Serial changes in inflammatory biomarkers after Roux-en-Y gastric bypass surgery

The association of bariatric surgery with myocardial infarction and coronary revascularization: a propensity score match analysis of National Inpatient Sample

BACKGROUND

Metabolic bariatric surgery (MBS) not only leads to a durable weight loss but also lowers mortality, and reduces cardiovascular risks.

OBJECTIVES

The current study aims to investigate the association of bariatric metabolic surgery (BMS) with admissions for acute myocardial infarction (AMI), including ST-elevation myocardial infarction (STEMI) and non-ST-elevation myocardial infarction (NSTEMI), as well as, coronary revascularization procedures, including percutaneous coronary intervention (PCI), coronary artery bypass graft (CABG), and thrombolysis.

SETTING

The National Inpatient Sample (NIS) database.

METHODS

The NIS data from 2016 to 2020 were analyzed. A propensity score matching in a 1:1 ratio was performed to match patients with history of MBS with non-MBS group.

RESULTS

Two hundred thirty-three thousand seven hundred twenty-nine patients from the non-MBS group were matched with 233,729 patients with history of MBS. The MBS group had about 52% reduced odds of admission for AMI compared to the non-MBS group (adjusted odd ratio: .477, 95% confidence interval: .454-.502, P value <.001). In addition, the odds of STEMI and NSEMI were significantly lower in the MBS group in comparison to the non-MBS group. Also, the MBS group had significantly lower odds of CABG, PCI, and thrombolysis compared to the non-MBS group. In addition, in patients with AMI, MBS was associated with lower in-hospital mortality (adjusted odd ratio: .627, 95% confidence interval: .469-.839, P value = .004), length of hospital stays, and total charges.

CONCLUSIONS

History of MBS is significantly associated with reduced risk of admission for AMI including STEMI and NSTEMI, as well as the, need for coronary revascularization such as PCI and CABG.

Advancements in Understanding and Preventing Obesity-Related Colon Cancer

ABSTRACT

Obesity and colorectal cancer are global public health issues, with the prevalence of both conditions increasing over the last 4 decades. In the United States alone, the prevalence of obesity is greater than 40%, and this percentage is projected to increase past 50% by 2030. This review focuses on understanding the association between obesity and the risk of colorectal cancer while also highlighting hypotheses about molecular mechanisms underlying the link between these disease processes. We also consider whether those linkages can be disrupted via weight loss therapies, including lifestyle modifications, pharmacotherapy, bariatric surgery, and endobariatrics.

Oxidative Stress Responses in Obese Individuals Undergoing Bariatric Surgery: Impact on Carcinogenesis

Obesity is a big public health problem that claims several thousand lives every year. Bariatric surgery has arisen as a suitable procedure for treating obesity, particularly morbid obesity. Oxidative stress, genotoxicity, apoptosis, and inflammatory responses are recognized as the most important occurrences in carcinogenesis, as they actively contribute to the multistep process. This study aimed to briefly review the connection between oxidative stress, genotoxicity, apoptosis, and inflammation in obese patients undergoing bariatric surgery, focusing on its impact on carcinogenesis. Regarding oxidative stress, bariatric surgery may inhibit the synthesis of reactive oxygen species. Moreover, a significant reduction in the inflammatory status after weight loss surgery was not observed. Bariatric surgery prevents apoptosis in several tissues, but the maintenance of low body weight for long periods is mandatory for mitigating DNA damage. In conclusion, the association between bariatric surgery and cancer risk is still premature. However, further studies are yet needed to elucidate the real association between bariatric surgery and a reduced risk of cancer.

The impact of bariatric surgery on admissions for gastrointestinal complications and conditions associated with obesity: A nationwide study

BACKGROUND

Obesity worsens various gastrointestinal pathologies. While bariatric surgery ameliorates obesity, it substantially modifies the gastrointestinal system depending on surgery type, with limited data on subsequent impact on obesity-related gastrointestinal admissions.

METHODS

Using the 2012-2014 Nationwide Readmission Database, we included individuals with obesity who received vertical sleeve gastrectomy (VSG), Roux-en-Y gastric bypass (RYGB), or hernia repair (HR-control surgery). Our main focus was the adjusted odds ratio (aOR) for gastrointestinal inpatient admissions within 6 months following surgery compared to the 6 months preceding it, while controlling for several confounding factors. Gastrointestinal admissions were grouped into postoperative complications or obesity-associated gastrointestinal conditions.

RESULTS

Our cohort included 140,103 adults with RYGB, 132,253 with VSG, and 12,436 HR controls. Postoperative gastrointestinal complications were most common after RYGB, prominently obstruction (aOR = 33.17, 95%CI: 18.01, 61.10), and Clostridium difficile infection (aOR: 12.52, 95%CI: 6.22, 25.19). VSG also saw significantly increased but less frequent similar conditions. Notably, for gastrointestinal conditions associated with obesity, acute pancreatitis risk was higher post-VSG (aOR = 6.26, 95%CI: 4.02, 9.73). Post-RYGB patients were most likely to be admitted for cholelithiasis with cholecystitis (aOR: 4.15, 95% CI: 3.24, 5.31), followed by chronic liver disease (aOR: 3.00, 95% CI: 2.33, 3.87). The risk of noninfectious colitis admissions was threefold higher after RYGB and VSG. No gastrointestinal conditions showed an increase after HR.

CONCLUSION

Despite weight loss, bariatric surgery was associated with an increased risk of hepato-pancreatobiliary and colitis admissions related to obesity in the first six postoperative months, with considerable variations in rates of gastrointestinal conditions by surgery type.

Distinctive patterns of sulfide- and butyrate-metabolizing bacteria after bariatric surgery: potential implications for colorectal cancer risk

Despite improved cardiometabolic outcomes following bariatric surgery, its long-term impact on colorectal cancer (CRC) risk remains uncertain. In parallel, the influence of bariatric surgery on the host microbiome and relationships with disease outcomes is beginning to be appreciated. Therefore, we investigated the impact of Roux-en-Y gastric bypass (RYGB) and vertical sleeve gastrectomy (VSG) on the patterns of sulfide-reducing and butyrate-producing bacteria, which are hypothesized to modulate CRC risk after bariatric surgery. In this single-center, cross-sectional study, we included 15 pre-surgery subjects with severe obesity and patients who are at a median (range) of 25.6 (9.9-46.5) months after RYGB (n = 16) or VSG (n = 10). The DNA abundance of fecal bacteria and enzymes involved in butyrate and sulfide metabolism were identified using metagenomic sequencing. Differences between pre-surgery and post-RYGB or post-VSG cohorts were quantified using the linear discriminant analysis (LDA) effect size (LEfSe) method. Our sample was predominantly female (87%) with a median (range) age of 46 (23-71) years. Post-RYGB and post-VSG patients had a higher DNA abundance of fecal sulfide-reducing bacteria than pre-surgery controls (LDA = 1.3-4.4, p < .05). The most significant enrichments were for fecal E. coli, Acidaminococcus and A. finegoldii after RYGB, and for A. finegoldii, S. vestibularis, V. parvula after VSG. As for butyrate-producing bacteria, R. faecis was more abundant, whereas B. dentium and A. hardus were lower post-RYGB vs. pre-surgery. B. dentium was also lower in post-VSG vs. pre-surgery. Consistent with these findings, our analysis showed a greater enrichment of sulfide-reducing enzymes after bariatric surgery, especially RYGB, vs. pre-surgery. The DNA abundance of butyrate-producing enzymes was lower post-RYGB. In conclusion, the two most used bariatric surgeries, RYGB and VSG, are associated with microbiome patterns that are potentially implicated in CRC risk. Future studies are needed to validate and understand the impact of these microbiome changes on CRC risk after bariatric surgery.

Variation of modulation and expression of biomarkers associated with inflammation in bariatric surgery patients: A systematic review and meta-analysis

BACKGROUND

Bariatric surgery is an effective intervention that causes a series of metabolic changes related to inflammatory processes; however, the variation of biomarkers related to these processes is not entirely understood. Our objective was to investigate the variation of modulation and expression of biomarkers associated with inflammation in patients who underwent bariatric surgery.

METHODS

We searched the MEDLINE (via PubMed), EMBASE (via Elsevier), Cochrane Central Register of Controlled Trials, Latin American and Caribbean Literature on Health Sciences (via virtual health library), Cumulative Index to Nursing and Allied Health Literature (via EBSCO), Web of Science core collection, and Scopus (via Elsevier) databases, and the gray literature was examined from inception to January 2022. Three pairs of reviewers performed data screening, extraction, and quality assessment independently. Meta-analysis with random effects models was used for general, subgroup, and sensitivity analyses. The I2 statistic was used to assess heterogeneity between studies.

RESULTS

In total, 96 articles were included in this systematic review; of these, 87 studies met the criteria for the meta-analysis, involving 3,533 participants. Five biomarkers were included in the meta-analysis (tumor necrosis factor alpha; interleukin 6; leptin; interleukin 1 beta, and lipopolysaccharides). Only leptin showed a significant decrease in the first month after surgery (mean difference -20.71; [95% confidence interval: -28.10 to -13.32, P < .0001; I2 = 66.7%), with moderate heterogeneity. The 12 months after surgery showed a significant decrease in tumor necrosis factor alpha (mean difference -0.89; [95% confidence interval: -1.37 to -0.42], P = .0002; I2 = 94.7%), interleukin 6 (mean difference -1.62; [95% confidence interval: -1.95 to -1.29], P < .0001; I2 = 94.9%), leptin (mean difference -28.63; [95% confidence interval: -34.02 to -23.25], P < .0001; I2 = 92.7%), and interleukin 1 beta (mean difference -2.46; [95% confidence interval: -4.23 to -0.68], P = .006; I2 = 98.3%), all with high heterogeneity. The type of surgery did not show significant differences for the biomarkers at the first month and 12 months, and the results have not changed with high-quality studies. In the 12-month measurement, variations in tumor necrosis factor alpha and leptin were associated with body mass index.

CONCLUSION

The findings of this meta-analysis suggest that Roux-en-Y gastric bypass and sleeve gastrectomy bariatric surgeries are associated with a significant reduction in leptin at 1 month after bariatric surgical intervention and tumor necrosis factor alpha, leptin, and interleukin 1 beta after 12 months.

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.

Cardiovascular Effects of Weight Loss in Obese Patients with Diabetes: Is Bariatric Surgery the Additional Arrow in the Quiver?

Obesity is an increasingly widespread disease worldwide because of lifestyle changes. It is associated with an increased risk of cardiovascular disease, primarily type 2 diabetes mellitus, with an increase in major cardiovascular adverse events. Bariatric surgery has been shown to be able to reduce the incidence of obesity-related cardiovascular disease and thus overall mortality. This result has been shown to be the result of hormonal and metabolic effects induced by post-surgical anatomical changes, with important effects on multiple hormonal and molecular axes that make this treatment more effective than conservative therapy in determining a marked improvement in the patient's cardiovascular risk profile. This review, therefore, aimed to examine the surgical techniques currently available and how these might be responsible not only for weight loss but also for metabolic improvement and cardiovascular benefits in patients undergoing such procedures.

Bariatric surgery in the prevention of obesity-associated cancers: mechanistic implications

Obesity is associated with an increased risk of at least 13 different cancers, as well as worse cancer outcomes and increased cancer mortality. As rates continue to rise both in the United States and worldwide, obesity is poised to become the leading lifestyle-related risk factor for cancer. Currently, the most effective treatment for patients with severe obesity is bariatric surgery. Multiple cohort studies have demonstrated a consistent >30% decreased risk of cancer incidence in women, but not men, following bariatric surgery. However, the physiologic mechanisms driving obesity-associated cancer and the cancer-protective effect of bariatric surgery are not clearly defined. In this review, we highlight emerging concepts in the mechanistic understanding of obesity-associated cancer. Evidence from both human studies and preclinical animal models suggest that obesity drives carcinogenesis through dysregulation of systemic metabolism, immune dysfunction, and an altered gut microbiome. Additionally, we present related findings to suggest that bariatric surgery may disrupt and even reverse many of these mechanisms. Finally, we discuss the use of preclinical bariatric surgery animal models in the study of cancer biology. The prevention of cancer is emerging as an important indication for bariatric surgery. Elucidating the mechanisms through which bariatric surgery limits carcinogenesis is critical to developing a variety of interventions that intercept obesity-driven cancer.

High preoperative HbA1c does not affect early or late complication rates after bariatric surgery

BACKGROUND

Preoperative HbA1c has been associated with an increased incidence of postoperative morbidity and mortality after abdominal and cardiovascular surgery. The literature on bariatric surgery is inconclusive and guidelines recommend postponement of surgery when HbA1c is above an arbitrary threshold (≥ 8.5%). In this study, we sought to understand the impact of preoperative HbA1c on early and late postoperative complications.

METHODS

We performed a retrospective analysis of prospectively collected data on obese patients with diabetes who underwent laparoscopic bariatric surgery. Patients were categorized into three groups according to their preoperative HbA1c level: < 6.5% (group 1), 6.5-8.4% (group 2) and ≥ 8.5% (group 3). Primary outcomes were early and late postoperative complications (< and > 30 days, respectively) that were differentiated based on severity (major/minor). Secondary outcomes were length of stay (LOS), duration of surgery, and rate of readmission.

RESULTS

In total, 6798 patients underwent laparoscopic bariatric surgery from 2006 to 2016, of which 1021 (15%) patients had Type 2 Diabetes (T2D). Complete data with a median follow-up of 45 months (3-120) were available for 914 patients with HbA1c < 6.5% (n = 227, 24.9%), 6.5-8.4% (n = 532, 58.5%) and ≥ 8.5% (n = 152, 16.6%). Early major surgical complication rate was similar across the groups ranging from 2.6 to 3.3%. No associations between high preoperative HbA1c and late complications-medical as well as surgical-was observed. Groups 2 and 3 had statistically significant more pronounced inflammatory status. LOS (1.8-1.9 days), readmission rates (1.7-2.0%) and surgical time was similar across the three groups.

CONCLUSION

Elevated HbA1c is not associated with more early or late postoperative complications, longer LOS, longer surgical time or higher rates of readmission.

Laparoscopic distal gastrectomy demonstrates acceptable outcomes regarding complications compared to open surgery for gastric cancer patients with pylorus outlet obstruction

Background

For gastric cancer (GC) patients with pylorus outlet obstruction (POO), whether laparoscopic surgery has advantages over open surgery remains unclear. This study aims to investigate the differences between patients with and without POO in open and laparoscopic groups and to determine the differences between laparoscopic distal gastrectomy (LDG) and open distal gastrectomy (ODG) in GC patients with POO.

Methods

A total of 241 GC patients with POO who underwent distal gastrectomy at the Department of Gastric Surgery of the First Affiliated Hospital of Nanjing Medical University between 2016 and 2021 were included in this study. A total of 1,121 non-POO patients who underwent laparoscopic surgery and 948 non-POO patients who underwent open surgery from 2016 to 2021 were also enrolled in the study. We compared complication rates and hospital stays between open and laparoscopic groups.

Results

There was no significant difference for LDG between GC patients with and without POO regarding the overall complication rates (P = 0.063), the Grade III-V complication rate (P = 0.673), and the anastomotic complication rate (P = 0.497) from 2016 to 2021. The patients with POO had longer preoperative hospital stay (P = 0.001) and postoperative hospital stay (P=0.007) compared to patients without POO. No significant difference was observed for open patients between POO and non-POO patients regarding the overall complication rate (P = 0.357), grade III-V complication rate (P = 1.000), and anastomosis-related complication rate (P = 0.766). Compared with open surgery in GC patients with POO (n = 111), the total complication rate of the LDG group was 16.2%, which was significantly lower than that of the open group (26.1%, P = 0.041). No significant differences in the Grade III-V complication rate (P = 0.574) and anastomotic complication rate (P = 0.587) were observed between laparoscopic and open groups. Patients receiving laparoscopic surgery had shorter postoperative hospital stay than open surgery (P = 0.001). More resected lymph nodes (LNs) were also observed in the laparoscopic group (P = 0.0145).

Conclusion

The comorbidity of GC with POO does not increase the complication rate after laparoscopic or open distal gastrectomy. In GC patients with POO, laparoscopic surgery shows advantages over open surgery with a lower overall complication rate, shorter postoperative hospital stay, and more harvested lymph nodes. Laparoscopic surgery is a safe, feasible, and effective treatment for GC with POO.

Inflammation and Metabolism of Influenza-Stimulated Peripheral Blood Mononuclear Cells From Adults With Obesity Following Bariatric Surgery

BACKGROUND

Obesity dysregulates immunity to influenza infection. Therefore, there is a critical need to investigate how obesity impairs immunity and to establish therapeutic approaches that mitigate the impact of increased adiposity. One mechanism by which obesity may alter immune responses is through changes in cellular metabolism.

METHODS

We studied inflammation and cellular metabolism of peripheral blood mononuclear cells (PBMCs) isolated from individuals with obesity relative to lean controls. We also investigated if impairments to PBMC metabolism were reversible upon short-term weight loss following bariatric surgery.

RESULTS

Obesity was associated with systemic inflammation and poor inflammation resolution. Unstimulated PBMCs from participants with obesity had lower oxidative metabolism and adenosine triphosphate (ATP) production compared to PBMCs from lean controls. PBMC secretome analyses showed that ex vivo stimulation with A/Cal/7/2009 H1N1 influenza led to a notable increase in IL-6 with obesity. Short-term weight loss via bariatric surgery improved biomarkers of systemic metabolism but did not improve markers of inflammation resolution, PBMC metabolism, or the PBMC secretome.

CONCLUSIONS

These results show that obesity drives a signature of impaired PBMC metabolism, which may be due to persistent inflammation. PBMC metabolism was not reversed after short-term weight loss despite improvements in measures of systemic metabolism.

Gastric Bypass Regulates Early Inflammatory Responses in High-Fat Diet-Induced Obese Mice

INTRODUCTION

Obesity and diabetes are characterized by chronic inflammatory responses. Roux-en-Y gastric bypass (RYGB) is increasingly regarded as an effective approach for the improvement of glucose homeostasis. In this study, we examined the effects of RYGB on the regulation of early inflammatory responses in the liver and adipose tissue in high-fat diet (HFD)-induced obese (DIO) mice.

MATERIALS AND METHODS

RYGB was performed in DIO mice followed by analyses of adiposity, insulin sensitivity, plasma and tissue cytokines and adipokines, tissue NF-κB and JNK/c-Jun activation, and tissue macrophage and T-cell subsets.

RESULTS

We found that RYGB resulted in sustained improvement of adiposity and insulin sensitivity. Plasma insulin and leptin levels were increased in untreated DIO mice and reduced in RYGB mice. RYGB maintained plasma adiponectin levels and inhibited monocyte chemoattractant protein-1 and interleukin 6 in white adipose tissue (WAT) and liver. RYGB inhibited NF-κB activation in WAT and muscle, but not in the liver. However, RYGB attenuated the JNK/c-Jun signaling pathway in the liver and WAT at 1 wk after surgery, suggesting that RYGB regulates the tissue-specific inflammatory pathway. RYGB reduced M1-like (F4/80+/CD11c+) differentiation and enhanced M2-like population (F4/80+/CD206c+). RYGB also regulated CD4+ and CD8+ T-cell infiltration and increased Treg cells in the liver and WAT at the same time point.

CONCLUSIONS

Our findings demonstrate that RYGB improves obesity and insulin resistance, which are associated with the regulation of early inflammatory reactions in the liver and WAT.

Early Changes in Immune Cell Count, Metabolism, and Function Following Sleeve Gastrectomy: A Prospective Human Study

OBJECTIVE

To characterize longitudinal changes in blood biomarkers, leukocyte composition, and gene expression following laparoscopic sleeve gastrectomy (LSG).

BACKGROUND

LSG is an effective treatment for obesity, leading to sustainable weight loss and improvements in obesity-related comorbidities and inflammatory profiles. However, the effects of LSG on immune function and metabolism remain uncertain.

METHODS

Prospective data were collected from 23 enrolled human subjects from a single institution. Parameters of weight, comorbidities, and trends in blood biomarkers and leukocyte subsets were observed from preoperative baseline to 1 year postsurgery in 3-month follow-up intervals. RNA sequencing was performed on pairs of whole blood samples from the first 6 subjects of the study (baseline and 3 months postsurgery) to identify genome-wide gene expression changes associated with undergoing LSG.

RESULTS

LSG led to a significant decrease in mean total body weight loss (18.1%) at 3 months and among diabetic subjects a reduction in hemoglobin A1c. Improvements in clinical inflammatory and hormonal biomarkers were demonstrated as early as 3 months after LSG. A reduction in neutrophil-lymphocyte ratio was observed, driven by a reduction in absolute neutrophil counts. Gene set enrichment analyses of differential whole blood gene expression demonstrated that after 3 months LSG induced transcriptomic changes not only in inflammatory cytokine pathways but also in several key metabolic pathways related to energy metabolism.

CONCLUSIONS

LSG induces significant changes in the composition and metabolism of immune cells as early as 3 months postoperatively. Further evaluation is required of bariatric surgery's effects on immunometabolism and the consequences for host defense and metabolic disease.

Weight Loss and Gastrointestinal Hormone Variation Caused by Gastric Artery Embolization: An Updated Analysis Study

OBJECTIVE

Many gastric artery embolizations (GAE) have been performed in recent years. We try to determine whether GAE caused weight loss by decreasing gastrointestinal hormone through the analysis of weight loss and gastrointestinal hormones changes.

METHODS

The PubMed and Medline databases, and the Cochrane Library, were searched using the following keywords. A total of 10 animal trials (n=144), 15 human trials (n=270) were included for analysis. After GAE, we mainly evaluated the changes in body weight loss (BWL) and body mass index (BMI), as well as metabolic indexes, such as blood glucose, lipids, and gastrointestinal hormones levels.

RESULTS

Animal subjects received either chemical or particle embolization, while human subjects only received particle embolization. In animal trials (growing period), the GAE group gained weight significantly slower than the sham-operated group, ghrelin levels decreased. In human trials, GAE brought more weight loss in the early stages, with a trend towards weight recovery after several months that was still lower than baseline levels. Besides weight loss, abnormal metabolic indicators, such as blood glucose and lipids were modified, and the quality of life (QOL) scores of obese patients improved. In addition, weight loss positively correlates with ghrelin.

CONCLUSION

GAE may help people lose weight and become a new minimally invasive and effective surgery for the treatment of modest obesity. Physiologic changes in gastrointestinal tract of gastrointestinal hormones level may be one reason for weight loss in GAE.

Bariatric surgery in patients with breast and endometrial cancer in California: population-based prevalence and survival

BACKGROUND

The number of bariatric surgeries performed in the United States has increased substantially since the 1990's. However, the prevalence and prognostic impact of bariatric surgery, or weight loss surgery (WLS), among patients with cancer are not known.

OBJECTIVES

We investigated the population-based prevalence of WLS in women with breast or endometrial cancer and conducted exploratory analysis to examine whether postdiagnosis WLS is associated with survival.

SETTING

Administrative statewide database.

METHODS

WLS records for women with nonmetastasized breast (n = 395,146) or endometrial (n = 69,859) cancer were identified from the 1991-2014 California Cancer Registry data linked with the California Office of Statewide Health Planning and Development database. Characteristics of the patients were examined according to history of WLS. Using body mass index data available since 2011, a retrospective cohort of patients with breast or endometrial cancer and obesity (n = 12,540) was established and followed until 2017 (5% lost to follow-up). Multivariable cause-specific Cox proportional hazards models were used to examine the associations between postdiagnostic WLS and time to death.

RESULTS

WLS records were identified for 2844 (.7%) patients with breast cancer and 1140 (1.6%) patients with endometrial cancer; about half of the surgeries were performed after cancer diagnosis. Postdiagnosis WLS was performed in ∼1% of patients with obesity and was associated with a decreased hazard for death (cause-specific hazard ratio = .37; 95% confidence interval = .014-.99; P = .049), adjusting for age, stage, co-morbidity, race/ethnicity, and socioeconomic status.

CONCLUSION

About 2000 patients with breast or endometrial cancer in California underwent post-diagnosis WLS between 1991 and 2014. Our data support survival benefits of WLS after breast and endometrial cancer diagnosis.

Impact of Bariatric Surgery on Adipose Tissue Biology

Bariatric surgery (BS) procedures are actually the most effective intervention to help subjects with severe obesity achieve significant and sustained weight loss. White adipose tissue (WAT) is increasingly recognized as the largest endocrine organ. Unhealthy WAT expansion through adipocyte hypertrophy has pleiotropic effects on adipocyte function and promotes obesity-associated metabolic complications. WAT dysfunction in obesity encompasses an altered adipokine secretome, unresolved inflammation, dysregulated autophagy, inappropriate extracellular matrix remodeling and insufficient angiogenic potential. In the last 10 years, accumulating evidence suggests that BS can improve the WAT function beyond reducing the fat depot sizes. The causal relationships between improved WAT function and the health benefits of BS merits further investigation. This review summarizes the current knowledge on the short-, medium- and long-term outcomes of BS on the WAT composition and function.

Biliopancreatic Limb Length of Small Intestinal Bypass in Non-obese Goto-Kakizaki (GK) Rats Correlates with Gastrointestinal Hormones, Adipokines, and Improvement in Type 2 Diabetes

BACKGROUND

The purpose of this study was to explore the effects on type 2 diabetes, gastrointestinal hormones, and adipokines after the small intestinal bypass of different biliopancreatic limb (BPL) lengths in non-obese type 2 diabetic rats.

METHOD

Small intestinal bypass with the BPL length at 10cm, 20cm, 30cm, and 40cm, respectively, and sham surgery were performed in non-obese GK rats. Fasting serum was collected at 2 days preoperatively and 1, 3, 6, and 9 weeks postoperatively. Body weight and fasting blood glucose (FBG) were measured during the experiment. Glycated hemoglobin (GHb), fasting insulin (FINS), C-peptide, ghrelin, leptin, adiponectin, and somatostatin were measured postoperatively.

RESULT

Rats with a bypassed length of 40cm died within 5-9 weeks. No statistically significant was observed in body weight between the sham group and the bypass groups at the 9th week postoperatively. FBG, GHb, FINS, C-peptide, and HOMA-IR in the bypass groups were lower than those in the sham group postoperatively and were negatively correlated with BPL length. Ghrelin and leptin declined compared with preoperative but were not associated with BPL length. Adiponectin of the bypass groups increased after operation and was positively correlated with BPL length. Somatostatin remained stable among groups during the experiment.

CONCLUSION

Ghrelin and leptin of non-obese GK rats decreased postoperatively without a linear relationship with the BPL length, while adiponectin increased with positively correlation with the BPL length. In addition, somatostatin remained steady after small intestinal bypass. Further studies are expected to confirm the effect of the BPL length of small intestinal bypass on gastrointestinal hormones and adipokines.

Metabolic shift precedes the resolution of inflammation in a cohort of patients undergoing bariatric and metabolic surgery

Bariatric and metabolic surgery has shown to promote weight loss and reduce systemic inflammation. However, the sequence and timing of events regarding metabolic improvement and inflammation resolution has been rarely explored. Furthermore, data on inflammatory markers of Th17 and Th1 cell responses after bariatric surgery is scarce. We conducted a prospective study in subjects with obesity that underwent bariatric and metabolic surgery, with follow-ups at 3 and 6 months. Anthropometric and metabolic markers such as insulin levels, HOMA-IR, and lipid parameters declined significantly 3 months after surgery; while hs-CRP, TNF-α, IL-1β, IL-6, and IL-8 serum concentrations decreased 6 months after the procedure. Concentrations of Th1 signature and driver cytokines, particularly IFN-γ, IL-12, and IL-18, and of Th17 driver IL-23 also decreased significantly after 6 months. Significant positive correlations between triglyceride levels and hs-CRP, IL-1β, and IFN-γ concentrations, and between Apo B and IFN-γ levels were observed 6 months after bariatric and metabolic surgery. In addition, BMI was associated with hs-CRP and TNF-α concentrations. Fat mass correlated with hs-CRP, TNF-α, and IL-12. Analysis of the temporality of metabolic and inflammatory events suggests that improvement in the metabolic status occurs before resolution of systemic inflammation and may be a requisite for the later event.

The Positive Impact of Resistance Training on Muscle Mass and Serum Leptin Levels in Patients 2-7 Years Post-Roux-en-Y Gastric Bypass: A Controlled Clinical Trial

PURPOSE

Resistance training program (RTP) assist the maintenance of optimal body composition and inflammatory response modulation in individuals in late Roux-en-Y gastric bypass (RYGB). This study aimed to investigate the effect of RTP on body composition and serum inflammatory profile in individuals 2-7 years post-RYGB.

METHODS

Volunteers were matched on body mass index (BMI), age, sex, and years after surgery, and they were allocated as control or RTP group. Body composition, visceral fat area (VFA), and inflammatory serum markers were measured at baseline and after 12 weeks of RTP.

RESULTS

The sample baseline characteristics (n = 63; BMI = 29.7 ± 5.3 kg/m²) were similar between the groups. After intervention, the RTP group presented higher fat-free mass (Δ 1.17 ± 1.12 kg, p = 0.003) and skeletal muscle mass (Δ 0.77 ± 0.66 kg, p = 0.002) and decreased leptin levels (Δ -0.15 ± 0.60 pg/mL, p = 0.028). Ultrasensitive C-reactive protein (CRPus), interleukin-6, adiponectin, and monocyte chemotactic protein-1 showed no significant time-by-group interaction. After the categorization of RTP group individuals by VFA median values (129.8 cm², IQR 90.9; 152.5), participants with VFA values above the median presented a significant decrease in CRPus (Δ -0.20 mg/L, IQR -7.59; -0.03, p = 0.022) when compared to the participants with VFA values below the median.

CONCLUSION

The RTP improved individuals' body composition by a modest but significant enhancing muscle mass and decreasing serum leptin and CRPus levels, especially in individuals with VFA values above the median. RTPs assist in maintaining the adequate body composition as they contribute to a decrease in proinflammatory markers in long-term RYGB.

The Immunophenotyping Changes of Peripheral CD4+ T Lymphocytes and Inflammatory Markers of Class III Obesity Subjects After Laparoscopic Gastric Sleeve Surgery - A Follow-Up Study

Purpose

Obesity is a chronic disorder characterized by a low-grade inflammatory state and immune cell irregularities. The study aimed to follow up on the changes in the peripheral CD4+ T lymphocytes and the pro-inflammatory cytokines; IL-6, TNF-alpha, MCP-1, and IL-10 at baseline and 12 weeks post-surgical intervention by the laparoscopic gastric sleeve (LGS) in morbidly obese patients (class III obesity subjects).

Materials and Methods

A prospective longitudinal research included 24 class III obesity subjects with a BMI > 40 kg/m². The subjects were enrolled from the Metabolic/Surgical Department at Hamad Medical Corporation (HMC)-Qatar. Fasting blood samples were collected at admission to LGS for weight loss and after 12 weeks of LGS. The immunophenotype of CD4+ T-cell populations; naïve (CD45RA⁺and CD27⁺), central memory T cells (CD45RO⁺ and CD27⁺), and effector memory (CD45RO⁺and CD27^-) and T-regulatory cell (CD4+CD25+ FoxP3+) were identified using flow cytometry. Plasma pro-inflammatory cytokines and adipokines were evaluated. A control group of lean subjects was used to compare changes of T-regulatory and inflammatory biomarkers with postoperative changes in obese patients.

Results

The means (SD) of age and BMI of class III obesity subjects was 32.32 (8.36) years and 49.02 (6.28) kg/m^2, respectively. LGS caused a significant reduction in BMI by 32%, p<0.0001. LGS intervention significantly decreased CD4+ T-lymphocytes and effector memory (TEM) cells but increased T-regulatory (Treg), naïve, and central memory (TCM) cells, with all p values < 0.05. The increase of Treg cells postoperative is significantly lower compared to lean subjects, p < 0.05. A significant reduction of plasma IL-6, TNF-α, and MCP-1, but IL-10 significantly increased after LGS, with all p<0.05. Adiponectin/leptin ratio improved after LGS by 2.9 folds, p<0.0001.

Conclusion

Weight loss by LGS accomplished a substantial rise of Treg and decreased EM T-lymphocytes with a shift from pro-inflammatory to the anti-inflammatory pattern.

Impact of bariatric surgery on periodontal status in an obese cohort at one year of follow-up

The effect of weight loss on the periodontal condition remains unclear. The present prospective study thus aimed to evaluate the effect of weight loss on the periodontal status of 57 obese patients (BMI ≥30 kg/m2) with ages ranging from 18 to 60 years, at 12 months following bariatric surgery. Demographic, biological and behavioral variables were analyzed. All participants underwent a periodontal examination, including plaque index (PI), bleeding on probing (BOP), pocket depth (PD) and clinical attachment level (CAL). Anthropometric measurements, such as weight, height and body mass index (BMI) were calculated. Fisher's exact test, ANOVA, Bonferroni, Spearman's rank correlation and Wilcoxon signed-rank tests were used for the statistical analysis (P<0.05). Prior to surgery, 49% of patients were classified as having obesity class I, 33% as obesity class II and 18% as obesity class III. Variables, such as BMI and PD exhibited statistically significant differences among the obesity class I, II and III groups (P<0.05). As regards periodontal diagnosis, 37% of patients were classified as having gingivitis, 46% as having periodontitis stages I-II, and 17% as having periodontitis stages III-IV. BMI, PI, BOP and PD exhibited statistically significant differences following bariatric surgery (P<0.0001). No statistically significant differences were observed in the CAL (P>0.05). Thus, the findings of the present study suggest that weight loss was associated with decreased periodontal inflammation and an improved plaque control following bariatric surgery. CAL remained unaltered during the study period.

Associations between Pre-Bariatric High-Sensitivity C-Reactive Protein and Post-Surgery Outcomes

Background: Obesity is a chronic inflammatory condition associated with increased circulating levels of C-reactive protein (CRP). Bariatric surgery has been reported to be effective in improving both inflammatory and liver status. Our aims were to elucidate the relationships between pre-surgery high sensitivity-CRP (hs-CRP) values and post-surgery weight loss and liver steatosis and fibrosis in patients with severe obesity undergoing Roux-en-Y gastric bypass. Methods: We conducted an observational prospective study on 90 individuals with morbid obesity, who underwent gastric bypass. Anthropometric indices, laboratory assessment (lipid panel, glycemic status, liver enzymes, and hs-CRP), liver stiffness and steatosis were evaluated at baseline and 6-months after surgery. Results: There was a significant post-surgery reduction in all the anthropometric variables, with an average weight loss of 33.93 ± 11.79 kg; the mean percentage of total weight loss (TWL) was 27.96 ± 6.43%. Liver elasticity was significantly reduced (from 6.1 ± 1.25 to 5.42 ± 1.52 kPa; p = 0.002), as well as liver aminotransferases, nonalcoholic fatty liver disease fibrosis score (NFS) and the grade of steatosis. Serum hs-CRP levels significantly reduced (from 9.26 ± 8.45 to 3.29 ± 4.41 mg/L; p < 0.001). The correlations between hs-CRP levels and liver fibrosis (elastography), steatosis (ultrasonography), fibrosis-4 index, NFS, and surgery success rate were not significant. Regression analyses showed that serum hs-CRP levels were not predictive of liver status and success rate after surgery in both unadjusted and adjusted models. Conclusions: In patients with morbid obesity, bariatric surgery caused a significant decrease in hs-CRP levels, liver stiffness and steatosis. Baseline hs-CRP values did not predict the weight-loss success rate and post-surgery liver status.

Preoperative Chemerin Level Is Predictive of Inflammatory Status 1 Year After Bariatric Surgery

BACKGROUND

Obesity is associated with chronic low-grade inflammation, which has been linked to increased morbidity. However, inflammation variably and unpredictably improves after bariatric surgery. This study aimed at (1) evaluating the relationship between amplitude of weight loss and variation of inflammatory parameters after bariatric surgery, and (2) identifying, among clinical and biological baseline parameters, predictive factors of variation in inflammatory parameters.

METHODS

In a prospective cohort of patients who underwent bariatric surgery, serum concentrations of interleukin (IL)-6, IL-10, resistin, leptin, adiponectin chemerin, and C-reactive protein (CRP) were measured preoperatively and 1 year after surgery, and routine clinical and biochemical parameters were retrieved. Univariate and multivariate analyses (partial least square method) were performed to assess how parameters were associated with weight loss and to predict improvement of inflammatory parameters.

RESULTS

Eighty-seven patients were included (mean weight ± SD 136.3 ± 3.2 kg, 35 gastric bypasses, 52 sleeve gastrectomies). In parallel with weight loss (39.5 ± 13.8 kg), pro-inflammatory markers (IL-6, CRP, leptin, resistin) significantly decreased, and anti-inflammatory markers (IL-10, adiponectin) increased. Multivariate analysis revealed a significant association between weight loss and improvement in inflammatory parameters. Among all the clinical and biological preoperative parameters, baseline chemerin level was the only parameter that was significantly associated with global improvement of the inflammatory status after surgery.

CONCLUSION

The amplitude of weight loss 1 year after bariatric surgery was strongly correlated with improvement of inflammatory profile, which could be predicted by baseline plasma level of chemerin. This suggests a key role of chemerin in obesity-driven inflammation, and a potential use as a biomarker.

Bariatric Surgery and Cardiovascular Outcomes in Patients With Obesity and Cardiovascular Disease:: A Population-Based Retrospective Cohort Study

BACKGROUND

Bariatric surgery has been shown to significantly reduce cardiovascular risk factors. However, whether surgery can reduce major adverse cardiovascular events (MACE), especially in patients with established cardiovascular disease, remains poorly understood. The present study aims to determine the association between bariatric surgery and MACE among patients with cardiovascular disease and severe obesity.

METHODS

This was a propensity score-matched cohort study using province-wide multiple-linked administrative databases in Ontario, Canada. Patients with previous ischemic heart disease or heart failure who received bariatric surgery were matched on age, sex, heart failure history, and a propensity score to similar controls from a primary care medical record database in a 1:1 ratio. The primary outcome was the incidence of extended MACE (first occurrence of all-cause mortality, myocardial infarction, coronary revascularization, cerebrovascular events, and heart failure hospitalization). Secondary outcome included 3-component MACE (myocardial infarction, ischemic stroke, and all-cause mortality). Outcomes were evaluated through a combination of matching via propensity score and subsequent multivariable adjustment.

RESULTS

A total of 2638 patients (n=1319 in each group) were included, with a median follow-up time of 4.6 years. The primary outcome occurred in 11.5% (151/1319) of the surgery group and 19.6% (259/1319) of the controls (adjusted hazard ratio [HR], 0.58 [95% CI, 0.48-0.71]; P<0.001). The association was notable for those with heart failure (HR, 0.44 [95% CI, 0.31-0.62]; P<0.001; absolute risk difference, 19.3% [95% CI, 12.0%-26.7%]) and in those with ischemic heart disease (HR, 0.60 [95% CI, 0.48-0.74]; P<0.001; absolute risk difference, 7.5% [95% CI, 4.7%-10.5%]). Surgery was also associated with a lower incidence of the secondary outcome (HR, 0.66 [95% CI, 0.52-0.84]; P=0.001) and cardiovascular mortality (HR, 0.35 [95% CI, 0.15-0.80]; P=0.001).

CONCLUSIONS

Bariatric surgery was associated with a lower incidence of MACE in patients with cardiovascular disease and obesity. These findings require confirmation by a large-scale randomized trial.

Plasma levels of soluble urokinase plasminogen activator receptor (suPAR) and high-sensitivity C-reactive protein after Roux-en-Y gastric bypass or sleeve gastrectomy: a 1-year prospective observational study

PURPOSE

Low-grade inflammation in obesity contributes to the development of cardiovascular disease, diabetes mellitus and cancer, and is associated with increased mortality. The purpose of this 1-year prospective observational study was to examine the weight loss effect of bariatric surgery on plasma concentrations of two inflammatory markers, namely high-sensitivity C-reactive protein (hsCRP) and soluble urokinase-type plasminogen activator receptor (suPAR), in patients with obesity.

METHODS

Sixteen subjects without obesity and 32 patients with obesity class III, who had already settled upon Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG) were included in the study. Subjects without obesity were examined once, at baseline; patients with obesity were examined preoperatively (baseline) and 3, 6 and 12 months postoperatively.

RESULTS

Plasma suPAR and hsCRP concentrations at baseline were higher in patients with obesity than in lean participants (2.68 ± 0.86 vs 1.86 ± 0.34 ng/mL, p < 0.001 and 9.83 ± 9.55 vs 1.36 ± 1.95 mg/dL, p < 0.001). Levels of suPAR following bariatric surgery increased significantly 3 months after either RYGB or SG (3.58 ± 1.58 vs 3.26 ± 0.7 ng/mL, respectively) and declined at 6 (3.19 ± 1.75 vs 2.8 ± 0.84 ng/mL, respectively) and 12 months (2.6 ± 1.5 vs 2.22 ± 0.49 ng/mL, respectively; p < 0.05 for the effect of time on suPAR levels during the study), whereas those of hsCRP declined consistently after bariatric surgery (3 months: 5.44 ± 3.99 vs 9.47 ± 11.98 mg/dL, respectively; 6 months; 5.39 ± 5.6 vs 10.25 ± 17.22 mg/dL, respectively; and 12 months: 2.23 ± 2.5 vs 3.07 ± 3.63 mg/dL, respectively; p < 0.001 for the effect of time on hsCRP levels during the study). 1-year change in BMI was negatively associated with suPAR levels at 12 months.

CONCLUSION

Our findings support an association between obesity and low-grade inflammation. Weight loss following bariatric surgery is associated with a consistent decline in plasma hsCRP, while plasma suPAR levels increase at 3 months and decline by 12 months.

Changes in Circulating Cytokines and Adipokines After RYGB in Patients with and without Type 2 Diabetes

OBJECTIVE

This study aimed to compare cytokine and adipokine levels in patients with obesity with and without type 2 diabetes (T2D) at baseline and 6 months after Roux-en-Y gastric bypass (RYGB) with healthy controls.

METHODS

A total of 34 patients (21 with T2D) with BMI of 30 to 45 kg/m² were compared with 25 healthy controls without obesity. Cytokines, adipokines, and peptides of relevance for inflammation and metabolism were analyzed in plasma.

RESULTS

Significant decreases in weight and glycated hemoglobin A_1c were observed. At baseline, interleukin-6 (IL-6), IFN-β, IL-18, leptin, and hepatocyte growth factor were higher in all patients with obesity compared with healthy controls. In patients without T2D, TNF-α, IL-1α, IL-2, IL-15, and visfatin were also increased, whereas bone morphogenic protein-4 was decreased. Following RYGB, IL-6 and hepatocyte growth factor were still increased in both groups compared with controls. In T2D patients, IFN-β, IL-27, IL-1α, IL-2, regenerating islet-derived protein 3A, visfatin, and osteopontin were found to be increased. In patients without T2D, TNF-α, IL-1α, IL-2, IL-15, leptin, and visfatin remained increased.

CONCLUSIONS

The altered cytokine profile of patients with obesity persisted after RYGB despite large weight loss and improved metabolic status, thus reflecting an inherent inflammatory state.

Weight Loss Following Roux-en-Y Gastric Bypass Causally Implicated with Serum Levels of IL-22: A Mendelian Randomization and Phenome-Wide Association Study

OBJECTIVE

Laparoscopic Roux-en-Y gastric bypass (RYGB) modulates the low-grade inflammatory state associated with severe obesity. This study sought to investigate whether weight loss is causally implicated with changes in serum levels of inflammatory molecules.

METHODS

Using the largest genome-wide association study (n = 1,020 individuals), this study curated five genetic variants associated with weight loss following RYGB. Phenome-wide association studies (PheWAS) were performed to identify other phenotypes associated with these variants. Subsequently, two-sample Mendelian randomization was used to study the causal effects of weight loss on the serum levels of 382 inflammatory proteins (measured in 3,033 individuals). This is the first systematic quasi-experimental investigation of weight loss following RYGB and serum markers of inflammation.

RESULTS

The PheWAS analysis revealed that four of the five variants are associated with phenotypes relating to metabolism and inflammation, including insulin response and levels of C-reactive protein. Two-sample Mendelian randomization of the 382 serum inflammatory markers revealed that weight loss following RYGB increases serum levels of interleukin 22 (IL-22) (beta = 0.021, P < 10-3 ; 95% CI: 0.010-0.031). Sensitivity analyses further supported the results and the causal direction.

CONCLUSIONS

Weight loss following RYGB may cause an increase in IL-22 serum levels, suggesting that weight loss directly contributes to immune modulation following bypass. These results demonstrate the utility of genetic studies to disentangling molecular cause and effect following bariatric surgery.

Early changes in immune cell metabolism and function are a hallmark of sleeve gastrectomy: a prospective human study

OBJECTIVE

To characterize longitudinal changes in blood biomarkers, leukocyte composition, and gene expression following laparoscopic sleeve gastrectomy (LSG).

BACKGROUND

LSG is an effective treatment for obesity, leading to sustainable weight loss and improvements in obesity-related co-morbidities and inflammatory profiles. However, the effects of LSG on immune function and metabolism remain uncertain.

METHODS

Prospective data was collected from 23 enrolled human subjects from a single institution. Parameters of weight, co-morbidities, and trends in blood biomarkers and leukocyte subsets were observed from pre-operative baseline to one year in three-month follow-up intervals. RNA-sequencing was performed on pairs of whole blood samples from the first six subjects of the study (baseline and three months post-surgery) to identify genome-wide gene expression changes associated with undergoing LSG.

RESULTS

LSG led to a significant decrease in mean total body weight loss (18.1%) at three months and among diabetic subjects a reduction in HbA1c. Improvements in clinical inflammatory and hormonal biomarkers were demonstrated as early as three months after LSG. A reduction in neutrophil-lymphocyte ratio was observed, driven by a reduction in absolute neutrophil counts. Gene set enrichment analyses of differential whole blood gene expression demonstrated that after three months, LSG induced transcriptomic changes not only in inflammatory cytokine pathways but also in several key metabolic pathways related to energy metabolism.

CONCLUSIONS

LSG induces significant changes in the composition and metabolism of immune cells as early as three months post-operatively. Further evaluation is required of bariatric surgery's effects on immunometabolism and consequences for host defense and metabolic disease.

Impact of Metabolic Surgery on Type 2 Diabetes Mellitus, Cardiovascular Risk Factors, and Mortality: A Review

BACKGROUND

The association between obesity and a reduction in life expectancy is well established, and cardiovascular disease is a leading cause of mortality. Bariatric surgery has long been established as the most effective and durable intervention for obesity, and is the only intervention for obesity that consistently improves multiple comorbidities, reduces cardiovascular disease and long-term mortality. The purpose of this review is to describe the impact of metabolic/bariatric surgery on type 2 diabetes mellitus and cardiometabolic parameters, including cardiovascular mortality.

METHODS

A systematic literature search of Pubmed, MEDLINE, and Cochrane Central Register was performed. We included randomized controlled trials, meta-analysis, case-control trials, and cohort studies that contain data on reductions in cardiovascular risk factors and cardiovascular mortality in subjects who underwent metabolic/bariatric surgery from January 1, 2005 to June 1, 2020.

CONCLUSION

There is sufficient evidence from randomized controlled trials that metabolic/bariatric surgery is associated with a significant improvement of all cardiovascular risk factors. Although studies are showing a reduction of macrovascular events and cardiovascular mortality, these findings come from observational studies and should be confirmed in randomized clinical trials.

Bariatric Surgery: Remission of Inflammation, Cardiometabolic Benefits, and Common Adverse Effects

Obesity is associated with increased mortality as a result of several comorbidities which occur in tandem with the obese state. Chronic inflammation is well documented in obesity, and evidence from numerous studies support the notion that the increased inflammation in individuals with obesity accentuates the comorbidities seen in this condition. The remission of comorbidities such as metabolic, cardiovascular, and neurological complications occurs following bariatric procedures. Bariatric surgery significantly reduces mortality and results in remarkable weight loss and reversal in several obesity-related comorbidities. There is indisputable evidence that the resolution of inflammation that occurs after bariatric surgery mitigates some of these comorbidities. With the increasing use of bariatric surgery for the treatment of severe obesity, it is pivotal to elucidate the underlying mechanisms responsible for the notable improvements seen after the procedure. This review summarizes underlying mechanisms responsible for the remission of obesity-related abnormalities and discusses the common adverse effects of bariatric surgery. Well-stratified, large-scale studies are still needed for a proper evaluation of these underlying mechanisms.

Effect of Bariatric Surgery on Serum Inflammatory Factors of Obese Patients: a Systematic Review and Meta-Analysis

Obesity is one of the main causes of inflammation. Previous studies have reported inconclusive results regarding the effect of bariatric surgery on inflammatory markers. This systematic review and meta-analysis is aimed at describing the effect of bariatric surgery on C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α). PubMed/Medline and Scopus were systematically searched for all eligible studies from inception to June 2018. Results are expressed as weighted mean difference (MD) with 95% confidence intervals (CI) using a random effects model. Overall, 116 studies which evaluated serum CRP, IL-6, and TNF-α after bariatric surgery were included. Pooled effect size showed significant reduction in serum CRP (- 5.30 mg/l, 95% CI - 5.46, - 5.15, P < 0.001), IL-6 (- 0.58 pg/ml, 95% CI - 0.64, - 0.53, P < 0.001), and TNF-α (- 0.20 pg/ml, 95% CI - 0.39, - 0.02, P = 0.031) with significant heterogeneity across studies (> 95% for all factors). Bariatric surgery significantly lowered inflammatory factors; however, baseline BMI, follow-up duration and type of surgery could impact the extent of observed effects.

Reduction of IL-6 gene expression in human adipose tissue after sleeve gastrectomy surgery

OBJECTIVE

There is increasing evidence that immune cell interactions in adipose tissue contribute to the development of metabolic dysfunction. Pro-inflammatory cytokines have been shown to mediate insulin resistance, and the presence of macrophages is a salient feature in the development of obesity. The present study aimed to evaluate adipocyte size and macrophage activation in women before and 3 months after laparoscopic vertical sleeve gastrectomy (VSG).

METHODS

Subcutaneous abdominal adipose tissue biopsies were obtained from women scheduled to undergo VSG. Histological evaluation of adipocytes and macrophages was performed as well as cytokine expression quantification before and after VSG-induced weight loss.

RESULTS

Weight loss following VSG resulted in a reduction in adipocyte size as well as a decrease in interleukin (IL)-6 cytokine mRNA expression in subcutaneous adipose tissue. There was no change in the presence of crownlike structures after weight loss.

CONCLUSIONS

Early weight loss after VSG is associated with a reduction in adipocyte size and a decline in IL-6 gene expression in local adipose tissue. Macrophage infiltration and crownlike density structures persist in adipose tissue from tissues impacted by excess body weight 3 months after VSG-induced weight loss.

Adipose Tissue Distribution, Inflammation and Its Metabolic Consequences, Including Diabetes and Cardiovascular Disease

Adipose tissue plays essential roles in maintaining lipid and glucose homeostasis. To date several types of adipose tissue have been identified, namely white, brown, and beige, that reside in various specific anatomical locations throughout the body. The cellular composition, secretome, and location of these adipose depots define their function in health and metabolic disease. In obesity, adipose tissue becomes dysfunctional, promoting a pro-inflammatory, hyperlipidemic and insulin resistant environment that contributes to type 2 diabetes mellitus (T2DM). Concurrently, similar features that result from adipose tissue dysfunction also promote cardiovascular disease (CVD) by mechanisms that can be augmented by T2DM. The mechanisms by which dysfunctional adipose tissue simultaneously promote T2DM and CVD, focusing on adipose tissue depot-specific adipokines, inflammatory profiles, and metabolism, will be the focus of this review. The impact that various T2DM and CVD treatment strategies have on adipose tissue function and body weight also will be discussed.

PYY, a Therapeutic Option for Type 2 Diabetes?

Metabolic surgery leads to rapid and effective diabetes reversal in humans, by weight-independent mechanisms. The crucial improvement in pancreatic islet function observed after surgery is induced by alteration in several factors, including gut hormones. In addition to glucagon-like peptide 1 (GLP-1), increasing lines of evidence show that peptide tyrosine tyrosine (PYY) plays a key role in the metabolic benefits associated with the surgery, ranging from appetite regulation to amelioration of islet secretory properties and survival. Here, we summarize the current knowledge and the latest advancements in the field, which pitch a strong case for the development of novel PYY-based therapy for the treatment of diabetes.

Obesity-related cognitive impairment: The role of endothelial dysfunction

Obesity is a global pandemic associated with macro- and microvascular endothelial dysfunction. Microvascular endothelial dysfunction has recently emerged as a significant risk factor for the development of cognitive impairment. In this review, we present evidence from clinical and preclinical studies supporting a role for obesity in cognitive impairment. Next, we discuss how obesity-related hyperinsulinemia/insulin resistance, systemic inflammation, and gut dysbiosis lead to cognitive impairment through induction of endothelial dysfunction and disruption of the blood brain barrier. Finally, we outline the potential clinical utility of dietary interventions, exercise, and bariatric surgery in circumventing the impacts of obesity on cognitive function.

Study of changes of obesity-related inflammatory cytokines after laparoscopic sleeve gastrectomy

BACKGROUND

Chronic inflammation in adipose tissue may play a substantial role in the pathogenesis of obesity-related metabolic disorders. The present study aims to evaluate the changes in adipocytokines, bile acids, fibroblast growth factor 19 (FGF-19) and pro-inflammatory cytokines 6 months after laparoscopic sleeve gastrectomy (LSG).

METHODS

This prospective study included 75 obese patients with body mass index >35 kg/m² who underwent LSG. All patients were recruited preoperatively and followed up post-operatively at 6 months, with laboratory assessment of their cytokines including adiponectin, leptin, resistin, bile acid, interleukin (IL)-6, IL-8, tumour necrosis factor-α, monocyte chemotactic protein-1, high-sensitivity C-reactive protein, plasminogen activator inhibitor-1, serum amyloid-A and FGF-19.

RESULTS

There were statistically highly significant changes regarding anthropometric parameters (weight, body mass index and waist-to-hip ratio), blood glucose and lipid profile as well as liver enzymes at 6 months post-sleeve gastrectomy. The present study showed that the levels of serum adiponectin and FGF-19 significantly increased at 6 months of follow-up after surgery (P < 0.001), while the levels of serum leptin, resistin, high-sensitivity C-reactive protein, plasminogen activator inhibitor-1 and serum amyloid-A significantly decreased at 6 months of follow-up after surgery (P < 0.001). There were no significant differences regarding serum bile acid, IL-6, IL-8, tumour necrosis factor-α and monocyte chemotactic protein-1.

CONCLUSION

Weight loss after LSG is associated with significant improvement of the adipokine levels towards anti-diabetic and anti-inflammatory profiles. Future studies should use a larger sample size and longer follow-up periods.

Body weight-dependent and independent improvement in lipid metabolism after Roux-en-Y gastric bypass in ApoE*3Leiden.CETP mice

BACKGROUND/OBJECTIVES

The incidence of obesity and metabolic syndrome (MetS) has rapidly increased worldwide. Roux-en-Y gastric bypass (RYGB) achieves long-term weight loss and improves MetS-associated comorbidities. Using a mouse model with a humanized lipoprotein metabolism, we elucidated whether improvements in lipid and glucose metabolism after RYGB surgery are body weight loss-dependent or not.

SUBJECTS/METHODS

Male ApoE*3Leiden.CETP (ApoE3L.CETP) mice fed Western type diet for 6 weeks underwent RYGB or Sham surgery. Sham groups were either fed ad libitum or were body weight-matched (BWm) to the RYGB mice to discriminate surgical effects from body weight loss-associated effects. Before and after surgery, plasma was collected to assess the metabolic profile, and glucose tolerance and insulin sensitivity were tested. Twenty days after surgery, mice were sacrificed, and liver was collected to assess metabolic, histological and global gene expression changes after surgery.

RESULTS

RYGB induced a marked reduction in body weight, which was also achieved by severe food restriction in BWm mice, and total fat mass compared to Sham ad libitum mice (Sham AL). Total cholesterol, non-high-density lipoprotein cholesterol (non-HDL-C) and ceramide were strongly reduced 20 days after surgery in RYGB compared to BWm mice. Glucose tolerance and insulin sensitivity improved 13 days after surgery similarly in RYGB and BWm mice. Liver histology confirmed lipid reduction in RYGB and BWm mice while the transcriptomics data indicated altered genes expression in lipid metabolism.

CONCLUSIONS

RYGB surgery improves glucose metabolism and greatly ameliorates lipid metabolism in part in a body weight-dependent manner. Given that ApoE3L.CETP mice were extensively studied to describe the MetS, and given that RYGB improved ceramide after surgery, our data confirmed the usefulness of ApoE3L.CETP mice after RYGB in deciphering the metabolic improvements to treat the MetS.

Serum proteome changes and accelerated reduction of fat mass after laparoscopic gastric plication in morbidly obese patients

Laparoscopic Gastric Plication (LGP) is a relatively new bariatric surgical procedure which no part of the stomach is removed. It is not clearly understood how LGP leads to fatty tissue reduction. We aimed to investigate the impact of LGP on serum proteome and understand molecular mechanisms of LGP-induced weight loss post-surgery. A Prospective observational study of 16 obese individuals who underwent LGP was performed. A Label-free quantitative shotgun proteomics approach was used to compare serum proteome of subjects before surgery with serum of the same individuals 1 to 2 months post-surgery (T1) and 4 to 5 months post-surgery (T2). The proteome analysis revealed that 48 proteins were differentially regulated between pre-surgery and T1, and seven proteins between pre-surgery and T2 of which six proteins were shared between the two timepoints. Among differentially regulated proteins, four proteins (SRGN, FETUB, LCP1 and CFP) have not previously been described in the context of BMI/weight loss. Despite few differences following LGP, most regulated serum proteins are in accordance with alternative weight loss procedures. Pathway analysis revealed changes to lipid- and inflammatory pathways, including PPARα/RXRα, LXR/RXR and FXR/RXR activation, especially at T1. At T2, the pathways related to inflammation and immune system are most affected. SIGNIFICANCE: Among the available clinical therapies for morbid obesity, bariatric surgery is considered as the most effective approach to achieve long-term weight loss, alongside a significant improvement in metabolic syndrome. However, very little is known about the underlying mechanism associated with significant weight loss post-surgery. Understanding such mechanisms could lead to development of safer non-surgical weight loss approaches. We here present the first analysis of the impact of LGP on the serum proteome, to bring new insights into the underlying molecular mechanism. Our findings indicate that LGP has a comprehensive systemic effect based on the blood serum proteome profile which might account for accelerated reduction of fat mass after surgery, thus, food restriction is not the only reason for weight loss following this unique surgical approach. As secretory regions of the stomach are preserved in LGP and it is associated with minimal physiological and anatomical changes, the findings are of high importance in the field of bariatric surgery and weight loss.

PYY plays a key role in the resolution of diabetes following bariatric surgery in humans

BACKGROUND

Bariatric surgery leads to early and long-lasting remission of type 2 diabetes (T2D). However, the mechanisms behind this phenomenon remain unclear. Among several factors, gut hormones are thought to be crucial mediators of this effect. Unlike GLP-1, the role of the hormone peptide tyrosine tyrosine (PYY) in bariatric surgery in humans has been limited to appetite regulation and its impact on pancreatic islet secretory function and glucose metabolism remains under-studied.

METHODS

Changes in PYY concentrations were examined in obese patients after bariatric surgery and compared to healthy controls. Human pancreatic islet function was tested upon treatment with sera from patients before and after the surgery, in presence or absence of PYY. Alterations in intra-islet PYY release and insulin secretion were analysed after stimulation with short chain fatty acids (SCFAs), bile acids and the cytokine IL-22.

FINDINGS

We demonstrate that PYY is a key effector of the early recovery of impaired glucose-mediated insulin and glucagon secretion in bariatric surgery. We establish that the short chain fatty acid propionate and bile acids, which are elevated after surgery, can trigger PYY release not only from enteroendocrine cells but also from human pancreatic islets. In addition, we identify IL-22 as a new factor which is modulated by bariatric surgery in humans and which directly regulates PYY expression and release.

INTERPRETATION

This study shows that some major metabolic benefits of bariatric surgery can be emulated ex vivo. Our findings are expected to have a direct impact on the development of new non-surgical therapy for T2D correction.

Contribution of Adipose Tissue Inflammation to the Development of Type 2 Diabetes Mellitus

The objective of this comprehensive review is to summarize and discuss the available evidence of how adipose tissue inflammation affects insulin sensitivity and glucose tolerance. Low-grade, chronic adipose tissue inflammation is characterized by infiltration of macrophages and other immune cell populations into adipose tissue, and a shift toward more proinflammatory subtypes of leukocytes. The infiltration of proinflammatory cells in adipose tissue is associated with an increased production of key chemokines such as C-C motif chemokine ligand 2, proinflammatory cytokines including tumor necrosis factor α and interleukins 1β and 6 as well as reduced expression of the key insulin-sensitizing adipokine, adiponectin. In both rodent models and humans, adipose tissue inflammation is consistently associated with excess fat mass and insulin resistance. In humans, associations with insulin resistance are stronger and more consistent for inflammation in visceral as opposed to subcutaneous fat. Further, genetic alterations in mouse models of obesity that reduce adipose tissue inflammation are-almost without exception-associated with improved insulin sensitivity. However, a dissociation between adipose tissue inflammation and insulin resistance can be observed in very few rodent models of obesity as well as in humans following bariatric surgery- or low-calorie-diet-induced weight loss, illustrating that the etiology of insulin resistance is multifactorial. Taken together, adipose tissue inflammation is a key factor in the development of insulin resistance and type 2 diabetes in obesity, along with other factors that likely include inflammation and fat accumulation in other metabolically active tissues. © 2019 American Physiological Society. Compr Physiol 9:1-58, 2019.