The impact and treatment of obesity in kidney transplant candidates and recipients

Kidney Transplantation in Patients After Bariatric Surgery: High-Volume Bariatric and Transplant Center Experience

BACKGROUND

Kidney transplantation (KTx) is the best type of treatment for patients with end-stage renal disease (ESRD). Unfortunately, obesity may be a contraindication for transplantation. Our study aimed to evaluate the results of KTx in patients who had bariatric surgery (BS) prior to transplantation.

METHODS

A single center, with experience in bariatric and transplant surgery, presents a retrospective study of 13 patients who received a kidney transplant after a gastric bypass (GB) operation between 2012 and 2019.

RESULTS

Thirteen patients, who were potential candidates for KTx, were previously qualified for BS because of a body mass index (BMI) > 35 kg/m². Additionally, all patients had arterial hypertension, 60% of patients had diabetes, and 30% of patients had coronary artery disease. Patients were activated on the waiting list when their BMI was < 35 kg/m². KTx was performed between 5 and 29 months after BS. One patient needed reoperation due to a urinary leak and another patient needed reoperation because of a high-pressure lymphocele. We diagnosed 2 delayed graft functions (DGFs) and 1 acute rejection. One patient died for reasons independent of surgery. The KTx observation period ranged from 3 to 8 years. Currently, 11 patients has stable renal function: creatinine concentration is 0.8-1.8 mg/dL and BMI is between 23 and 35 kg/m².

CONCLUSIONS

Despite the small group of patients, we can assume that kidney transplantation can be safely performed in patients with end-stage renal disease (ESRD) who have previously undergone gastric bypass (GB) as a graft bridging procedure. In some cases, BS may be the only chance of getting an organ.

The Impact of Obesity and Associated Comorbidities on the Outcomes after Renal Transplantation with a Living Donor vs. Deceased Donor Grafts

Background: Obesity among kidney transplant (KT) recipients can lead to metabolic comorbidity-associated deaths. This study compares post-KT survival between obese and non-obese patients and outcomes of living donor (LD) and deceased donor (DD) grafts. Methods: Between January 2005−May 2019, 1403 KT recipients from a single center were included in the study, as well as 314 patients (22.4%) with obesity (BMI > 30 kg/m2), 137 DD transplants, and 177 LD transplants. Of the 1089 (77.6%) in the control group (BMI ≤ 30 kg/m2), 384 were DD transplants and 705 LD transplants. The Kaplan−Meier method was used for survival analysis and a Cox regression was used to identify risk factors for graft loss and mortality. Propensity score matching analysis adjusting for age, IHD, and T2DM was performed. Results: The study group had higher incidence of obesity related comorbidities, delayed graft function and primary non function (p < 0.001). One-, 5-and 10-year patient and graft survival were lower in the study group (p < 0.001). Subgroup analysis of graft survival according to type of graft shows a difference in the DD (p = 0.002) but not in the LD group (p = 0.220). However, mortality was higher in both groups (LD, p = 0.045; DD, p = 0.004). Risk factors for mortality were age, T2DM, IHD, and DD, and for graft failure: IHD, BMI, donor age, re-transplant, and DD. Propensity score analysis shows an odds ratio of 0.81 for graft failure and 0.93 for death in the study group (95% CI = 0.55, 1.21, p = 0.3 and CI = 0.59, 1.46, p = 0.7, respectively). Conclusions: Recipient age and metabolic comorbidities should be emphasized when evaluating patients with obesity. We suggest considering weight loss interventions using the new GLP-1 inhibitors and bariatric procedures in selected patients to prepare overweight patients for transplant.

Update on Treatment of Hypertension After Renal Transplantation

PURPOSE OF REVIEW

To incorporate novel findings on pathophysiology and treatment of posttransplant hypertension.

RECENT FINDINGS

(1) The sodium retaining effects of CNIs are mediated by stimulation of the thiazide-sensitive sodium chloride co-transporter in the distal convoluted tubule and in this regard chlorthalidone was proven to be an effective antihypertensive drug in renal transplantation. (2) Local and not systemic activation of the renin-angiotensin-aldosterone system plays a crucial role in the pathogenesis of posttransplant hypertension. (3) Recent randomized controlled trials failed to prove the presumed superiority of renin-angiotensin blockers in kidney transplantation. (4) Steroid-free and mammalian target of rapamycin-based immunosuppressive drug combinations did not show favorable effects on blood pressure control. (5) In a recent report the risk of non-melanoma skin cancer was higher with thiazide diuretics. But the increased cancer risk in transplant recipients is mainly attributed to comorbidities, such as diabetes and hypertension and of course to the transplantation condition itself or the obligatory application of immunosuppression, and has little to do with the antihypertensive medication Actual recommendations about BP targets in adult renal transplant recipients are coming from a post hoc analysis of a large randomized trial with another primary endpoint. Unless convincing studies on treatment of hypertension after renal transplantation are available, the ESC/ESH Guidelines 2018 should apply for these patients.

Conservative Management of Obesity in Kidney Transplant Candidates

OBJECTIVE

Obesity is prevalent in patients with chronic kidney disease and is associated with increased complications after kidney transplantation (KT). A body mass index limit is used in most transplant programs, though few studies have focused on conservative weight loss in KT candidates. The objective of this retrospective study is to evaluate the efficacy of a basic conservative weight management program in morbidly obese KT candidates and to perform a comprehensive nutritional evaluation.

METHODS

This retrospective study included patients with a body mass index (BMI) >35 kg/m^2, with grade IV or V chronic kidney disease. The conservative weight loss program consisted of anthropometric measurements every 3 months, consultation with a nutritionist, daily exercise, and counseling for healthier eating habits. Overall and quarterly BMI targets were defined. A subset of patients further underwent a comprehensive nutritional evaluation to measure socioeconomic characteristics, food intake behavior, motivation for change, and a 4-day food diary.

RESULTS

Eighty patients were observed for a mean of 24 months. Successful weight loss (BMI < 35 kg/m²) was achieved in 26.3%, associated with women and those already close to the limit. The mean 1-year excess body weight loss was 8.4%. No patient with a BMI >40 kg/m² was successful. The comprehensive nutritional evaluation was performed with 44 patients and found that only 14.6% had previously received nutritional counseling for weight loss. Cognitive restraint scored highest in the food-intake behavior. Most patients were motivated to lose weight with 66% in the action phase. There was little evidence of overeating with a recommended mean calculated daily caloric intake of 82.9%.

CONCLUSION

The conservative weight loss program can have limited but non-negligible, success. Future successful nutritional interventions should take into consideration this surprising comprehensive profile of morbidly obese KT candidates.

Study of weight and body mass index on graft loss after transplant over 5 years of evolution

Patients frequently experience a weight gain after organ transplantation. This increase in weight is the result of multiple factors, and is usually intensified by glucocorticoids and immunosuppressive drugs. It can also delay graft function and cause serious health problems. The objective of this study was to study the obesity as well as its causes and consequences in kidney transplant patients. The sample population consisted of 282 renal transplant patients, 170 men and 112 women, 18-74 years of age, who were monitored over a period of five years. For the purposes of our research, the patients were divided into two groups: (1) normal weight 18.5 ≤ BMI <25; (2) overweight 25 ≤ BMI ≤30. The association between BMI as an independent variable and graft survival was determined by means of a Cox regression analysis. Overweight patients were characterized by a higher comorbidity prevalence. In the Cox multivariate analysis, the initial BMI, evaluated as a continuous variable continued to be an independent predictor of delayed graft function and chronic nephropathy. This study evaluated the BMI as a continuous value instead of a categorical value. In conclusion, our results suggest that an increase in BMI without categorical variation can be an independent risk factor for graft loss. Consequently, obesity prevention for renal transplant patients should include dietary counseling and management, moderate physical activity, and steroid minimization.

Bariatric Surgery Is Efficacious and Improves Access to Transplantation for Morbidly Obese Renal Transplant Candidates

BACKGROUND

The surgical risk of morbidly obese patients is high and even higher for kidney transplant candidates. A BMI > 35-40 kg/m² is often a contraindication for that surgery. The safety, feasibility, and outcome of bariatric surgery for those patients are inconclusive.

METHODS

We conducted a retrospective chart review of prospectively collected data on morbidly obese renal transplant candidates who underwent laparoscopic sleeve gastrectomy (LSG) or laparoscopic Roux-en-Y gastric bypass (LRYGB) in our institution between January 2009 and September 2017. The reported outcome included body weight and graft status after a mean follow-up of 47 months (range 0.5-5 years).

RESULTS

Twenty-four patients (8 females, 16 males, average age 54 years, average preoperative BMI 41 kg/m² [range 35-51]) underwent LSG (n = 17) or LRYGB (n = 7). Sixteen of them (67%) proceeded to kidney transplantation. Of the 8 pre-transplant and post-bariatric surgery patients, 5 are on the waitlist, and 2 patients died (one of staple line leakage, and one from sepsis unrelated to the bariatric surgery). The average time from bariatric surgery to transplantation was 1.5 years (range 1 month to 4.3 years). The average pre-transplantation BMI was 28 kg/m² (range 19-36). The mean percentage of excess weight loss was 66% (n = 21), and the total percentage of weight loss was 29% (n = 21). Comorbidities (type 2 diabetes, hypertension, and dyslipidemia) improved significantly following both surgical approaches.

CONCLUSIONS

LSG and LRYGB appear to effectively address obesity issues before kidney transplantation and improve surgical access. Morbidly obese transplant candidates would benefit from prior bariatric surgery.

Orthostatic Renal Transplant Compression Following Weight Gain Leading to Acute Kidney Injury

BACKGROUND

We present a first case of orthostatic renal graft compression and acute kidney injury following weight gain.

CASE REPORT

A 61-year-old male with a second cadaveric transplant presented with acute kidney injury - creatinine rise from 80 to 210 μmol/L (0.90 to 2.38 mg/dL). His medical history included diabetes, hypertension, ischemic heart disease, and obesity despite bariatric surgery. Renal biopsy was consistent with acute tubular necrosis. Serial renovascular duplex studies showed absence of diastolic flow and reduced renal perfusion despite a patent renal transplant artery and vein. Raising the fatty apron cephalad normalized renal blood flow with resistive indices throughout the kidney. Subsequent laparascopy ruled out adhesional obstruction and carbon dioxide angiogram confirmed normal transplant vessels, anastomotic sites, and intrarenal branches. He was treated with bedrest and an abdominal support belt with improvement of creatinine to 100 to 110 μmol/L (1.1-1.2 mg/dL).

CONCLUSIONS

Transplant physicians and surgeons need to be aware of positional renal graft compression from an enlarged bulky omentum and fatty apron. Diagnosis requires positional sonography.

Obesity in kidney transplantation

The prevalence of obesity among patients with chronic kidney disease continues to increase as a reflection of the trend observed in the general population. Factors affecting the access to the waiting list and the transplantability of this specific population will be analysed. From observational studies, kidney transplantation in obese patients carries an increased risk of surgical complications compared to the nonobese population; therefore, many centres have been reluctant to proceed with transplantation, despite this treatment modality confers a survival advantage over dialysis. As a consequence, obese patients continue to face decreased access to the waiting list, with a lower likelihood of being transplanted and higher waiting times when compared to the nonobese candidates. In this review will be described the current strategies for treatment of obesity in different settings (pretransplant, at transplant and post-transplant). Obesity represents a risk factor for surgical complications but not a contraindication for kidney transplantation; outcomes could be greatly improved with its multidisciplinary and multimodal treatment. The modern technology with minimally invasive techniques, mainly using robotic platform, allows a reduction in the surgical complications rate, with graft and patient survival rates comparable to the nonobese counterpart.

The Effects of Bariatric Surgery on Renal Outcomes: a Systematic Review and Meta-analysis

BACKGROUND/OBJECTIVE

Although promising, data regarding the renal impact and safety of bariatric surgery (BS) are insufficient. We aimed at investigating the benefits and harms of BS for weight loss on kidney function.

METHODS

A systematic review and meta-analysis of observational studies reporting data about the impact of BS (any techniques) on serum/plasma creatinine, creatinine clearance, glomerular filtration rate (GFR), proteinuria, nephrolithiasis, and need for renal replacement therapy (RRT)) was performed. Obese adults (non-chronic kidney disease (CKD), CKD or transplanted patients) that underwent BS for weight loss were included. After searching MEDLINE (inception to August 2017), the Cochrane Library (Issue 10-12, October 2017), and the websiteclinicaltrials.gov (August 2017), data were extracted and summarized using a random-effects model.

RESULTS

The final analysis included 23 cohort studies, comprising 3015 participants. Compared with renal function before treatment, BS significantly decreased serum creatinine level (mean difference (MD), - 0.08 mg dl^-1; 95% confidence interval (CI), - 0.10 to - 0.06); p < 0.001) and proteinuria (MD, - 0.04 g 24 h^-1; 95% CI, - 0.06 to - 0.02; p < 0.001) in the overall group. GFR significantly improved 6 months or more after BS both in the hyperfiltration and CKD subgroups. Renal function also tended to improve in renal transplant patients. Data on nephrolithiasis and the need for RRT were scarce or not reported.

CONCLUSIONS

BS apparently has positive effects on kidney function and tends to normalize GFR across different categories of renal impairment (hyperfiltration and CKD patients).

Obesity in Kidney Transplantation: Impact on Transplant Candidates, Recipients, and Donors

Obesity is now common among children and adults who are kidney transplant candidates and recipients. It is associated with an increased risk of cardiovascular disease and kidney failure. This also pertains to potential living kidney donors with obesity. Obese patients with end-stage renal disease benefit from transplantation as do nonobese patients, but obesity is also associated with more risk. A complicating factor is that obesity is also associated with increased survival on maintenance dialysis in adults, but not in children. The assessment of obesity and body habitus should be individualized. Body mass index is a common but imperfect indicator of obesity. The medical management of obesity in renal failure patients is often unsuccessful. Bariatric surgery, specifically laparoscopic sleeve gastrectomy, can result in significant weight loss with reduced morbidity, but many patients do not agree to undergo this treatment. The best approach to manage obese transplant candidates and recipients is yet unresolved.

Obesity as a barrier to kidney transplantation: Time to eliminate the body weight bias?

There is clear evidence that survival rates following transplantation far exceed those for remaining on dialysis, regardless of body size measured by body mass index (BMI). Studies over the past 15 years also suggest little to no difference in long-term outcomes, including graft survival and mortality, irrespective of BMI, in contrast to earlier evidence. However, weight bias still exists, as access to kidney transplantation remains inequitable in centers using arbitrary BMI limits. Clinicians faced with the decision regarding listing based on body size are not helped by conflicting recommendations in national and international guidelines. Therefore, in clinical practice, obesity, and recommendations for weight loss, remain a controversial issue when assessing suitability for kidney transplantation. Obesity management interventions in end-stage kidney disease (ESKD), whether for weight loss for transplantation listing or for slowing kidney disease progression, are under-explored in trial settings. Bariatric surgery is the most successful treatment for obesity, but carries increased risk in the ESKD population, and the desired outcome of kidney transplant listing is not guaranteed. Centers that limit transplants to those meeting arbitrary levels of body mass, rather than adopting an individualized assessment approach, may be unfairly depriving many ESKD patients of the survival and quality of life benefits derived from kidney transplantation. However, robotic kidney transplantation surgery holds promise for reducing perioperative risks related to obesity, and may therefore represent an opportunity to remove listing criteria based on size.

Gastric sleeve surgery in hemodialysis: A case report

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Obese patients with end-stage renal disease on hemodialysis, decreases the access to kidney transplantation.

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Bariatric surgery has proven to be safe and effective for weight loss.

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Dialysis-dependency does not independently increase the risk for adverse outcomes after bariatric surgery.

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The estimation of DW through BIA is an effective method for avoiding complications generated by excessive or deficient ultrafiltration.

Introduction

Morbid obesity in chronic kidney disease patients on hemodialysis limits access to renal transplantation. We report here a case of a surgical procedure for weight reduction in a hemodialysis patient and adjustment of dry weight through bioelectrical impedance.

Case presentation

A 44-year-old male with CKD on hemodialysis for 26 years. After 3 years on dialysis, he underwent a cadaveric kidney transplant. However, after 8 years of transplant, he loses the kidney graft and returns to dialysis treatment. The patient’s BMI increased to 42 kg/m² and he had difficult-to-control hypertension and severe sleep apnea. Behavioral, nutritional and pharmacologic measures were not sufficient to achieve an adequate weight control. Thus, a surgical procedure for weight reduction was considered. The patient underwent a laparoscopic gastric sleeve without any complications. Dry weight was adjusted through bioelectrical impedance before each hemodialysis session. The patient did not display hypotension, cramps, or fluid overload. After a 30 kg weight loss, the patient’s BMI was 28.3 kg/m², allowing registration on the kidney transplant waitlist.

Discussion

Obesity in CKD restricts access to kidney transplant waitlist. Bariatric surgery has proven to be safe and effective for sustained weight loss and it seems that the fact that a patient is dialysis dependent does not independently increase post-operatory complications.

Conclusion

Surgical procedures for weight reduction in dialysis patients does not independently increase the risk for adverse outcomes after bariatric surgery. The estimation of DW through BIA is an effective method for avoiding complications generated by excessive or deficient ultrafiltration.

Laparoscopic Sleeve Gastrectomy for Morbid Obesity in Patients After Orthotopic Liver Transplant: a Matched Case-Control Study

INTRODUCTION

Obesity is frequently encountered in patients with orthotopic liver transplant (OLT). The role of bariatric surgery is still unclear for this specific population. The aim of this study was to review our experience with laparoscopic sleeve gastrectomy (LSG) after OLT.

MATERIAL AND METHODS

We performed a retrospective case-control study of patients undergoing LSG after OLT from 2010 to 2016. OLT-LSG patients were matched by age, sex, body mass index (BMI), and year to non-OLT patients undergoing LSG. Demographics, operative variables, postoperative events, and long-term weight loss with comorbidity resolution were collected and compared between cases and controls.

RESULTS

Of 303 patients undergoing LSG, 12 (4%) had previous OLT. They were matched to 36 non-OLT patients. No difference was found between groups in the American Society of Anesthesiologists class, mean operative time, or postoperative morbidity. The non-OLT group, however, had a significantly shorter mean hospital stay than the OLT group (1.7 vs 3.1 days; P < .001). There were no conversions to open procedures. For patients with long-term follow-up, change in BMI after LSG was similar between the groups, but the non-OLT patients had significantly more excess body weight loss at 2 years (53.7 vs 45.2%; P < .001). Similar resolution of comorbid conditions was noted in both groups. LSG caused no changes in dosage of immunosuppressive medications, and no liver complications occurred.

CONCLUSION

LSG after OLT in appropriately selected patients appears to have similar outcomes to LSG in non-OLT patients.

Laparoscopic Sleeve Gastrectomy in Kidney Transplant Candidates: a Case Series

BACKGROUND

Patients with a body mass index (BMI) >35 kg/m² who need kidney transplant present with increased postoperative mortality and reduced kidney graft survival compared to patients with a lower BMI. For this reason, obese patients are often excluded from the transplantation waiting list. The aim of this study was to evaluate the feasibility and the results of laparoscopic sleeve gastrectomy (LSG) for obese patients awaiting a kidney transplant.

METHODS

This was a retrospective study on patients with dialysis-dependent renal failure (DDRF) operated on at two first-level bariatric centers in Paris (France). All the patients were contraindicated for kidney transplantation due to the presence of morbid obesity.

RESULTS

Nine DDFR patients with a mean BMI of 45.9 kg/m² underwent LSG for the treatment of obesity. Furthermore, all patients presented with hypertension and sleep apnea and six out nine were diabetics. In the immediate postoperative period, all patients were transferred to the intensive care unit (mean stay of 2.1 days). The only major adverse event was a delayed weaning from mechanical ventilation in one patient. The mean hospital stay was 5.5 days (3-12). The total weight loss (TWL) was 27.1, 33.6, and 39.5 kg at 6, 12, and 18 months, respectively. One patient underwent renal transplantation 18 months after LSG, and the other five patients were actively listed for kidney transplantation.

CONCLUSIONS

According to the results of this small sample series, LSG seems to be an effective and safe procedure in DDRF patients with concomitant obesity and can increase access to transplantation.

Hypertension in the Kidney Transplant Recipient: Overview of Pathogenesis, Clinical Assessment, and Treatment

Cardiovascular disease is the leading cause of death in patients with chronic renal disease and the most common cause of death and allograft loss among kidney transplant recipients. Transplant patients often have multiple cardiovascular risk factors antedating transplantation. Among the most prominent is hypertension (HTN), which affects at least 90% of transplant patients. Uncontrolled HTN is an independent risk factor for allograft loss. The etiology of HTN in transplant recipients is complex and multifactorial, including the use of essential immunosuppressive medications. Post-transplant HTN management requires a systematic and individualized approach with nonpharmacologic and pharmacologic therapies. There is no single ideal agent or treatment algorithm. Patients should regularly monitor and record their blood pressure at home. Often, multiple antihypertensive drugs are needed to achieve a goal blood pressure of 120-140/70-90 mm Hg. As transplant recipients commonly must take 8 to 12 different medications daily, adherence must be continually encouraged and monitored. Special attention must be paid to potential drug side effects and drug interactions with immunosuppressive medications.

Bariatric Surgery and Kidney-Related Outcomes

The prevalence of severe obesity in both the general and the chronic kidney disease (CKD) populations continues to rise, with more than one-fifth of CKD patients in the United States having a body mass index of ≥35 kg/m². Severe obesity has significant renal consequences, including increased risk of end-stage renal disease (ESRD) and nephrolithiasis. Bariatric surgery represents an effective method for achieving sustained weight loss, and evidence from randomized controlled trials suggests that bariatric surgery is also effective in improving blood pressure, reducing hyperglycemia, and even inducing diabetes remission. There is also observational evidence suggesting that bariatric surgery may diminish the long-term risk of kidney function decline and ESRD. Bariatric surgery appears to be relatively safe in patients with CKD, with postoperative complications only slightly higher than in the general bariatric surgery population. The use of bariatric surgery in patients with CKD might help prevent progression to ESRD or enable selected ESRD patients with severe obesity to become candidates for kidney transplantation. However, there are also renal risks in bariatric surgery, namely, acute kidney injury, nephrolithiasis, and, in rare cases, oxalate nephropathy, particularly in types of surgery involving higher degrees of malabsorption. Although bariatric surgery may improve long-term kidney outcomes, this potential benefit remains unproved and must be balanced with potential adverse events.

An Integrative Literature Review of Physical Activity Recommendations for Adult Renal Transplant Recipients

OBJECTIVE

To establish the current state of knowledge regarding physical activity interventions for adult kidney transplant recipients.

DATA SOURCES

A comprehensive literature search was conducted for the years 2009 to 2015 using 5 electronic databases: PubMed, CINAHL, Cochrane Library, Ovid, and ScienceDirect.

DATA EXTRACTION

Of the 110 articles identified, only 6 met inclusion requirements. These studies were conducted between 2009 and 2015 and found that weight gain was reported most often within the first year of transplantation and that kidney transplant recipients desired early interventions to help them become more physically active.

CONCLUSION

Further research is recommended to design age-appropriate physical activity interventions among this aging population living with a chronic condition known to have a high prevalence of obesity and cardiovascular disease.

The impact of morbid obesity on resource utilization after renal transplantation

BACKGROUND

A growing number of renal transplant recipients have a body mass index ≥40. While previous studies have shown that patient and graft survival are significantly decreased in renal transplant recipients with body mass indexes ≥40, less is known about perioperative outcomes and resource utilization in morbidly obese patients. We aimed to analyze the effects of morbid obesity on these parameters in renal transplant.

METHODS

Using a linkage between the Scientific Registry of Transplant Recipients and the databases of the University HealthSystem Consortium, we identified 29,728 adult renal transplant recipients and divided them into 2 cohorts based on body mass index (<40 vs ≥40 kg/m²). The body mass index ≥40 group comprised 2.5% (n = 747) of renal transplant recipients studied.

RESULTS

Body mass index ≥40 recipients incurred greater direct costs ($84,075 vs $79,580, P < .01), index admission costs ($91,169 vs $86,141, P < .01), readmission costs ($5,306 vs $4,596, P = .01), and combined costs ($99,590 vs $93,939, P < .001). Thirty-day readmission rates were also greater among body mass index ≥40 recipients (33.92% vs 26.9%, P < .01). Morbid obesity was not predictive of stay (odds ratio 1.01, P = .75).

CONCLUSION

Morbidly obese renal transplant recipients incur greater costs and readmission rates compared with nonobese patients. Recognition of increased resource utilization should be accompanied by appropriate, risk-adjustment reimbursement.