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

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.

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.

Weight Loss Surgery Increases Kidney Transplant Rates in Patients With Renal Failure and Obesity

OBJECTIVE

To describe the outcomes of kidney transplant (KT) candidates with obesity undergoing sleeve gastrectomy (SG) to meet the criteria for KT.

METHODS

Retrospective analysis was conducted of electronic medical records of KT candidates with obesity (body mass index >35 kg/m2) who underwent SG in our institution. Weight loss, adverse health events, and the listing and transplant rates were abstracted and compared with the nonsurgical cohort.

RESULTS

The SG was performed in 54 patients; 50 patients did not have surgery. Baseline demographic characteristics were comparable at the time of evaluation. Mean body mass index ± SD of the SG group was 41.7±3.6 kg/m2 at baseline (vs 41.5±4.3 kg/m2 for nonsurgical controls); at 2 and 12 months after SG, it was 36.4±4.1 kg/m2 and 32.6±4.0 kg/m2 (P<.01 for both). In the median follow-up time of 15.5 months (interquartile range, 6.4 to 23.9 months), SG was followed by active listing (37/54 people), and 20 of 54 received KT during a median follow-up time of 20.9 months (interquartile range, 14.7 to 28.3 months) after SG. In contrast, 14 of 50 patients in the nonsurgical cohort were listed, and 5 received a KT (P<.01). Three patients (5.6%) experienced surgical complications. There was no difference in overall hospitalization rates and adverse health outcomes, but the SG cohort experienced a higher risk of clinically significant functional decline.

CONCLUSION

In KT candidates with obesity, SG appears to be effective, with 37% of patients undergoing KT during the next 18 months (P<.01). Further research is needed to confirm and to improve the safety and efficacy of SG for patients with obesity seeking a KT.

Case Study: The Weighty Issue of Treatment Options for Obese Dialysis Patients

Obesity is a complex chronic disease and common comorbidity in kidney failure and is the leading causes of death and disability in this population. Guidelines do not specifically address the preferred weight management option(s) for obesity while on dialysis. Large body size is a limiting factor for consideration of a kidney transplantation. We report on a successful bariatric surgery with a young adult after 5.5 years on dialysis with hope for a future transplant. Success was demonstrated with progressive weight loss without adverse changes in renal clinical markers accompanied by improvements in exercise tolerance and health status thereby improving her suitability for a kidney transplant. Further studies and guidelines are needed to address weight loss options for those with obesity on dialysis and want to lose weight.

Baseline Psychosocial, Environmental, Health, and Behavioral Correlates of 1- and 3-Year Weight Loss After Bariatric Surgery

PURPOSE

Weight loss surgery is an effective, long-term treatment for severe obesity but individual response to surgery varies widely. The purpose of this study was to test a comprehensive theoretical model of factors that may be correlated with the greatest surgical weight loss at 1-3 years following surgery. Such a model would help determine what predictive factors to measure when patients are preparing for surgery that may ensure the best weight outcomes.

MATERIALS AND METHODS

The Bariatric Experience Long Term (BELONG) study collected self-reported and medical record-based baseline information as correlates of 1- and 3-year % total weight loss (TWL) in n = 1341 patients. Multiple linear regression was used to determine the associations between 120 baseline variables and %TWL.

RESULTS

Participants were 43.4 ± 11.3 years old, Hispanic or Black (52%; n = 699), women (86%; n = 1149), and partnered (72%; n = 965) and had annual incomes of ≥ $51,000 (60%; n = 803). A total of 1006 (75%) had 3-year follow-up weight. Regression models accounted for 10.1% of the variance in %TWL at 1-year and 13.6% at 3 years. Only bariatric operation accounted for a clinically meaningful difference (~ 5%) in %TWL at 1-year. At 3 years after surgery, only bariatric operation, Black race, and BMI ≥ 50 kg/m2 were associated with clinically meaningful differences in %TWL.

CONCLUSIONS

Our findings combined with many others support a move away from extensive screening and selection of patients at the time of surgery to a focus on improving access to this treatment.

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.

The Beneficial Effects of Bariatric-Surgery-Induced Weight Loss on Renal Function

Obesity represents an independent risk factor for the development of chronic kidney disease (CKD), leading to specific histopathological alterations, known as obesity-related glomerulopathy. Bariatric surgery is the most effective means of inducing and maintaining sustained weight loss. Furthermore, in the context of bariatric-surgery-induced weight loss, a reduction in the proinflammatory state and an improvement in the adipokine profile occur, which may also contribute to the improvement of renal function following bariatric surgery. However, the assessment of renal function in the context of obesity and following marked weight loss is difficult, since the formulas adopted to estimate glomerular function use biomarkers whose production is dependent on muscle mass (creatinine) or adipose tissue mass and inflammation (cystatin-c). Thus, following bariatric surgery, the extent to which reductions in plasma concentrations reflect the actual improvement in renal function is not clear. Despite this limitation, the available literature suggests that in patients with hyperfiltration at baseline, GFR is reduced following bariatric surgery, whereas GFR is increased in patients with decreased GFR at baseline. These findings are also confirmed in the few studies that have used measured rather than estimated GFR. Albuminuria is also decreased following bariatric surgery. Moreover, bariatric surgery seems superior in achieving the remission of albuminuria and early CKD than the best medical treatment. In this article, we discuss the pathophysiology of renal complications in obesity, review the mechanisms through which weight loss induces improvements in renal function, and provide an overview of the renal outcomes following bariatric surgery.

Obesity and Chronic Kidney Disease A Current Review

Background

Obesity poses significant challenges to healthcare globally, particularly through its bi-directional relationship with co-morbid metabolic conditions such as type 2 diabetes and hypertension. There is also emerging evidence of an association between obesity and chronic kidney disease (CKD) which is less well characterized.

Methods

A literature search of electronic libraries was conducted to identify and present a narrative review of the interplay between obesity and CKD.

Findings

Obesity may predispose to CKD directly as it is linked to the histopathological finding of obesity-related glomerulopathy and indirectly through its widely recognized complications such as atherosclerosis, hypertension, and type 2 diabetes. The biochemical and endocrine products of adipose tissue contribute to pathophysiological processes such as inflammation, oxidative stress, endothelial dysfunction, and proteinuria. The prevention and management of obesity may prove critical in counteracting both the development and advancement of CKD. Moreover, measures of abdominal adiposity such as waist circumference, are generally associated with worse morbidity and mortality in individuals receiving maintenance hemodialysis.

Conclusion

Obesity is a risk factor for the onset and progression of CKD and should be recognized as a potential target for a preventative public health approach to reduce CKD rates within the general population. Future research should focus on the use of glucagon-like peptide-1 receptor agonists and sodium-glucose cotransporter 2 inhibitors in patients with CKD and obesity due to their multi-faceted actions on major outcomes.

Modifiable Lifestyle Behaviors and CKD Progression: A Narrative Review

Living a healthy lifestyle is one of the safest and most cost-effective ways to improve one's quality of life and prevent and/or manage chronic disease. As such, current CKD management guidelines recommend that patients adhere to a healthy diet, perform ≥150 minutes per week of physical activity, manage their body weight, abstain from tobacco use, and limit alcohol. However, there are limited studies that investigate the relationship between these lifestyle factors and the progression of CKD among people with established CKD. In this narrative review, we examine the reported frequencies of health lifestyle behavior engagement among individuals with non-dialysis-dependent CKD and the existing literature that examines the influences of diet, physical activity, weight management, alcohol consumption, and tobacco use on the progression of CKD, as measured by decline in GFR, incident ESKD, or elevated proteinuria or albuminuria in individuals with CKD. Many of the available studies are limited by length of follow-up and small sample sizes, and meta-analyses were limited because the studies were sparse and had heterogeneous classifications of behaviors and/or referent groups and of CKD progression. Further research should be done to determine optimal methods to assess behaviors to better understand the levels at which healthy lifestyle behaviors are needed to slow CKD progression, to investigate the effect of combining multiple lifestyle behaviors on important clinical outcomes in CKD, and to develop effective techniques for behavior change. Despite the lack of evidence of efficacy from large trials on the ability of lifestyle behaviors to slow CKD progression, maintaining a healthy lifestyle remains a cornerstone of CKD management given the undisputed benefits of healthy lifestyle behaviors on cardiovascular health, BP control, and survival.

Obesity-related kidney disease: Beyond hypertension and insulin-resistance

Chronic kidney disease (CKD) causes considerable morbidity, mortality, and health expenditures worldwide. Obesity is a significant risk factor for CKD development, partially explained by the high prevalence of diabetes mellitus and hypertension in obese patients. However, adipocytes also possess potent endocrine functions, secreting a myriad of cytokines and adipokines that contribute to insulin resistance and induce a chronic low-grade inflammatory state thereby damaging the kidney. CKD development itself is associated with various metabolic alterations that exacerbate adipose tissue dysfunction and insulin resistance. This adipose-renal axis is a major focus of current research, given the rising incidence of CKD and obesity. Cellular senescence is a biologic hallmark of aging, and age is another significant risk factor for obesity and CKD. An elevated senescent cell burden in adipose tissue predicts renal dysfunction in animal models, and senotherapies may alleviate these phenotypes. In this review, we discuss the direct mechanisms by which adipose tissue contributes to CKD development, emphasizing the potential clinical importance of such pathways in augmenting the care of CKD.

Evaluation of Intensive Telephonic Nutritional and Lifestyle Counseling to Enhance Outcomes of Bariatric Surgery

BACKGROUND

To determine the impact of an intensive perioperative nutritional and lifestyle support protocol on long-term outcomes of bariatric surgery.

METHODS

A retrospective observational study was conducted of 955 patients who underwent gastric bypass surgery between 2005 and 2015. Patients were divided into two cohorts: (1) 2005 through August 2013: these 767 patients were required to participate in the intensive telephone-based nutritional support program from 8 weeks preoperative through 44 weeks postoperative; (2) after August 2013, the program was discontinued and 188 patients did not have intensive telephonic nutritional support. Inverse probability weighting was used to obtain weight loss estimates at 1 and 3 years postoperative. Time-to-event analyses were used to investigate hospitalization rates postoperative. Poisson models were used to investigate healthcare utilization.

RESULTS

Patients who participated in the program exhibited 1.97% (95% CI 0.7, 3.3) greater %TWL at 1 year and 2.2% (95% CI -0.3, 4.1) greater %TWL at 3 years postoperative than patients who did not participate. Secondary analyses indicated participation in the program was associated with 44% shorter time to first hospitalization postoperative (p < 0.001).

CONCLUSIONS

In this health system, intensive nutritional support was associated with greater weight loss at 1 and 3 years postoperative and higher hospitalization rates.

Obesity-Related Glomerulopathy: Clinical Management

Obesity-related glomerulopathy (ORG) and other obesity-associated kidney diseases pose a major challenge to the treating nephrologist. We review the benefits of weight loss and optimal management of ORG and kidney disease in the setting of obesity. Therapeutic strategies in ORG were limited mainly in the past to weight loss through lifestyle interventions and bariatric surgery, antihypertensive treatment, and renin-angiotensin-aldosterone system blockade. Current approaches to obtain the desired weight loss include novel pharmacologic therapies that have been approved for the treatment of diabetes while offering kidney protection, such as sodium-glucose cotransporter-2 inhibitors and glucagon-like peptide-1-receptor agonists. This review focuses on the nephroprotective role of the renin-angiotensin-aldosterone system blockade and of these new pharmacologic agents, and on the renal effects of bariatric surgery in chronic kidney disease.