Bariatric surgery for the treatment of chronic kidney disease in obesity and type 2 diabetes mellitus

Kidney consequences of obesity

Herein, we review the devastating consequences of the worldwide obesity epidemic on kidney health and outcomes. We submit that the obesity epidemic is the most pressing public health crisis facing the nephrology community today. A historical approach has been undertaken, wherein major breakthroughs in the recognition and understanding of obesity-related kidney disease (ORKD) are highlighted. We begin with a description of the worldwide obesity epidemic followed by an account of the discovery and characterization of ORKD. A detailed summary of the pathophysiology of ORKD disease is presented, wherein we set forth the following two propositions: first, ORKD is due to a maladaptive response to caloric surplus; and second, this maladaptive response causes kidney damage via hemodynamic (hyperfiltration), hormonal (adipokine dysregulation), and lipotoxic pathways. Each of these pathways is described, with particular emphasis on the relatively recent discovery that the final stage of cellular injury in ORKD is mitochondrial oxidative damage. The prevention and treatment of ORKD are then discussed, including environmental, behavioral, pharmacologic, and surgical options. Finally, we conclude with suggestions for future research to improve early recognition and treatment of ORKD.

Assessment of predictors of acute kidney injury and progression to chronic kidney disease following bariatric surgery

BACKGROUND

Despite the overall safety of metabolic and bariatric surgery (MBS), the potential for postoperative complications such as acute kidney injury (AKI) remains a critical concern. Decade-old studies from our institution reported rates of AKI following MBS between 5.8% and 8.6%, with factors such as higher body mass index (BMI), diabetes, and hypertension identified as potential contributors. However, the incidence and factors associated with AKI following MBS have remained underexplored in contemporary literature.

OBJECTIVES

To investigate the incidence and risk factors associated with postoperative AKI, as well as the potential for progression to CKD and renal failure.

SETTING

Quaternary academic medical center with a high-volume MBS practice.

METHODS

A retrospective review of adult patients undergoing primary laparoscopic MBS between 2008 and 2022 to identify patients who developed AKI, defined as postoperative increase in serum creatinine (sCr) by .3 mg/dL within 72 hours. A multivariable logistic regression was constructed to identify potential AKI risk factors.

RESULTS

Among 1697 patients, the incidence of AKI was 3.0% (n = 51). The distribution of AKI was not significantly different between procedure types. There was no significant correlation between anesthesia medications given and the occurrence of AKI. Male gender was the most significant predictor of AKI (adjusted odds ratio [aOR] = 3.87, 95% confidence interval {CI} [2.14-6.99]), followed by hypertension (aOR = 2.12, 95% CI [1.03-4.83]) and longer surgical duration (aOR = 1.19, 95% CI [1.05-1.35]) per 30 minutes. Of those who developed AKI, 7 (13.7%) required dialysis acutely for management, while 3 patients (5.9%) progressed to chronic renal failure and required transplant.

CONCLUSIONS

AKI is a rare but serious complication following MBS that occurs in approximately 3% of cases. AKI incidence is higher in male patients, those with hypertension, insulin-requiring diabetes, renal insufficiency, and longer procedure durations. Heightened awareness of the identified risk factors should help guide patient selection, and additional efforts should be directed towards refining postoperative follow-up.

Reduced Risk of Cardiovascular Diseases After Bariatric Surgery Based on the New Predicting Risk of Cardiovascular Disease EVENTs Equations

BACKGROUND

We applied the novel Predicting Risk of Cardiovascular Disease EVENTs equations to evaluate cardiovascular-kidney-metabolic (CKM) health and estimated cardiovascular disease (CVD) risk after bariatric surgery.

METHODS

Among 7804 patients (aged 20-79 years) undergoing bariatric surgery at Vanderbilt University Medical Center during 1999 to 2022, CVD risk factors from before surgery to 2 years after surgery were extracted from electronic health records. The 10- and 30-year risks of total CVD, atherosclerotic CVD, coronary heart disease, stroke, and heart failure (HF) were estimated for patients without CVD history at each time point (n=124-2910), using the social deprivation index-enhanced Predicting Risk of Cardiovascular Disease EVENTs equations. Paired t tests or McNemar tests were used to compare pre- with postsurgery CKM health and CVD risk. Two-sample t tests were used to compare CVD risk reduction between patient subgroups.

RESULTS

CKM health was significantly improved after surgery with lower systolic blood pressure, non-high-density lipoprotein cholesterol, and diabetes prevalence, and higher high-density lipoprotein and estimated glomerular filtration rate. The 10-year risks of total CVD and its subtypes decreased by 21.7% to 56.3% at 1 year after surgery and by 14.6% to 46.5% at 2 years after surgery, with the largest reduction observed for HF. Younger age, White race, >30% weight loss, and diabetes history were associated with greater HF risk reductions. Similar results were found for the 30-year CVD risk estimates.

CONCLUSIONS

Bariatric surgery significantly improves CKM health and reduces estimated CVD risk, particularly HF, by 47% to 56% within 1 to 2 years after surgery. HF risk reduction may vary by patient's demographics, weight loss, and disease history, which warrants further research.

The Impact of Metabolic and Bariatric Surgery on Diabetic Kidney Disease in Patients with Type 2 Diabetes: A Systematic Review and Meta-analysis

We aimed to determine the effect of metabolic and bariatric surgery (MBS) on the improvement of diabetic nephropathy (DN) in patients with obesity and type 2 diabetes (T2DM). A systematic search was performed in the PubMed, Embase, Scopus, and Web of Science databases. Meta-analysis of 31 studies with 2594 patients showed that urine albumin-to-creatinine ratio (UACR) was significantly reduced with a mean difference of - 28.19 mg/g (95% CI - 41.17, - 15.21, P-value < 0.001). In addition, subgroup analysis of studies showed a significant decrease after Roux-en-Y gastric bypass (RYGB) but not after sleeve gastrectomy (SG). These results suggest that MBS may lead to better kidney function and improvement in DN.

The Impact of Bariatric Surgery on Type 2 Diabetes Mellitus Remission: A Systematic Review

Bariatric surgery has been shown to significantly affect type 2 diabetes mellitus (T2DM) remission, particularly in obese individuals. This systematic review aims to evaluate the effectiveness of bariatric surgical interventions in inducing remission of T2DM as well as to identify factors influencing surgical outcomes. The systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive literature search was performed across multiple databases, including PubMed, Embase, and Cochrane Library, utilizing text words and controlled vocabulary in various combinations with Boolean operators "AND" and "OR." The search was limited to open-access, full-text articles in English published from 2005 to 2024, including studies involving human subjects. The quality of the included studies was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist. In the study selection process for the systematic review, records were initially identified from three databases: Cochrane (31 records), Embase (62 records), and PubMed (52 records). This yielded 145 records. After removing 107 records, 38 records remained for screening. Of these, five records were excluded based on irrelevant problems and irrelevant outcomes. Subsequently, 33 reports were sought for full-text retrieval, with all reports being retrievable. The 33 reports were assessed for eligibility. Out of these, six were excluded due to an inaccessible full-text record. Finally, 33 studies met the inclusion criteria and were included in the review. Bariatric surgery is a highly effective intervention for individuals with T2DM, particularly those with obesity. It leads to significant weight loss and improved glycemic control through mechanisms that reduce stomach size and alter hormonal responses. This surgery not only helps many patients achieve remission from diabetes but also decreases the risk of obesity-related health issues. Beyond physical health, patients often report enhanced psychological well-being and quality of life. Overall, bariatric surgery can transform the health trajectory of select individuals, offering them a renewed sense of control and improved overall health.

Elucidating the role of weight loss and glycaemic control in patients with type 2 diabetes

AIMS

To investigate the independent contributions of glycated haemoglobin (HbA1c) reduction and weight loss to clinical outcomes in patients with type 2 diabetes (T2D) treated with antidiabetic drugs, including glucagon-like peptide-1 receptor agonists (GLP-1RAs).

MATERIALS AND METHODS

This observational, retrospective cohort study used deidentified electronic health record-derived data from patients evaluated at the Cleveland Clinic (1 January 2000-31 December 2020). Cohort A included 8876 patients with newly diagnosed T2D treated with any of six antidiabetic drug classes. Cohort B included 4161 patients with T2D initiating GLP-1RA treatment. The effects of body mass index (BMI) and HbA1c reduction, variability, and durability on clinical outcomes were investigated.

RESULTS

In Cohort A, each 1% BMI reduction was associated with 3%, 1%, and 4% reduced risk of heart failure (p = 0.017), hypertension (p = 0.006), and insulin initiation (p = 0.001), respectively. Each 1% (~11 mmol/mol) HbA1c reduction was associated with 4% and 29% reduced risk of hypertension (p = 0.041) and insulin initiation (p = 0.001), respectively. In Cohort B, each 1% BMI reduction was associated with 4% and 3% reduced risk of cardiovascular disease (p = 0.008) and insulin initiation (p = 0.002), respectively. Each 1% (~11 mmol/mol) HbA1c reduction was associated with 4% and 16% reduced risk of chronic kidney disease (p = 0.014) and insulin initiation (p = 1 × 10-4), respectively. Lower BMI variability and greater BMI durability were associated with decreased risk of clinical outcomes in both cohorts.

CONCLUSIONS

Antidiabetic medication-associated, and specifically GLP-1RA-associated, weight loss and HbA1c reductions independently reduce real-world clinical outcome risk.

Nutritional Management for Chronic Kidney Disease Undergoing Bariatric Surgery: A Case Report

Nutrition support is an essential aspect of treatment after bariatric surgery (BS). A high-protein diet with an intake of up to 1.5 g/kg of ideal body weight (IBW) per day is recommended to minimize loss of lean body mass after BS. However, protein intake recommendations may need to be adjusted for patients with compromised renal function, necessitating an individualized approach tailored to each patient's clinical status. This case report aimed to demonstrate nutritional evaluation, education, and counseling for a male patient with chronic kidney disease (CKD) who underwent BS one year after surgery. Following BS, the patient adhered to the standard Seoul National University Hospital BS diet protocol. Considering his postoperative renal function, protein requirement was set at 1.0 g/kg of IBW. A total of 10 individualized nutritional counseling sessions were conducted according to renal function and complications. One year after BS, he successfully lost weight with % excess weight loss of 93%, maintained CKD stage 3, reduced prescription of oral hypoglycemic agent, improved glycated hemoglobin levels, and improved eating habits significantly. Thus, individualized nutrition intervention is important for supporting patients with CKD to reach their goal weight after BS, improve nutritional status, and prevent post-operative complications.

Circulating B Cell-Derived Small RNA Delivered by Extracellular Vesicles: A Dialogue Mechanism for Long-Range Targeted Renal Mitochondrial Injury in Obesity

The intricate processes that govern the interactions between peripatetic immune cells and distal renal injury in obesity are not fully understood. Employing transcriptomic analysis of circulating extracellular vesicles (EVs), a marked amplification of small RNA (miR-3960) is discerned within CD3-CD19+ B cells. This RNA is found to be preferentially augmented in kidney tissues, contrasting with its subdued expression in other organs. By synthesizing dual-luciferase reporter assay with co-immunoprecipitation analysis, it is pinpointed that miR-3960 specifically targets the nuclear gene TRMT5, a pivotal actor in the methylation of mitochondrial tRNA. This liaison instigates aberrations in the post-transcriptional modifications of mitochondrial tRNA, engendering deficiencies within the electron respiratory chain, primarily attributable to the diminution of the mitochondrial bioenergetic compound (NDUFA7) complex I. Such perturbations lead to a compromised mitochondrial respiratory capacity in renal tubular cells, thereby exacerbating tubular injury. In contrast, EV blockade or miR-3960 depletion markedly alleviates renal tubular injury in obesity. This investigation unveils a hitherto unexplored pathway by which obesity-induced circulating immune cells remotely manipulate mitochondrial metabolism in target organs. The strategic targeting of obese EVs or infiltrative immune cells and their specifically secreted RNAs emerges as a promising therapeutic avenue to forestall obesity-related renal afflictions.

Ileum excision partially reverses improvement of glucose metabolism in diabetic rats after biliopancreatic diversion with duodenal switch

BACKGROUND

Bile acids can stimulate the secretion of glucagon-like peptide-1 (GLP-1) and be mostly reabsorbed in the ileum.

OBJECTIVES

We aimed to investigate whether ileum excision could reverse the glucose improvement after biliopancreatic diversion with duodenal switch (BPD/DS).

SETTING

Peking Union Medical College Hospital.

METHODS

Thirty diabetic rats were randomly divided into the BPD/DS group, BPD/DS plus ileectomy (BDI) group, and control group. The fasting blood glucose, bile acids, and glucagon-like peptide-1(GLP-1) levels in plasma samples were analyzed.

RESULTS

In postoperative week 20, the fasting blood glucose level in the BDI group was significantly higher than that in the BPD/DS group (11.5 ± 1.4 mmol/L versus 7.6 ± 1.0 mmol/L, P < .001), and the AUCOGTT value was also significantly higher than that in the BPD/DS group (2186.1 ± 237.2 mmol/L·min versus 1551.2 ± 136.9 mmol/L·min, P < .001). The plasma level of bile acids in the BDI group was lower than that in the BPD/DS group (P = .012) and was not significantly different from that in the control group (P = .629). The plasma level of GLP-1 in the BDI group was lower than that in the BPD/DS group (P = .009) and was not significantly different from that in the control group (P = .530). Moreover, the intestinal TGR5 expression in the BDI group was significantly lower than that in the BPD/DS group (P < .001).

CONCLUSIONS

The results show that excision of the ileum can partially reverse the improvement in glucose metabolism after BPD/DS.

Study protocol for a non-inferiority, multicenter, randomized study to evaluate a smartphone app-based follow-up program after bariatric surgery (BELLA plus trial)

INTRODUCTION

Adherence to follow-up (FU) care after bariatric surgery is poor despite strong recommendations. In our pilot Bella trial, we demonstrated that a completely remote follow-up program via smartphone is feasible and safe for patients after bariatric surgery. Building on this, we aim to verify our results in a multicenter, randomized controlled setting.

METHODS

This trial plans to enroll 410 participants undergoing primary bariatric surgery in seven German bariatric centers. Participants are randomized into two groups: a control group receiving in-person FU according to the standard in the bariatric centers, and an interventional group monitored using a smartphone application (app). The app sends standardized questionnaires and reminders regarding regular vitamin intake and exercises. The built-in messaging function enables patients to communicate remotely with medical care professionals. After one year, all participants are evaluated at their primary bariatric centers. The primary outcome is weight loss 12 months after surgery. The secondary outcomes include obesity-related comorbidities, quality of life, serum values of vitamins and minerals, body impedance analysis, visits to the emergency department or readmission, patient compliance, and medical staff workload.

DISCUSSION

The current study is the first prospective, individually randomized-controlled, multicenter trial where a mobile application completely replaces traditional in-person visits for post-bariatric surgery follow-ups in bariatric centers.

Association of Obesity With Kidney and Cardiac Outcomes Among Patients With Glomerular Disease: Findings From the Cure Glomerulonephropathy Network

RATIONALE & OBJECTIVE

The influence of obesity on cardiorenal outcomes in individuals with glomerular disease is incompletely known. This study examined the association between obesity and kidney and cardiovascular outcomes in children and adults with glomerular kidney disease.

STUDY DESIGN

Prospective, multicenter, observational study.

SETTING & PARTICIPANTS

Participants in the Cure Glomerulonephropathy Network (CureGN) who were≥5 years of age at enrollment.

EXPOSURE

Adult body mass index (BMI) groups: 20-24 (healthy) versus 25-34 (overweight/class 1 obesity) versus≥35 (class 2-3 obesity); and pediatric BMI percentiles: 5th-84th (healthy) versus 85th-94th (overweight) versus≥95th (obese).

OUTCOME

A composite kidney outcome (40% estimated glomerular filtration rate [eGFR] decline or kidney failure) and a composite cardiovascular outcome (myocardial infarction, stroke, heart failure, or death).

ANALYTICAL APPROACH

Time to composite primary outcomes by BMI strata were estimated using Kaplan-Meier analysis. The adjusted associations between BMI and outcomes were estimated using Cox proportional hazards analysis.

RESULTS

The study included 2,301 participants (1,548 adults and 753 children). The incidence of the primary kidney end point was 90.8 per 1,000 person-years in adults with class 2-3 obesity, compared with 58.0 in normal weight comparators. In the univariable analysis, class 2-3 obesity was associated with the primary kidney outcome only in adults (HR, 1.6 [95% CI, 1.1-2.2], P=0.006) compared with the healthy weight groups. In the multivariable adjusted analysis, class 2-3 obesity did not remain significant among adults when controlling for baseline eGFR and proteinuria. Adults with class 2-3 obesity had an incidence of 19.7 cardiovascular events per 1,000 person-years and greater cardiovascular risk (HR, 3.9 [95% CI, 1.4-10.7], P=0.009) in the fully adjusted model.

LIMITATIONS

BMI is an imperfect indicator of adiposity. Residual confounding may exist from socioeconomic factors.

CONCLUSIONS

Among adult patients in CureGN, class 2-3 obesity is associated with cardiovascular but not kidney outcomes when adjusted for potential confounding factors.

PLAIN-LANGUAGE SUMMARY

Obesity is a risk factor for adverse heart and kidney outcomes in patients with chronic kidney disease, but whether it is associated with these outcomes in patients with glomerulonephropathy is not known. This study used existing data from a large sample of adults and children with glomerular diseases to address this question. The findings suggest that obesity increases the risk of cardiovascular but not kidney disease events in adult patients with glomerular 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.

Research progress on bariatric surgery for hyperuricemia

Hyperuricemia is closely linked to obesity. As lifestyles and dietary patterns evolve, the prevalence of hyperuricemia has been on the rise. Bariatric surgery, an efficacious intervention for morbid obesity and its associated metabolic disorders, not only manages the weight of patients with severe obesity but also exerts beneficial therapeutic effects on hyperuricemia and gout. Moreover, it demonstrates substantial efficacy against other obesity-related metabolic conditions. However, the dramatic fluctuations in serum uric acid levels and acute gouty attacks in the immediate postoperative period are issues that should not be overlooked, and effective preventative strategies for some related adverse complications are still underexplored. This review discusses and reviews the advancements in the treatment of obese patients with hyperuricemia through bariatric surgery. By reviewing pertinent literature, it summarizes the short-term and long-term therapeutic outcomes of bariatric surgery for hyperuricemia, as well as common adverse reactions. Furthermore, by discussing preoperative and postoperative interventional measures and influential factors, this review aims to provide novel perspectives for the clinical management of hyperuricemia and offer insights for the prevention of related complications.

Reduced Risk of Cardiovascular Diseases after Bariatric Surgery Based on the New PREVENT Equations

Background

We applied the novel Predicting Risk of Cardiovascular Disease EVENTs (PREVENT) equations to evaluate cardiovascular-kidney-metabolic (CKM) health and estimated CVD risk, including heart failure (HF), after bariatric surgery.

Methods

Among 7804 patients (20-79 years) undergoing bariatric surgery at Vanderbilt University Medical Center during 1999-2022, CVD risk factors at pre-surgery, 1-year, and 2-year post-surgery were extracted from electronic health records. The 10- and 30-year risks of total CVD, atherosclerotic CVD (ASCVD), coronary heart disease (CHD), stroke, and HF were estimated for patients without a history of CVD or its subtypes at each time point, using the social deprivation index-enhanced PREVENT equations. Paired t-tests or McNemar tests were used to compare pre- with post-surgery CKM health and CVD risk. Two-sample t-tests were used to compare CVD risk reduction between patient subgroups defined by age, sex, race, operation type, weight loss, and history of diabetes, hypertension, and dyslipidemia.

Results

CKM health was significantly improved after surgery with lower systolic blood pressure, non-high-density-lipoprotein cholesterol (non-HDL), and diabetes prevalence, but higher HDL and estimated glomerular filtration rate (eGFR). The 10-year total CVD risk decreased from 6.51% at pre-surgery to 4.81% and 5.08% at 1- and 2-year post-surgery (relative reduction: 25.9% and 16.8%), respectively. Significant risk reductions were seen for all CVD subtypes (i.e., ASCVD, CHD, stroke, and HF), with the largest reduction for HF (relative reduction: 55.7% and 44.8% at 1- and 2-year post-surgery, respectively). Younger age, White race, >30% weight loss, diabetes history, and no dyslipidemia history were associated with greater HF risk reductions. Similar results were found for the 30-year risk estimates.

Conclusions

Bariatric surgery significantly improves CKM health and reduces estimated CVD risk, particularly HF, by 45-56% within 1-2 years post-surgery. HF risk reduction may vary by patient's demographics, weight loss, and disease history, which warrants further research.

Knowledge, attitude, and practice regarding malnutrition amongst patients with chronic kidney disease in China: A qualitative study

BACKGROUND

Chronic kidney disease (CKD) can be complicated by malnutrition, which has adverse implications on patients' health outcomes and quality of life. CKD patients from different sociocultural contexts may have varying perceptions of knowledge, attitudes, and practices of malnutrition. However, information on the perception of malnutrition in patients with CKD is limited. This study aimed to explore and describe the knowledge, attitude, and practice of patients with CKD disease regarding malnutrition.

MATERIALS AND METHODS

A qualitative-descriptive design was used. Thirteen participants were selected through a purposive sampling technique among malnourished CKD patients from a hospital in Xi'an Provincial Hospital of Traditional Chinese Medicine between November 2022 and January 2023. Data were collected through face-to-face semistructured interviews until data saturation. All participants were informed about the study. Data obtained were analyzed by content analysis.

RESULTS

Three main categories and seven subcategories were extracted from the data analysis: 1) knowledge (basic knowledge acquisition and understanding, knowledge misconceptions, and confusion, nutrition knowledge, and culture collision); 2) attitude (negative attitudes and adverse situations, positive attitude and self-awareness); 3) practice (disadvantageous and passive practice, favorable practice).

CONCLUSION

This study provided insight into the knowledge, attitude, and practice of malnutrition in patients with CKD. Our findings can serve as important baseline data for the development of future interventions that can help reduce the risk of malnutrition, slow disease progression, and improve the quality of life in patients with CKD.

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.

Obesity and the kidney: mechanistic links and therapeutic advances

Obesity is strongly associated with the development of diabetes mellitus and chronic kidney disease (CKD), but there is evidence for a bidirectional relationship wherein the kidney also acts as a key regulator of body weight. In this Review, we highlight the mechanisms implicated in obesity-related CKD, and outline how the kidney might modulate feeding and body weight through a growth differentiation factor 15-dependent kidney-brain axis. The favourable effects of bariatric surgery on kidney function are discussed, and medical therapies designed for the treatment of diabetes mellitus that lower body weight and preserve kidney function independent of glycaemic lowering, including sodium-glucose cotransporter 2 inhibitors, incretin-based therapies and metformin, are also reviewed. In summary, we propose that kidney function and body weight are related in a bidirectional fashion, and that this interrelationship affects human health and disease.

Bariatric Surgery as a Bridge to a Successful Kidney Transplantation: A Case Report

BACKGROUND

Severe obesity impairs renal function and outcomes in kidney transplant recipients. Bariatric surgery benefits those unresponsive to medical treatments. Limited case reports exist on its efficacy and long-term prognosis for transplant candidates. Thus, this study aims to present a case in which laparoscopic sleeve gastrectomy was safely performed on a patient with severe obesity awaiting kidney transplantation.

CASE PRESENTATION

This study included a dialysis patient with a body mass index of 47 kg/m2. Living-donor kidney transplantation using his younger sister as a donor was considered, but it was determined that the risk of complications during and after surgery was high. Medical treatment was first performed, but the obesity did not improve; therefore, a laparoscopic sleeve gastrectomy was performed. Although postoperative bleeding occurred, the patient was discharged from the hospital on the 14th postoperative day. Subsequently, his weight steadily decreased, and living-donor kidney transplantation was performed 13 months after laparoscopic sleeve gastrectomy was performed. Furthermore, the patient's progress after kidney transplantation was good, and he was freed from hemodialysis.

CONCLUSION

Improving severe obesity before kidney transplantation is effective in improving prognosis, and bariatric surgery should be considered when medical treatment is ineffective. Future research are needed to determine the optimal time between the performance of this procedure and kidney transplantation, as well as the long-term prognosis after kidney transplantation.

Effects of bariatric surgery on renal function: a retrospective cohort study comparing one-year outcomes between one-anastomosis gastric bypass and Roux-en-Y gastric bypass

BACKGROUND

Evidence on the effect of one-anastomosis gastric bypass (OAGB) on renal function is limited.

OBJECTIVE

To compare the evolution of estimated renal function observed 1 year after OAGB and Roux-en-Y gastric bypass (RYGB) in individuals with obesity.

DESIGN AND SETTING

Observational, analytical, and retrospective cohort study. Tertiary-level university hospital.

METHODS

This study used a prospectively collected database of individuals who consecutively underwent bariatric surgery. Renal function was assessed by calculating the estimated glomerular filtration rate (eGFR), according to the Chronic Kidney Disease Epidemiology Collaboration. The one-year variation in the eGFR was compared between the procedures.

RESULTS

No significant differences in age, sex, obesity-associated conditions, or body mass index were observed among individuals who underwent either OAGB or RYGB. OAGB led to a significantly higher percentage of total (P = 0.007) and excess weight loss (P = 0.026). Both OAGB and RYGB led to significantly higher values of eGFR (103.9 ± 22 versus 116.1 ± 13.3; P = 0.007, and 102.4 ± 19 versus 113.2 ± 13.3; P < 0.001, respectively). The one-year variation in eGFR was 11 ± 16.2% after OAGB and 16.7 ± 26.3% after RYGB (P = 0.3). Younger age and lower baseline eGFR were independently associated with greater postoperative improvement in renal function (P < 0.001).

CONCLUSION

Compared with RYGB, OAGB led to an equivalent improvement in renal function 1 year after the procedure, along with greater weight loss.

Effect of Zusanli Acupoint Injection with Anisodamine on Postoperative Recovery Quality of Patients Undergoing Bariatric Surgery

PURPOSE

To evaluate the influence of anisodamine injection at the Zusanli (ST36) on early postoperative recovery quality in patients who have undergone laparoscopic sleeve gastrectomy.

MATERIALS AND METHODS

141 patients undergoing laparoscopic sleeve gastrectomy were randomly divided into the control group (group C), the normal saline group (group S) and the anisodamine group (group A). Acupuncture point injections were administered after induction of general anesthesia. The quality of recovery-40 questionnaire (QoR-40) scores were documented preoperatively (D0) and on the 1st (D1), 3rd (D3) and 7th (D7) days postoperatively. Additional metrics included: the numerical rating scale (NRS) for pain, postoperative nausea and vomiting (PONV), assessment and analgesic consumption 24-h post-extubation and the initial postoperative times for ambulation and anal exhaust. Substance P (SP), β-endorphin (β-EP), motilin (MTL) and gastrin (GAS) were quantified at 24-h post-surgery.

RESULTS

Compared with group C, group A demonstrated an elevation in QoR-40 scores and physical comfort dimensions during D1-3, and an increased pain scores during D1-7; group S exhibited an augmentation in QoR-40 scores and pain scores on D1 (p < 0.05). Compared with group S, group A improved QoR-40 scores on D1 and pain scores during D1-3 (p < 0.05). SP, β-EP, MTL and GAS presented significant variances among the groups 24-h post-surgery (p < 0.05). There were significant differences between the groups in NRS pain scores and PONV scores at 24-h postoperatively, dosage of dizocin on the first postoperative day, and time to first anal defecation (p < 0.05).

CONCLUSION

The administration of anisodamine via ST36 acupoint injections has been demonstrated to facilitate the recuperation of gastrointestinal functionality, to alleviate postoperative pain and nausea, and substantially to enhance the quality of early postoperative recovery.

Obesity Treatments to Improve Type 1 Diabetes (OTID): a randomized controlled trial of the combination of glucagon-like peptide 1 analogues and sodium-glucose cotransporter 2 inhibitors-protocol for Obesity Treatments to Improve Type 1 Diabetes (the OTID trial)

BACKGROUND

The guidelines of the American Diabetes Association and European Association for the Study of Diabetes suggest that patients with obesity type 2 diabetics and chronic kidney disease need either glucagon-like peptide 1 receptor analogues or sodium-glucose cotransporter-2 inhibitors. If neither achieve metabolic control, then the recommendation is to combine both drugs. The evidence base for combining glucagon-like peptide 1 receptor analogues and sodium-glucose cotransporter-2 inhibitors is not well researched, and hence, the impact of the guidelines is limited. The aim of this randomized controlled trial is to test the impact of the combination of glucagon-like peptide 1 receptor analogues/sodium-glucose cotransporter-2 inhibitors on body weight and kidney damage, in patients with type 1 diabetes and chronic kidney disease. In addition, we will explore the associated changes in the metabolic pathways with each of the treatments used in this randomized controlled trial.

METHODS

In this 6-month randomized control trial, 60 participants aged between 21 and 65 years, with a body mass index above 25 kg/m2, and type 1 diabetics with chronic kidney disease will be randomized to receive 1 of 5 possible treatments: (1) standard care (control), (2) glucagon-like peptide 1 receptor analogues alone, (3) sodium-glucose cotransporter-2 inhibitors alone, (4) combination of glucagon-like peptide 1 receptor analogues and sodium-glucose cotransporter-2 inhibitors and (5) combination of glucagonlike peptide 1 receptor analogues and sodium-glucose cotransporter-2 inhibitors with intensive lifestyle advice. The primary objective will be the percentage change in total body weight from baseline at 6 months. The secondary objectives are to compare the change in glycaemia; blood pressure; dyslipidaemia; albuminuria; proportion of participants reaching weight loss of ≥ 5%, ≥ 10% and ≥ 15%; and change in BMI (kg/m2) from baseline and change in waist circumference (cm). All the experiments will be conducted at the Dasman Diabetes Institute after approval from the local research and ethics committee.

DISCUSSION

The present randomized controlled trial aims to investigate the impact of the combination of glucagon-like peptide 1 receptor analogues and sodium-glucose cotransporter-2 inhibitors on body weight and kidney damage in patients with type 1 diabetes mellitus and chronic kidney disease, as well as exploring the associated changes in the metabolic pathways with each of the treatments used. This study addresses the current gap in the evidence base regarding the combination of these two drugs, which is particularly relevant given the American Diabetes Association and European Association for the Study of Diabetes guidelines recommending their combined use for patients with obesity, type 2 diabetes, and chronic kidney disease who do not achieve metabolic control with either drug alone.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT05390307 Trial registration date - 25th May 2022.

Role of TFEB-autophagy lysosomal pathway in palmitic acid induced renal tubular epithelial cell injury

Lysosomal dysfunction and impaired autophagic flux are involved in the pathogenesis of lipotoxicity in the kidney. Here, we investigated the role of transcription factor EB (TFEB), a master regulator of autophagy-lysosomal pathway, in palmitic acid induced renal tubular epithelial cells injury. We examined lipid accumulation, autophagic flux, expression of Ps211-TFEB, and nuclear translocation of TFEB in HK-2 cells overloaded with palmitic acid (PA). By utilizing immunohistochemistry, we detected TFEB expression in renal biopsy tissues from patients with diabetic nephropathy and normal renal tissue adjacent to surgically removed renal carcinoma (controls), as well as kidney tissues from rat fed with high-fat diet (HFD) and low-fat diet (LFD). We found significant lipid accumulation, increased apoptosis, accompanied with elevated Ps211-TFEB, decreased nuclear TFEB, reduced lysosome biogenesis and insufficient autophagy in HK-2 cells treated with PA. Kidney tissues from patients with diabetic nephropathy had lower nuclear and total levels of TFEB than that in control kidney tissues. Level of renal nuclear TFEB in HFD rats was also lower than that in LFD rats. Exogenous overexpression of TFEB increased the nuclear TFEB level in HK-2 cells treated with PA, promoted lysosomal biogenesis, improved autophagic flux, reduced lipid accumulation and apoptosis. Our results collectively indicate that PA is a strong inducer for TFEB phosphorylation modification at ser211 accompanied with lower nuclear translocation of TFEB. Impairment of TFEB-mediated lysosomal biogenesis and function by palmitic acid may lead to insufficient autophagy and promote HK-2 cells injury.

Comprehensive strategy for identifying extracellular vesicle surface proteins as biomarkers for chronic kidney disease

Chronic kidney disease (CKD) poses a significant health burden worldwide. Especially, obesity-induced chronic kidney disease (OCKD) is associated with a lack of accuracy in disease diagnostic methods. The identification of reliable biomarkers for the early diagnosis and monitoring of CKD and OCKD is crucial for improving patient outcomes. Extracellular vesicles (EVs) have emerged as potential biomarkers in the context of CKD. In this review, we focused on the role of EVs as potential biomarkers in CKD and OCKD and developed a comprehensive list of EV membrane proteins that could aid in the diagnosis and monitoring of the disease. To assemble our list, we employed a multi-step strategy. Initially, we conducted a thorough review of the literature on EV protein biomarkers in kidney diseases. Additionally, we explored papers investigating circulating proteins as biomarkers in kidney diseases. To further refine our list, we utilized the EV database Vesiclepedia.org to evaluate the qualifications of each identified protein. Furthermore, we consulted the Human Protein Atlas to assess the localization of these candidates, with a particular focus on membrane proteins. By integrating the information from the reviewed literature, Vesiclepedia.org, and the Human Protein Atlas, we compiled a comprehensive list of potential EV membrane protein biomarkers for CKD and OCKD. Overall, our review underscores the potential of EVs as biomarkers in the field of CKD research, providing a foundation for future studies aimed at improving CKD and OCKD diagnosis and treatment.

Characteristics of changes in plasma proteome profiling after sleeve gastrectomy

Bariatric surgery (BS), recognized as the most effective intervention for morbid obesity and associated metabolic comorbidities, encompasses both weight loss-dependent and weight loss-independent mechanisms to exert its metabolic benefits. In this study, we employed plasma proteomics technology, a recently developed mass spectrometric approach, to quantitatively assess 632 circulating proteins in a longitudinal cohort of 9 individuals who underwent sleeve gastrectomy (SG). Through time series clustering and Gene Ontology (GO) enrichment analysis, we observed that complement activation, proteolysis, and negative regulation of triglyceride catabolic process were the primary biological processes enriched in down-regulated proteins. Conversely, up-regulated differentially expressed proteins (DEPs) were significantly associated with negative regulation of peptidase activity, fibrinolysis, keratinocyte migration, and acute-phase response. Notably, we identified seven proteins (ApoD, BCHE, CNDP1, AFM, ITIH3, SERPINF1, FCN3) that demonstrated significant alterations at 1-, 3-, and 6-month intervals post SG, compared to baseline. These proteins play essential roles in metabolism, immune and inflammatory responses, as well as oxidative stress. Consequently, they hold promising potential as therapeutic targets for combating obesity and its associated comorbidities.

Global trends in the burden of chronic kidney disease attributable to type 2 diabetes: An age-period-cohort analysis

AIM

To assess temporal trends of chronic kidney disease (CKD) attributable to type 2 diabetes (T2D) globally and in five sociodemographic index (SDI) regions.

MATERIALS AND METHODS

We extracted the population data and CKD burden attributable to T2D from the Global Burden of Disease Study 2019. We evaluated the trends of disability-adjusted life years (DALYs), mortality, prevalence and incidence through age-period-cohort modelling, and calculated net drifts (overall annual percentage changes), local drifts (annual percentage changes in each age group), longitudinal age curves (fitted longitudinal age-specific rates), period relative risks (RRs) and cohort RRs.

RESULTS

From 1990 to 2019, the global burden of CKD attributable to T2D showed increasing trends in general. The burden of CKD attributable to T2D was highest in the middle SDI region and lowest in the low SDI region. Age effects increased with age, and peaked at the ages of 75-79 and 80-84 years for incidence and prevalence, respectively. Period RRs in the burden of CKD attributable to T2D increased, with the high SDI being the most remarkable in DALYs and mortality, and the middle SDI being the most notable in incidence. Cohort RRs showed unfavourable trends in incidence and prevalence among recent cohorts.

CONCLUSIONS

After a lengthy period of multi-initiative diabetes management, the high-middle SDI region exhibited improvement. However, unresolved issues and improvement gaps were still remarkable. Future efforts to reduce the burden of CKD attributable to T2D in the population should prioritize addressing the unfavourable patterns identified.

Body Fat Depletion: the Yin Paradigm for Treating Type 2 Diabetes

PURPOSE OF REVIEW

To highlight that body fat depletion (the Yin paradigm) with glucose-lowering treatments (the Yang paradigm) are associated with metabolic benefits for patients with type 2 diabetes mellitus (T2DM).

RECENT FINDINGS

The sodium-glucose cotransporter-2 inhibitor-mediated sodium/glucose deprivation can directly improve glycemic control and kidney outcome in patients with T2DM. The glucose deprivation might also promote systemic fatty acid β-oxidation to deplete ectopic/visceral fat and thereby contribute to the prevention of cardiovascular diseases. As with metabolic surgery, bioengineered incretin-based medications with potent anorexigenic and insulinotropic efficacy can significantly reduce blood glucose as well as body weight (especially in the ectopic/visceral fat depots). The latter effects could be a key contributor to their cardiovascular-renal protective effects. In addition to a healthy diet, the newer glucose-lowering medications, with body fat reduction effects, should be prioritized when treating patients with T2DM, especially for those with established cardiovascular/renal risks or diseases.

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).

Glomerular hyperfiltration and hypertrophy: an evaluation of maximum values in pathological indicators to discriminate "diseased" from "normal"

The success of sodium-glucose cotransporter 2 inhibitors and bariatric surgery in patients with chronic kidney disease has highlighted the importance of glomerular hyperfiltration and hypertrophy in the progression of kidney disease. Sustained glomerular hyperfiltration and hypertrophy can lead to glomerular injury and progressive kidney damage. This article explores the relationship between obesity and chronic kidney disease, focusing on the roles of glomerular hyperfiltration and hypertrophy as hallmarks of obesity-related kidney disease. The pathological mechanisms underlying this association include adipose tissue inflammation, dyslipidemia, insulin resistance, chronic systemic inflammation, oxidative stress, and overactivation of the sympathetic nervous system, as well as the renin-angiotensin aldosterone system. This article explains how glomerular hyperfiltration results from increased renal blood flow and intraglomerular hypertension, inducing mechanical stress on the filtration barrier and post-filtration structures. Injured glomeruli increase in size before sclerosing and collapsing. Therefore, using extreme values, such as the maximal glomerular diameter, could improve the understanding of the data distribution and allow for better kidney failure predictions. This review provides important insights into the mechanisms underlying glomerular hyperfiltration and hypertrophy and highlights the need for further research using glomerular size, including maximum glomerular profile, calculated using needle biopsy specimens.

Assessment and management of chronic kidney disease in people living with obesity

Obesity and chronic kidney disease (CKD) are common and frequently coexisting medical conditions. Already well known to be a risk factor for type 2 diabetes mellitus (T2DM), ischaemic heart disease, stroke, hypertension, malignancy and premature death, obesity also predisposes to CKD. Elevated weight leads to declining renal function through several mechanisms, including established pathways via metabolic syndrome, hypertension and T2DM, but also through relatively recently understood glomerulosclerosis, directly related to obesity. Compared with non-obese comparators, people living with obesity and established CKD develop faster decline in glomerular filtration, progression to end-stage renal disease (ESRD) and death. Importantly, treatment of obesity can influence these crucial renal outcomes and significantly improve quality of life. Declining renal function also impacts the medical and surgical treatment options available to treat patients with overweight and obesity. In this article, we briefly outline the epidemiology of obesity and renal disease and review the pathological interactions between these diseases before focusing on considerations for assessment and evidence-based treatments for obesity and renal disease.

State of art on the mechanisms of laparoscopic sleeve gastrectomy in treating type 2 diabetes mellitus

Obesity and type-2 diabetes mellitus (T2DM) are metabolic disorders. Obesity increases the risk of T2DM, and as obesity is becoming increasingly common, more individuals suffer from T2DM, which poses a considerable burden on health systems. Traditionally, pharmaceutical therapy together with lifestyle changes is used to treat obesity and T2DM to decrease the incidence of comorbidities and all-cause mortality and to increase life expectancy. Bariatric surgery is increasingly replacing other forms of treatment of morbid obesity, especially in patients with refractory obesity, owing to its many benefits including good long-term outcomes and almost no weight regain. The bariatric surgery options have markedly changed recently, and laparoscopic sleeve gastrectomy (LSG) is gradually gaining popularity. LSG has become an effective and safe treatment for type-2 diabetes and morbid obesity, with a high cost-benefit ratio. Here, we review the me-chanism associated with LSG treatment of T2DM, and we discuss clinical studies and animal experiments with regard to gastrointestinal hormones, gut microbiota, bile acids, and adipokines to clarify current treatment modalities for patients with obesity and T2DM.

Remote Follow-up with a Mobile Application Is Equal to Traditional Outpatient Follow-up After Bariatric Surgery: the BELLA Pilot Trial

PURPOSE

Medical follow-up after bariatric surgery is recommended. However, the compliance was poor. This study aimed to evaluate the feasibility of a smartphone-based fully remote follow-up (FU) program for patients after bariatric surgery.

METHODS

In the interventional group, patients were followed up using a smartphone application (app), through which questionnaires were sent regularly. Participants in the control group underwent standard FU at the outpatient clinic every three months. After 12 months, all the participants were evaluated at an outpatient clinic.

RESULTS

Between August 2020 and March 2021, 44 and 43 patients in the interventional and control groups, respectively, were included in the analysis after three patients were lost to FU, and three withdrew their informed consent because they wished for more personal contact with medical caregivers. After 12 months, total weight loss (TWL), %TWL, and percentage of excess weight loss (%EWL) did not differ between groups. There were no significant differences in the complication rates, including surgical complications, malnutrition, and micronutrition deficiency. The parameters of bioelectrical impedance analysis and quality of life did not differ between the groups. Vitamins and minerals in serum were similar in both groups except for calcium, which was significantly higher in the interventional group (2.52 mmol/L vs. 2.35 mmol/L, p = 0.038).

CONCLUSION

Fully remote FU with a smartphone application is at least as effective as traditional in-person FU in an outpatient clinic after bariatric surgery. Through remote FU, patients can save time and medical professionals may have more resources for patients with more severe problems.

Association Between Obesity and Chronic Kidney Disease: Multivariable Mendelian Randomization Analysis and Observational Data From a Bariatric Surgery Cohort

Obesity is postulated to independently increase chronic kidney disease (CKD), even after adjusting for type 2 diabetes (T2D) and hypertension. Dysglycemia below T2D thresholds, frequently seen with obesity, also increases CKD risk. Whether obesity increases CKD independent of dysglycemia and hypertension is unknown and likely influences the optimal weight loss (WL) needed to reduce CKD. T2D remission rates plateau with 20-25% WL after bariatric surgery (BS), but further WL increases normoglycemia and normotension. We undertook bidirectional inverse variance weighted Mendelian randomization (IVWMR) to investigate potential independent causal associations between increased BMI and estimated glomerular filtration rate (eGFR) in CKD (CKDeGFR) (<60 mL/min/1.73 m2) and microalbuminuria (MA). In 5,337 BS patients, we assessed whether WL influences >50% decline in eGFR (primary outcome) or CKD hospitalization (secondary outcome), using <20% WL as a comparator. IVWMR results suggest that increased BMI increases CKDeGFR (b = 0.13, P = 1.64 × 10-4; odds ratio [OR] 1.14 [95% CI 1.07, 1.23]) and MA (b = 0.25; P = 2.14 × 10-4; OR 1.29 [1.13, 1.48]). After adjusting for hypertension and fasting glucose, increased BMI did not significantly increase CKDeGFR (b = -0.02; P = 0.72; OR 0.98 [0.87, 1.1]) or MA (b = 0.19; P = 0.08; OR 1.21 [0.98, 1.51]). Post-BS WL significantly reduced the primary outcome with 30 to <40% WL (hazard ratio [HR] 0.53 [95% CI 0.32, 0.87]) but not 20 to <30% WL (HR 0.72 [0.44, 1.2]) and ≥40% WL (HR 0.73 [0.41, 1.30]). For CKD hospitalization, progressive reduction was seen with increased WL, which was significant for 30 to <40% WL (HR 0.37 [0.17, 0.82]) and ≥40% WL (HR 0.24 [0.07, 0.89]) but not 20 to <30% WL (HR 0.60 [0.29, 1.23]). The data suggest that obesity is likely not an independent cause of CKD. WL thresholds previously associated with normotension and normoglycemia, likely causal mediators, may reduce CKD after BS.

Visceral fat and attribute-based medicine in chronic kidney disease

Visceral adipose tissue plays a central role in obesity and metabolic syndrome and is an independent risk factor for both cardiovascular and metabolic disorders. Increased visceral adipose tissue promotes adipokine dysregulation and insulin resistance, leading to several health issues, including systemic inflammation, oxidative stress, and activation of the renin-angiotensin-aldosterone system. Moreover, an increase in adipose tissue directly and indirectly affects the kidneys by increasing renal sodium reabsorption, causing glomerular hyperfiltration and hypertrophy, which leads to increased proteinuria and kidney fibrosis/dysfunction. Although the interest in the adverse effects of obesity on renal diseases has grown exponentially in recent years, the relationship between obesity and renal prognosis remains controversial. This may be attributed to the long clinical course of obesity, numerous obesity-related metabolic complications, and patients' attributes. Multiple individual attributes influencing the pathophysiology of fat accumulation make it difficult to understand obesity. In such cases, it may be effective to elucidate the pathophysiology by conducting research tailored to individual attributes from the perspective of attribute-based medicine/personalized medicine. We consider the appropriate use of clinical indicators necessary, according to attributes such as chronic kidney disease stage, level of visceral adipose tissue accumulation, age, and sex. Selecting treatments and clinical indicators based on individual attributes will allow for advancements in the clinical management of patients with obesity and chronic kidney disease. In the clinical setting of obesity-related nephropathy, it is first necessary to accumulate attribute-based studies resulting from the accurate evaluation of visceral fat accumulation to establish evidence for promoting personalized medicine.

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.

[Diabetic kidney disease (update 2023) : Position paper of the Austrian Diabetes Association and the Austrian Society for Nephrology]

Epidemiological investigations have shown that approximately 2-3% of all Austrians have diabetes mellitus with renal involvement, leaving 250,000 people in Austria affected. The risk of occurrence and progression of this disease can be attenuated by lifestyle interventions as well as optimization of blood pressure, blood glucose control and special drug classes. The present article represents the joint recommendations of the Austrian Diabetes Association and the Austrian Society of Nephrology for the diagnostic and treatment strategies of diabetic kidney disease.

2022 American Society of Metabolic and Bariatric Surgery (ASMBS) and International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO) Indications for Metabolic and Bariatric Surgery

MAJOR UPDATES TO 1991 NATIONAL INSTITUTES OF HEALTH GUIDELINES FOR BARIATRIC SURGERY: Metabolic and bariatric surgery (MBS) is recommended for individuals with a body mass index (BMI) >35 kg/m2, regardless of presence, absence, or severity of co-morbidities.MBS should be considered for individuals with metabolic disease and BMI of 30-34.9 kg/m2.BMI thresholds should be adjusted in the Asian population such that a BMI >25 kg/m2 suggests clinical obesity, and individuals with BMI >27.5 kg/m2 should be offered MBS.Long-term results of MBS consistently demonstrate safety and efficacy.Appropriately selected children and adolescents should be considered for MBS.(Surg Obes Relat Dis 2022; https://doi.org/10.1016/j.soard.2022.08.013 ) © 2022 American Society for Metabolic and Bariatric Surgery. All rights reserved.

Sleeve gastrectomy versus Roux-en-Y Gastric Bypass for remission of type 2 diabetes mellitus at 1, 3 and 5 years: a systematic review and meta-analysis

BACKGROUND

Sleeve gastrectomy (SG) and Roux-en-Y Gastric Bypass (RYGB) are the two procedures used in the management of patient with obesity and type 2 diabetes mellitus (T2DM); however, it is still unclear which of the two is more efficient in the remission of type-2 diabetes mellitus.

METHODS

The aim of this study was to analyze the efficiency of RYGB and SG in the remission of type-2 diabetes mellitus after 1, 3 and 5 years of surgery. Three databases (i.e., PubMed, Scopus, Central and Web of Science) were searched. All randomized control trial studies with at least 12-year follow-up were selected with type-2 diabetes mellitus in patients undergoing Roux-en-Y Gastric Bypass or sleeve gastrectomy. The broad and the narrow criteria were lined with individual patients reported, being analyzed and pooled using the random-effects model.

RESULTS

The 15 selected articles, including 707 obese type 2 diabetes patients, met the eligibility criteria for this meta-analysis. RYGB when compared with SG shows increased broad remissions (RR=1.43, 95% CI: 1.13-1.80; P=0.003) and narrow remissions (RR=1.32, 95% CI: 1.15-1.58; P=0.003) after one year of surgery, and broad remissions 5 years after surgery (RR=1.58, 95% CI: 0.97-2.56; P=0.06). No significant difference was identified between the two groups in broad and narrow remissions 3 years after surgery and narrow remissions 5 years after surgery.

CONCLUSIONS

Our results suggest that RYGB was more effective in the remission of type-2 diabetes mellitus at 1 year and 5 years considering the broad and narrow criteria, while there was no difference found 3 years after surgery.

2022 American Society for Metabolic and Bariatric Surgery (ASMBS) and International Federation for the Surgery of Obesity and Metabolic Disorders (IFSO): Indications for Metabolic and Bariatric Surgery

Major updates to 1991 National Institutes of Health guidelines for bariatric surgery.

Dietary restriction and medical therapy drives PPARα-regulated improvements in early diabetic kidney disease in male rats

The attenuation of diabetic kidney disease (DKD) by metabolic surgery is enhanced by pharmacotherapy promoting renal fatty acid oxidation (FAO). Using the Zucker Diabetic Fatty and Zucker Diabetic Sprague Dawley rat models of DKD, we conducted studies to determine if these effects could be replicated with a non-invasive bariatric mimetic intervention. Metabolic control and renal injury were compared in rats undergoing a dietary restriction plus medical therapy protocol (DMT; fenofibrate, liraglutide, metformin, ramipril, and rosuvastatin) and ad libitum-fed controls. The global renal cortical transcriptome and urinary 1H-NMR metabolomic profiles were also compared. Kidney cell type-specific and medication-specific transcriptomic responses were explored through in silico deconvolution. Transcriptomic and metabolomic correlates of improvements in kidney structure were defined using a molecular morphometric approach. The DMT protocol led to ∼20% weight loss, normalized metabolic parameters and was associated with reductions in indices of glomerular and proximal tubular injury. The transcriptomic response to DMT was dominated by changes in fenofibrate- and peroxisome proliferator-activated receptor-α (PPARα)-governed peroxisomal and mitochondrial FAO transcripts localizing to the proximal tubule. DMT induced urinary excretion of PPARα-regulated metabolites involved in nicotinamide metabolism and reversed DKD-associated changes in the urinary excretion of tricarboxylic acid (TCA) cycle intermediates. FAO transcripts and urinary nicotinamide and TCA cycle metabolites were moderately to strongly correlated with improvements in glomerular and proximal tubular injury. Weight loss plus pharmacological PPARα agonism is a promising means of attenuating DKD.

Successful therapeutic strategy for a patient with obese end-stage kidney disease by simultaneous laparoscopic sleeve gastrectomy and implantation of a buried peritoneal dialysis catheter: A case report

For morbidly obese patients with end-stage kidney disease (ESKD), there are often difficulties in accessing, implementing, and maintaining kidney replacement therapy (KRT). Although recent weight-loss surgery has the potential to solve these problems, its therapeutic strategy and appropriate perioperative management for morbidly obese patients with ESKD have not been established. Here, we describe the case history of a 47-year-old man diagnosed with ESKD due to obesity-related glomerulopathy with an uncorrected estimated glomerular filtration rate (eGFR) of 16.1 ml/min. He hoped for kidney transplantation but was not eligible due to his high body mass index (BMI) (36.9 kg/m²). Therefore, a combination strategy for both attaining weight loss and preparing for KRT was needed. We performed modified laparoscopic sleeve gastrectomy (LSG) combined with a buried catheter for peritoneal dialysis (PD), which resulted in reduction of multiple surgical invasions while simultaneously preparing for PD. After these operations, his body mass dropped to below 30.0 kg/m², making him a candidate for kidney transplantation, while maintaining PD. Finally, he was able to have kidney transplantation with success. Collectively, in this case, our novel therapeutic approach was able to avoid multiple surgeries, to assist catheter insertion by laparoscopy, and to provide optimal KRT for an obese patient with ESKD. Simultaneous LSG and implantation of a buried PD catheter may be a promising strategy for morbidly obese patients with ESKD.

Novel Insights in the Physiopathology and Management of Obesity-Related Kidney Disease

Obesity is recognized as an independent risk factor for the development of kidney disease, which has led to the designation of obesity-related glomerulopathy (ORG). Common renal features observed in this condition include glomerular hypertrophy, glomerulosclerosis, haemodynamic changes and glomerular filtration barrier defects. Additionally, and although less studied, obesity-related kidney disease also involves alterations in renal tubules, including tubule hypertrophy, lipid deposition and tubulointerstitial fibrosis. Although not completely understood, the harmful effects of obesity on the kidney may be mediated by different mechanisms, with alterations in adipose tissue probably playing an important role. An increase in visceral adipose tissue has classically been associated with the development of kidney damage, however, recent studies point to adipose tissue surrounding the kidney, and specifically to the fat within the renal sinus, as potentially involved in the development of ORG. In addition, new strategies for the treatment of patients with obesity-related kidney disease are focusing on the management of obesity. In this regard, some non-invasive options, such as glucagon-like peptide-1 (GLP-1) receptor agonists or sodium–glucose cotransporter-2 (SGLT2) inhibitors, are being considered for application in the clinic, not only for patients with diabetic kidney disease but as a novel pharmacological strategy for patients with ORG. In addition, bariatric surgery stands as one of the most effective options, not only for weight loss but also for the improvement of kidney outcomes in obese patients with chronic kidney disease.

Effect of weight change after renal transplantation on outcomes of graft survival

BACKGROUND AND OBJECTIVE

After kidney transplantation, there is an overall increase in weight, which may increase the risk of chronic kidney disease (CKD) and graft loss. But, not all patients gain weight, and the impact on the graft of this different evolution has not been well studied. The objective was to determine the causes of this different evolution and its effect on the graft.

PATIENTS AND METHODS

Retrospective single-center cohort study of 201 patients followed up after transplantation, analyzing the determinants of the variation in weight at one year using logistic regression, and its effect on graft survival at the end of follow-up using Cox regression.

RESULTS

Globally, there was an average weight gain of 4.5 kg in the first year, but 26.6% lost weight. 37.2% increased their BMI, while 9.5% decreased it. The determinants of the different evolution of weight were age (OR for every 10 years: 0.6, p = 0.002), previous dialysis modality (ref. hemodialysis) (OR 0.3, p = 0.003), and BMI before transplantation (OR 0.9, p = 0.017). The different evolution of weight did not influence the final situation of the graft. The BMI at one year did influence as a continuous variable (HR 1.3, p = 0.003), and obesity, with a worse evolution (HR 7.0, p = 0.025).

CONCLUSIONS

Although not all patients gain weight after kidney transplantation, the different evolution of weight does not influence graft survival.

Approach to Patients with Obesity and Other Cardiovascular Risk Factors in Primary Care Using the Delphi Methodology

BACKGROUND

Implementing preventive strategies for patients with obesity would improve the future burden of cardiovascular diseases. The objective was to present the opinions of experts on the approach to treating patients with obesity and other cardiovascular risk factors from a primary care perspective in Spain; Methods: Using the Delphi technique, a 42-question questionnaire was developed based on results from the scientific literature, and sent to 42 experts in primary care. Two rounds of participation were held; Results: There is a close relationship between obesity and cardiovascular risk factors among primary care physicians. It is necessary to use a checklist in primary care that includes metabolic parameters such as body mass index, waist circumference, and levels of C-reactive protein and ferritin. It is also useful to combine pharmacological treatment, such as liraglutide, with a change in lifestyle to achieve therapeutic goals in this population; Conclusions: There is a high level of awareness among experts in Spain regarding obesity and other cardiovascular risk factors, and the need to address this pathology comprehensively. The need to incorporate specific tools in primary care consultations that allow for better assessment and follow-up of these patients, such as cuffs adapted to arm size or imaging techniques to assess body fat, is evident. Teleconsultation is imposed as a helpful tool for follow-up. Experts recommend that patients with obesity and associated comorbidities modify their lifestyle, incorporate a Mediterranean diet, and administer liraglutide.

Renal Function Following Bariatric Surgery: a Literature Review of Potential Mechanisms

Obesity is a major and independent risk factor for onset and progression of many renal diseases. Bariatric surgery (BS) improves renal function by improving obesity-related metabolic disorders. However, the procedure is also accompanied by renal risks, including acute kidney injury (AKI) and oxalate nephropathy. Here, we briefly review the history and principle of frequently applied technique for BS and summarize the comprehensive BS effect on kidney function. Importantly, we highlight the possible molecular mechanisms associated with the recovery of renal function to provide novel ideas for future studies and clinical applications.

Urinary Metabolomic Changes Accompanying Albuminuria Remission following Gastric Bypass Surgery for Type 2 Diabetic Kidney Disease

In the Microvascular Outcomes after Metabolic Surgery randomised clinical trial (MOMS RCT, NCT01821508), combined metabolic surgery (gastric bypass) plus medical therapy (CSM) was superior to medical therapy alone (MTA) as a means of achieving albuminuria remission at 2-year follow-up in patients with obesity and early diabetic kidney disease (DKD). In the present study, we assessed the urinary ¹H-NMR metabolome in a subgroup of patients from both arms of the MOMS RCT at baseline and 6-month follow-up. Whilst CSM and MTA both reduced the urinary excretion of sugars, CSM generated a distinctive urinary metabolomic profile characterised by increases in host–microbial co-metabolites (N-phenylacetylglycine, trimethylamine N-oxide, and 4-aminobutyrate (GABA)) and amino acids (arginine and glutamine). Furthermore, reductions in aromatic amino acids (phenylalanine and tyrosine), as well as branched-chain amino acids (BCAAs) and related catabolites (valine, leucine, 3-hydroxyisobutyrate, 3-hydroxyisovalerate, and 3-methyl-2-oxovalerate), were observed following CSM but not MTA. Improvements in BMI did not correlate with improvements in metabolic and renal indices following CSM. Conversely, urinary metabolites changed by CSM at 6 months were moderately to strongly correlated with improvements in blood pressure, glycaemia, triglycerides, and albuminuria up to 24 months following treatment initiation, highlighting the potential involvement of these shifts in the urinary metabolomic profile in the metabolic and renoprotective effects of CSM.

Medications Activating Tubular Fatty Acid Oxidation Enhance the Protective Effects of Roux-en-Y Gastric Bypass Surgery in a Rat Model of Early Diabetic Kidney Disease

Background

Roux-en-Y gastric bypass surgery (RYGB) improves biochemical and histological parameters of diabetic kidney disease (DKD). Targeted adjunct medical therapy may enhance renoprotection following RYGB.

Methods

The effects of RYGB and RYGB plus fenofibrate, metformin, ramipril, and rosuvastatin (RYGB-FMRR) on metabolic control and histological and ultrastructural indices of glomerular and proximal tubular injury were compared in the Zucker Diabetic Sprague Dawley (ZDSD) rat model of DKD. Renal cortical transcriptomic (RNA-sequencing) and urinary metabolomic (1H-NMR spectroscopy) responses were profiled and integrated. Transcripts were assigned to kidney cell types through in silico deconvolution in kidney single-nucleus RNA-sequencing and microdissected tubular epithelial cell proteomics datasets. Medication-specific transcriptomic responses following RYGB-FMRR were explored using a network pharmacology approach. Omic correlates of improvements in structural and ultrastructural indices of renal injury were defined using a molecular morphometric approach.

Results

RYGB-FMRR was superior to RYGB alone with respect to metabolic control, albuminuria, and histological and ultrastructural indices of glomerular injury. RYGB-FMRR reversed DKD-associated changes in mitochondrial morphology in the proximal tubule to a greater extent than RYGB. Attenuation of transcriptomic pathway level activation of pro-fibrotic responses was greater after RYGB-FMRR than RYGB. Fenofibrate was found to be the principal medication effector of gene expression changes following RYGB-FMRR, which led to the transcriptional induction of PPARα-regulated genes that are predominantly expressed in the proximal tubule and which regulate peroxisomal and mitochondrial fatty acid oxidation (FAO). After omics integration, expression of these FAO transcripts positively correlated with urinary levels of PPARα-regulated nicotinamide metabolites and negatively correlated with urinary tricarboxylic acid (TCA) cycle intermediates. Changes in FAO transcripts and nicotinamide and TCA cycle metabolites following RYGB-FMRR correlated strongly with improvements in glomerular and proximal tubular injury.

Conclusions

Integrative multi-omic analyses point to PPARα-stimulated FAO in the proximal tubule as a dominant effector of treatment response to combined surgical and medical therapy in experimental DKD. Synergism between RYGB and pharmacological stimulation of FAO represents a promising combinatorial approach to the treatment of DKD in the setting of obesity.