Long-term impact of bariatric surgery in diabetic nephropathy

Sleeve gastrectomy links the attenuation of diabetic kidney disease to the inhibition of renal tubular ferroptosis through down-regulating TGF-β1/Smad3 signaling pathway

PURPOSE

To investigate how sleeve gastrectomy (SG), a typical operation of bariatric surgery, attenuated symptom, and progression of diabetic kidney disease (DKD).

METHODS

DKD model was induced by high-fat diet (HFD) combined with streptozocin in Wistar rats. SG was performed, and the group subjected to sham surgery served as control. The animals were euthanized 12 weeks after surgery, followed by sample collection for the subsequent experiment. The HK-2, a renal proximal tubular epithelial cell line derived from human, was utilized to investigate the potential mechanisms.

RESULTS

SG improved metabolic parameters and glucose homeostasis, and could alleviate DKD in terms of renal function indices as well as histological and morphological structures in DM rats, accompanied with a significant reduction in renal tubular injury. Compared with sham group, SG reduced the renal tubular ferroptosis. To further clarify the mechanism involved, in vitro experiments were performed. In the presence of high glucose, renal tubular TGF-β1 secretion was significantly increased in HK-2 cell line, which led to activation of ferroptosis through TGF-β1/Smad3 signaling pathway. Inhibition of TGF-β1 receptor and phosphorylation of Smad3 significantly ameliorated TGF-β1-mediated ferroptosis. In vivo experiments also found that SG improved the hyperglycemic environment, reduced renal TGF-β1 concentrations, and down-regulated the TGF-β1/Smad3 signaling pathway.

CONCLUSIONS

With the capacity to lower the glucose, SG could attenuate the ferroptosis by inhibiting TGF-β1/Smad3 signaling pathway in DKD rats, and eventually attenuated DKD.

Significant Promising Effects of Bariatric Surgery on the Biochemical Control of Glycemia and Lipidemia in Diabetic Patients in Western Saudi Arabia: A Tertiary Center Experience and a Retrospective Study

BACKGROUND

The prevalence of obesity has increased globally and is associated with many comorbidities such as type 2 diabetes and fatty liver and cardiovascular diseases. Bariatric surgery is considered an effective intervention for achieving weight loss and controlling lipidemia and glycemia.

OBJECTIVES

This Saudi retrospective observational study evaluates the clinical and biochemical benefits following bariatric surgery to obese diabetic patients.  Methodology: After gaining ethical committee approval, data was collected from the patients' medical records at a tertiary medical center (King Fahad General Hospital, Al-Madinah Al-Munawwarah, Saudi Arabia). The total sample size was 61 patients, of whom 78.33% (n=48) had a body mass index (BMI) of 40 or greater (obese class III).

RESULTS

Following bariatric surgery, there were statistically significant reductions (p<0.001) in BMI and HbA1C (decreased from 45.53±7.791 kg/m2 and 7.9±1.82% to 33.42±6.18 kg/m2 and 6.06±1.35%, respectively, after surgery). Likewise, significant reductions (p<0.001) occurred to serum total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides that decreased from 234.4±26.7 mg/dl, 152.2±19.4 mg/dl, and 187.3±24.6 mg/dl to 158.4±17.3 mg/dl, 95.6±15.7 mg/dl, and 132.5±19.5 mg/dl, respectively. Interestingly, serum high-density lipoprotein (HDL) significantly increased (p<0.001) from 43.8±6.2 mg/dl to 52.3±4.6 mg/dl. Using the novel clinical therapeutic index, bariatric surgery decreased BMI by about 26.6%. Using the novel biochemical therapeutic index, bariatric surgery decreased HbA1C, serum total cholesterol, serum LDL cholesterol, and serum triglycerides by about 22.99%, 32.42%, 37.18%, and 29.26%, respectively, while serum HDL increased by about 19.4%.

CONCLUSION

Bariatric surgery is an effective intervention for obese diabetic patients resulting in weight loss, better control of diabetes and hyperlipidemia, and the metabolic profile. It is also recommended in Saudi Arabia for the high prevalence of obesity and diabetes mellitus.

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

BACKGROUND

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

OBJECTIVES

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

SETTING

Meta-analysis.

METHODS

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

RESULTS

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

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.

Obstacles and Opportunities in Managing Coexisting Obesity and CKD: Report of a Scientific Workshop Cosponsored by the National Kidney Foundation and The Obesity Society

The National Kidney Foundation (NKF) and The Obesity Society (TOS) cosponsored a multispecialty international workshop in April 2021 to advance the understanding and management of obesity in adults with chronic kidney disease (CKD). The underlying rationale for the workshop was the accumulating evidence that obesity is a major contributor to CKD and adverse outcomes in individuals with CKD, and that effective treatment of obesity, including lifestyle intervention, weight loss medications, and metabolic surgery, can have beneficial effects. The attendees included a range of experts in the areas of kidney disease, obesity medicine, endocrinology, diabetes, bariatric/metabolic surgery, endoscopy, transplant surgery, and nutrition, as well as patients with obesity and CKD. The group identified strategies to increase patient and provider engagement in obesity management, outlined a collaborative action plan to engage nephrologists and obesity medicine experts in obesity management, and identified research opportunities to address gaps in knowledge about the interaction between obesity and kidney disease. The workshop's conclusions help lay the groundwork for development of an effective, scientifically based, and multidisciplinary approach to the management of obesity in people with CKD.

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.

Remission as an Emerging Therapeutic Target in Type 2 Diabetes in the Era of New Glucose-Lowering Agents: Benefits, Challenges, and Treatment Approaches

Type 2 diabetes mellitus (T2DM) is a progressive disease with a growing prevalence, associated with an increased risk of complications. The introduction of new classes of antidiabetic drugs into clinical practice has dramatically changed the landscape of diabetes therapy. However, despite the progress made in the pharmacotherapy of T2DM, mitigating the burden of the disease on individuals, societies and health care systems remains a challenge. Remission has recently emerged as a therapeutic target in T2DM, achievable through a wide range of interventions. Recent studies have shown that extensive lifestyle changes, such as weight reduction, bariatric surgery, and intensive glucose lowering therapy, can prompt the remission of diabetes, but some unanswered questions remain regarding its long-term effects on diabetic complications. Metabolic surgery and novel classes of glucose-lowering medications are currently the most effective interventions to induce weight loss and by extension remission in patients with diabetes; however, the ideal strategy to achieve the long-term maintenance of remission remains doubtful. In this narrative review, we discuss the available therapeutic approaches to target the remission of diabetes through personalized multimodal care, based on the latest evidence.

Impact of Weight Loss on the Severity of Albuminuria in Obese Diabetic Patients Undergoing Laparoscopic Sleeve Gastrectomy and One-Anastomosis Gastric Bypass

Aim

To examine the effect of weight-loss induced bariatric procedures on albuminuria levels among diabetic patients suffering from obesity.

Methods

Adults patients who suffer from morbid obesity and type 2 diabetes mellitus (T2DM) were included in a prospective cohort study. Subjects were scheduled to undergo laparoscopic sleeve gastrectomy (LSG) or one-anastomosis gastric bypass (OAGB). The albumin-to-creatinine ratio (ACR) was adopted to assess the degree of albuminuria. Microalbuminuria was determined as a ratio of >2.5-30 mg/mmol and >3.5-30 mg/mmol for males and females, respectively, while macroalbuminuria was diagnosed when the ACR exceeded >30 mg/mmol.

Results

The mean uACR decreased significantly from 20.95±16.89 to 9.92±12.69mg/mmol in LSG cohort (p <0.001), and from 19.52±16.65 to 9.34±11.77mg/mmol in the OAGB cohort, with no statistically considerable differences between both cohorts at the end of follow-up (p = 0.78). Twelve months after the procedures, the percentages of cases with microalbuminuria decreased significantly to 23.8% and 23.9%, respectively (p < 0.001); likewise, the percentages of cases with macroalbuminuria significantly decreased to 7.9% and 7.5% in the LSG and OAGB groups, respectively (p < 0.001). There were no statistically considerable differences between LSG and OAGB regarding the percentages of patients with micro or macroalbuminuria at the end of follow-up. Besides, there were no significant associations between the degree of weight loss and improvement (p = 0.959) or remission (p = 0.73) of microalbuminuria.

Conclusion

Bariatric surgery significantly reduced the severity of albuminuria 1-year after the procedure, with no preference for one procedure over the other.

Cardiovascular Outcomes in Patients With Type 2 Diabetes and Obesity: Comparison of Gastric Bypass, Sleeve Gastrectomy, and Usual Care

OBJECTIVE

To determine which one of the two most common metabolic surgical procedures is associated with greater reduction in risk of major adverse cardiovascular events (MACE) in patients with type 2 diabetes mellitus (T2DM) and obesity.

RESEARCH DESIGN AND METHODS

A total of 13,490 patients including 1,362 Roux-en-Y gastric bypass (RYGB), 693 sleeve gastrectomy (SG), and 11,435 matched nonsurgical patients with T2DM and obesity who received their care at the Cleveland Clinic (1998-2017) were analyzed, with follow-up through December 2018. With multivariable Cox regression analysis we estimated time to incident extended MACE, defined as first occurrence of coronary artery events, cerebrovascular events, heart failure, nephropathy, atrial fibrillation, and all-cause mortality.

RESULTS

The cumulative incidence of the primary end point at 5 years was 13.7% (95% CI 11.4-15.9) in the RYGB groups and 24.7% (95% CI 19.0-30.0) in the SG group, with an adjusted hazard ratio (HR) of 0.77 (95% CI 0.60-0.98, P = 0.04). Of the six individual end points, RYGB was associated with a significantly lower cumulative incidence of nephropathy at 5 years compared with SG (2.8% vs. 8.3%, respectively; HR 0.47 [95% CI 0.28-0.79], P = 0.005). Furthermore, RYGB was associated with a greater reduction in body weight, glycated hemoglobin, and use of medications to treat diabetes and cardiovascular diseases. Five years after RYGB, patients required more upper endoscopy (45.8% vs. 35.6%, P < 0.001) and abdominal surgical procedures (10.8% vs. 5.4%, P = 0.001) compared with SG.

CONCLUSIONS

In patients with obesity and T2DM, RYGB may be associated with greater weight loss, better diabetes control, and lower risk of MACE and nephropathy compared with SG.

Improvement of Renal Function After Bariatric Surgery: a Systematic Review and Meta-analysis

BACKGROUND/OBJECTIVE

The effect of bariatric surgery in renal function varies and the postoperative benefit time point remains unclear. We aim to assess the changes of renal function after bariatric surgery (BS) in different postoperative periods and subgroups.

METHODS

We searched the databases of PubMed and Cochrane from inception to December 14, 2020. Articles included in the study were drawn from all recipients of BS that provided assessments of renal function pre and post-surgery. Meta-analysis was performed to compare glomerular filtration rate (GFR), serum creatinine, albumin-to-creatinine ratio (ACR), and albuminuria before and after BS.

RESULTS

The study included 49 articles involving 8515 patients. Compared with pre-operative renal function, the overall analysis showed that bariatric surgery significantly reduced serum creatinine levels, ACR, and albuminuria. There was significant increase of GFR in the CKD subgroup, yet a noticeable decrease in the hyperfiltration subgroup. The most significant improvement in GFR was seen 6-12 months after BS, while ACR dropped most dramatically 12-24 months after BS.

CONCLUSIONS

Bariatric surgery can improve renal function in obese patients with kidney dysfunction, especially 1 year after surgery.

The Effect of Bariatric Surgery versus Intensive Medical Care on Prevention of Microalbuminuria in Patients with Type 2 Diabetes: 3 Year Experience of a Prospective Study

BACKGROUND: Bariatric surgery could improve diabetic kidney disease; however, the effect of surgery versus medical therapy on renal out comes needs further evaluation. AIM: The aim of the study was to investigate the effect of sleeve-gastrectomy versus intensive medical therapy on the prevention of albuminuria in patients with Type 2 diabetes mellitus (T2DM). METHODS: This is a prospective study of 33 patients with T2DM undergoing sleeve gastrectomy matched for age, sex, and duration of diabetes to 64 medically treated patients. Urinary albumin/creatinine ratio (uACR) was assessed before and 3–year after intervention. RESULTS: At baseline, there was no significant difference between surgical and medical group regarding body mass index (BMI), blood pressure, Hemoglobin A1c (HbA1c), or uACR. After 3 years of interventions the mean BMI (kg/m2) and HbA1c (%) became significantly lower in the surgical group compared to medical group. Although mean uACR (g/mg) increased after interventions compared to its levels before interventions in both surgical (11.7 ± 4.8 vs.18.2 ± 5.9) g/mg and medical (13.4 ± 4.5 vs.17.1 ± 6) g/mg groups, albuminuria developed in only three surgical patients and two medical patients (p > 0.05). CONCLUSION: Although bariatric surgery is associated with more reduction in body weight and better glycemic control than intensive medical therapy, sleeve-gastrectomy may not be superior to intensive medical care in prevention of microalbuminuria in patients with T2DM.

Cardiovascular Risk Reduction Following Metabolic and Bariatric Surgery

Cardiovascular disease (CVD) remains a leading cause of morbidity and mortality in developed countries, with worsening pandemics of type 2 diabetes mellitus and obesity as major cardiovascular (CV) risk factors. Clinical trials of nonsurgical obesity treatments have not shown benefits in CVD, although recent diabetes trials have demonstrated major CV benefits. In many retrospective and prospective cohort studies, however, metabolic (bariatric) surgery is associated with substantial and reproducible CVD benefits. Despite a lack of prospective, randomized clinical trials, data suggest metabolic surgery may be the most effective modality for CVD risk reduction, likely through weight loss and weight loss-independent mechanisms.

Metabolic surgery: A clinical update

Metabolic and bariatric surgery has grown beyond 'experimental' weight-loss surgery. As techniques have advanced over the last few decades, so has the growing body of research and evidence, proving that both weight-loss and metabolic health improvement are induced. Metabolic surgery has become the more appropriate term for weight-loss surgery because of the altered gastrointestinal anatomy and subsequent beneficial metabolic effects. Although the tool of metabolic surgery has been well refined, a large portion of the global population does not have adequate access to it. This clinical update aims to (a) inform healthcare providers from all disciplines about the myriad of benefits of metabolic surgery and (b) equip them with the necessary knowledge to bridge the gap between patients in need of metabolic treatment and the therapies in metabolic surgery available to them.

Effect of Conventional Medical Therapy or Laparoscopic Sleeve Gastrectomy on Urinary Albumin in Japanese Subjects with Severe Obesity: An Observational Study

INTRODUCTION

In patients with severe obesity, albuminuria can be improved by both conventional medical therapy and bariatric surgery. The purpose of this study was to compare the impact of weight loss achieved through conventional medical therapy or laparoscopic sleeve gastrectomy (LSG) on albuminuria in Japanese subjects with severe obesity and identify the factors involved.

METHODS

We retrospectively evaluated the clinical characteristics including the urinary albumin/creatinine ratio (UACR) of 340 consecutive subjects with a body mass index ≥35 who received LSG (n = 242) or medical therapy (n = 98) between 2010 and 2018 and were followed for at least 12 months.

RESULTS

The baseline of the UACR was not different between the 2 groups. At the 12-month follow-up, total weight loss (TWL) and decreases in glycosylated hemoglobin (HbA1c) and loge UACR were greater in the LSG group than in the medical therapy group (body weight; -35.7 kg vs. -8.0 kg, p < 0.001, HbA1c; -1.4% vs. -0.7%, p < 0.001, loge UACR; -0.3 vs. 0.9, p < 0.001). The rate of complete remission of diabetes was significantly higher in the LSG group than in the medical therapy group. At 12 and 36 months (n = 111 in the medical therapy group, n = 56 in the LSG group at 36 months), loge UACR increased in the medical therapy group, while it remained unchanged or decreased in the LSG group. In subjects with microalbuminuria and macroalbuminuria, changes in the loge UACR correlated with percent total body weight loss (%TWL) in both groups at 12 months. Percent TWL contributed independently to the change in the loge UACR, irrespective of whether LSG was performed. In receiver-operating characteristic analysis, a weight loss of 7.8% predicted a decrease in the UACR (∆UACR <0 at 12 months).

CONCLUSION

Our analysis suggests that albuminuria may increase over time if only medical therapy is continued. To improve albuminuria, weight loss may be more important than whether LSG is performed.

Effects of gastric bypass surgery on expression of glucose transporters and fibrotic biomarkers in kidney of diabetic fatty rats

BACKGROUND

Diabetic nephropathy is the leading cause of chronic kidney disease. Observational studies suggest Roux-en-Y gastric bypass (RYGB) reduces progression of diabetic nephropathy.

OBJECTIVES

To unravel the mechanisms by which RYGB is beneficial and protective for diabetic nephropathy.

SETTING

Academic laboratories.

METHODS

Forty-eight Zucker diabetic fatty rats were randomized to RYGB, sham surgery (SHAM), or pair-fed (PF) groups. An oral glucose tolerance test was performed at 25 days post intervention and kidneys were harvested at 30 days. Primary outcome measures included expression of key genes and proteins in the glucose transport, oxidative stress, inflammation, and fibrosis pathways.

RESULTS

Thirty days post intervention, RYGB rats weighed 349 ± 8 g, which was lower than SHAM (436 ± 14 g, P < .001), but not PF (374 ± 18 g) rats. RYGB rats had lower fasting glucose than PF animals and improved homeostatic model assessment of insulin resistance compared with PF and SHAM groups. These enhanced metabolic outcomes were accompanied by reduced sodium-glucose co-transporter 1 (Sglt1) gene expression (-23% versus PF, P = .01) in the kidney of RYGB rats. Expression of Sglt2, Glut1, or Glut2 mRNA, or oxidative stress and inflammation markers did not differ significantly. However, RYGB surgery induced a 19% lower expression of transforming growth factor (Tgfβ) mRNA (P = .004) compared with SHAM treated animals. Notably, adenosine monophosphate-activated protein kinase phosphorylation was increased (P = .04) in kidneys of the RYGB surgery animals.

CONCLUSIONS

Improvement of hyperglycemia after RYGB may reduce the glucose load on the kidney leading to a downregulation of specific glucose transporters. RYGB surgery may also attenuate kidney fibrosis through the adenosine monophosphate-activated protein kinase/TGFβ pathway.

Metabolic and cardiovascular outcomes of bariatric surgery

PURPOSE OF REVIEW

Bariatric surgery is an effective therapy for morbid obesity that also improves weight-related metabolic parameters and reduces morbidity and mortality. The purpose of this review is to consolidate our current understanding of metabolic, macrovascular and microvascular benefits of bariatric surgery and to provide an update.

RECENT FINDINGS

Early resolution of insulin resistance and type 2 diabetes mellitus (T2DM) varies by type of bariatric surgery and appears to be mediated by changes in secretion of gut hormones, metabolism of bile acids, expression of glucose transporters and the gut microbiome. Dyslipidaemia, atherosclerosis, microvascular complications of obesity and diabetes, systemic and tissue-level inflammation show evidence of regression and hypertension improves significantly after bariatric surgery.

SUMMARY

Bariatric surgery leads to improvements in obesity-related metabolic comorbidities such as dyslipidaemia, HDL functionality, hypertension, T2DM, insulin resistance and inflammation. It slows the atherosclerotic process and reduces cardiovascular and all-cause mortality. Recent data have demonstrated regression of the microvascular complications of obesity and diabetes including the regeneration of small nerve fibres. The magnitude of change in short-term metabolic effects depends on the surgical procedure whilst longer term effects are related to the amount of sustained excess weight loss.

The Effects of Bariatric Surgery on Renal, Neurological, and Ophthalmic Complications in Patients with Type 2 Diabetes: the Taiwan Diabesity Study

Background

Bariatric surgery has been shown to improve glycemic control in patients with type 2 diabetes. However, less is known whether it can also reduce diabetic renal, neurological, and ophthalmic complications.

Methods

This prospective multicenter cohort study compared renal, ophthalmic, and neurological complications between 49 patients with obesity/overweight receiving bariatric surgery and 338 patients receiving standard medical treatment after follow-up for 2 years. Patients received neurological examinations including toe tuning fork vibration test, ankle tendon reflex test, 10-g monofilament test, and ophthalmic examinations including visual acuity measurement and fundus examinations. Multiple regressions, propensity score weighting, and matching were employed to adjust for baseline differences.

Results

After 2 years of follow-up, patients with type 2 diabetes receiving bariatric surgery had greater reduction in BMI, HbA1c, and urine albumin–creatinine ratio, greater improvement in estimated glomerular filtration rate, and greater increase in tuning fork test score of right and left toes compared with the medical group. However, there is no improvement in 10 g-monofilament test, visual acuity, diabetic non-proliferative retinopathy, and proliferative retinopathy. Similar results were obtained using multiple regression adjustment, propensity-score weighting, or comparing age-, sex-, and BMI-matched subjects.

Conclusions

After 2-year follow-up, patients with obesity/overweight and type 2 diabetes receiving bariatric surgery have increased glomerular filtration rate, reduced albuminuria, and improved tuning folk vibration sensation.

Electronic supplementary material

The online version of this article (10.1007/s11695-020-04859-9) contains supplementary material, which is available to authorized users.

Renal and Cardiovascular Outcomes After Weight Loss From Gastric Bypass Surgery in Type 2 Diabetes: Cardiorenal Risk Reductions Exceed Atherosclerotic Benefits

OBJECTIVE

We examined detailed renal and cardiovascular (CV) outcomes after gastric bypass (GBP) surgery in people with obesity and type 2 diabetes mellitus (T2DM), across several renal function categories, in a nationwide cohort study.

RESEARCH DESIGN AND METHODS

We linked data from the National Diabetes Register and the Scandinavian Obesity Surgery Register with four national databases holding information on socioeconomic variables, medications, hospitalizations, and causes of death and matched 5,321 individuals with T2DM who had undergone GBP with 5,321 who had not (age 18-65 years, mean BMI >40 kg/m², mean follow-up >4.5 years). The risks of postoperative outcomes were assessed with Cox regression models.

RESULTS

During the first years postsurgery, there were small reductions in creatinine and albuminuria and stable estimated glomerular filtration rate (eGFR) in the GBP group. The incidence rates of most outcomes relating to renal function, CV disease, and mortality were lower after GBP, being particularly marked for heart failure (hazard ratio [HR] 0.33 [95% CI 0.24, 0.46]) and CV mortality (HR 0.36 [(95% CI 0.22, 0.58]). The risk of a composite of severe renal disease or halved eGFR was 0.56 (95% CI 0.44, 0.71), whereas nonfatal CV risk was lowered less (HR 0.82 [95% CI 0.70, 0.97]) after GBP. Risks for key outcomes were generally lower after GBP in all eGFR strata, including in individuals with eGFR <30 mL/min/1.73 m².

CONCLUSIONS

Our data suggest robust benefits for renal outcomes, heart failure, and CV mortality after GBP in individuals with obesity and T2DM. These results suggest that marked weight loss yields important benefits, particularly on the cardiorenal axis (including slowing progression to end-stage renal disease), whatever the baseline renal function status.

Bariatric surgery as a renoprotective intervention

PURPOSE OF REVIEW

Through its direct adverse effects on the kidney and via associated intermediate disease states like type 2 diabetes and hypertension, obese has arguably become the master risk factor for chronic kidney disease (CKD). The purpose of this review is to critically evaluate bariatric surgery, which is the most effective weight reduction strategy available, as a renoprotective strategy.

RECENT FINDINGS

Recent randomized studies confirm that bariatric surgery is effective at improving or even remitting major CKD risk factors such as type 2 diabetes and hypertension. In addition, observational studies performed primarily in patients without preexisting CKD report improvements in estimated glomerular filtration rate and albuminuria after bariatric surgery. Yet this literature is limited by study design, participant selection, statistical power, and measurement issues that must be overcome to better define kidney-related benefits, especially with regard to harder kidney-related and other clinical endpoints.

SUMMARY

Encouraging data exist on the renoprotective effects of bariatric surgery. However, important knowledge gaps still remain. Future research should focus on studying, ideally in randomized fashion, the renoprotective effects of bariatric surgery in patients with preexisting CKD to better define the benefit-risk ratio for each patient.

Obesity, Metabolic Syndrome and the Risk of Microvascular Complications in Patients with Diabetes mellitus

BACKGROUND

Obesity frequently co-exists with type 2 diabetes mellitus (T2DM), leading to the socalled "diabesity epidemic". The metabolic syndrome (MetS), a cluster of central obesity, hypertension, dysglycemia, insulin resistance and/or atherogenic dyslipidemia, as well as non-alcoholic fatty liver disease (NAFLD), a hepatic manifestation of MetS, has been associated with increased cardiovascular disease (CVD), T2DM and chronic kidney disease (CKD) incidence. However, the association between obesity, MetS (including NAFLD) and diabetic microvascular complications is less evident.

METHODS

The present narrative review discusses the associations of obesity, MetS and NAFLD with diabetic kidney disease (DKD), diabetic retinopathy (DR) and diabetic peripheral neuropathy (DPN) as well as cardiac autonomic neuropathy (CAN). The available data on the effects of lifestyle measures and bariatric surgery on these diabetic complications are also briefly discussed.

RESULTS

Overall, both obesity and MetS have been related to DKD, DR and DPN, although conflicting results exist. Links between NAFLD and diabetic microvascular complications have also been reported but data are still limited. Lifestyle intervention and bariatric surgery may prevent the development and/or progression of these microvascular complications but more evidence is needed.

CONCLUSION

Clinicians should be aware of the frequent co-existence of MetS and/or NAFLD in T2DM patients to prevent or treat these metabolic disorders, thus potentially minimizing the risk for both CVD and diabetic microvascular complications.

Association of Metabolic Surgery With Major Adverse Cardiovascular Outcomes in Patients With Type 2 Diabetes and Obesity

IMPORTANCE

Although metabolic surgery (defined as procedures that influence metabolism by inducing weight loss and altering gastrointestinal physiology) significantly improves cardiometabolic risk factors, the effect on cardiovascular outcomes has been less well characterized.

OBJECTIVE

To investigate the relationship between metabolic surgery and incident major adverse cardiovascular events (MACE) in patients with type 2 diabetes and obesity.

DESIGN, SETTING, AND PARTICIPANTS

Of 287 438 adult patients with diabetes in the Cleveland Clinic Health System in the United States between 1998 and 2017, 2287 patients underwent metabolic surgery. In this retrospective cohort study, these patients were matched 1:5 to nonsurgical patients with diabetes and obesity (body mass index [BMI] ≥30), resulting in 11 435 control patients, with follow-up through December 2018.

EXPOSURES

Metabolic gastrointestinal surgical procedures vs usual care for type 2 diabetes and obesity.

MAIN OUTCOMES AND MEASURES

The primary outcome was the incidence of extended MACE (composite of 6 outcomes), defined as first occurrence of all-cause mortality, coronary artery events, cerebrovascular events, heart failure, nephropathy, and atrial fibrillation. Secondary end points included 3-component MACE (myocardial infarction, ischemic stroke, and mortality) and the 6 individual components of the primary end point.

RESULTS

Among the 13 722 study participants, the distribution of baseline covariates was balanced between the surgical group and the nonsurgical group, including female sex (65.5% vs 64.2%), median age (52.5 vs 54.8 years), BMI (45.1 vs 42.6), and glycated hemoglobin level (7.1% vs 7.1%). The overall median follow-up duration was 3.9 years (interquartile range, 1.9-6.1 years). At the end of the study period, 385 patients in the surgical group and 3243 patients in the nonsurgical group experienced a primary end point (cumulative incidence at 8-years, 30.8% [95% CI, 27.6%-34.0%] in the surgical group and 47.7% [95% CI, 46.1%-49.2%] in the nonsurgical group [P < .001]; absolute 8-year risk difference [ARD], 16.9% [95% CI, 13.1%-20.4%]; adjusted hazard ratio [HR], 0.61 [95% CI, 0.55-0.69]). All 7 prespecified secondary outcomes showed statistically significant differences in favor of metabolic surgery, including mortality. All-cause mortality occurred in 112 patients in the metabolic surgery group and 1111 patients in the nonsurgical group (cumulative incidence at 8 years, 10.0% [95% CI, 7.8%-12.2%] and 17.8% [95% CI, 16.6%-19.0%]; ARD, 7.8% [95% CI, 5.1%-10.2%]; adjusted HR, 0.59 [95% CI, 0.48-0.72]).

CONCLUSIONS AND RELEVANCE

Among patients with type 2 diabetes and obesity, metabolic surgery, compared with nonsurgical management, was associated with a significantly lower risk of incident MACE. The findings from this observational study must be confirmed in randomized clinical trials.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03955952.