Metabolic surgery in treatment of obese Japanese patients with type 2 diabetes: a joint consensus statement from the Japanese Society for Treatment of Obesity, the Japan Diabetes Society, and the Japan Society for the Study of Obesity

Clinical Efficacy and Safety of Anti-Obesity Medications Among Adult East Asian People with Obesity: A Systematic Literature Review and Indirect Treatment Comparison

INTRODUCTION

The prevalence of obesity has increased worldwide over the past decades. Regional variations exist in the relationship between body mass index (BMI), body fat, and health risks: Asians typically have a lower BMI than people of European descent, but a higher risk of obesity-related comorbidities. However, there is a paucity of evidence for anti-obesity medications (AOMs) in East Asian populations. In this study, we aimed to systematically review evidence regarding the safety and efficacy of AOMs among adults with obesity disease in East Asia, and to assess the feasibility of conducting an indirect treatment comparison (ITC) between the semaglutide and mazindol trials.

METHODS

The Embase, MEDLINE, and ICHUSHI databases were searched via the Ovid SP platform for randomized controlled trials, in English or Japanese, reporting data on semaglutide or mazindol therapy with placebo or diet and exercise as comparators. The potential risks of bias in conducting a population-adjusted ITC were determined based on the heterogeneity of potential effect modifiers and variations in study design.

RESULTS

Of 21 publications, 2 were included in this study based on the eligibility criteria. The STEP 6 study established the clinical efficacy of subcutaneous semaglutide compared with placebo in the reduction of body weight and cardiometabolic risk factors [glycated hemoglobin (HbA1c), total cholesterol, and systolic blood pressure] among Japanese and South Korean people with obesity disease. Mazindol also proved beneficial in reducing body weight and total cholesterol compared with placebo in Japan. Both semaglutide and mazindol were associated with higher rates of adverse events and treatment discontinuation than placebo. An ITC between the two studies was not deemed feasible based on the potential risks of bias.

CONCLUSIONS

Semaglutide and mazindol are associated with significant body weight reduction among people with obesity in East Asia. Further research based on label indications and up-to-date real-world data among East Asian people with obesity would help determine additional clinical benefits.

Relationship between the changes in hepatokine levels and metabolic effects after laparoscopic sleeve gastrectomy in severely obese patients

PURPOSE

To clarify the relationships between the changes in hepatokines and weight loss, and between these changes and the metabolic effects, and the roles played by these changes, after laparoscopic sleeve gastrectomy (LSG).

METHODS

We recruited 25 Japanese patients with severe obesity, who underwent LSG. We measured two hepatokines: selenoprotein P (SeP) and leukocyte cell-derived chemotaxin 2 (LECT2), at the baseline, and then 6 months and 1 year after LSG. Finally, we compared the changes in the hepatokines with the parameters of type 2 diabetes (T2D) and non-alcoholic steatohepatitis (NASH).

RESULTS

Changes in LECT2 were correlated with the percentage of total weight loss (ρ = - 0.499, P = 0.024) and the decrease in total fat area (ρ = 0.559, P = 0.003). The changes in SeP were correlated with those in hemoglobin A1c (ρ = 0.526, P = 0.043) and the insulinogenic index (ρ = 0.638, P = 0.010) in T2D patients. In patients with NASH, the LECT2 levels were correlated with liver steatosis (ρ = 0.601).

CONCLUSIONS

SeP levels decrease in association with HbA1c reduction, whereas LECT2 levels are associated with reductions in fat mass and NASH scores after LSG. Hepatokines may be involved in the pathology of obesity and its complications.

Predictive value of insulin resistance surrogates for the development of diabetes in individuals with baseline normoglycemia: findings from two independent cohort studies in China and Japan

BACKGROUND

Insulin resistance (IR) plays a crucial role in the occurrence and progression of diabetes. This study aimed to evaluate and compare the predictive value of four IR surrogates, including the triglycerides glucose (TyG) index, TyG and body mass index (TyG-BMI), triglycerides/high-density lipoprotein cholesterol (TG/HDL-C) ratio, and the metabolic score for IR (MetS-IR) for diabetes in two large cohorts.

METHODS

A total of 116,661 adult participants from the China Rich Healthcare Group and 15,464 adult participants from the Japanese NAGALA cohort were included in the study. Multivariable Cox proportional hazards models were used to assess the standardized hazard ratio (HR) of the TyG index, TyG-BMI, TG/HDL-C ratio, and MetS-IR directly associated with diabetes. Receiver operating characteristic (ROC) curve and time-dependent ROC curve analysis were performed to evaluate and compare the predictive value of the four IR surrogates for diabetes.

RESULTS

In the two independent cohorts, the average follow-up time was 3.1 years in the China cohort, with 2681(2.30%) incident cases of diabetes recorded, and 6.13 years in the Japan cohort, with 373 incident cases (2.41%) of diabetes recorded. After adjusting for potential confounding factors, we found that among the four IR surrogates, TyG-BMI and MetS-IR showed stronger associations with diabetes. The stronger associations persisted even after further stratification by age, sex, hypertension, and obese subgroups. In terms of diabetes prediction, based on ROC analysis, TyG-BMI demonstrated the highest predictive accuracy for diabetes in the Chinese population, while both TyG-BMI and MetS-IR showed the highest predictive accuracy in the Japanese population. The results of further subgroup ROC analysis confirmed the robustness of these findings. Furthermore, the time-dependent ROC results indicated that among the four IR surrogates, MetS-IR exhibited the highest accuracy in predicting future diabetes at various time intervals in the Japanese population.

CONCLUSION

Our findings suggest that evaluating TyG-BMI and MetS-IR as IR surrogates may be the most useful for predicting diabetes events and assessing the risk of developing diabetes in East Asian populations.

Once-weekly semaglutide administered after laparoscopic sleeve gastrectomy: Effects on body weight, glycemic control, and measured nutritional metrics in Japanese patients having both obesity and type 2 diabetes

Background

Glucagon-like peptide (GLP)-1 analogue may be useful for controlling weight recurrence and diabetes relapse after bariatric surgery, but may also adversely affect the measured nutritional metrics. This study aimed to investigate the effect of treatment with once-weekly semaglutide after laparoscopic sleeve gastrectomy (LSG) in patients with type 2 diabetes (T2D). We also examined the effects of combined use with a low-energy, high-protein formula diet (FD).

Methods

This study was a single-center retrospective database analysis. We enrolled 29 Japanese patients with T2D who underwent LSG, and more than 12 months later received semaglutide. The patients were divided retrospectively into a FD group (=6) and a conventional diet (CD) group (n = 23).

Results

BMI and HbA1c decreased significantly by 10.7 kg/m2 and 1.1 %, respectively, 12 months after LSG, and decreased by an additional 1.6 kg/m2 and 0.6 % after 12-months of treatment with semaglutide. Decreases in serum albumin, vitamin B12 and zinc were observed only after semaglutide administration. A ratio of energy from protein, fat and carbohydrates changed from 13:31:56 before to 19:30:50 after LSG, and from 17:32:51 before to 15:29:56 after semaglutide. Skeletal muscle ratio, which is the ratio of skeletal muscle mass to body weight, increased after LSG, but did not change after semaglutide. FD group showed a significant increase in skeletal muscle mass per 1 % body weight compared to CD group during semaglutide treatment.

Conclusion

Semaglutide after LSG in patients with obesity and T2D resulted in additional weight reduction and improved glycemic control, but worsened measured nutritional metrics. Administration of a low-energy, high protein formula diet may ameliorate adverse nutritional effects of semaglutide in patients with T2D after LSG. (Ethics Committee of Toho University Sakura Medical Center approval number S18061).

Clinical significance of colonoscopy before laparoscopic bariatric/metabolic surgery in Japanese patients

PURPOSE

Obesity is known to be associated with colorectal adenoma (CRA) and colorectal cancer (CRC); yet colonoscopy is not considered an essential preoperative evaluation before bariatric/metabolic surgery. The aim of this study was to clarify the clinical significance of preoperative colonoscopy for obese Japanese patients.

METHODS

The subjects of this retrospective study were 114 patients who underwent screening colonoscopy before bariatric/metabolic surgery. Multivariate analyses were performed to evaluate the independent predictors of CRA/CRC among the characteristics identified as significant or nearly significant by univariate analyses.

RESULTS

Colonoscopy revealed abnormal findings indicating the need for biopsy or polypectomy in 20 of the 114 patients (17.5%), and CRA was diagnosed in 13 patients (11.4%). Three patients (2.6%), who were all ≥ 56 years old, had a CRA ≥ 10 mm in diameter. The multivariate analysis showed that older age and male sex were significant predictors of CRA/CRC, which was identified in 46.2% of the male patients aged ≥ 46 years.

CONCLUSION

Our findings suggest that older age and male sex may be risk factors for CRA/CRC in obese Japanese candidates for bariatric/metabolic surgery; thus, preoperative colonoscopy should be considered for these high-risk patients.

Treatments for Staple Line Leakage after Laparoscopic Sleeve Gastrectomy

The number of laparoscopic sleeve gastrectomies (LSGs) performed in patients with obesity who are eligible for bariatric and metabolic surgery is currently much lower in Japan than in other countries. Considering the large number of potential patients with obesity and type 2 diabetes and the unique Japanese national health insurance system that guarantees fair healthcare delivery, there is room to increase the number of LSGs in Japan in the near future. However, strict health insurance regulations may limit access to mandatory devices needed to treat postoperative complications, such as staple line leakage, which can cause severe morbidity and even mortality. Therefore, understanding the pathogenesis and treatment options for this complication is crucial. This article examined the current situation in Japan and its impact on staple line leakage management, including the role of endoscopic treatment in reducing reoperation. The authors suggest increasing education and collaboration between healthcare professionals to optimize management and improve patient outcomes.

Feasibility of Laparoscopic Sleeve Gastrectomy for Patients with Obesity and Disorders of Intellectual Development: a Single Institutional Experience

BACKGROUND

Owing to their difficulty following clinical advice for procedural safety and ideal surgical outcomes, bariatric and metabolic surgery (BMS) for patients with disorders of intellectual development (DID) is concerning. Studies reporting the feasibility of BMS for this population remain scarce. This study aims to clarify the feasibility of laparoscopic sleeve gastrectomy (LSG) for patients with clinically severe obesity and DID.

METHODS

A retrospective analysis of a single institutional prospective database collected from 2010 to 2022 was performed. The Wechsler Adult Intelligence Scale (WAIS) was used to measure intellectual ability before LSG. A multidisciplinary team approach was implemented to give special support and care to patients with DID. Patients were categorized into groups according to their WAIS scores. LSG outcomes were statistically compared between the DID and average intellectual ability groups.

RESULTS

Using the WAIS to measure intellectual ability among patients who underwent LSG, we identified 14 patients with DID (IQ score: < 69, mean IQ: 63.4) and 71 with average intellectual ability (IQ score: 90-109, mean IQ: 98.9). Operative outcomes were comparable between the groups as follows: operation time (DID: 163 ± 41 min, average intelligence: 162 ± 30 min), hospital stay (DID: 4 [4-5] days, average intelligence: 5 [4-6] days), and total comorbidities (DID: 7.1%, average intelligence: 8.4%). No reoperations were performed, and no mortalities were observed.

CONCLUSIONS

With medical and social support and care, performing LSG on patients with clinically severe obesity and DID is safe, with good short-term results.

Changes in Eating Behaviors and Their Associations with Weight Loss in Japanese Patients Who Underwent Laparoscopic Sleeve Gastrectomy

BACKGROUND

Metabolic and bariatric surgery (MBS) has been established to provide long-term weight loss in severe obesity. In this study, we investigated the factors that affect post-operative weight loss, with a particular focus on changes in eating behaviors.

METHODS

Time-course changes in body weight and eating behaviors were examined in 49 Japanese patients who underwent laparoscopic sleeve gastrectomy from the first visit to 12 months after surgery. Each eating behavior was evaluated via the questionnaire of the Japan Society for the Study of Obesity.

RESULTS

Pre-operative weight reduction mediated by dietary and lifestyle interventions showed significant positive correlations with weight loss outcomes at 12 months after surgery. We observed significant decreases in scores for most of the eating behaviors 12 months after surgery. However, "emotional eating behavior" scores declined temporarily in the early post-operative period of one month but thereafter returned to the pre-operative level at 12 months. Furthermore, increases in the scores for "emotional eating behavior" and "sense of hunger" from 1 to 12 months post-operatively were significantly associated with poor weight loss.

CONCLUSIONS

Our results demonstrate the beneficial effects of MBS on obesity-related eating behaviors, as well as highlighting "emotional eating behavior" as requiring particular attention.

A novel second-stage surgical strategy for severely obese patient with pancreatic neuroendocrine tumor: a case report

Background

Severely obese patients can have other diseases requiring surgical treatment. In such patients, bariatric surgeries are considered a precursor to operations targeting the original disease for the purpose of reducing severe perioperative complications. Pancreatic ectopic fat deposition increases pancreas volume (PV) and thickness, which can worsen insulin resistance and islet β cell function. To address this problem, we present a novel two-stage surgical strategy performed on a severely obese patient with pancreatic neuroendocrine tumor (PNET) consisting of laparoscopic sleeve gastrectomy (LSG) as a metabolic surgery followed by laparoscopic spleen-preserving distal pancreatectomy (LSPDP).

Case presentation

A 56-year-old man was referred to our hospital for further investigation of a pancreatic tumor. His initial body weight and body mass index (BMI) were 94.0 kg and 37.2 kg/m², respectively. Contrast computed tomography revealed an enhanced tumor measuring 15 mm on the pancreatic body. The pancreas thickness and PV were 32 mm and 148 mL, respectively. An endoscopic ultrasonographic fine needle aspiration identified the tumor as PNET-G1. We first performed LSG, the patient’s body weight and BMI had decreased dramatically to 64.0 kg and 25.3 kg/m² at 6 months after LSG. The pancreas thickness and PV had also decreased to 17 mm and 99 mL, respectively, with no tumor growth. Since LSG has been shown to reduce the perioperative risk factors of LSPDP, and to improve insulin resistance and recovery of islet β cell function, we performed LSPDP for PNET-G1 as a second-stage surgery. The postoperative course was unremarkable, and the patient was discharged on postoperative day 14 without symptomatic postoperative pancreatic fistula (POPF). He was followed without recurrence or type 2 diabetes (T2D) onset for 6 months after LSPDP.

Conclusions

We present a novel two-stage surgical strategy for a severely obese patient with PNET, consisting of LSG as a metabolic surgery for severe obesity, followed by LSPDP after confirmation of good weight loss and metabolic effects. LSG before pancreatectomy may have a potential to reduce pancreas thickness and recovery of islet β cell function in severely obese patients, thereby reducing the risk of clinically relevant POPF and post-pancreatectomy T2D onset.

Identification of a Fatty Acid for Diagnosing Non-Alcoholic Steatohepatitis in Patients with Severe Obesity Undergoing Metabolic Surgery

The prevalence of nonalcoholic steatohepatitis (NASH) in severely obese Japanese patients is extremely high. However, there are currently no methods other than liver biopsy to assess hepatic steatosis and fibrosis. The purpose of this study was to comprehensively analyze changes in fatty acid (FA) and serum-free fatty acid (FFA) metabolism in severely obese Japanese patients to determine whether these could be surrogate markers. In this study, we enrolled 20 Japanese patients who underwent laparoscopic sleeve gastrectomy (LSG) for severe obesity and intraoperative liver biopsy. Serum FFAs were analyzed with liquid chromatography-mass spectrometry, and FAs in liver tissue were assessed using matrix-assisted laser desorption/ionization-imaging mass spectrometry to determine FAs that may be indicative of a positive NASH diagnosis. All patients showed significant weight loss and metabolic improvement following LSG. Regarding weight loss and metabolic improvement indices, 23 FFAs showed significant correlations with the baseline data. Narrowing down the phospholipids to commonly detected FAs detected in liver tissue, PC(18:1e_20:4) was significantly changed in the NASH group, suggesting that it could be used as a surrogate marker for NASH diagnosis. The results suggest that specific postoperative changes in blood phospholipids could be used as surrogate markers for NASH treatment.

Improvements of lung volumes and respiratory symptoms after weight loss through laparoscopic sleeve gastrectomy

PURPOSE

This study evaluated the improvement of respiratory function and airway volumes using spirometry and computed tomography (CT) in severely obese Japanese patients undergoing laparoscopic sleeve gastrectomy (LSG). We also evaluated the quality of life (QOL) of enrolled patients using questionnaires.

METHODS

A total of 71 patients who underwent LSG at Iwate Medical University Hospital between October 2013 and September 2020 were enrolled. The changes and relationships between respiratory parameters including CT volumetry and weight-loss effects were evaluated. Improvements to QOL and bronchial asthma (BA) were also assessed before LSG and 1 year after LSG.

RESULTS

The mean excess weight loss percentage (%EWL) and total weight loss percentage (%TWL) were measured at 55.1% and 26.1%, respectively. The attack frequency of BA significantly decreased (6.1/month vs. 1.5/month; P < 0.001), and the disease severity decreased according to severity classification (P = 0.032). Almost spirometric parameters, lung volume (LV) (4905.0 mL vs. 5490.3 mL; P < 0.001), and airway volume (AV) (108.6 mL vs. 119.3 mL; P = 0.022) significantly improved. The change of functional residual capacity (FRC) was correlated with both %EWL (ρ = 0.69, P < 0.001) and %TWL (ρ = 0.62, P < 0.001). The increase of LV (ρ = 0.79, P < 0.001) and AV (ρ = 0.69, P < 0.001) were correlated with the increase of FRC. Scores of QOL questionnaires dramatically became better owing to improvements in dyspnea.

CONCLUSION

Weight loss effects and the reduction of body fat mass correlated significantly with increase in LV and AV. Improvements of respiratory functions after LSG contributes to QOL and BA symptoms.

East Asian perspectives in metabolic and bariatric surgery

The prevalence of diabetes and obesity continues to rise in East Asia. As the risk of diabetes increases at a lower body mass index (BMI) in East Asians than in Europeans, the threshold of BMI values for metabolic and bariatric surgery (MBS) is lower in East Asians. MBS is considered upon reaching a BMI of 27.5 kg/m2 and is recommended at a BMI of ≥ 32.5 kg/m2 , depending on the status of glucose homeostasis. The most commonly performed MBS in East Asia is sleeve gastrectomy, followed by Roux-en-Y gastric bypass (RYGB). Because the incidence of gastric cancer is higher in East Asia than in other regions, concerns regarding surveillance for gastric cancer might be related to a preference for sleeve gastrectomy over RYGB in this region. Even though there is a paucity of data on direct comparisons of the efficacy of MBS among different ethnic groups, the degree of weight reduction in East Asians is not inferior to other ethnic groups. Moreover, studies suggest that the diabetes remission rate in East Asians seemed to be higher than in other ethnic groups. Future studies involving multiethnic groups are necessary to identify possible ethnic differences in diabetes remission and to determine the appropriate BMI threshold for MBS according to ethnicity.

The Concept of Indeterminable NASH Inducted by Preoperative Diet and Metabolic Surgery: Analyses of Histopathological and Clinical Features

Practitioners routinely perform intraoperative liver biopsies during laparoscopic sleeve gastrectomy (LSG) to evaluate nonalcoholic fatty liver disease (NAFLD). In some patients, hepatocyte ballooning, inflammation, and fibrosis without steatosis are observed, even in the absence of other etiologies. We call this finding indeterminable nonalcoholic steatohepatitis (Ind-NASH). In this study, we clarified the prevalence, as well as histopathological and clinical features, of Ind-NASH through intraoperative liver biopsy in Japanese patients presenting with severe obesity. We enrolled 63 patients who had undergone LSG and intraoperative liver biopsy. In patients diagnosed with histopathological NASH, we performed protocol liver biopsies at 6 and 12 months after LSG. We statistically analyzed these histopathological findings and clinical parameters and found the prevalence rate of Ind-NASH discovered through intraoperative biopsy to be 15.9%. Protocol liver biopsy also revealed that Ind-NASH was an intermediate condition between NASH and normal liver. The clinical features of patients with Ind-NASH are a higher body weight compared to NASH (134.9 kg vs. 114.7 kg; p = 0.0245), stronger insulin resistance compared to nonalcoholic fatty liver (homeostasis model assessment–insulin resistance: 7.1 vs. 4.9; p = 0.0188), and mild liver dysfunction compared to NASH. Patients with Ind-NASH observed positive weight-loss effects from a preoperative diet compared to the postoperative course (percentage total weight loss: 32.0% vs. 26.7%; p < 0.0001). Patients with Ind-NASH may also be good candidates for metabolic surgery owing to their good treatment response; therefore, efforts should be made by specialists in the near future to deeply discuss and define Ind-NASH.