Metabolic effects and safety of Roux-en-Y gastric bypass surgery vs. conventional medication in obese Chinese patients with type 2 diabetes

Clinical outcomes of roux-en-Y gastric bypass versus medical therapy in type 2 diabetes mellitus: a systematic review and meta-analysis

Background

The growing incidence of obesity has led to a proportionate rise in type 2 diabetes mellitus (T2DM) and its associated complications. We aimed to compare the long-term outcomes of Roux-en-y Gastric Bypass surgery (RYGB) and conventional medical management in T2DM obese patients.

Methods

PubMed, Google Scholar, and Clinicaltrial.gov were searched from inception to September 2023. Randomized Controlled Trials (RCTs) and cohort studies were included in this meta-analysis. The primary outcomes were the T2DM remission at 1, 2, 3, and 5 years and the accomplishment of the ADA composite triple treatment goal. The revised Cochrane risk of bias tool 2.0 and New-Castle Ottawa scale were used to assess the quality of the studies. This meta-analysis was registered prospectively on PROSPERO CRD42023466324.

Results

Of the 3,323 studies yielded from our initial search, 22 were included in this evidence analysis, with 5,176 total patients (1,984 and 3,192 patients in RYGB and conventional medical management groups). A significant increase in the accomplishment in the ADA's composite triple treatment goal was observed in RYGB group as compared to the conventional medical management group (RR 2.41, 95% CI 1.39-4.15, p-value 0.002, I2 35%). Diabetes remission was a clinically successful outcome after 1, 2, 3, and 5 years of the RYGB surgery in the patients (1 year; RR 4.74, 95%CI 2.46-9.12, p-value < 0.00001, I2 0%, 2 years; RR 8.95, 95% CI 1.71-46.71, p-value 0.009, I2 92%3 years; RR 18.18 95%CI 7.57-43.62, p-value < 0.00001, I2 0%, 5 years; RR 0.22, 95% CI 2.31-16.75, p-value 0.0003, I2 = 71%).

Conclusion

The pooled analysis of the given data concluded that the RYGB surgery was more effective in treating T2DM in patients than conventional medical management.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-024-01526-z.

Effectiveness of Roux-en-Y Gastric Bypass in Patients with Type 2 Diabetes: A Meta-analysis of Randomized Controlled Trials

This meta-analysis aimed to evaluate the effectiveness of Roux-en-Y gastric bypass (RYGB) in people living with type 2 diabetes mellitus (T2DM). A comprehensive search was conducted in the PubMed database up to January 2024. A random-effects model was used to calculate the pooled standard mean differences (SMDs) and odds ratios (ORs). Ten studies were included in our review. The RYGB group demonstrated significantly better outcomes compared to the non-surgical group in multiple measures. These included higher triple criteria compliance rates (OR 9.04, 95% CI 3.22-25.36), complete T2DM remission (OR 15.37, 95% CI 4.42-53.41), and partial T2DM remission (OR 11.49, 95% CI 3.57-37.03). Additionally, improvements were observed in glycated hemoglobin A1c (HbA1c) levels (SMD - 1.41, 95% CI - 2.22 to - 0.61), with HbA1c < 6.0% (OR 8.54, 95% CI 3.38-21.62) and HbA1c < 7.0% (OR 5.62, 95% CI 3.20-9.86). Fasting blood glucose (FBG) levels also showed improvement (SMD - 0.43, 95% CI - 0.71 to - 0.14), with a higher proportion achieving FBG < 100 mg/dl (OR 11.83, 95% CI 4.75-29.43). Other notable outcomes included significant percentage of total weight loss (%TWL: SMD 1.88, 95% CI 1.39-2.37), reductions in body mass index (BMI: SMD - 2.28, 95% CI - 3.52 to - 1.04), and improvements in lipid profiles, including low-density lipoprotein (LDL) levels (SMD - 1.01, 95% CI - 1.91 to - 0.11) and LDL < 2.59 mmol/L (OR 3.65, 95% CI 1.94-6.87). In addition, high-density lipoprotein (HDL) levels increased (SMD 1.30, 95% CI 0.55-2.05), while triglycerides (SMD - 1.11, 95% CI - 1.70 to - 0.52), systolic blood pressure (SBP: SMD - 0.38, 95% CI - 0.70 to - 0.06), and diastolic blood pressure (DBP: SMD - 0.41, 95% CI - 0.63 to - 0.18) decreased. A greater proportion of patients in the RYGB group achieved SBP < 130 mmHg (OR 3.15, 95% CI 1.61-6.13). Moreover, reductions were noted in insulin use (OR 0.25, 95% CI 0.14-0.46), diabetes medication use (SMD - 1.95, 95% CI - 3.32 to - 0.57), and peripheral neuropathy (OR 0.13, 95% CI 0.02-0.79). However, no significant differences were observed in hypertension medication use or retinopathy between the two groups. RYGB was found to be effective in improving glycemic control, promoting weight loss, enhancing lipid profiles, and managing blood pressure. It also significantly reduced the need for postoperative diabetes medications and the incidence of diabetic peripheral neuropathy in people living with T2DM.

Short-Term and Long-Term Effects of Bariatric Surgery on Diabetic Retinopathy: A Systematic Review

Background and Objectives: Diabetic retinopathy (DR) is a common diabetes complication and a leading cause of blindness. Although bariatric surgery (BS) is well studied for diabetes management, its effects on DR onset and progression, particularly long-term outcomes, remain underexplored. This review seeks to evaluate the short- and long-term retinal outcomes of BS in diabetic patients. Materials and Methods: A systematic search of PubMed, Web of Science, and Cochrane Library was conducted following PRISMA 2020 guidelines, including the use of the PRISMA checklist and flow diagram. The search included English-language articles (2014-2024) using keywords like "diabetic retinopathy" and "bariatric surgery". The review excluded studies published in languages other than English, as well as reviews, case reports, and those lacking adequate data or relevance. The risk of bias was determined by using the Downs and Black checklist. A systematic review of the literature was conducted, and the results were organized and displayed in tables to summarize and compare the main findings. Results: After screening 158 articles, 13 studies involving 17,903 patients were selected, focusing on the effects of BS on DR progression and regression. Short-term data suggest that BS may stabilize or improve DR but poses risks of worsening in advanced cases, requiring careful monitoring. However, long-term findings are inconsistent, with evidence of both DR regression and progression. These variations highlight the need for further research. Discussion: BS generally improves DR progression, but its effect depends on preoperative severity and glycemic control. Further studies should explore additional risk factors to better predict DR outcomes post-surgery. Conclusions: BS improves weight management, blood pressure, and diabetes control, potentially benefiting DR. However, the long-term effects remain uncertain due to conflicting findings. Rapid glycemic changes after surgery may pose risks of DR progression. Large-scale, longitudinal studies are needed to clarify the role of BS in DR progression and regression.

The effect of bariatric surgery on diabetes related foot complications among patients with type 2 diabetes: A systematic review

BACKGROUND

Bariatric surgery leads to considerable weight loss and improved glycaemic control and seems to have a favourable impact on diabetes related foot complications (DFC).

OBJECTIVES

To assess the effect of bariatric surgery on diabetes related foot complications in patients with type 2 diabetes and determine whether DFC symptoms are improved after bariatric surgery.

METHODS

We searched MEDLINE, Embase and Cochrane Central Register of Controlled Trials. The primary outcome was the presence of DFC after bariatric surgery. The secondary outcome was the improvement of DFC after bariatric surgery among patients who already had DFC before surgery.

RESULTS

There were nine studies showing the presence of DFC post bariatric surgery and six detailing the changes in DFC post bariatric surgery. Bariatric surgery was not associated with a lower risk of developing or worsening DFC compared to conventional medical treatment based on 4 randomised control trials (IR 0.87, 95 % CI, 0.26, 2.98), while from observational studies was associated with 51 % lower risk of DFC (IR 0.49, 95 % CI, 0.31, 0.77). Bariatric surgery was associated with improvement in diabetic neuropathy assessment parameters including toe tuning fork score, self-reported neuropathy symptoms, neuropathy symptom score, and neuropathy symptom profile.

CONCLUSION

Bariatric surgery led to a greater reduction in developing or worsening DFC among patients with type 2 diabetes compared to medical treatment in observational studies, but not among RCTs. Bariatric surgery was associated with improvements in diabetic neuropathy related assessment parameters and symptoms. Bariatric surgery could be a promising treatment for patients with type 2 diabetes who are at high risk of DFC.

Microvascular complications of obesity and diabetes-Role of bariatric surgery

Bariatric surgery in people with obesity can lead to long-term remission of type 2 diabetes mellitus (T2DM) and a reduction in the incidence of macrovascular complications. The impact of bariatric surgery on microvascular complications is less clear. In this narrative review, we sought to evaluate the effect of bariatric surgery on microvascular complications in patients with and without diabetes. The risk of developing microvascular complications is increased in people with obesity, and this is amplified in those with T2DM. The impact of metabolic surgery on microvascular complications is limited to a subgroup analysis of studies or statistical modeling to predict the glycemia-independent effect of bariatric surgery. While bariatric surgery halts the progression of retinopathy in those with minimal retinopathy, it may worsen in those with advanced retinopathy. Bariatric surgery improves proteinuria and major renal outcomes, regardless of the severity of renal impairment. Bariatric surgery in patients with obesity with or without diabetes is associated with an improvement in neuropathic symptoms and regeneration of small nerve fibers. In conclusion, bariatric surgery is associated with an improvement in microvascular complications. Further studies are needed to elucidate the underlying mechanisms for the favorable effect of bariatric surgery on microvascular outcomes.

Weight loss and metabolic benefits of bariatric surgery in China: A multicenter study

BACKGROUND

This retrospective multicenter study evaluated the efficacy and safety of bariatric surgery in Chinese patients with obesity.

METHODS

Patients with obesity who underwent laparoscopic sleeve gastrectomy or laparoscopic Roux-en-Y gastric bypass and completed a 12-month follow-up between February 2011 and November 2019 were enrolled. Weight loss, glycemic and metabolic control, insulin resistance, cardiovascular risk, and surgery-related complications at 12 months were analyzed.

RESULTS

We enrolled 356 patients aged 34.3 ± 0.6 years with a mean body mass index of 39.4 ± 0.4 kg/m2 . Successful weight loss occurred in 54.6%, 86.8%, and 92.7% of patients at 3, 6, and 12 months, respectively, with no difference in percent excess weight loss between the laparoscopic sleeve gastrectomy and laparoscopic Roux-en-Y gastric bypass surgery groups. The average percentage of total weight loss was 29.5% ± 0.6% at 12 months; 99.4%, 86.8%, and 43.5% of patients achieved at least 10%, 20%, and 30% weight loss, respectively, at 12 months. Significant improvements in metabolic indices, insulin resistance, and inflammation biomarkers were observed at 12 months.

CONCLUSIONS

Bariatric surgery resulted in successful weight loss and improved metabolic control, insulin resistance, and cardiovascular risk in Chinese patients with obesity. Both laparoscopic sleeve gastrectomy and laparoscopic Roux-en-Y gastric bypass are suitable approaches for such patients.

Benefits of bariatric surgery on microvascular outcomes in adult patients with type 2 diabetes: a systematic review and meta-analysis

BACKGROUND

Microvascular diabetes complications impair patients' health-related quality of life. Bariatric surgery (BS) emerged as a compelling treatment that demonstrated to have beneficial effects on patients with diabetes and obesity.

OBJECTIVE

We aimed to synthesize the benefit of bariatric surgery on microvascular outcomes in adult patients with type 2 diabetes.

SETTING

2011-2021.

METHODS

We included both cohort studies and randomized trials that evaluated bariatric surgery added to medical therapy compared with medical therapy alone in the treatment of adult patients with type 2 diabetes. Studies must have evaluated the incidence of any microvascular complication of the disease for a period of at least 6 months. We performed our search using PubMed, Scopus, EMBASE, Web of Science, and COCHRANE Central database which was performed from inception date until March 2021. PROSPERO (CRD42021243739).

RESULTS

A total of 25 studies (160,072 participants) were included. Pooled analysis revealed bariatric surgery to reduce the incidence of any stage of retinopathy by 71% (odds ratio [OR] .29; 95% confidence interval [CI] .10-.91), nephropathy incidence by 59% (OR .41; 95% CI 17-96), and hemodialysis/end-stage renal disease by 69% (OR .31 95% CI .20-.48). Neuropathy incidence revealed no difference between groups (OR .11; 95% CI .01-1.37). Bariatric surgery increased the odds of albuminuria regression by 15.15 (95% CI 5.96-38.52); higher odds of retinopathy regression were not observed (OR 3.73; 95% CI .29-47.71). There were no statistically significant differences between groups regarding the change in surrogate outcomes.

CONCLUSIONS

Bariatric surgery in adult patients with diabetes reduced the odds of any stage of retinopathy, hemodialysis/end-stage renal disease, and nephropathy composite outcome. However, its effect on many individual outcomes, both surrogates, and clinically significant, remains uncertain.

Retinal Vascular Lesions in Patients with Nonalcoholic Fatty Liver Disease: A Systematic Review and Meta-Analysis

Background: This systematic review and meta-analysis aimed to summarize and compare data on retinal vascular lesions between patients with nonalcoholic fatty liver disease (NAFLD) and individuals without the disease. Methods: Search was performed in PubMed, Scopus and Cochrane Library, complemented by handsearching (PROSPERO ID: CRD42022345558). Thirty-six studies comprising 24,985 individuals (12,387 NAFLD patients and 12,598 controls) were selected for the meta-analysis. Results: Apart from retinopathy, no study with a different type of retinal vascular lesion was retrieved. Overall, there was no significant difference in the presence of retinopathy in NAFLD patients compared to controls (Odds Ratio (OR) = 1.20; 95% Confidence Interval (CI): 0.91-1.59). Heterogeneity among studies was high (I² = 93%; p < 0.00001), while Egger's test revealed no publication bias (p = 0.60). However, subgroup analysis showed positive association between retinopathy and NAFLD in type 1 diabetes mellitus (T1DM) (OR = 2.35; 95% CI: 1.53-3.60), but not in type 2 diabetes mellitus patients. Meta-regression analysis exploring potential confounders revealed no significant association. Conclusions: The presence of retinopathy was not overall different between individuals with and without NAFLD; however, T1DM patients with NAFLD had higher rates of retinopathy compared to T1DM patients without NAFLD, a finding warranting further research to show whether NAFLD may predict retinopathy in T1DM patients.

Diabetes remission of bariatric surgery and nonsurgical treatments in type 2 diabetes patients who failure to meet the criteria for surgery: a systematic review and meta-analysis

BACKGROUND

The efficacy of bariatric surgery in moderate and severe obesity patients to reach diabetes remission is clear, but for mild obesity patients, the choice of surgical and non-surgical treatment is still unclear. This study we aim to compare the effect of surgical and nonsurgical treatment on patients BMI < 35 kg/m² to reach diabetes remission.

METHOD

We searched relevant articles publish between Jan 1,2010 and Jan 1, 2023 in the following databases: Embase, PubMed/MEDLINE, Scopus, and Cochrane Library. We got the OR, MD and P-value using random effect model to compare the efficiency between bariatric surgery and nonsurgical treatment on diabetes remission, the reduction of BMI, Hb1Ac and FPG.

RESULTS

In 7 included studies including 544 participants, bariatric surgery is more effective than non-surgical treatment to reach diabetes remission [OR 25.06, 95%CL 9.58-65.54]. Bariatric surgery more likely resulted in significant reductions in HbA1c [MD -1.44, 95%CL (-1.84)-(-1.04)] and FPG [MD -2.61, 95%CL (-3.20)-(-2.20)]. Bariatric surgery may resulted in reductions in BMI [MD -3.14, 95%CL (-4.41)-(-1.88)], which more significant in Asian.

CONCLUSION

In type 2 diabetes patients who BMI < 35 kg/m², bariatric surgery is more likely to achieve diabetes remission and better blood glucose control than nonsurgical treatment.

Two-year outcomes of Roux-en-Y gastric bypass vs medical treatment in type 2 diabetes with a body mass index lower than 32.5 kg/m2: a multicenter propensity score-matched analysis

BACKGROUND

Roux-en-Y gastric bypass (RYGB) has been widely reported to be safe and feasible, and has a powerful effect on improving metabolism and weight loss in patients with a high body mass index (BMI). A few studies have focused on the comparison of RYGB with medical treatment in type 2 diabetes (T2D) patients with a lower BMI.

OBJECTIVES

To compare the metabolic effects and safety of RYGB versus medical treatment during a 2 years follow-up in T2D patients with a BMI of 25 to 32.5 kg/m².

METHODS

This retrospective and multicenter cohort study participants were extracted from the T2D patients with a lower BMI (25-32.5 kg/m²) from three bariatric centers between 2009 and 2018. Propensity score matching (PSM) was used to minimize bias, and each patient in the surgical group was matched 1:2 to the patients in the medical group with the closest propensity score. Finally, 71 patients who received RYGB and 142 patients who underwent medical treatment with a 2 years follow-up were enrolled to compare the effects of RYGB and medical treatment. The primary endpoint was achievement of the triple endpoint (the simultaneous achievement of hemoglobin A1c (HbA1c) < 7.0%, fasting low-density lipoprotein cholesterol (LDL-C) < 100 mg/dL (2.6 mmol/L), and systolic blood pressure (SBP) < 130 mmHg at the year-1 visit). Changes in weight, BMI, medication usage, complications, and adverse events were assessed.

RESULTS

In total, 213 patients (mean age of 47.4 ± 9.5 years, 70.4% male, mean BMI of 28.6 ± 2.2 kg/m²) were included in this study. At the end of the first year, 17 patients (23.9%) in the surgical group and 10 (7.0%) in the medical group had achieved the composite triple endpoint (OR 4.64; 95% CI 1.82-11.81; p = 0.001). Additionally, 43 patients (60.6%) in the surgical group and 11 patients (19.7%) in the medical group experienced remission of T2D. However, more complications were observed in the surgical group (36 vs. 22, p < 0.01).

CONCLUSIONS

Among T2D patients with a BMI between 25.0 and 32.5 kg/m², RYGB was more effective than medical treatment in resolving metabolic disorders and also resulted in more complications. The risk for complications should be considered in the clinical decision-making process for T2D patients with a low BMI.

Improvement of Type 2 Diabetes Mellitus and Attenuation of NAFLD Are Associated with the Success of Obesity Therapy

Obesity and type 2 diabetes mellitus (T2D) represent important comorbidities of the metabolic syndrome, which are associated with non-alcoholic fatty liver disease (NAFLD)-related hepatic fibrosis. In total, 160 morbidly obese patients-81 following a low-calorie formula diet (LCD) program and 79 undergoing bariatric surgery (Roux-en-Y gastric bypass, RYGB)-were examined for anthropometric and metabolic parameters at base-line and during 12 months of weight loss, focusing on a putative co-regulation of T2D parameters and liver fibrosis risk. High NAFLD fibrosis scores (NFS) before intervention were associated with elevated HbA1c levels and T2D. Loss of weight and body fat percentage (BFL) were associated with improved glucose and lipid metabolism and reduced risk of NAFLD-related fibrosis, with particularly beneficial effects by RYGB. Both T2D improvement and NFS decrease were positively associated with high BFL. A highly significant correlation of NFS reduction with BFL was restricted to male patients while being absent in females, accompanied by generally higher BFL in men. Overall, the data display the relation of BFL, T2D improvement, and reduced NAFLD-related fibrosis risk during weight loss in morbidly obese individuals induced by diet or RYGB. Furthermore, our data suggest a considerable sexual dimorphism concerning the correlation of fat loss and improved risk of liver fibrosis.

Changes in Antihypertensive Medication Following Bariatric Surgery

Obesity is a leading cause of hypertension (i.e., high blood pressure [BP]). While hypertension can be managed with antihypertensive medication, substantial weight loss can also lower BP, reducing the need for antihypertensive medication. Articles in this review (n = 60) presented data on antihypertensive medication use among adults pre- and postoperatively. Roux-en-Y gastric bypass was the most studied surgical approach followed by Laparoscopic Sleeve Gastrectomy. Antihypertensive medication was discontinued in a large proportion of patients after surgery, and the mean number of antihypertensive medications decreased by approximately one. In almost a third of the studies, over 75% of participants experienced hypertension remission. All articles aside from two reported a decrease in systolic BP, with about 40% reporting a decrease of ≥ 10 mm Hg.

Outcomes of Diabetic Retinopathy Post-Bariatric Surgery in Patients with Type 2 Diabetes Mellitus

Bariatric surgery is an emerging therapeutic approach for obese type 2 diabetes mellitus (T2DM) patients, with proven benefits for achieving target glucose control and even remission of diabetes. However, the effect of bariatric surgery upon diabetic retinopathy is still a subject of debate as some studies show a positive effect while others raise concerns about potential early worsening effects. We performed a systematic review, on PubMed, Science Direct, and Web of Science databases regarding the onset and progression of diabetic retinopathy in obese T2DM patients who underwent weight-loss surgical procedures. A total of 6375 T2DM patients were analyzed. Most cases remained stable after bariatric surgery (89.6%). New onset of diabetic retinopathy (DR) was documented in 290 out of 5972 patients (4.8%). In cases with DR at baseline, progression was documented in 50 out of 403 (12.4%) and regression in 90 (22.3%). Preoperative careful preparation of hemoglobin A1c (HbA1c), blood pressure, and lipidemia should be provided to minimize the expectation of DR worsening. Ophthalmologic follow-up should be continued regularly in the postoperative period even in the case of diabetic remission. Further randomized trials are needed to better understand the organ-specific risk factors for progression and provide personalized counseling for T2DM patients planned for bariatric surgery.

Is Bariatric Surgery Effective for Chinese Patients with Type 2 Diabetes Mellitus and Body Mass Index < 35 kg/m2? A Systematic Review and Meta-analysis

BACKGROUND

Bariatric surgery has been applied for weight loss and comorbidity control in China since 2000. Recent studies have shown positive results for bariatric surgery in patients with a body mass index (BMI) of less than 35 kg/m². However, the effect of surgery on Chinese patients with type II diabetes mellitus (T2DM) has not yet been systematically investigated.

METHODS

A comprehensive literature search was performed in the Cochrane Library, Embase, PubMed, and Web of Science from January 2014 to March 2020. All studies examined bariatric surgery outcomes on Chinese patients at 12-, 36-, and 60-month follow-up. The research followed the guidance of Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols (PRISMA-P) recommendations.

RESULTS

Eleven studies containing 611 patients were included in this meta-analysis. Clinical indices at 12-, 36-, and 60-month follow-up were analyzed. Significant decreases were identified in body weight, BMI, waist circumference (WC), blood pressure (BP), fasting plasma glucose (FPG), glycosylated hemoglobin A1c (hemoglobin A1c, or HbA1c), triglyceride (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) postoperatively. An increasing trend in the T2DM remission rate was discovered. The remission group was observed to have significantly lower HbA1c and C-peptide level, a shorter duration of T2DM, and a higher BMI than the nonremission group at 12 months.

CONCLUSIONS

Bariatric surgery successfully provided significant BMI control as well as a reduction and normalization of glucose- and lipid-related metabolism at 12, 36, and 60 months postoperatively in Chinese patients with T2DM with a preoperative BMI of less than 35 kg/m². An increasing trend in the T2DM remission rate suggested promising future applications in this population.

Metabolic surgery in China: present and future

Obesity and its related complications comprise a serious public health problem worldwide, and obesity is increasing in China. Metabolic surgery is a new type of treatment with unique advantages in weight loss and obesity-related metabolic complications. The pathogenesis of obesity is complex and not yet fully understood. Here, we review the current efficacy and safety of metabolic surgery, as well as recent progress in mechanistic studies and surgical procedures in China. The exciting and rapid advances in this field provide new opportunities for patients with obesity and strike a balance between long-term effectiveness and safety.

Are Chinese Patients with Type 2 Diabetes and a Body Mass Index of 27.5-32.5 kg/m2 Suitable for Metabolic Surgery? A One-Year Post-Surgery Study

INTRODUCTION

The aim of this study was to clarify the efficacy and safety of metabolic surgery in Chinese patients with type 2 diabetes mellitus (T2DM) and a body mass index (BMI) of 27.5-32.5 kg/m².

METHODS

A total of 99 patients with T2DM were enrolled in this retrospective cohort study. Of these patients, 53 had a BMI of 27.5-32.5 kg/m² and had undergone metabolic surgery (n = 21) or were on conventional antidiabetic therapy (n = 32)]; 46 had a BMI ≥ 32.5 kg/m² and all had undergone metabolic surgery. Primary endpoints included the triple endpoint [hemoglobin A1c < 6.5%, low-density lipoprotein cholesterol (LDL-C) < 2.6 mmol/L, and systolic blood pressure (SBP) < 130 mmHg] and successful weight loss 1 year later. Remission of diabetes, glucose and lipid metabolism, medication usage, and adverse events were evaluated.

RESULTS

Of patients with BMI 27.5-32.5 kg/m² undergoing metabolic surgery, 33.33% achieved the composite endpoints, and 100% achieved successful weight loss. This result was similar to that in patients with BMI ≥ 32.5 and better than those with BMI 27.5-32.5 kg/m² receiving conventional antidiabetic therapy. A significant and similar reduction in BMI, waist circumference, SBP, serum LDL-C, hemoglobin A1c, and uric acid, as well as similar frequency postoperative adverse events, were confirmed in both metabolic surgery groups. Patients with BMI 27.5-32.5 kg/m² who had undergonemetabolic surgery showed more metabolic improvement than those only receiving medications but they experienced more adverse events.

CONCLUSION

A BMI cutoff of 27.5 kg/m² for metabolic surgery may be suitable for Chinese patients with T2DM.

The Impact of Bariatric Surgery on Diabetic Retinopathy: A Systematic Review and Meta-Analysis

OBJECTIVE

While bariatric surgery induces remission of type 2 diabetes mellitus and reduces other microvascular complications, its impact on diabetic retinopathy (DR) is unclear. Some trials suggest early worsening of DR postsurgery because of rapid improvements in hyperglycemia. This meta-analysis sought to estimate the impact of bariatric surgery on DR for obese patients compared with medical treatment.

DESIGN

Systematic review and meta-analysis.

METHODS

The Medline, Embase, and PubMed Central databases were searched to March 2020. Primary studies comparing DR in patients undergoing bariatric surgery with those undergoing medical management were included. Results were meta-analyzed using a random-effects model. Primary outcomes included prevalence of all DR and sight-threatening DR after surgery. Secondary outcomes included worsening of DR within and beyond 12 months.

RESULTS

Overall, 14 studies comprised of 110,300 surgical patients and 252,289 control subjects were included. Surgical patients had a statistically significantly lower postoperative prevalence of all DR (relative risk [RR] 0.17 [95% confidence interval {CI} 0.13-0.22]) and sight-threatening DR (RR 0.47 [95% CI 0.27-0.82]). Early worsening of DR and progression to sight-threatening DR had occurred more often in those with more severe DR initially. However, beyond 12 months, bariatric surgery resulted in significantly fewer patients with worsened DR (RR 0.29 [95% CI 0.16-0.54]). The overall risk of bias was low; estimates of relative effects had low to moderate certainty of evidence.

CONCLUSION

While bariatric surgery was associated with fewer cases of all and sight-threatening DR, early worsening was more severe in patients with existing sight-threatening DR. These findings argue for frequent monitoring during the first postoperative year.

Microbial Adaptation Due to Gastric Bypass Surgery: The Nutritional Impact

Bariatric surgery leads to sustained weight loss and the resolution of obesity-related comorbidities. Recent studies have suggested that changes in gut microbiota are associated with the weight loss induced by bariatric surgery. Several studies have observed major changes in the microbial composition following gastric bypass surgery. However, there are inconsistencies between the reported alterations in microbial compositions in different studies. Furthermore, it is well established that diet is an important factor shaping the composition and function of intestinal microbiota. However, most studies on gastric bypass have not assessed the impact of dietary intake on the microbiome composition in general, let alone the impact of restrictive diets prior to bariatric surgery, which are recommended for reducing liver fat content and size. Thus, the relative impact of bariatric surgery on weight loss and gut microbiota remains unclear. Therefore, this review aims to provide a deeper understanding of the current knowledge of the changes in intestinal microbiota induced by bariatric surgery considering pre-surgical nutritional changes.

Five-year effectiveness of bariatric surgery on disease remission, weight loss, and changes of metabolic parameters in obese patients with type 2 diabetes: A population-based propensity score-matched cohort study

AIMS

To compare disease remission rates, weight loss, and changes of metabolic parameters of patients after bariatric surgery with nonsurgical patients.

METHODS

Based on the 2006-2017 Hospital Authority database, a population-based retrospective cohort of obese type 2 diabetes mellitus (T2DM) patients with and without bariatric surgery were identified. Surgical patients were matched with nonsurgical patients on 1-to-5 propensity score. Remission rates of diabetes, hypertension, and dyslipidaemia were reported annually up to 60 months. Changes in weight loss measurements (Body Mass Index [BMI], percentage of total weight loss [%TWL], percentage of excess weight loss [%EWL], and percentage of rebound in excess weight loss [%REWL]) and metabolic parameters (haemoglobin A_1c [HbA_1c ], systolic blood pressure [SBP], diastolic blood pressure [DBP], and low-density lipoprotein cholesterol [LDL-C]) were measured for both groups.

RESULTS

Four hundred one surgical patients (310 restrictive surgeries; 91 bypass surgeries) and 1894 nonsurgical patients were included. Surgical patients had higher remission rates in diabetes and dyslipidaemia and better glycaemic control at 12 to 60 months (all Ps < .01). SBP and DBP were significantly lower for surgical group up to 12 months and similar between two groups after 12 months. Surgical patients had significantly lower BMI during follow-up period. %TWL and %EWL were higher in the surgery group (15.7% vs 3.7%; 48.8% vs 12.0%) at 60 months (P < .001); differences in %REWL between two groups were insignificant. The effectiveness of restrictive and bypass surgeries was similar at 60 months, although restrictive surgeries were slightly more effective in T2DM remission.

CONCLUSIONS

Bariatric surgery was effective in weight loss, remission of diabetes, and dyslipidaemia in 5-year post-surgery.