve adequate clearance, increased metabolic complications particularly with PD, and obesity is a barrier to kidney transplantation. In this article, we review special considerations in performing PD, hemodialysis and transplant in the obese patient, as well as the evidence behind medical and surgical management of obesity in dialysis patients.

Intensive weight loss combining flexible dialysis with a personalized, ad libitum, coach-assisted diet program. A "pilot" case series

Obesity is a growing problem on dialysis. The best approach to weight loss has not been established. The risks of malnutrition may offset the advantages of weight loss. Personalized hemodialysis schedules, with an incremental approach, are gaining interest; to date, no studies have explored its potential in allowing weight loss. This case series reports on combining flexible, incremental hemodialysis, and intensive weight loss.

SETTING

a small Dialysis Unit, following incremental personalized schedules (2-6 sessions/week, depending on residual function), tailored to an equivalent renal clearance >12 mL/min. Four obese and two overweigh patients (5 male, 1 female; age: 40-63 years; body mass index [BMI] 31.1 kg/m(2)) were enrolled in a coach-assisted weight loss program, with an "ad libitum" approach (3-6 foods/day chosen on the basis of their glycemic index and glycemic load). The diet consists of 8 weeks of rapid weight loss followed by 8-12 weeks of maintenance; both phases can be repeated. This study measures weight loss, side effects, and patients' opinions. Over 12-30 months, all patients lost weight (median -10.3 kg [5.7-20], median ΔBMI-3.2). Serum albumin (pre-diet 3.78; post-diet 3.83 g/dL), hemoglobin (pre-diet 11; post-diet 11.2 g/dL), and acid-base balance (HCO(3) pre-diet: 23.3; post-diet: 23.4 mmol/L) remained stable, with decreasing needs for erythropoietin and citrate or bicarbonate supplements. Calcium-phosphate-parathyroid hormone (PTH) balance improved (PTH-pre 576; post 286 pg/mL). Three out of 4 hypertensive patients discontinued, 1 decreased antihypertensives. None experienced severe side effects. Patient satisfaction was high (9 on a 0-10 analog scale). Personalized, incremental hemodialysis schedules allow patient enrollment in intensive personalized weight loss programs, with promising results.

Bariatric surgery in patients with reduced kidney function: an analysis of short-term outcomes

BACKGROUND

With rates of obesity among patients with chronic kidney disease (CKD) mirroring that of the general population, there is growing interest in offering bariatric surgery to these patients. We sought to determine the safety of bariatric surgery in this patient population.

METHODS

Patients who underwent selected laparoscopic bariatric procedures between 2005 and 2011. Estimated glomerular filtration rate (eGFR) was calculated and divided into stages of CKD. Procedures included Roux-en-Y gastric bypass (RYGB), laparoscopic adjustable gastric band (LAGB), and laparoscopic sleeve gastrectomy (SG). Univariable analysis and multivariable adjustment was used to compare complication rates across stages of eGFR.

RESULTS

A total of 64,589 patients were included: 64.5% underwent RYGB, 29.8% LAGB, and 5.7% SG. A total of 61.7% of patients had normal eGFR (Stage 1), 32.0% were stage 2, 5.3% were stage 3, and 1.0% were stage 4/5. After adjusting for relevant patient characteristics, there was a trend toward increasing complications from stage 1 to stage 4/5 CKD among RYGB, LAGB, and SG groups, but none were statistically significant. Similarly, major complications generally increased across stages of CKD for each procedure, but was only significant for RYGB comparing stage 3 to stage 1 (OR 1.22; 95% CI: 1.01-1.47; P = .042) and risk difference .96% (95% CI: .03-1.96). Considering only stage 4/5 CKD, overall (P = .114) and major complications (P = .032) were highest in the RYGB group, followed by SG and LAGB.

CONCLUSION

More advanced stages of CKD do not appear to be statistically associated with an increased risk of 30-day postoperative complications.

Kidney transplantation in the obese transplant candidates: to transplant or not to transplant?

The prevalence of obesity (body mass index ≥30 kg/m(2)) at the time of transplantation among kidney transplant recipients in the United States has doubled between 1987 and 2001 and continues to increase inexorably. Single-center and large registry studies in kidney transplant recipients demonstrated that high body mass index (BMI) at transplant is associated with increased risk of wound and surgical site infections, delayed graft function (DGF), acute rejection episodes, and graft loss, among others. Hence, in many centers, obese transplant candidates are denied a transplant based on their body mass index (BMI) alone. The impact of obesity on short- and long-term graft and patient outcomes after kidney transplantation are herein revisited, followed by the authors' proposed approach to evaluate and select obese transplant candidates for a kidney transplant. Suggested interventions to optimize the health of such candidates are also discussed.