National Postoperative Bariatric Surgery Outcomes in Patients with Chronic Kidney Disease and End-Stage Kidney Disease

Evaluating the safety of bariatric surgery as a bridge to kidney transplant: a retrospective cohort study

BACKGROUND

Bariatric surgery has been proven safe in end-stage kidney disease (ESKD); however, few studies have evaluated whether a history of bariatric surgery impacts transplant-specific outcomes. We hypothesize that a history of bariatric surgery at the time of transplant does not adversely impact transplant-specific outcomes.

METHODS

The IBM MarketScan Commercial Claims and Encounters database was queried for patients with a history of kidney transplant between 2000 and 2021. Patients were stratified into three groups based on bariatric surgery status and body mass index (BMI) at the time of transplant: patients with obesity (O), patients without obesity (NO), and patients with a history of bariatric surgery (BS). Inverse probability of treatment weighting was used to control for confounding. Adjusted hazard ratios (aHRs) describing the risk of transplant-specific and postoperative outcomes were estimated using weighted Kaplan-Meier curves. Primary outcomes included 30-day and 1-year risk of transplant-specific outcomes. Secondary outcomes included 30-day and 1-year postoperative complications and 30-day and 1-year risk of wound-related complications.

RESULTS

We identified 14,806 patients; 128 in the BS group, 1572 in the O group, and 13,106 in the NO group. There was no difference in 30-day or 1-year risk of transplant-specific complications between the BS and NO group or the O and NO group. Patients with obesity (O) were more likely to experience wound infection (aHR 1.49, 95% CI 1.12-1.99), wound dehiscence (aHR 2.2, 95% CI 1.5-3.2), and minor reoperation (aHR 1.52, 95% CI 1.23-1.89) at 1 year. BS patients had increased risk of wound infection at 1 year (aHR 2.79, 95% CI 1.26-6.16), but were without increase in risk of minor or major reoperation.

CONCLUSION

A history of bariatric surgery does not adversely affect transplant-specific outcomes after kidney transplant. Bariatric surgery can be safely utilized to improve the transplant candidacy of patients with obesity with CKD and ESKD.

Scientific Evidence for the Updated Guidelines on Indications for Metabolic and Bariatric Surgery (IFSO/ASMBS)

The 2022 American Society of Metabolic and Bariatric Surgery (ASMBS) and International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) updated the indications for Metabolic and Bariatric Surgery (MBS), replacing the previous guidelines established by the NIH over 30 years ago. The evidence supporting these updated guidelines has been strengthened to assist metabolic and bariatric surgeons, nutritionists, and other members of multidisciplinary teams, as well as patients. This study aims to assess the level of evidence and the strength of recommendations compared to the previously published criteria.

Obesity, organ failure, and transplantation: A review of the role of metabolic and bariatric surgery in transplant candidates and recipients

Obesity is a risk factor for kidney, liver, heart, and pulmonary diseases, as well as failure. Solid organ transplantation remains the definitive treatment for the end-stage presentation of these diseases. Among many criteria for organ transplant, efficient management of obesity is required for patients to acquire transplant eligibility. End-stage organ failure and obesity are 2 complex pathologies that are often entwined. Metabolic and bariatric surgery before, during, or after organ transplant has been studied to determine the long-term effect of bariatric surgery on transplant outcomes. In this review, a multidisciplinary group of surgeons from the Society of American Gastrointestinal and Endoscopic Surgeons and the American Society for Transplant Surgery presents the current published literature on metabolic and bariatric surgery as a therapeutic option for patients with obesity awaiting solid organ transplantation. This manuscript details the most recent recommendations, pharmacologic considerations, and psychological considerations for this specific cohort of patients. Since level one evidence is not available on many of the topics covered by this review, expert opinion was implemented in several instances. Additional high-quality research in this area will allow for better recommendations and, therefore, treatment strategies for these complex patients.

Impact of progressive chronic kidney disease stage on postoperative outcomes in metabolic surgery-a propensity-matched analysis using the Metabolic and Bariatric Surgery Accreditation and Quality Improvement database

BACKGROUND

Metabolic surgery (MS) is effective in improving renal parameters for individuals with obesity and chronic kidney disease (CKD). Despite recognized benefits, concerns linger about the perioperative safety of patients with CKD undergoing MS. This study aimed to identify the CKD stage associated with the most significant increase in postoperative complications.

METHODS

The Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database (2017-2021) was used to identify patients undergoing laparoscopic gastric sleeve (SG) or Roux-en-Y gastric bypass (RYGB). Propensity matching was used to quantify the risk for adverse outcomes associated with progressive CKD stage.

RESULTS

In total, 688,583 patients (483,898 without CKD and 204,685 with CKD stages I-V) were examined. Endpoints included length of stay (LOS) >5 days, infection, serious complications, major adverse cardiovascular events (MACE), and death. Both SG and RYGB exhibited a linear increase in risk of infection and death. For SG, patients who were stage IIIa/IIIb demonstrated the greatest risk for LOS >5 days (odds ratio [OR] 1.23; 95% confidence interval [CI] (1.05-1.45); P = .011), serious complications (OR 2.83; 95% CI 1.87-4.30; P < .001), and MACE (OR 2.82; 95% CI 1.81-4.37; P < .001). For RYGB, patients who were stage IIIa/IIIb the exhibited greatest risk of MACE (OR 1.67; 95% CI 1.06-2.62; P = .027).

CONCLUSIONS

Although it is generally accepted that worsening CKD correlates with greater surgical risk, this analysis identified CKD stage III as a major inflection point for risk of LOS >5 days, serious complications, and MACE. These findings are useful for counseling and procedure selection and suggest a need for heightened attention to CKD stage III patients undergoing MS.

Obesity, organ failure, and transplantation: a review of the role of metabolic and bariatric surgery in transplant candidates and recipients

Obesity is a risk factor for kidney, liver, heart, and pulmonary diseases, as well as failure. Solid organ transplantation remains the definitive treatment for the end-stage presentation of these diseases. Among many criteria for organ transplant, efficient management of obesity is required for patients to acquire transplant eligibility. End-stage organ failure and obesity are 2 complex pathologies that are often entwined. Metabolic and bariatric surgery before, during, or after organ transplant has been studied to determine the long-term effect of bariatric surgery on transplant outcomes. In this review, a multidisciplinary group of surgeons from the Society of American Gastrointestinal and Endoscopic Surgeons and the American Society for Transplant Surgery presents the current published literature on metabolic and bariatric surgery as a therapeutic option for patients with obesity awaiting solid organ transplantation. This manuscript details the most recent recommendations, pharmacologic considerations, and psychological considerations for this specific cohort of patients. Since level one evidence is not available on many of the topics covered by this review, expert opinion was implemented in several instances. Additional high-quality research in this area will allow for better recommendations and, therefore, treatment strategies for these complex patients.

Long-term systemic effects of metabolic bariatric surgery: A multidisciplinary perspective

Background

Obesity is a global health crisis with profound implications on various body systems, contributing to a series of comorbidities. Metabolic Bariatric Surgery (MBS) has emerged as an effective treatment option for severe obesity, with significant weight reduction and potential systemic physiological alterations.

Objectives

This narrative review aims to provide a comprehensive analysis of the long-term effects of MBS on a wide array of body systems, including the heart, liver, kidneys, reproductive system, skin, lungs, digestive tract, pancreas, and blood, as well as related cancers of these organs.

Methods

A systematic search was conducted in academic databases (PubMed, ISI Web of Science, and Scopus) for observational studies and reviews published between July 2000 and December 2023, investigating the association between MBS and the subsequent function of different organ systems. High-quality studies were prioritized to ensure reliable evidence synthesis.

Results

MBS has demonstrated favorable outcomes in reducing cardiovascular disease risk, improving cardiac function, and alleviating heart failure symptoms. It has also been associated with improved respiratory function, remission of obstructive sleep apnea, and reduced cancer incidence and mortality. Additionally, MBS has shown benefits in managing gastrointestinal disorders, enhancing glycemic control, and promoting pancreatic beta-cell regeneration in type 2 diabetes mellitus. However, some methods of MBS are associated with a higher risk of cholelithiasis, GERD, and pancreatic exocrine insufficiency.

Conclusion

MBS has far-reaching systemic effects beyond weight loss, offering potential long-term benefits for various organ systems and comorbidities associated with obesity. For many patients with severe obesity, the potential benefits of Metabolic and Bariatric Surgery (MBS) can outweigh the associated risks. However, careful evaluation by a qualified healthcare professional is crucial to determine candidacy and ensure a successful outcome. Further research is needed to fully elucidate the long-term impacts and tailor personalized treatment approaches.

Bariatric surgery and the diseased kidney: a 5-year assessment of safety and postoperative renal outcomes

BACKGROUND

Obesity and its related medical conditions are well-established contributors to the development of chronic kidney disease (CKD). Metabolic and bariatric surgery (MBS), including procedures such as sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB), is a potential intervention for these individuals. However, the heightened risk of postoperative complications casts doubts on the suitability of MBS in this population. Our aim is to evaluate the long-term safety, anthropometric and renal outcomes of MBS in patients with CKD.

METHODS

A retrospective review of patients who underwent primary laparoscopic MBS with a BMI ≥ 35 kg/m2 and a preoperative diagnosis of stage 2 to 5 CKD. Criteria for CKD diagnosis and staging were based on estimated glomerular filtration rate measurements in accordance with established guidelines. Anthropometric and renal outcomes were measured at 3-, 6-, 12-, 24- and 60-months postoperatively.

RESULTS

A total of 302 patients (177 SG, 125 RYGB) were included. RYGB was preferred for patients with stage 3 CKD, while SG was more common in stages 4 and 5. At 5-year follow-up, percentage of total weight loss was higher in the RYGB cohort compared to SG (25.1% vs. 18.6%, p = 0.036). Despite SG patients having more advanced CKD, the incidence of late complications was significantly higher following RYGB, with 11 incidents (8.8%), compared to the SG cohort with only 4 cases (2.3%) (p = 0.014). In those with preoperative CKD stage 3, 76 patients (43.2%) improved to stage 2, with another 9 patients (5.1%) improving further to stage 1. Of all patients, 63 (20.8%) eventually received a successful renal transplant.

CONCLUSIONS

MBS is an effective strategy for sustained weight loss in patients with CKD with acceptable complications rates. RYGB leads to a higher percentage of overall weight loss, albeit with an elevated likelihood of late surgical complications. Future studies are needed to determine the safety of MBS in this demographic.

Blockbuster Medications for Obesity: A Primer for Nephrologists

The prevalence of obesity in the United States and across the world continues to climb, imparting increased risk of chronic disease. This impact is doubly felt in nephrology because obesity not only increases the risk of chronic kidney disease (CKD) but also exacerbates existing cardiovascular morbidity and mortality. The role of medical weight loss therapy in CKD has been debated, but increasing evidence suggests that intentional weight loss is protective against adverse kidney and cardiovascular outcomes. This may be particularly true with the advent of novel pharmacotherapies taking advantage of the incretin system, resulting in weight loss approaching that seen with surgical interventions. Moreover, these novel therapies have repeatedly demonstrated protective effects on the cardiovascular system. Here, we review the impact of obesity and weight loss on CKD, and the biological basis and clinical evidence for incretin therapy. This perspective provides recommended prescribing practices as a practical tool to engage nephrologists and patients with CKD in the treatment of obesity-related morbidity.

Patient and Health Care Professional Perspectives on Addressing Obesity in ESKD

RATIONALE & OBJECTIVE

Obesity is common among patients with end-stage kidney disease (ESKD) and is a pervasive barrier to kidney transplantation. Patient perspectives about barriers to weight loss and patient and health care professionals' viewpoints about optimal obesity management in ESKD are needed.

STUDY DESIGN

Qualitative study using a descriptive phenomenological approach to understand ESKD patients' lived experiences with obesity and weight loss and patients' and health professionals' perceptions about optimal obesity care for ESKD patients.

SETTING & PARTICIPANTS

Between October 2020 and December 2021, we conducted 90-minute semistructured interviews with 40 ESKD patients with obesity (body mass index [BMI] ≥30kg/m2) and 60-minute interviews with 20 ESKD health care professionals.

ANALYTICAL APPROACH

Deductive and inductive thematic analysis of interviews.

RESULTS

Among patients with ESKD, the median age was 55 (IQR, 46-63) years, median BMI was 39.5 (IQR, 35.3-41.6) kg/m2, and median dialysis vintage was 5 (IQR, 3-8) years; 58% were female, and 46% were non-Hispanic White. Among health care professionals, 50% were renal dietitians, 20% were nephrologists, and the remainder were transplant professionals (surgeons, nephrologists, and dietitians). ESKD patients described unique weight loss challenges, including (1) conflicting tenets of "kidney-friendly" versus popular diets, (2) fatigue due to dialysis that affects dietary choices, and (3) perceived pressure and unrealistic expectations from health professionals to lose weight for kidney transplantation. Professionals and patients described a lack of transparent and honest communication about obesity and unclear roles and responsibilities for obesity counseling.

LIMITATIONS

Lack of caregiver perspectives and potential lack of transferability to overall dialysis population given overrepresentation of patients with severe obesity and previous weight loss surgery.

CONCLUSIONS

Obesity interventions for ESKD patients should be tailored to meet the unique challenges reported by patients with ESKD. Clarifying ESKD health professionals' roles and responsibilities for obesity care would help to ensure that patients have consistent and effective support to manage obesity.

PLAIN-LANGUAGE SUMMARY

Adults with coexisting obesity and end-stage kidney disease (ESKD) are often required to lose weight for kidney transplantation. Yet there is little knowledge about barriers to healthy weight loss in this population. In this study, we conducted interviews with 40 ESKD patients with coexisting obesity and 20 ESKD health care professionals to learn about opportunities to improve obesity-related health care in ESKD. Patients reported that fatigue and dialysis affected dietary choices, and fluid and food restrictions hampered weight loss. Professionals described a lack of training, comfort, and time to address obesity. Patients and professionals reported a lack of open communication about obesity management. Improving obesity-related education and clinical communication should be prioritized to improve care for patients with ESKD and obesity.

Bariatric Surgery Outcomes in Patients with Chronic Kidney Disease

Obesity increases the risk of developing chronic kidney disease (CKD), which has a major negative impact on global health. Bariatric surgery (BS) has demonstrated a substantial improvement of obesity-related comorbidities and thus, it has emerged as a potential therapeutic tool in order to prevent end-stage renal disease. A limited number of publications to date have examined the beneficial effects and risks of BS in patients with non-advanced stages of CKD. We aimed to investigate the safety of BS in patients with CKD stages 3-4 (directly related or not to obesity) and both the metabolic/renal outcomes post-BS. A total of 57 individuals were included (n = 19 for CKD-group; n = 38 for patients with obesity, but normal eGFR [control-group]). Weight loss and obesity comorbidities resolution after BS were similar in both groups. Renal function (eGFR [CKD-EPI]) improved significantly at the 1-year follow-up: Δ10.2 (5.2-14.9) (p < 0.001) for CKD-group and Δ4.0 (-3.9-9.0) mL/min/1.73 m2 (p = 0.043) for controls. Although this improvement tended to decrease in the 5-year follow-up, eGFR remained above its basal value for the CKD-group. Noteworthy, eGFR also improved in those patients who presented CKD not directly attributed to obesity. For patients with CKD, BS appears to be safe and effective regarding weight loss and obesity comorbidities resolution, irrespective of the main cause of CKD (related or not to obesity).

Bariatric surgery in patients with obesity and end-stage renal disease

BACKGROUND

Bariatric surgery has been suggested as a treatment for obesity and end-stage renal disease (ESRD). Although the number of bariatric surgeries in patients with ESRD is increasing, its safety and effectiveness in these patients are still controversial and the surgical method of choice in these patients is under debate.

OBJECTIVES

To compare the outcomes of bariatric surgery between patients with and without ESRD and to assess different methods of bariatric surgery in patients with ESRD.

SETTING

Meta-analysis.

METHODS

A comprehensive search was conducted in Web of Science and Medline (via Pubmed) until May 2022. Tow meta-analyses were performed: A) to compare bariatric surgery outcomes among patients with and without ESRD, and B) to compare outcomes of Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) in patients with ESRD. Using a random-effect model, odds ratios (ORs) and mean differences (MDs) with 95% confidence intervals (CIs) were computed for surgical and weight loss outcomes.

RESULTS

Of 5895 articles, 6 studies were included in meta-analysis A and 8 studies in meta-analysis B. The risk of bias was moderate to serious among studies. Major postoperative complications (OR = 2.82; 95% CI = 1.66-4.77; P = .0001), reoperation (OR = 2.66; 95% CI = 1.99-3.56; P < .00001), readmission (OR = 2.37; 95% CI = 1.55-3.64; P < .0001), and in-hospital/90-d mortality (OR = 4.03; 95% CI = 1.80-9.03; P = .0007) were higher in patients with ESRD. Patients with ESRD also had a longer hospital stay (MD = 1.23; 95% CI = .32-2.14; P = .008). Bleeding, leakage, and total weight loss were comparable among groups. SG showed a 10% lower rate of overall complications and significantly shorter hospital stay than RYGB did. The quality of evidence was very low for the outcomes CONCLUSIONS: Bariatric surgery in patients with ESRD seems to have higher rates of major complications and perioperative mortality than in patients without ESRD, but a comparable rate of overall complications. SG has fewer postoperative complications and could be the method of choice in these patients. These findings should be interpreted cautiously in light of the moderate to high risk of bias in most included studies.

The Effect of Chronic Kidney Disease or End-stage Kidney Disease on Perioperative Outcomes and Healthcare Utilization in Patients Undergoing Bariatric Surgery

BACKGROUND

As chronic kidney disease (CKD) has a higher prevalence in patients with obesity, there is an increasing need to understand the safety of bariatric surgery for patients with advanced CKD. This study determined if short-term bariatric surgical outcomes and healthcare utilization differ in patients with advanced CKD.

METHODS

A retrospective analysis of the Healthcare Cost and Utilization Project National Inpatient Sample (NIS) was performed. Patients with obesity who underwent bariatric surgery from 2015 to 2019 were included. Patients without CKD, with CKD, and end-stage kidney disease (ESKD) were compared for outcome differences. Univariate and multivariable regression was used to determine the association between perioperative outcomes to CKD status.

RESULTS

The unadjusted analysis found significantly higher mortality and overall complication rate in CKD and ESKD patients, however, after adjustment for confounders, only the ICU admission rate remained significantly higher for patients CKD compared to non-CKD patients (odds ratio 4.21, 95% CI [3.29-5.39]). Length of stay was longer for patients with CKD (mean difference (MD) 0.14 days, 95% CI, [0.04, 0.23]) and patients with ESKD (MD 0.27 days, 95% CI, [0.10, 0.43]) compared to non-CKD patients. Patients with ESKD had higher admission costs compared to non-CKD patients (MD $1982.65).

CONCLUSION

Patients with CKD and ESKD have increased healthcare utilization and higher rates of ICU admission after bariatric surgery compared to non-CKD patients. Otherwise, there is no significant difference in other post-operative complications and mortality. Bariatric surgery may therefore be safely offered to this patient population in hospitals with on-site ICU capacity.

Factors influencing bariatric surgery outcomes

The outcomes of bariatric surgery, while often impressive, are not universally satisfactory; they vary from patient to patient and from operation to operation. Between 20-30% of patients experience suboptimal weight loss or substantial weight regain early in their postoperative course. Confronted with this chronic disease, and given that failures are difficult to manage, it is essential to better characterize obesity preoperatively, considering other metrics beyond just the body mass index (BMI), to select the best candidates for surgery and optimize the benefit/risk ratio. Based on the data of the most recent studies on bariatric surgery, our objective is to identify the predictive factors of weight loss as well as the risk factors of failure. Our analysis indicates that the choice of the surgical technique, age, initial BMI, ethnic origin, the presence of eating disorders and metabolic factors all have an impact on weight-loss outcomes after bariatric surgery. Thus, it is of major importance to carefully select patients during a preoperative multidisciplinary discussion in order to optimize weight loss and metabolic outcomes.

A 5-year propensity-matched analysis of perioperative outcomes in patients with chronic kidney disease undergoing bariatric surgery

BACKGROUND

Bariatric surgery can improve renal function in patients with comorbid chronic kidney disease (CKD) and obesity. Additionally, bariatric surgery can enhance outcomes following renal transplantation. The safety of bariatric surgery in patients with CKD has been debated in the literature. This study evaluates the frequency of perioperative complications associated with CKD.

METHODS

The Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) database was queried from 2015-2019. Patients were included if they had a vertical sleeve gastrectomy (VSG) or Roux-en-Y gastric bypass (RYGB) and were stratified based on CKD status. An unmatched and propensity-matched analysis was performed comparing 30-day perioperative outcomes between the groups.

RESULTS

A total of 717,809 patients included in this study, 5817(0.8%) had CKD, of whom 2266(0.3%) were on dialysis. 74.3% of patients with CKD underwent VSG with 25.7% underwent RYGB. Comparing RYGB to VSG, patients who underwent RYGB had a higher rate of deep organ space infection (0.7%vs.0.1%,p = 0.021) and re-intervention (5.0% vs. 2.2%,p < 0.001). Within the VSG cohort, a matched analysis was performed for those with CKD and without CKD. The CKD cohort had higher risk of complications such as bleeding (2.1%vs. 0.9%,p < 0.001), readmission (9.3%vs.4.9%,p < 0.001), reoperation (2.7%vs.1.3%,p < 0.001), and need for reintervention (2.2%vs.1.3%,p < 0.001). Notably, patients with CKD also had a higher mortality (0.6%vs.0.2%,p = 0.003). No difference was seen between patients with renal insufficiency and patients on dialysis.

CONCLUSION

VSG has been the operation of choice in patients with CKD. Our results showed it is the safer option for patients with CKD compared to RYGB. Although this patient population does have an increased risk of adverse perioperative events, dialysis didn't affect the outcome. Bariatric surgeons who operate on patients with CKD should be well informed and remain vigilant given the increased perioperative risk. The risk is still considerably low, and the potential benefit on renal function and improvement in candidacy for renal transplant outweigh the risk. They should be considered as surgical candidates.

Obesity and renal disease: Benefits of bariatric surgery

The prevalence of obesity, a preventable and reversible condition with a high impact on health, continues to rise, especially after the COVID-19 pandemic. Severe overweight is well recognized as a risk factor for diabetes and hypertension, among other conditions, that may increase cardiovascular risk. Obesity has grown simultaneously with a rise in the prevalence of chronic kidney disease, and a pathophysiological link has been established, which explains its role in generating the conditions to facilitate the emergence and maximize the impact of the risk factors of chronic kidney disease and its progression to more advanced stages. Knowing the mechanisms involved and having different tools to reverse the overweight and its consequences, bariatric surgery has arisen as a useful and efficient method, complementary or alternative to others, such as lifestyle changes and/or pharmacotherapy. In a detailed review, the mechanisms involved in the renal consequences of obesity, the impact on risk factors, and the potential benefit of bariatric surgery at different stages of the disease and its progression are exposed and analyzed. Although the observational evidence supports the value of bariatric surgery as a renoprotective measure in individuals with obesity, diabetic or not, randomized studies are expected to establish evidence-based recommendations that demonstrate its positive risk-benefit balance as a complementary or alternative therapeutic tool.

Bariatric Surgery and Risk of Death in Persons With Chronic Kidney Disease

OBJECTIVE

A retrospective cohort study investigated the association between having surgery and risk of mortality for up to 5 years and if this association was modified by incident ESRD during the follow-up period. Summary of Background Data: Mortality risk in individuals with pre-dialysis CKD is high and few effective treatment options are available. Whether bariatric surgery can improve survival in people with CKD is unclear.

METHODS

Patients with class II and III obesity and pre-dialysis CKD stages 3-5 who underwent bariatric surgery between January 1, 2006 and September 30, 2015 (n = 802) were matched to patients who did not have surgery (n = 4933). Mortality was obtained from state death records and ESRD was identified through state-based or healthcare system-based registries. Cox regression models were used to investigate the association between bariatric surgery and risk of mortality and if this was moderated by incident ESRD during the follow-up period.

RESULTS

Patients were primarily women (79%), non-Hispanic White (72%), under 65 years old (64%), who had a body mass index > 40kg/m 2 (59%), diabetes (67%), and hypertension (89%). After adjusting for incident ESRD, bariatric surgery was associated with a 79% lower 5-year risk of mortality compared to matched controls (hazard ratio = 0.21; 95% confidence interval: 0.14-0.32; P < 0.001). Incident ESRD did not moderate the observed association between surgery and mortality (hazard ratio = 1.59; 95% confidence interval: 0.31-8.23; P =0.58).

CONCLUSIONS

Bariatric surgery is associated with a reduction in mortality in pre-dialysis patients regardless of developing ESRD. These findings are significant because patients with CKD are at relatively high risk for death with few efficacious interventions available to improve survival.

Gastric bypass versus best medical treatment for diabetic kidney disease: 5 years follow up of a single-centre open label randomised controlled trial

BACKGROUND

We compared the albuminuria-lowering effects of Roux-en-Y gastric bypass (RYGB) to best medical treatment in patients with diabetic kidney disease and obesity to determine which treatment is better.

METHODS

A 5 year, open-label, single-centre, randomised trial studied patients with diabetic kidney disease and class I obesity after 1:1 randomization to best medical treatment (n = 49) or RYGB (n = 51). The primary outcome was the proportion of patients achieving remission of microalbuminuria after 5 years. Secondary outcomes included improvements in diabetic kidney disease, glycemic control, quality of life, and safety. For efficacy outcomes, we performed an intention-to-treat (ITT) analysis. This study was registered with ClinicalTrials.gov, NCT01821508.

FINDINGS

88% of patients (44 per arm) completed 5-year follow-up. Remission of albuminuria occurred in 59.6% (95% CI = 45.5-73.8) after best medical treatment and 69.7% (95% CI = 59.6-79.8) after RYGB (risk difference: 10%, 95% CI, -7 to 27, P = 0.25). Patients after RYGB were twice as likely to achieve an HbA1c ≤ 6.5% (60.2% versus 25.4%, risk difference, 34.9%; 95% CI = 15.8-53.9, P < 0.001). Quality of life after five years measured by the 36-Item Short Form Survey questionnaire (standardized to a 0-to-100 scale) was higher in the RYGB group than in the best medical treatment group for several domains. The mean differences were 13.5 (95% CI, 5.5-21.6, P = 0.001) for general health, 19.7 (95% CI, 9.1-30.3, P < 0.001) for pain, 6.1 (95% CI, -4.8 to 17.0, P = 0.27) for social functioning, 8.3 (95% CI, 0.23 to 16.3, P = 0.04) for emotional well-being, 12.2 (95% CI, 3.9-20.4, P = 0.004) for vitality, 16.8 (95% CI, -0.75 to 34.4, P = 0.06) for mental health, 21.8 (95% CI, 4.8-38.7, P = 0.01) for physical health and 11.1 (95% CI, 2.24-19.9, P = 0.01) for physical functioning. Serious adverse events were experienced in 7/46 (15.2%) after best medical treatment and 11/46 patients (24%) after RYGB (P = 0.80).

INTERPRETATION

Albuminuria remission was not statistically different between best medical treatment and RYGB after 5 years in participants with diabetic kidney disease and class 1 obesity, with 6-7 in ten patients achieving remission of microalbuminuria (uACR <30 mg/g) in both groups. RYGB was superior in improving glycemia, diastolic blood pressure, lipids, body weight, and quality of life.

FUNDING

The study was supported by research grants from Johnson & Johnson Brasil, Oswaldo Cruz German Hospital, and by grant 12/YI/B2480 from Science Foundation Ireland (Dr le Roux) and grant 2015-02733 from the Swedish Medical Research Council (Dr le Roux). Dr Pereira was funded by the Chevening Scholarship Programme (Foreign and Commonwealth Office, UK).

Comparison of Kidney Transplantation Outcomes Between Patients with and Without Pre-transplantation Bariatric Surgery: a Systematic Review

This systematic review evaluated the impact of bariatric surgery, performed to improve eligibility for kidney transplantation, on post-transplantation outcomes. A systematic literature search was performed for articles published by 30 January 2022. A total of 31 studies were included. Among patients without pre-transplantation bariatric surgery, 18 studies reported 13.7% graft loss and 9.1% mortality within 5 years' post-transplantation. Among recipients with pre-transplantation bariatric surgery, 15 studies reported 8.7% graft loss and 2.8% mortality within 1 month to over 5 years' post-transplantation. Two case-control studies comparing post-transplantation outcomes between recipients with and without prior bariatric surgery demonstrated no significant differences between groups for graft loss, patient mortality, delayed graft function, wound complications and lymphocele. Non-randomized selection of patients and different lengths of follow-up limit the results of this study.

Early Postoperative Bleeding After Laparoscopic Roux-En-Y Gastric Bypass: a Single Center Analysis

PURPOSE

Early postoperative bleeding is a common complication after laparoscopic Roux-en-Y gastric bypass (LRYGB) and is associated with significant morbidity. We aimed to identify predictors of early postoperative bleeding after LRYGB and characterize hemorrhagic events and 30-day postoperative outcomes.

MATERIAL AND METHODS

We conducted a retrospective cohort study regarding all patients submitted to LRYGB in 2019 at a high-volume obesity center. Early postoperative bleeding was defined as any clinically significant evidence of hemorrhage in the early postoperative period. Demographic, preoperative, and intraoperative factors were evaluated for associations with postoperative bleeding. Postoperative outcomes were compared between patients with and without hemorrhage.

RESULTS

Of 340 patients submitted to LRYGB, 14 (4.1%) had early postoperative bleeding. Patients with bleeding had an increased preoperative left hepatic lobe diameter (8.4 vs. 7.3 cm, p = 0.048). Prior cholecystectomy (28.6 vs. 14.5%) and previous bariatric surgery (35.7 vs. 23.9%) tended to be more prevalent among these patients. Bleeding occurred at a median time of 31.2 [IQR 19.7-38.5] h. Thirteen patients presented with intraluminal bleeding and one with extraluminal bleeding. Melena was the most common symptom. All hemorrhages were clinically diagnosed, and 92.9% were managed conservatively. Postoperative bleeding was associated with longer hospital stay (3.5 vs. 2.0 days), higher reintervention (7.1 vs. 0%), and readmission (14.3 vs. 0%), all p < 0.05.

CONCLUSIONS

Bleeding was the most frequent early complication after LRYGB. Patients with hepatomegaly and prior surgeries may have technically challenging LRYGB and should be carefully assessed. Perioperative strategies should be encouraged in high-risk patients to prevent bleeding.

Chronic kidney disease and its health-related factors: a case-control study

BACKGROUND

Chronic kidney disease (CKD) is a non-communicable disease that includes a range of different physiological disorders that are associated with abnormal renal function and progressive decline in glomerular filtration rate (GFR). This study aimed to investigate the associations of several behavioral and health-related factors with CKD in Iranian patients.

METHODS

A hospital-based case-control study was conducted on 700 participants (350 cases and 350 controls). Logistic regression was applied to measure the association between the selected factors and CKD.

RESULTS

The mean age of cases and controls were 59.6 ± 12.4 and 58.9 ± 12.2 respectively (p = 0.827). The results of multiple logistic regression suggested that many factors including low birth weight (OR yes/no = 4.07, 95%CI: 1.76-9.37, P = 0.001), history of diabetes (OR yes/no = 3.57, 95%CI: 2.36-5.40, P = 0.001), history of kidney diseases (OR yes/no = 3.35, 95%CI: 2.21-5.00, P = 0.001) and history of chemotherapy (OR yes/no = 2.18, 95%CI: 1.12-4.23, P = 0.02) are associated with the risk of CKD.

CONCLUSIONS

The present study covered a large number of potential risk/ preventive factors altogether. The results highlighted the importance of collaborative monitoring of kidney function among patients with the above conditions.

Post-Transplant Cardiovascular Disease

Cardiovascular disease remains a leading cause of death and morbidity in kidney transplant recipients and a common reason for post-transplant hospitalization. Several traditional and nontraditional cardiovascular risk factors exist, and many of them present pretransplant and worsened, in part, due to the addition of immunosuppression post-transplant. We discuss optimal strategies for identification and treatment of these risk factors, including the emerging role of sodium-glucose cotransporter 2 inhibitors in post-transplant diabetes and cardiovascular disease. We present common types of cardiovascular disease observed after kidney transplant, including coronary artery disease, heart failure, pulmonary hypertension, arrhythmia, and valvular disease. We also discuss screening, treatment, and prevention of post-transplant cardiac disease. We highlight areas of future research, including the need for goals and best medications for risk factors, the role of biomarkers, and the role of screening and intervention.

Management of obesity in kidney transplant candidates and recipients: A clinical practice guideline by the Descartes working group of ERA

The clinical practice guideline Management of Obesity in Kidney Transplant Candidates and Recipients was developed to guide decision-making in caring for people with end-stage kidney disease (ESKD) living with obesity. The document considers the challenges in defining obesity, weighs interventions for treating obesity in kidney transplant candidates as well as recipients and reflects on the impact of obesity on the likelihood of wait-listing as well as its effect on transplant outcomes. It was designed to inform management decisions related to this topic and provide the backdrop for shared decision-making. This guideline was developed by the European Renal Association’s Developing Education Science and Care for Renal Transplantation in European States working group. The group was supplemented with selected methodologists to supervise the project and provide methodological expertise in guideline development throughout the process. The guideline targets any healthcare professional treating or caring for people with ESKD being considered for kidney transplantation or having received a donor kidney. This includes nephrologists, transplant physicians, transplant surgeons, general practitioners, dialysis and transplant nurses. Development of this guideline followed an explicit process of evidence review. Treatment approaches and guideline recommendations are based on systematic reviews of relevant studies and appraisal of the quality of the evidence and the strength of recommendations followed the Grading of Recommendations Assessment, Development and Evaluation approach. Limitations of the evidence are discussed and areas of future research are presented.

Bariatric surgery prior to transplantation and risk of early hospital re-admission, graft failure, or death following kidney transplantation

Bariatric surgery has been shown to be safe in the dialysis population. Whether bariatric surgery before kidney transplantation influences posttransplant outcomes has not been examined nationally. We included severely obese (BMI >35) dialysis patients between 18 and 70 years who received a kidney transplant according to the US Renal Data System. We determined the association between history of bariatric surgery and risk of 30-day readmission, graft failure, or death after transplantation using multivariable logistic, Fine-Gray, and Cox models. We included 12 573 patients, of whom 503 (4%) received bariatric surgery before transplantation. Median age at transplant was 53 years; 42% were women. Overall, history of bariatric surgery was not statistically significantly associated with graft failure (HR 1.02; 95% CI 0.77-1.35) or death (HR 1.10; 95% CI 0.84-1.45). However, sleeve gastrectomy (vs. no bariatric surgery) was associated with lower risk of graft failure (HR 0.39; 95% CI 0.16-0.95). In conclusion, history of bariatric surgery prior to kidney transplantation was not associated with allograft or patient survival, but findings varied by surgery type. Sleeve gastrectomy was associated with better graft survival and should be considered in severely obese transplant candidates receiving dialysis.

Obesity Management in Kidney Transplant Candidates: Current Paradigms and Gaps in Knowledge

In this review, we discuss the increasing prevalence of obesity among people with chronic and end-stage kidney disease (ESKD) and implications for kidney transplant (KT) candidate selection and management. Although people with obesity and ESKD receive survival and quality-of-life benefits from KT, most KT programs maintain strict body mass index (BMI) cutoffs to determine transplant eligibility. However, BMI does not distinguish between visceral adiposity, which confers higher cardiovascular risks and risks of perioperative and adverse posttransplant outcomes, and muscle mass, which is protective in ESKD. Furthermore, requirements for patients with obesity to lose weight before KT should be balanced with the findings of numerous studies that show weight loss is a risk factor for death among patients with ESKD, independent of starting BMI. Data suggest that KT is associated with survival benefits relative to remaining on dialysis for candidates with obesity although recipients without obesity have higher delayed graft function rates and longer transplant hospitalization durations. Research is needed to determine the optimal body composition metrics for KT candidacy assessments and risk stratification. In addition, ESKD-specific obesity management guidelines are needed that will address the neurologic, behavioral, socioeconomic, and physical underpinnings of this increasingly common disease.

Expert opinion on the preoperative medical optimization of adults with diabetes undergoing metabolic surgery

Diabetes mellitus (DM) and obesity are interrelated in a complex manner, and their coexistence predisposes patients to a plethora of medical problems. Metabolic surgery has evolved as a promising therapeutic option for both conditions. It is recommended that patients, particularly those of Asian origin, maintain a lower body mass index threshold in the presence of uncontrolled DM. However, several comorbidities often accompany these chronic diseases and need to be addressed for successful surgical outcome. Laparoscopic Roux-en-Y gastric bypass (RYGB) and laparoscopic sleeve gastrectomy (LSG) are the most commonly used bariatric procedures worldwide. The bariatric benefits of RYGB and LSG are similar, but emerging evidence indicates that RYGB is more effective than LSG in improving glycemic control and induces higher rates of long-term DM remission. Several scoring systems have been formulated that are utilized to predict the chances of remission. A glycemic target of glycated hemoglobin < 7% is a reasonable goal before surgery. Cardiovascular, pulmonary, gastrointestinal, hepatic, renal, endocrine, nutritional, and psychological optimization of surgical candidates improves perioperative and long-term outcomes. Various guidelines for preoperative care of individuals with obesity have been formulated, but very few specifically focus on the concerns arising from the presence of concomitant DM. It is hoped that this statement will lead to the standardization of presurgical management of individuals with DM undergoing metabolic surgery.

Perioperative Risks of Sleeve Gastrectomy Versus Roux-en-Y Gastric Bypass Among Patients With Chronic Kidney Disease: A Review of the MBSAQIP Database

OBJECTIVE

To determine whether patients with CKD experience higher rates of perioperative complications after RYGB compared to sleeve gastrectomy.

SUMMARY OF BACKGROUND DATA

For obese CKD patients who qualify for bariatric surgery, sleeve gastrectomy is often preferred to RYGB based on perceptions of prohibitively-high perioperative risks surrounding RYGB. However, some patients with CKD are not candidates for sleeve gastrectomy and the incremental increased-risk from RYGB has never been rigorously tested in this population.

METHODS

CKD patients who underwent RYGB or sleeve gastrectomy between 2015 and 2017 were identified from the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program Participant Use File. RYGB patients were 1:1 propensity-score matched with sleeve gastrectomy patients based on preoperative factors that influence operative choice. Primary outcomes included 30-day readmissions, surgical complications, medical complications, and death. Secondary outcomes included the individual complications used to create the composite surgical/medical complications. Univariate logistic regression was used to compare outcomes. E-value statistic was used to test the strength of outcome point estimates against possible unmeasured confounding.

RESULTS

Demographics were similar between RYGB (n = 673) and sleeve gastrectomy (n = 673) cohorts. There were no statistically significant differences in primary outcomes. Among secondary outcomes, only acute kidney injury was statistically-significantly higher among RYGB patients (4.9% vs 2.7%, P = 0.035, E-value 1.27).

CONCLUSIONS

Among well-matched cohorts of RYGB and sleeve gastrectomy patients, incidence of primary outcomes were similar. Among secondary outcomes, only acute kidney injury was statistically-significantly higher among RYGB patients; however, the E-value for this difference was small and relatively weak confounder(s) could abrogate the statistical difference. The perception that RYGB has prohibitively-high perioperative risks among CKD patients is disputable and operative selection should be weighed on patient candidacy and anticipated long-term benefit.

Obesity and bariatric surgery in kidney transplantation: A clinical review

Obesity is increasing worldwide, and this has major implications in the setting of kidney transplantation. Patients with obesity may have limited access to transplantation and increased posttransplant morbidity and mortality. Most transplant centers incorporate interventions aiming to target obesity in kidney transplant candidates, including dietary education and lifestyle modifications. For those failing nutritional restriction and medical therapy, the use of bariatric surgery may increase the transplant candidacy of patients with obesity and end-stage renal disease (ESRD) and may potentially improve the immediate and late outcomes. Bariatric surgery in ESRD patients is associated with weight loss ranging from 29.8% to 72.8% excess weight loss, with reported mortality and morbidity rates of 2% and 7%, respectively. The most commonly performed bariatric surgical procedures in patients with ESRD and in transplant patients are laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-en-Y gastric bypass. However, the correct timing of bariatric surgery and the ideal type of surgery have yet to be determined, although pretransplant LSG seems to be associated with an acceptable risk-benefit profile. We review the impact of obesity on kidney transplant candidates and recipients and in potential living kidney donors, exploring the potential impact of bariatric surgery in addressing obesity in these populations, thereby potentially improving posttransplant outcomes.

Obesity as an isolated contraindication to kidney transplantation in the end-stage renal disease population: A cohort study

OBJECTIVE

The aim of this study was to characterize end-stage renal disease (ESRD) patients with obesity as their only contraindication to listing and to quantify wait-list and transplant access.

METHODS

Using the US Renal Data System, a retrospective cohort study of incident dialysis cases (2012 to 2014) was performed. The primary outcomes were time to wait-listing and time to transplantation.

RESULTS

Of 157,572 dialysis patients not already listed, 39,844 had BMI as their only demonstrable transplant contraindication. They tended to be younger, female, and Black. Compared with patients with BMI < 35, those with BMI 35 to 39.9, 40 to 44.9, and ≥45 were, respectively, 15% (adjusted hazard ratio [aHR] 0.85; 95% CI: 0.83-0.88; p < 0.001), 45% (aHR 0.55; 95% CI: 0.52-0.57; p < 0.001), and 71% (aHR 0.29; 95% CI: 0.27-0.31; p < 0.001) less likely to be wait-listed. Wait-listed patients with BMI 35 to 39.9 were 24% less likely to achieve transplant (aHR 0.76; 95% CI: 0.72-0.80; p < 0.0001), BMI 40 to 44.9 were 21% less likely (aHR 0.79; 95% CI: 0.72-0.86; p < 0.0001), and BMI ≥ 45 were 15% less likely (aHR 0.85; 95% CI: 0.75-0.95; p = 0.004) compared with patients with BMI < 35.

CONCLUSIONS

Obesity was the sole contraindication to wait-listing for 40,000 dialysis patients. They were less likely to be wait-listed. For those who were, they had a lower likelihood of transplant. Aggressive weight-loss interventions may help this population achieve wait-listing and transplant.

Improvement of kidney function in patients with chronic kidney disease and severe obesity after bariatric surgery: A systematic review and meta-analysis

The general management for chronic kidney disease (CKD) includes treating reversible causes, including obesity, which may be both a driver and comorbidity for CKD. Bariatric surgery has been shown to reduce the likelihood of CKD progression and improve kidney function in observational studies. We performed a systematic review and meta-analysis of patients with at least stage 3 CKD and obesity receiving bariatric surgery. We searched Embase, MEDLINE, CENTRAL and identified eligible studies reporting on kidney function outcomes in included patients before and after bariatric surgery with comparison to a medical intervention control if available. Risk of bias was assessed with the Newcastle-Ottawa Risk of Bias score. Nineteen studies were included for synthesis. Bariatric surgery showed improved eGFR with a mean difference (MD) of 11.64 (95%CI: 5.84 to 17.45, I²  = 66%) ml/min/1.73m² and reduced SCr with MD of -0.24 (95%CI -0.21 to -0.39, I²  = 0%) mg/dl after bariatric surgery. There was no significant difference in the relative risk (RR) of having CKD stage 3 after bariatric surgery, with a RR of -1.13 (95%CI: -0.83 to -2.07, I²  = 13%), but there was reduced likelihood of having uACR >30 mg/g or above with a RR of -3.03 (95%CI: -1.44 to -6.40, I²  = 91%). Bariatric surgery may be associated with improved kidney function with the reduction of BMI and may be a safe treatment option for patients with CKD. Future studies with more robust reporting are required to determine the feasibility of bariatric surgery for the treatment of CKD.

Intensive management of obesity in people with severe chronic kidney disease: A review

Obesity is highly prevalent worldwide, including among people with chronic kidney disease (CKD). The presence of severe and/or end-stage kidney disease complicates the treatment of obesity for several reasons, including restrictions on protein and fluid intake and renal excretion of several medications indicated for the treatment of obesity. The aim of this review is to assess the safety of intensive obesity treatments, such as very-low-energy diets (VLEDs), obesity pharmacotherapy and/or bariatric surgery, in people with end-stage kidney disease. A literature search was conducted to identify studies reporting safety outcomes for VLEDs, liraglutide, phentermine, phentermine-topiramate, naltrexone-bupropion and bariatric surgery in people with an estimated glomerular filtration rate of less than 30 mL/min/1.73m² or on dialysis. Limited data were insufficient to recommend VLEDs but highlighted their potential efficacy and the need for close clinical and biochemical monitoring. There were no data regarding centrally acting obesity pharmacotherapy in this population, although some glucagon-like peptide-1 analogues appear to safely induce weight loss at doses used for the treatment of type 2 diabetes. Some studies suggest an increased rate of complications of bariatric surgery in individuals with severe or end-stage CKD. Further prospective evaluation of intensive obesity management in the growing population with obesity and severe, end-stage and dialysis-dependent CKD is required.

Weight Loss After Bariatric Surgery in Morbidly Obese End-Stage Kidney Disease Patients as Preparation for Kidney Transplantation. Matched Pair Analysis in a High-Volume Bariatric and Transplant Center

Background

The number of morbidly obese kidney transplant candidates is growing. They have limited access to kidney transplantation and are at a higher risk of postoperative complications. Bariatric surgery is considered as a safe weight loss method in those patients.

Objectives

Matched pair analysis was designed to analyze the preparatory and postoperative weight loss after bariatric procedures in end-stage kidney disease (ESKD) and non-ESKD morbidly obese patients.

Methods

Twenty patients with ESKD underwent bariatric surgery in our Centre of Excellence for Bariatric and Metabolic Surgery between 2015 and 2019 (nine one-anastomosis gastric bypasses, nine Roux-en-Y gastric bypasses, and two sleeve gastrectomies). They were compared with matched pairs from a dataset of 1199 morbidly obese patients without ESKD. Data on demographic factors and comorbidities was recorded. BMI was obtained at the start of the preparatory period preceding the bariatric procedure, at the time of procedure, and during the 1-year follow-up.

Results

The ESKD and non-ESKD patients did not differ significantly in preoperative weight loss (13.00 ± 11.69 kg and 15.22 ± 15.96 kg respectively, p = 0.619). During the 1-year follow-up, the weight loss was similar to the non-ESKD group. In the first 3 months, faster weight loss in ESKD was observed. Initial and follow-up BMI values did not differ significantly between groups. We demonstrated that obese patients with ESKD can lose weight as effectively as non-ESKD patients.

Conclusion

Morbidly obese ESKD patients have an equal weight loss to patients without ESKD. Bariatric surgery could improve access to kidney transplantation and may potentially improve transplantation outcomes of obese patients with ESKD.

The Relationship Between Preoperative Kidney Function and Weight Loss After Bariatric Surgery in Patients with Estimated Glomerular Filtration Rate ≥ 30 mL/min: Tehran Obesity Treatment Study

INTRODUCTION

Severe obesity can lead to progressive kidney injury and chronic kidney disease (CKD). The current study aimed at determining whether preoperative kidney function level in patients with estimated glomerular filtration rate (eGFR) ≥30 mL/min affects weight loss after bariatric surgery.

METHODS

A total of 1958 bariatric patients underwent laparoscopic sleeve gastrectomy and gastric bypass from March 2013 to March 2017. The patients were categorized according to preoperative eGFR (30-59, 60-89, 90-124, and ≥ 125 mL/min). Changes in body mass index (BMI), percentage of total weight loss (TWL%), and percentage of excess weight loss (EWL%) were compared across the eGFR categories. Moreover, multivariable logistic regression analysis was used to evaluate the relationship between eGFR and insufficient weight loss (defined as not achieving 50% EWL at 12 months after surgery).

RESULTS

Preoperative eGFR was positively associated with unadjusted ΔBMI (P trend < 0.001), TWL% (P trend < 0.001), and EWL% (P trend = 0.007) after 12 months of surgery. However, these associations were no longer significant after multivariable adjustment. Further, univariate analysis demonstrated a positive relationship between preoperative eGFR and insufficient weight loss (odds ratio [OR] 1.38; 95% confidence interval [CI] 1.11-1.71; P = 0.004). By contrast, preoperative eGFR was not a predictor of insufficient weight loss in multivariable logistic regression analysis (OR 0.98; 95% CI 0.46-1.24; P = 0.886).

CONCLUSION

Although patients with lower preoperative eGFR experience less weight loss after bariatric surgery, preoperative kidney function does not appear to have an independent impact on postoperative weight loss in patients with eGFR ≥ 30 mL/min.

Management of Obesity in Adults with CKD

Obesity is a leading public health problem that currently affects over 650 million individuals worldwide. Although interest in the adverse effects of obesity has grown exponentially in recent years, less attention has been given to studying its management in individuals with CKD. This relatively unexplored area should be considered a high priority because of the rapid growth and high prevalence of obesity in the CKD population, its broad impact on health and outcomes, and its modifiable nature. This article begins to lay the groundwork in this field by providing a comprehensive overview that critically evaluates the available evidence related to obesity and kidney disease, identifies important gaps in our knowledge base, and integrates recent insights in the pathophysiology of obesity to help provide a way forward in establishing guidelines as a basis for managing obesity in CKD. Finally, the article includes a kidney-centric algorithm for management of obesity that can be used in clinical practice.

Comparison of eGFR formulas in determining chronic kidney disease stage in bariatric patients and the impact on perioperative outcomes

BACKGROUND

Chronic kidney disease (CKD) independently increases the risk of 30-day adverse outcomes following metabolic and bariatric surgery (MBS). However, no studies have evaluated the stage of CKD at which increased perioperative risk is manifested. Here, we correlate 30-day major morbidities after MBS with extent of renal disease based on CKD Stage.

OBJECTIVES

To determine the impact of CKD stage on perioperative outcomes after bariatric surgery.

SETTING

Academic Hospital.

METHODS

From the 2017 Metabolic and Bariatric Surgery Quality Improvement Program (MBSAQIP) database, we identified patients with CKD who underwent sleeve gastrectomy or laparoscopic gastric bypass surgery. Glomerular filtration rates (GFRs) were calculated and cohorts were generated based on CKD Stage. Complication rates and rates of morbidity and mortality were compared between stages, and strengths of correlation were calculated.

RESULTS

GFR and CKD Stage were calculated for 150,283 patients. There was a significant increase in the risk of major morbidity at each progressive stage of CKD (P < .001 for all compared stages). There was a strong positive linear correlation between increasing CKD Stage and total morbidity (r² = .983), including reoperation ( r² = .784), readmission (r² = .936), unplanned ICU transfer (r² = .853), and aggregate complications such as pulmonary (r² = .900), bleeding (r² = .878), or progressive worsening of renal function (r² = .845). In logistic regression, for every 10-point decrease in GFR, odds of total morbidity increased by 6%.

CONCLUSION

An increased risk of perioperative complications may be seen in early stages of CKD, and risk is compounded in more advanced stages. Bariatric surgical candidates should be counseled on their increased risk of surgical complications even with mild CKD, and the benefits of bariatric surgery should be carefully weighed against significantly increased risks of complications in severe CKD.

Strategies to Treat Obesity in Patients With CKD

Obesity prevalence continues to increase worldwide, accompanied by a rising tide of hypertension, diabetes, and chronic kidney disease (CKD). Although body mass index is typically used to assess obesity in clinical practice, altered body composition (eg, reduced muscle mass and increased visceral adiposity) are common among patients with CKD. Weight loss achieved through behavioral modification or medications reduces albuminuria and in some cases slows the decline in estimated glomerular filtration rate. Use of medications that promote weight loss with favorable cardiovascular risk profiles should be promoted, particularly in patients with type 2 diabetes, obesity, and CKD. For those who fail to achieve weight loss through lifestyle modification, bariatric surgery should be considered because observational studies have shown reductions in risk for estimated glomerular filtration rate decline and kidney failure. Uncertainty persists on the risk to benefit ratio of intentional weight loss in patients with kidney failure due to the lack of prospective trials and limitations of observational data. Regardless, sleeve gastrectomy is increasingly being used for patients with kidney failure and severe obesity, with success in achieving sustained weight loss, improved access to kidney transplantation, and favorable posttransplantation outcomes. More research is needed assessing long-term cardiovascular and kidney outcomes of most weight loss medications.

Sleeve gastrectomy enables simultaneous pancreas and kidney transplantation in severely obese recipients

BACKGROUND

Obesity adversely affects wait-listing and precludes patients with concomitant end-stage renal disease and type 1 diabetes mellitus from getting a simultaneous pancreas and kidney transplantation (SPK).

OBJECTIVE

To analyze safety and efficacy of laparoscopic sleeve gastrectomy (LSG) before SPK in severely obese type I diabetics.

METHODS

We assessed weight curve, complications, and graft function of three patients who underwent LSG before SPK.

RESULTS

LSG was uneventful in all patients. Body mass index dropped from 38.4 (range 35.7 - 39.9) before LSG to 28.5 (26.8 - 30.9) until SPK, with a mean loss of 25.8% (22.4 - 32.3). Interval between LSG and SPK was 364.3 (173 - 587) days. Pancreas and kidney graft function was excellent, with 100% insulin-free and dialysis-free survival over a mean follow-up of 3.6 (2.9 - 4.5) years. A1C dropped from 7% (6.3 - 8.2) before LSG to 4.9% (4.7 - 5.3) and 4.8% (4.5 - 5.1) 1 and 2 years after SPK, respectively.

CONCLUSION

LSG before SPK is safe and effective to enable severely obese type I diabetics to receive a lifesaving transplant. This is the first study analyzing the role of bariatric surgery before simultaneous pancreas and kidney transplantation.

The Impact of CKD on Perioperative Risk and Mortality after Bariatric Surgery

Background

Twenty percent of patients with CKD in the United States have a body mass index (BMI) ≥35 kg/m². Bariatric surgery reduces progression of CKD to ESKD, but the risk of perioperative complications remains a concern.

Methods

The 24-month data spanning 2017-2018 were obtained from the Metabolic and Bariatric Surgery Quality Improvement Program (MBSAQIP) database and analyzed. Surgical complications were assessed on the basis of the length of hospital stay, mortality, reoperation, readmission, surgical site infection (SSI), and worsening of kidney function during the first 30 days after surgery.

Results

The 277,948 patients who had primary bariatric procedures were 44±11.9 (mean ± SD) years old, 79.6% were women, and 71.2% were White. Mean BMI was 45.7±7.6 kg/m². Compared with patients with an eGFR≥90 ml/min per BSA, those with stage 5 CKD/ESKD were 1.91 times more likely to be readmitted within 30 days of a bariatric procedure (95% CI, 1.37 to 2.67; P<0.001). Similarly, length of hospital stay beyond 2 days was 2.05-fold (95% CI, 1.64 to 2.56; P<0.001) higher and risk of deep incisional SSI was 6.92-fold (95% CI, 1.62 to 29.52; P=0.009) higher for those with stage 5 CKD/ESKD. Risk of early postoperative mortality increased with declining preoperative eGFR, such that patients with stage 3b CKD were 3.27 (95% CI, 1.82 to 5.89; P<0.001) times more likely to die compared with those with normal kidney function. However, absolute mortality rates remained relatively low at 0.53% in those with stage 3b CKD. Furthermore, absolute mortality rates were <0.5% in those with stages 4 and 5 CKD, and these advanced CKD stages were not independently associated with an increased risk of early postoperative mortality.

Conclusions

Increased severity of kidney disease was associated with increased complications after bariatric surgery. However, even for the population with advanced CKD, the absolute rates of postoperative complications were low. The mounting evidence for bariatric surgery as a renoprotective intervention in people with and without established kidney disease suggests that bariatric surgery should be considered a safe and effective option for patients with CKD.

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.