Roux-en-Y Gastric Bypass vs Sleeve Gastrectomy for Remission of Type 2 Diabetes

Abstract

Context

Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) are the bariatric procedures most commonly used for the management of obesity. Whether one or the other is associated with a higher chance of remission of type 2 diabetes (T2D) is unclear.

Objective

This work aims to compare the efficacy of RYGB and SG for T2D remission at 1, 3, and 5 years after surgery.

Data Sources

Four databases were searched until January 2020.

Study Selection

Randomized controlled studies with at least 12 months of follow-up of patients with T2D allocated to RYGB or SG were selected.

Data Extraction

To ensure uniformity, broad and narrow criteria for T2D remission were defined. The number of patients achieving remission of T2D at each assessment was extracted. Data were pooled using a random-effects model.

Data Synthesis

Ten studies were included, evaluating 778 patients. The overall prevalence of achievement of broad and narrow criteria for T2D remission was 73% and 53% at the 1-year, 60% and 48% at the 3-year, and 51% and 43% at the 5-year assessment. Compared to SG, RYGB was associated with a higher chance of achieving broad and narrow criteria for remission at 1 year after surgery (risk ratio [RR] = 1.34 vs RR = 1.22) and broad criteria for remission at 5 years (RR = 1.18). No other differences were found.

Conclusions

The present meta-analysis suggests a more favorable effect of RYGB than SG on achieving T2D remission in the short-term only, although the evidence currently available does not clarify whether differences in this outcome are confirmed long term or fade thereafter.

Roux-en-Y gastric bypass, sleeve gastrectomy, type 2 diabetes, remission, lifestyle, meta-analysis

Bariatric surgery is the most effective treatment for obesity. It is associated with a long-term excess weight loss of more than 50%, with some differences depending on the procedure adopted (1), resulting in a reduced risk of mortality and cardiovascular events, as well as improvements in comorbidities and quality of life (2-4). Both weight loss-dependent and independent mechanisms have been proposed to explain these effects, including calorie restriction and modified gut-brain signaling pathways among the former, and changes in β-cell function, tissue-specific insulin sensitivity, bile acid composition, and flow and gut microbiota among the latter (5). In patients suffering from both type 2 diabetes (T2D) and obesity, bariatric surgery has been shown to be superior to various lifestyle/medical interventions in improving glycemic control and reducing drug consumption, cardiovascular risk factors, microvascular complications, cancer, and all-cause mortality. In particular, it has been documented to induce remission of T2D (6-8).

The 2 procedures most commonly used are Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG) (1, 9). In RYGB, a small gastric pouch is created just distal to the gastroesophageal junction and is connected directly to the small intestine, bypassing the stomach, duodenum, and the proximal part of the jejunum. In SG, a narrow gastric tube is created along the lesser curvature of the stomach (1). Several meta-analyses comparing the 2 procedures in terms of efficacy and safety have been published. RYGB was generally associated with a greater percentage excess weight loss, and remission of dyslipidemia and gastroesophageal reflux compared to SG. Similar readmission rates, reoperation rates, and 30-day mortality were reported for both procedures. Concerning remission of T2D, discordant results have been found to date (10-18). Several issues may explain this finding, including the design of included studies, their sample size, and statistical power to assess differences, as well as the duration of follow-up. Moreover, despite the definitions proposed by the American Diabetes Association, different criteria for remission were used in the literature, possibly leading to discrepancies in the interpretation of the available evidence (19). Therefore, we conducted the present study to achieve solid information on the remission of T2D after RYGB and SG, adopting broad and narrow criteria for remission. A systematic search was carried out, to identify randomized controlled trials (RCTs) reporting data on the prevalence of remission after RYGB and SG. We also performed a meta-analysis of available data to 1) determine the prevalence of remission of T2D at 1 year, 3 years, and 5 years after surgery; and 2) compare the prevalence of T2D remission after each procedure at each assessment.

Materials and Methods

This meta-analysis was registered in PROSPERO (CRD42020168564) and performed in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement (20).

Search strategy

A 6-step search strategy was planned. First, we searched for sentinel studies in PubMed. Second, we identified keywords in PubMed. Third, the following complete search strategy was used in PubMed: sleeve [All Fields] AND (bypass [All Fields] OR roux [All Fields]) AND randomized [All Fields]. Fourth, CENTRAL, Scopus, and Web of Science were searched with the same strategy. Fifth, RCT with at least 12 months of follow-up of patients with T2D randomly assigned to laparoscopic or open RYGB or SG were selected. RCTs with fewer than 5 eligible patients per arm, studies on procedures other than RYGB or SG, nonrandomized studies, letters, commentaries, and posters were excluded. Last, references of included studies were searched to find additional papers. The last search was performed January 28, 2020. No language restriction was adopted. Two investigators (M.C. and F.P.) independently searched for papers, screened titles and abstracts of the retrieved articles, reviewed the full-texts, and selected articles for inclusion.

Data extraction

The following information was extracted independently by the same investigators in a piloted form: 1) general information on the study (author, year of publication, country, study type, follow-up period, inclusion criteria, number of patients with T2D); 2) criteria for remission of T2D; 3) number of patients with T2D with available data at 1 year, 3 years, and 5 years after surgery; and 4) number of patients with T2D achieving broad and narrow criteria for remission at 1 year, 3 years, and 5 years after surgery. For those studies whose results were published in separate reports, one set of data at each follow-up was extracted. According to the American Diabetes Association, remission should be defined as complete if glycated hemoglobin (HbA_1c) is less than 6.0% (42 mmol/mol) and fasting plasma glucose (FPG) is less than 100 mg/dL, or partial if HbA_1c is less than 6.5% (48 mmol/mol) and FPG is 100 to 125 mg/dL for at least 1 year’s duration in the absence of active pharmacologic therapy or ongoing procedures (19). These criteria were heterogeneously adopted in the literature, as already stated. Also, according to the previously listed criteria, the classification of some achievements (eg, HbA_1c of 6.2% [44 mmol/mol] and FPG of 95 mg/dL) was unclear. Therefore, for the purpose of the present meta-analysis, as broad and narrow criteria for remission we adopted HbA_1c of less than 6.5% (48 mmol/mol) and less than 6.0% (42 mmol/mol) with or without any reference to FPG in the absence of active pharmacologic therapy or ongoing procedures. Minor variations (eg, HbA_1c ≤ 6.0% instead of < 6.0%) were allowed. This was established in view of the known advantages of HbA_1c, including preanalytical stability, low day-to-day perturbations, and association with the risk of complications (21). For each selected article, the main paper and supplementary data were searched; if data were missing, authors were contacted via e-mail. Data were cross-checked, and any discrepancy was discussed.

Study quality assessment

The risk of bias of the included studies was assessed independently by 2 reviewers (M.C. and F.P.) according to the Cochrane Collaboration tool. The following aspects were evaluated: random sequence generation; allocation concealment; blinding of participants and personnel; blinding of outcome assessment; incomplete outcome data; selective reporting. For other bias, funding was assessed. Each domain was assigned a low, unclear or high risk of bias (22).

Data analysis

The primary outcome was the difference between RYGB and SG in achieving broad and narrow criteria for remission of T2D mellitus at 1 year, 3 years, and 5 years after surgery. First, a meta-analysis of proportions was carried out to obtain the pooled rate of each remission at each follow-up after any procedure, RYGB, and SG. Second, head-to-head comparisons were conducted to assess differences in the rate of each remission at each follow-up after RYGB and SG. A subgroup analysis on criteria adopted for remission (eg, American Diabetes Association vs other) was performed (19). End points were analyzed as dichotomous variables, and proportions and risk ratios (RR) were estimated. Heterogeneity between studies was assessed using I², with 50% or more being regarded as high. Publication bias was assessed with the Egger test and visually with funnel plots; the trim-and-fill method was used to estimate its effect. All analyses were 2-sided and carried out using RevMan5.3 (The Cochrane Collaboration) and StatsDirect with a random-effect model; significance was set at P less than .05.

Results

Study characteristics

In total, 1694 papers were found: 258 on PubMed, 389 on CENTRAL, 485 on Scopus, and 562 on Web of Science. After the removal of 710 duplicates, 984 articles were analyzed for title and abstract; 924 records were excluded (review, meta-analysis, guidelines, study protocol, ongoing trial, nonrandomized study, procedures other than RYGB and SG, follow-up shorter than 12 months, commentary, poster, case report/series, not in humans). The remaining 60 papers were retrieved in full text and 46 records were excluded because of overlapping data (n = 24), no data of interest (n = 8), including fewer than 5 patients per arm (n = 6), adopting unclear definitions or not reporting clear criteria for remission of T2D (n = 4), or a nonrandomized study design (n = 4). Finally, 14 articles reporting 10 studies were included in the meta-analysis (Fig. 1) (23-36). No additional study was retrieved from references of included studies.

Figure 1.

Flowchart of the systematic review.

Study quality assessment

The risk of bias of the included studies is shown in the Supplemental material (37). Information on random sequence generation was generally adequate. Blinding of participants and personnel and blinding of outcome assessment bias were rated as low because studies were double-blinded or open-label, but T2D remission is not likely to be influenced by lack of blinding. No selective reporting bias was found. Concerning allocation concealment bias, a nonconcealed procedure was reported in Yang et al (30). As regards incomplete outcome data bias, all studies reported similar rates of loss to follow-up in the 2 arms, ranging from 0% to 20%; in 1 study only, there was a significant difference between the arms (33). Finally, an industrial sponsor funded 2 studies (24, 33).

Qualitative analysis

The characteristics of the included articles are summarized in Table 1 (23-36). The studies were published between 2011 and 2019, had T2D patients sample sizes ranging from 26 to 120 patients, and follow-up from 1 to 5 years. Two studies were conducted in Spain, one in China, one in Finland, one in New Zealand, one in Norway, one in Poland, one in Switzerland, one in Taiwan, and one in the United States. Participants were generally adults with obesity, with or without T2D randomly assigned to laparoscopic RYGB (LRYGB) or laparoscopic SG (LSG); patients with body mass index (BMI) less than 30 kg/m² were included in 3 studies (Supplemental material) (23, 26, 30, 37). Relevant to the primary outcome of this meta-analysis, individuals could be excluded according to the duration of T2D, complications, C-peptide, and/or autoantibodies levels (Supplemental material) (37). Broad and narrow criteria for remission differed, and only 4 studies adopted the definition proposed by the American Diabetes Association (29, 31, 32, 35) (Table 2). Overall, 778 patients with T2D were included; LRYGB had been performed in 387, and LSG in 391.

Table 1.

Characteristics of included studies

First author, y	Country	Study design	Intervention	Comparator	Follow-up, y	Patients, No.	1-y Remission	3-y Remission	5-y Remission	ADA criteria?
Lee, 2011 (23)	Taiwan	RCT	LRYGB	LSG	1	60	x			No
Schauer, 2017 (24-26)	USA	RCT	LRYGB	LSG	5	100	x	x	x	No
Peterli, 2018 (27-29)	Switzerland	RCT	LRYGB	LSG	5	54		x	x	Yes
Yang, 2015 (30)	China	RCT	LRYGB	LSG	3	64		x		No
Casajoana, 2017 (31)	Spain	RCT	LRYGB	LSG	1	30	x			Yes
Kalinowski, 2017 (32)	Poland	RCT	LRYGB	LSG	1	26	x			Yes
Murphy, 2018 (33)	New Zealand	RCT	LRYGB	LSG	1	114	x			No
Ruiz‑Tovar, 2018 (34)	Spain	RCT	LRYGB	LSG	5	120	x		x	No
Salminen, 2018 (35)	Finland	RCT	LRYGB	LSG	5	101	x	x	x	Yes
Hofsø, 2019 (36)	Norway	RCT	LRYGB	LSG	1	109	x			No

The number of patients with type 2 diabetes included in each study is reported.

Abbreviations: ADA, definition of type 2 diabetes remission according to criteria proposed by the American Diabetes Association (19); LRYGB, laparoscopic Roux-en-Y gastric bypass; LSG, laparoscopic sleeve gastrectomy; RCT, randomized controlled study; USA, United States of America.

Table 2.

Broad and narrow criteria for remission of type 2 diabetes adopted for data extraction

First author, y	Broad criteria for remission	Narrow criteria for remission
Lee, 2011 (23)	HbA1c < 6.5% (48 mmol/mol) and FPG < 126 mg/dL without therapy	NA
Schauer, 2017 (24-26)	HbA1c ≤ 6.5% (48 mmol/mol) without pharmacologic therapy	HbA1c ≤ 6.0% (42 mmol/mol) without pharmacologic therapy
Peterli, 2018 (27-29)	NA	HbA1c < 6.0% (42 mmol/mol) and FPG < 100 mg/dL for at least 1 y without pharmacologic therapy or ongoing procedures
Yang, 2015 (30)	HbA1c ≤ 6.5% (48 mmol/mol) without pharmacologic therapy	HbA1c < 6.0% (42 mmol/mol) and FPG < 126 mg/dL without pharmacologic therapy
Casajoana, 2017 (31)	HbA1c < 6.5% (48 mmol/mol) and FPG 100-125 mg/dL for 1 y without therapy	HbA1c < 6.0% (42 mmol/mol) and FPG < 100 mg/dL without therapy for 1 y
Kalinowski, 2017 (32)	NA	HbA1c < 6.0% (42 mmol/mol) and FPG < 100 mg/dL without pharmacologic therapy
Murphy, 2018 (33)	HbA1c < 6.5% (48 mmol/mol) without pharmacologic therapy	HbA1c < 6.0% (42 mmol/mol) without pharmacologic therapy
Ruiz‑Tovar, 2018 (34)	HbA1c < 6.5% [48 mmol/mol) and FPG < 126 mg/dL without pharmacologic therapy	HbA1c < 6.0% (42 mmol/mol) and FPG < 100 mg/dL without pharmacologic therapy
Salminen, 2018 (35)	HbA1c < 6.5% (48 mmol/mol) and FPG 100-125 mg/dL for at least 1 y without pharmacologic therapy or ongoing procedures	HbA1c < 6.0% (42 mmol/mol) and FPG < 100 mg/dL for at least 1 y without pharmacologic therapy or ongoing procedures
Hofsø, 2019 (36)	HbA1c < 6.5% (48 mmol/mol) without pharmacologic therapy	HbA1c ≤ 6.0% (42 mmol/mol) without pharmacologic therapy

Abbreviations: FPG, fasting plasma glucose; HbA_1c, glycated hemoglobin; NA, not applicable.

Quantitative analysis

Overall, bariatric surgery was associated with a prevalence of achievement of broad and narrow criteria for remission of T2D of 73% and 53% at the 1-year, 60% and 48% at the 3-year, and 51% and 43% at the 5-year assessment. RYGB was associated with a prevalence of achievement of broad and narrow criteria for 1-year remission of 84% and 60%, 3-year remission of 64% and 55%, 5-year remission of 56% and 48%. SG was associated with a prevalence of achievement of broad and narrow criteria for 1-year remission of 60% and 47%, 3-year remission of 55% and 42%, 5-year remission of 45% and 38% (Fig. 2). A high heterogeneity was found for all the outcomes. Comparing the prevalence of remission at each follow-up with the previous one, a statistically significant lower prevalence was generally found for the 3-year vs the 1-year assessments (Table 3).

Table 3.

Prevalence of remission of type 2 diabetes after any bariatric surgery, Roux-en-Y gastric bypass or sleeve gastrectomy at each follow-up according to criteria for remission

	1-y Assessment			3-y Assessment			5-y Assessment
	No. of patients (No. of studies)	Prevalence (95% CI)	I  2  ,%	No. of patients (No. of studies)	Prevalence (95% CI)	I  2  , %	No. of patients (No. of studies)	Prevalence (95% CI)	I  2  , %
Any bariatric surgery
Broad criteria	521 (6)	73 (61-83)	87	240 (3)	60 (39-79)a	91	297 (3)	51 (28-73)	94
Narrow criteria	586 (7)	53 (42-64)	86	294 (4)	48 (29-68)a	92	351 (4)	43 (23-64)	94
Roux-en-Y gastric bypass
Broad criteria	257 (6)	84 (71-93)	83	117 (3)	64 (34-89)a	91	148 (3)	56 (20-89)	96
Narrow criteria	291 (7)	60 (44-75)	86	145 (4)	55 (28-81)	92	176 (4)	48 (20-77)	94
Sleeve gastrectomy
Broad criteria	264 (6)	60 (46-74)	82	123 (3)	55 (22-86)a	94	149 (3)	45 (16-77)	94
Narrow criteria	295 (7)	47 (32-61)	85	149 (4)	42 (15-71)a	93	175 (4)	38 (11-70)	95

^a  P less than .05 vs the previous assessment with the same procedure.

Figure 2.

Prevalence of remission of type 2 diabetes after Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) at each follow-up according to criteria for remission.

Then, we compared remissions after RYGB and SG at each follow-up. RYGB was associated with a higher chance of achieving broad and narrow criteria for remission at 1 year after surgery (RR = 1.34; 95% CI, 1.10-1.63; P = .003 vs RR = 1.22; 95% CI, 1.06-1.40; P = .006) and broad criteria for remission at 5 years after surgery (RR = 1.18; 95% CI, 1.01-1.38; P = .04). No differences were found concerning the chance of achieving broad and narrow criteria for remission at 3 years after surgery and narrow criteria for remission at 5 years after surgery. No difference was found between studies adopting the criteria proposed by the American Diabetes Association or other criteria. No heterogeneity was found for analyses among studies adopting narrow criteria for remission (Fig. 3 and Fig. 4).

Figure 3.

Forest plot of meta-analysis for relative risk of achieving broad criteria for remission after Roux-en-Y gastric bypass (RYGB) vs sleeve gastrectomy (SG) A, 1 year, B, 3 years, and C, 5 years after surgery.

Figure 4.

Forest plot of meta-analysis for relative risk of achieving narrow criteria for remission after Roux-en-Y gastric bypass (RYGB) vs sleeve gastrectomy (SG) A, 1 year, B, 3 years, and C, 5 years after surgery.

There was no evidence of publication bias, with the exception of the relative risk for achieving narrow criteria for remission after RYGB vs SG at 3 years after surgery (Egger test, P = .027); the trim‐and‐fill method did not change the statistical significance of this result (Supplemental material) (37).

Discussion

The aim of this meta-analysis was to identify the best available evidence of the efficacy of RYGB and SG in inducing remission of T2D. In particular, we aimed to assess the prevalence of remission at 1 year, 3 years, and 5 years after each procedure, and whether one or the other of the procedures was associated with a higher chance of remission at each assessment. To avoid any bias related to the study design, we included only RCTs allocating patients to RYGB or SG. Also, to avoid any bias related to the criteria for remission adopted in each study, we pooled results in 2 categories (ie, broad and narrow criteria for remission). To our knowledge, this is the first meta-analysis focused on remission of T2D after bariatric surgery and using consistent definitions. We believe this to be a significant contribution to the current understanding, since studies evaluating populations from different countries and with different inclusion criteria could thus be interpreted together.

A limited number of studies with heterogeneous enrollment criteria and duration of follow-up is available in the literature. Specifically, included participants were generally adults younger than 60 to 65 years, with a BMI of at least 40 kg/m² or 35 kg/m² with established obesity-related chronic diseases/comorbidities/complications, in line with current guidelines (38-40). Individuals with overweight or obesity class I (eg, BMI 30-34.9 kg/m²) and T2D could also be eligible according to some protocols (23, 26, 30). Concerning exclusion criteria, while general principles were reported in all (ie, previous bariatric surgery or contraindication for general anesthesia), a reference to specific data that could affect the chance of achieving remission of T2D was described in some of them. Patients were excluded according to the duration of T2D in one study (30), C-peptide levels in 3 studies (23, 30, 33) or autoantibodies levels in 2 studies (31, 36). Indeed, a shorter duration of T2D as well as higher C-peptide levels are known to be associated with a higher chance of achieving remission of T2D, whereas in patients with phenotypic T2D, positivity to one or more serum autoantibodies against pancreatic β-cells is associated with a higher risk of progression to insulin dependence (41-43). RCTs are generally developed to assess the efficacy and safety of a therapeutic agent under ideal conditions, and only those patients with the highest chance of showing an effect, if any, tend to be selected (44). Therefore, the exclusion of individuals depending on the previously mentioned factors seems reasonable to assess the long-term performance of bariatric surgery in terms of remission of T2D, although possibly leading to some applicability concerns (45).

Based on data from 10 studies, including 778 patients with T2D, the present meta-analysis found that the prevalence of remission after any procedure at 1 year, 3 years, and 5 years after surgery according to broad and narrow criteria was 73% and 53%, 60% and 48%, and 51% and 43%, respectively. This confirms the efficacy of bariatric surgery in improving T2D management both in the short and midterm. A reduced prevalence of remission was found when results from the 3-year and 1-year assessment were compared, in line with results reported for other outcomes (eg, body weight loss) (26, 29, 35). However, whether the relapse of T2D should be considered as a treatment failure can be debated. Indeed, this finding should be weighed against the known risk of obesity, poorly controlled T2D, and other comorbidities, as well as the time spent with a significant improvement of these disorders (eg, legacy effect). In line with this, a study including patients who experienced late relapse following bariatric surgery found glycemic control and cardiovascular risk significantly improved compared with baseline and the trajectory of these chronic conditions changed by surgery (46).

In a patient with T2D for whom bariatric surgery is indicated, the choice of the specific procedure should often be made between RYGB and SG (38, 47). The present meta-analysis found RYGB to be associated with a higher chance of achieving remission at 1 year. No difference was found at 3 years. At the 5-year assessment, a higher chance of achieving remission in favor of RYGB was found when considering broad criteria only. Therefore, both procedures can be considered effective in the management of obesity and T2D, with RYGB being associated with more favorable outcomes when considering the short-term remission of T2D. However, the evidence currently available does not clarify whether differences for this outcome are confirmed in the long term or fade thereafter.

In January 2020, a meta-analysis was published on the same topic. Ten RCTs were included, enrolling 705 patients with T2D. A higher remission rate was found for RYGB at 1 year (RR = 1.20; 95% CI, 1.00-1.45), whereas no difference was found when the findings of the 2- to 5-year assessments were pooled (RR = 1.06; 95% CI, 0.94-1.20) (18). The authors acknowledged that definitions of remission of T2D varied between studies and seemingly small differences in glycemic thresholds used to define diabetes remission may affect the proportions achieving remission, making it difficult to compare different studies. Nevertheless, they concluded that the likelihood of remission was 20% higher among patients undergoing RYGB compared with SG 1 year after surgery, but with no difference between the surgical procedures at 2 to 5 years after surgery. Three studies were excluded from our analysis because of the time of assessment (ie, 2 years), unclear criteria adopted for remission, or limited sample size (48-50). The results of our meta‐analysis were based on 3 additional articles (23, 31, 33), on separate analyses conducted for the 3-year and 5-year follow-ups, and on a specific data extraction performed to ensure that consistent criteria were used to define the remission of T2D before pooling data. This resulted in a more objective and accurate interpretation of the available evidence, with discordant results when assessing the 5-year chance of achieving broad and narrow criteria for remission.

Limitations of the present paper should be discussed. First, a limited number of studies, usually with a short-term follow-up, was found, as stated. Specifically, we were able to find data related to 778 patients followed up only to 5 years. This is in conflict with the number of procedures reported in registries. The limited follow-up did not enable assessment of long-term outcomes and differences in terms of remission or late relapse of T2D other than those reported (5, 46). A number of patients were lost to follow-up and only 4 studies reported data at the 5-year assessment, and this is a second limitation. On one hand, given that rates of discontinuation were generally similar between arms, as stated, our findings based on relative measures (ie, RR) should not be affected. On the other hand, while 1-year assessments for both broad and narrow criteria for remission of T2D could be deemed adequately statistically powered, the same does not hold true for the other analyses (Supplemental material) (37). Third, a different performance of RYGB and SG according to T2D severity has been reported, with RYGB being significantly more effective than SG only in the intermediate group (41). Given that the independent predictors of long-term remission (eg, duration, number of diabetes medications, insulin use, glycemic control) were not extensively reported, we could not assess the influence of these factors. Finally, the decision to treat patients with established T2D and a high risk of cardiovascular and/or renal events with a glucagon-like peptide-1 receptor agonist or sodium glucose cotransporter 2 inhibitor, to reduce death, myocardial infarction, stroke, heart failure, or progression of chronic kidney disease, should be considered independently of baseline HbA_1c or individualized HbA_1c target (51). Therefore, the definition of remission proposed by the American Diabetes Association, including the absence of active pharmacologic therapy, should possibly be revised (19).

In conclusion, RYGB and SG both proved to be reliable treatment options for achieving short and midterm remission in patients with T2D and overweight or obesity. Despite a progressively reduced efficacy over time, about 1 in 2 patients was still in remission at the 5-year assessment. Compared to SG, RYGB was associated with a higher chance of achieving broad and narrow criteria for remission at 1 year after surgery and broad criteria for remission at 5 years after surgery. Therefore, in patients with T2D in whom a surgical approach is indicated, RYGB may be preferred for the purpose of achieving remission of T2D in the short-term only. However, given the still relatively limited available data and follow-up, further studies comparing RYGB with SG are needed to fully assess potential differences in long-term outcomes.

Abbreviations

Abbreviations
 
• BMI

  body mass index

 
• FPG

  fasting plasma glucose

 
• HbA_1c

  glycated hemoglobin

 
• LRYGB

  laparoscopic Roux-en-Y gastric bypass

 
• LSG

  laparoscopic sleeve gastrectomy

 
• RCT

  randomized controlled trial

 
• RYGB

  Roux-en-Y gastric bypass

 
• RR

  risk ratio

 
• SG

  sleeve gastrectomy

 
• T2D

  type 2 diabetes.

Acknowledgments

The authors thank Prof Jaime Ruiz Tovar (Madrid, Spain) for providing the requested data and Mary V.C. Pragnell, BA, (Monopoli, Italy) for editing.

Financial Support: This research did not receive any specific grant from any funding agency in the public, commercial, or not-for-profit sector.

Author Contributions: M.C. conceived the meta-analysis. M.C. and F.P. developed the search strategy and provided statistical expertise. M.C. drafted the manuscript. All authors contributed to the development of the selection criteria, the risk of bias assessment strategy, and data extraction criteria, and all read, provided feedback on, and approved the final manuscript.

Additional Information

Disclosure Summary: The authors have nothing to disclose.

Data Availability

The data sets generated during and/or analyzed during the present study are not publicly available but are available from the corresponding author on reasonable request.