Search

Bariatric surgery has been widely performed for the treatment of obesity and type 2 diabetes. Efforts have been made to investigate the mechanisms underlying the metabolic effects achieved by bariatric surgery and to identify candidates who will benefit from this surgery. Metabolomics, which includes comprehensive profiling of metabolites in biological samples, has been utilized for various disease entities to discover pathophysiological metabolic pathways and biomarkers predicting disease progression or prognosis. Over the last decade, metabolomic studies on patients undergoing bariatric surgery have identified significant biomarkers related to metabolic effects. This review describes the significance, progress, and challenges for the future of metabolomics in the area of bariatric surgery.

Studies on morbid obesity have shown remarkable improvement of diabetes in patients who have undergone bariatric operations. It was subsequently shown that these operations induce diabetes remission independent of the resultant weight loss; as a result, surgeons began to investigate whether operations for gastric cancer (GC) could have the same beneficial effect on diabetes as bariatric operations. It was then shown in multiple reports that followed that certain operations for GC were able to improve or even cure type 2 diabetes mellitus (T2DM) in GC patients. This finding gave rise to the concept of "oncometabolic surgery", in which a patient diagnosed with both GC and T2DM undergo a single operation with the purpose of treating both diseases. With the increasing incidence of T2DM, oncometabolic surgery has the potential to improve the quality of life and even extend survival of many GC patients. However, because the GC patient population and the bariatric patient population are wildly different and because different GC operations have different properties, the effect of oncometabolic surgery must be carefully assessed and engineered in order to maximize benefit and avoid harm. This manuscript aims to summarize the findings made so far in the field of oncometabolic surgery and to provide an outlook regarding the possibility of oncometabolic surgery being incorporated into standard clinical practice.

The micronutrient status and optimal monitoring schedule after bariatric surgery have not been sufficiently assessed. This systematic review and meta-analysis investigated the longitudinal changes in micronutrient status after bariatric surgery. PubMed, EMBASE, and Cochrane Library were searched for articles that measured preoperative and postoperative serum micronutrient levels in patients undergoing Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG). Among guideline-adherent studies, the longitudinal changes in micronutrient status were investigated using weighted mean difference (WMD) using a random-effects model. Among the 82 included studies, the guideline adherence rates for micronutrient supplementation after bariatric surgery did not exceed 20%. In patients supplemented per guidelines, vitamin A significantly decreased after RYGB by -7.54 (95% confidence interval [CI], -10.16 to -4.92) μg/dl at 12-23 months, vitamin E decreased after RYGB by -2.35 (95% CI, -3.65 to -1.05) μg/dl at ≥24 months, and ferritin by -54.93 (95% CI, -77.19 to -32.67] μg/L at ≥24 months after SG, compared with baseline, with moderate level of evidence. Significant decreases in micronutrient levels at certain follow-up intervals in studies with supplementation per guidelines need to be considered to establish a post-bariatric micronutrient monitoring schedule for timely detection and management of micronutrient deficiencies.

Large neutral amino acids (LNAAs) and gut microbial metabolites have been linked to insulin secretion and resistance. We investigated whether baseline LNAAs and kynurenine pathway metabolites and changes in tryptophan-derived gut microbial metabolites (TDGMs), such as indole compounds, were associated with improvements in insulin secretion and resistance after sleeve gastrectomy. In this prospective single-arm longitudinal study, 23 patients with type 2 diabetes underwent sleeve gastrectomy. Twelve diabetes-related amino acid metabolites were quantified before surgery, and the following three indices were assessed as outcome measures: insulinogenic index, homeostasis model assessment–insulin resistance (HOMA-IR), and quantitative insulin sensitivity check index (QUICKI). We also measured changes in TDGMs, including four indole compounds, 3 months after bariatric surgery. A linear regression model and receiver operating characteristic curves were assessed. The mean age and body mass index of study participants were 41.8 years (standard deviation (SD), 13.1 years) and 38.9 kg/m2 (SD, 5.2 kg/m2), respectively. Several baseline amino acid metabolites were significantly associated with a change in insulin secretion or resistance 3 months after bariatric surgery. Phenylalanine and LNAAs showed superior performance for predicting improvements in insulin secretion and resistance. Among the TDGMs, Δindole-3-propionic acid was significantly associated with the Δinsulinogenic index, and Δindole-3-acetic acid was significantly associated with the ΔHOMA-IR and ΔQUICKI. Our findings underscore the importance of baseline amino acid profiles, especially those of LNAAs and phenylalanine, and alterations in TDGMs for improving insulin secretion and resistance in the early postoperative period after sleeve gastrectomy.

Background : The survival benefit of excess body weight is controversial across various subpopulations. We assessed the effect of weight status on all-cause mortality among patients with type 2 diabetes (T2DM) undergoing subtotal gastrectomy for gastric cancer. Methods : Medical charts of 210 patients with T2DM treated at 2 university hospitals were examined retrospectively. All patients had undergone subtotal gastrectomy for cancer between January 1993 and December 2012. Participants were categorized as normal weight (body mass index [BMI], 18.5-24.99 kg/m²) or overweight/obese (BMI≥25 kg/m²). The association between weight status and all-cause mortality was assessed using weighted Cox proportional hazard regression models and inverse probability weighting. Results : The mortality rate was 25.2% after a median follow-up duration of 6.1 years (interquartile range, 3.5-8.3 years; maximum, 14.4 years). The overweight/obese group had a significantly lower risk of all-cause mortality (hazard ratio, 0.51; 95% confidence interval, 0.34-0.77; p=0.001) compared with the normal weight group. Overweight/obesity was associated with reduced all-cause mortality in patients aged

In this modern era, laparoscopic distal gastrectomy (LDG) has largely replaced open distal gastrectomy for the treatment of gastric cancer; however, a quantitative review of reconstruction methods applied exclusively using LDG has not yet been published. Thereafter, we compared three reconstruction methods (Billroth I, Billroth II, and Roux-en Y) using the data derived solely from LDG patients. A systematic search was conducted using electronic bibliographic databases (Google Scholar, PubMed, and Embase), for articles that compared reconstruction methods in LDG, published within the last decade. A systematic review comparing 12 outcome parameters and sensitivity analyses were performed to increase the statistical power and minimize the inconsistency and heterogeneity of results. Twenty-three clinical trials involving 5797 patients were included in the meta-analysis. There were no significant differences in the postoperative recovery and intraoperative parameters, except for operation time. B1 demonstrated a significantly shorter operation time when compared with B2 and RY by 21.6 min (P

Background We investigated whether preoperative clinical parameters predict diabetes remission and relapse after conventional gastrectomy for cancer and whether postoperative weight changes influence diabetes remission and relapse. Study design This study included 5,150 patients with diabetes who underwent gastrectomy for cancer from 2004 to 2014. Diabetes remission was defined in 3 ways, according to postoperative antidiabetic medication and fasting plasma glucose (FPG) levels. Diabetes relapse was defined as reinitiating antidiabetic medication among patients in diabetes remission. Results Six predictors (higher body mass index [BMI], total gastrectomy, younger age, FPG levels, number of oral hypoglycemic agents [OHAs], and no insulin use) of diabetes remission increased the likelihood of remission by >13-fold (odds ratio [OR], 13.67; 95% confidence interval [CI], 8.65‒19.11). Three factors (younger age, lower FPG levels, and use of only 1 OHA) predicted a 58% decreased likelihood of diabetes relapse (hazard ratio, 0.42; 95% CI 0.35‒0.48). The lowest interval of postoperative BMI decrease ( 3-fold increased likelihood of diabetes remission than the highest interval (≥-5%; OR 3.14; 95% CI 2.08‒4.75), independent of baseline BMI. Conclusions Six variables (BMI, type of gastrectomy, age, FPG levels, number of OHAs used, and insulin use/non-use), and 3 variables (age, FPG levels, number of OHAs used) significantly predict diabetes remission and relapse after gastrectomy for cancer, respectively. Greater postoperative weight decrease may increase the likelihood of diabetes remission, independent of baseline weight. Our results may serve as a basis for the establishment of diabetes and weight management strategies after conventional gastrectomy for cancer.

Background Studies have reported that Billroth II (BII) reconstruction after subtotal gastrectomy for cancer or intractable ulcers can more effectively improve type 2 diabetes mellitus (T2D) than Billroth I (BI) reconstruction by allowing patients to achieve normoglycemia without or with lower doses of diabetes medications. Thus, we conducted a systematic review and meta-analysis of studies to assess the effect of Billroth techniques on postoperative T2D status and identify the clinical predictors of amelioration. Methods The MEDLINE and EMBASE databases and the Cochrane Central Register of Controlled Trials were searched for studies using a list of keywords. Moreover, reference lists from relevant review articles were searched. We included studies comparing BI with BII reconstruction as well as those with available outcome data for postoperative T2D status. Of the 52 potentially relevant studies, 8 met the inclusion criteria. Data were combined using a fixed- or random-effects model. Results Compared with the BI group, the relative risk for postoperative T2D remission and amelioration in the BII group was 1.49 (95% confidence interval [CI], 1.01 to 2.19) and 1.31 (95% CI, 1.11 to 1.54), respectively. Patients who achieved amelioration had a higher body mass index than those who did not (weighted mean difference, .88 kg/m 2 ; 95% CI, .38 to 1.37) and shorter duration of diabetes (weighted mean difference, −0.40; 95% CI, −0.23 to −.70) at baseline. Conclusions BII reconstruction after subtotal gastrectomy for cancer or intractable ulcers more effectively improved T2D than BI reconstruction. Thus, BII reconstruction may provide a treatment strategy for diabetic patients with gastric cancer or ulcers and enable metabolic surgery for nonobese patients.

The effective treatment of postoperative anemia and nutritional deficiencies is critical for the successful management of bariatric patients. However, the evidence for nutritional risk or support of bariatric patients remains scarce. The aims of this study were to assess current evidence of the association between 2 methods of bariatric surgery, sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB), and postoperative anemia and nutritional deficiencies.MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched for English-language studies using a list of keywords. Reference lists from relevant review articles were also searched. In the authors' meta-analysis, they included studies with a duration of12 months, those comparing SG with RYGB, and those with available outcome data for postoperative anemia and iron and vitamin B12 deficiencies. Of 36 potentially relevant studies, 9 met the inclusion criteria. Data were combined by means of a fixed-effects model or random-effects model.Compared with the SG group, the odds ratio for postoperative vitamin B12 deficiency in the RYGB group was 3.55 (95% confidence interval, 1.26-10.01; P.001). In the subgroup analysis, studies in which prophylactic iron or vitamin B12 was administered lost significance in the odds ratio for postoperative vitamin B12 deficiency.The authors' findings suggest that SG is more beneficial than RYGB with regard to postoperative vitamin B12 deficiency risk, whereas the 2 methods are comparable with regard to the risk of postoperative anemia and iron deficiency. Postoperative prophylactic iron and B12 supplementation, in addition to general multivitamin and mineral supplementation, is recommended based on the comparable deficiency risk of the 2 methods as indicated by subgroup analysis.

Background The question of whether pure metabolic surgery could be used in nonobese patients with type 2 diabetes has been considered. The objective of this study was to assess the comparative effects of the Billroth I (BI) and Billroth II (BII) reconstruction methods on remission of type 2 diabetes in nonobese patients undergoing subtotal gastrectomy for cancer. Methods The charts of 404 patients who underwent radical subtotal gastrectomy for cancer between January 2008 and December 2010 were retrospectively reviewed. From these patients, 49 with type 2 diabetes were included in this study. Diabetes remission rates, the percentage change in fasting plasma glucose levels, glycated hemoglobin levels, body mass index, and fasting total cholesterol levels at 2 years were observed. Outcomes were compared using propensity scores and inverse probability-weighting adjustment that reduced treatment-selection bias. Covariate-adjusted logistic regression models were assessed. Results The 2-year diabetes remission rate for the 23 patients who underwent BI reconstruction was 39.1%, compared with 50.0% for the 26 patients who underwent BII reconstruction. At 2 years, the BII group showed lower glycated hemoglobin levels (BI, 6.4%; BII, 6.1%; P = .003) and had greater percent reductions in their average glycated hemoglobin levels from baseline (BI,−11.6%; BII,−14.5%; P = .043). BII reconstruction was significantly associated with an increased diabetes remission rate (odds ratio, 3.22; 95% confidence interval, 1.05–9.83) in covariate-adjusted logistic regression analysis. Conclusions These propensity score-adjusted analyses of patients who had undergone subtotal gastrectomy indicated that BII reconstruction was associated with increased diabetes remission compared with BI reconstruction during the 2-year follow-up period. This study suggests the possibility of employing the surgical duodenal switch for the treatment of nonobese type 2 diabetes patients.

Purpose Metabolic surgery has been performed as a treatment option for uncontrolled type 2 diabetes (T2D), and several scoring systems for predicting postoperative T2D remission have been proposed. This study was designed to assess consistency of 3 existing scoring systems in patients with T2D duration

Objective We conducted a systematic review and meta-analysis of studies to quantify the association between body mass index (BMI) and the risks of all-cause and cardiovascular mortality in patients with type 2 diabetes. Methods We included studies assessing the impact of BMI on all-cause and cardiovascular mortality in patients with type 2 diabetes. Data were combined using a random-effects dose-response model. Results Sixteen cohort studies on all-cause mortality (n = 445,125) and two studies on cardiovascular mortality (n = 92,841) were evaluated in the meta-analysis. A non-linear association was observed between BMI and all-cause mortality among patients with type 2 diabetes. With a BMI nadir of 28–30 kg/m2, the risk of all-cause mortality displayed a U-shaped increase. With a BMI nadir of 29–31 kg/m2, the risk of cardiovascular mortality exhibited a gradual non-linear increase for BMI > 31 kg/m2. Subgroup analyses suggested that study location, diabetes duration, and smoking history may have contributed to heterogeneity among the studies. Conclusions An obesity paradox exists for patients with type 2 diabetes with respect to all-cause and cardiovascular mortality. Study location, diabetes duration, and smoking history might contribute to heterogeneity among obesity paradox studies of patients with type 2 diabetes.

Background To assess the safety of transorally-inserted anvil (TOA) for use during esophagojejunostomy (EJ) reconstruction during laparoscopic total gastrectomy (LTG). Methods Between March 2009 and December 2011, 39 consecutive open total gastrectomies (OTGs) and 36 LTGs using TOA for gastric cancer were comparatively evaluated. We investigated postoperative complications, using the Clavien–Dindo classification. To evaluate the effect of a learning period in using TOA for LTG, we also investigated shifts in the patterns of complications and changes in total operation time over the course of the study. Results The patient characteristics at baseline were not different between both groups, except for the extent of lymphadenectomy ( P P = 0.003). Multivariate analysis revealed that TOA usage elevated the occurrence of infectious complications significantly (OR = 3.32, P = 0.042), but was not associated with EJ-related complications. TOA usage did not need a learning period for the length of time required to complete the operation, or the likelihood of developing an EJ-related or infectious complication. Conclusions TOA use for EJ during LTG is relatively simple and easy enough not to require a learning period for surgeons. This procedure did not elevated the occurrence of EJ-related complications compared to circular stapling in open surgery, but it does require special prevention efforts to avoid infectious complications.