Effect of Bariatric Surgery on Flow-Mediated Vasodilation as a Measure of Endothelial Function: A Systematic Review and Meta-Analysis

The Effect of Bariatric Surgery on PAI-1 Levels: A Systematic Review and Meta-analysis

The purpose of this meta-analysis was to determine the effect of bariatric surgery on circulating PAI-1. The meta-analysis was provided by comprehensive meta-analysis (CMA) V4 software. Meta-analysis of 33 studies showed a significant decrease in circulating PAI-1 after bariatric surgery (p < 0.001). A significant reduction was observed for two types of surgery) (p < 0.001 for LSG and p < 0.001 for RYGB). Furthermore, there was a significant change in circulating PAI-1 based on the follow-up duration (p < 0.001 for follow-up < 12 months and p < 0.001 for follow-up ≥ 12). We showed that bariatric surgery changed PAI-1 level significantly and changes in BMI after surgery were not related to PAI-1 alteration. Furthermore, this result was consistent based on follow-up duration and type of surgery.

The differential expression of adipose tissue genes in short, medium and long-term periods after bariatric surgery

Bariatric surgery is an approved treatment for obesity that consistently improves metabolic syndrome, with well-documented beneficial effects on dyslipidemia, cardiovascular risk, nonalcoholic fatty liver disease and glucose homeostasis. In this study, we determined the differential expression genes in three periods after bariatric surgery: short-term (4-months), medium-term (1- and 2-years), and long-term (5-years) periods. Two microarray profiles were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified by comparing the expression of adipose tissue genes before surgery compared to short, medium and long-term periods following surgery. Shared DEGs for the medium-term were evaluated by comparing the DEGs for both 1 and 2 years. 165, 65, and 59 DEGs were identified in short-medium-long periods. The protein-protein interactions were analyzed by STRING. A co-expression network was constructed by mapping the DEGs onto the GeneMANIA plugin of Cytoscape. Gene Ontology (GO) enrichment, Kyoto Encyclopedia of Genes and Genomes (KEGG) and wikipathway analysis were done for each group of DEGs. Interleukin-8 receptor activity, complement receptor activity and opsonin receptor activity/N-formyl peptide receptor activity in GO Function enrichment and cellular response to interleukin-8, positive regulation of hippocampal neuron apoptotic process, and positive regulation of hippocampal neuron apoptotic process in GO Process showed the best scores in short-, medium-, and long-term periods, respectively. Eight genes, including CCL2 (Chemokine ligand 2), CXCR4 (CXC motif chemokine receptor 4), EGR2 (Early Growth Response 2), FPR1 (Formyl Peptide Receptor 1), IL6 (interleukin-6), RGS2 (regulator of gene protein signaling2), SELPLG (Selectin P Ligand), and THBS1 (Thrombospondin 1) were identified as shared DEGs in the three periods after surgery. Importantly, results of DAVID database analysis showed 7, 6, 4, and 4 of these genes have roles in immune/ cancer/cardiovascular diseases, type 2 diabetes, myocardial infarct, and atherosclerosis, respectively.

Impact of bariatric surgery on circulating irisin levels: a systematic review and meta‑analysis

This systematic review and meta-analysis evaluated changes in circulating irisin levels after bariatric surgery. A systematic search was performed across Embase, Scopus, PubMed, and Web of Science for this study. The meta-analysis was conducted using Comprehensive Meta-Analysis (CMA) V4 software. The overall effect size was depicted through a random-effects meta-analysis and the leave-one-out method. The meta-analysis, which included 13 studies with a total of 407 participants, showed a statistically non-significant reduction in circulating irisin levels following bariatric surgery (SMD:  - 0.089, 95% CI  - 0.281, 0.102, 95% PI:  - 0.790, 0.611, p = 0.360; I2:70.56). Our research found no significant change in irisin levels after bariatric surgery. Moreover, these findings were not associated with the type of surgery or the duration of follow-up.

Bariatric Surgery Improves Serum CD40L Levels as a Predictor of Cardiovascular Risk: Systematic Review and Meta-analysis

CD40 and its ligand have been recently implicated in the pathogenesis of cardiovascular disease (CVD). This meta-analysis examined the effect of bariatric surgery in reducing circulating CD40L levels. A systematic review was performed using Embase, Google Scholar, PubMed, Scopus, and Web of Science. The meta-analysis was provided by Comprehensive Meta-Analysis (CMA) V4 software. The overall effect size was detected by a random-effects meta-analysis and the leave-one-out approach. Random-effects meta-analysis of 7 studies including 191 subjects showed a significant reduction in CD40L after bariatric surgery (standardized mean difference (SMD), - 0.531; 95% CI, - 0.981, - 0.082; p = 0.021; I2, 87.00). Circulating levels of CD40L are decreased after bariatric surgery which may represent a mechanism for improvement of metabolic profile.

Improvement of Triglyceride-Glucose Index Following Bariatric Surgery: a Systematic Review and Meta-analysis

BACKGROUND

Bariatric surgery is an effective intervention for the management of severe obesity and its associated comorbidities, including metabolic abnormalities. This meta-analysis aimed to evaluate the impact of bariatric surgery on the triglyceride-glucose (TyG) index, a novel marker of insulin resistance and metabolic syndrome.

METHODS

A systematic search was conducted in Embase, PubMed, Web of Science, and Scopus. The meta-analysis was performed using Comprehensive Meta-Analysis (CMA) V4 software. The overall effect size was determined by a random-effects meta-analysis and the leave-one-out approach.

RESULTS

A total of 9 trials including 1620 individuals confirmed a significant reduction in TyG following bariatric surgery (weighted mean difference (WMD) - 0.770, 95% CI - 1.006, - 0.534, p < 0.001). In a sub-analysis according to the type of bariatric surgery there was a significant reduction in TyG index for Roux-en-Y gastric bypass (WMD - 0.775, 95% CI - 1.000, - 0.550, p < 0.001), and sleeve gastrectomy (WMD - 0.920, 95% CI - 1.368, - 0.473, p < 0.001). In a sub-analysis according to the follow-up duration there was similarly a significant reduction in TyG index for both < 12 months (WMD - 1.645, 95% CI - 2.123, - 1.167, p < 0.001), and ≥ 12 months follow-up (WMD - 0.954, 95% CI - 1.606, - 0.303, p < 0.001).

CONCLUSION

The results of this meta-analysis demonstrated a significant reduction in the TyG index following bariatric surgery, indicating improved insulin sensitivity and metabolic health. These findings highlight the potential of bariatric surgery as a valuable therapeutic option for individuals with obesity and its metabolic consequences.

Meta-analysis of the Impact of Bariatric Surgery on Circulating TMAO Levels as a Predictor of Cardiovascular Disease Risk

INTRODUCTION

Trimethylamine N-oxide (TMAO) is a metabolite of the gut microbiota that is considered a cardiovascular risk factor. Because bariatric surgery (BS) produces changes in the composition of the gut microbiota, the production of TMAO can be compromised. Thus, the purpose of this meta-analysis was to determine the effect of BS on circulating TMAO levels.

METHODS

A systematic search was carried on in Embase, PubMed, Web of Science, and Scopus databases. The meta-analysis was conducted using Comprehensive Meta-Analysis (CMA) V2 software. The overall effect size was determined by a random-effects metaanalysis and the leave-one-out approach.

RESULTS

Random-effects meta-analysis of 5 studies consisting of 142 subjects demonstrated a significant increase in circulating TMAO levels after BS (SMD: 1.190, 95% CI: 0.521, 1.858, p<0.001; I2:89.30%).

CONCLUSION

Considering that levels of TMAO are affected after BS due to gut microbial metabolism alteration, there has been a significant elevation in TMAO concentrations observed to occur after BS in obese subjects.

Effect of Bariatric Surgery on Serum Amyloid A Protein: a Systematic Review and Meta-analysis

BACKGROUND

Obesity is a chronic inflammatory condition and this meta-analysis evaluated the impact of bariatric surgery on SAA.

METHODS

Studies included all types of bariatric surgery where SAA was measured before and after the surgical procedure.

RESULTS

Meta-analysis of 11 clinical studies (n = 394 individuals) confirmed a significant reduction in SAA following bariatric surgery (SMD: - 0.971, 95% CI: - 2.721, 0.779, p < 0.001). Meta-regression did not show any association between the changes in BMI and the absolute difference in SAA levels. No relationship between the changes in SAA and the length of follow-up was found.

CONCLUSION

Bariatric surgery significantly improved SAA. The decrease in SAA was not related to time after surgery or changes in BMI. Bariatric surgery may thus have an independent effect on SAA.

Ischemia with Nonobstructive Coronary Artery Disease and Atrial Cardiomyopathy-Two Sides of the Same Story?

Ischemia with nonobstructive coronary artery disease (INOCA) is increasingly recognized as a significant cause of angina, myocardial remodeling, and eventually heart failure (HF). Coronary microvascular dysfunction (CMD) is a major endotype of INOCA, and it is caused by structural and functional alterations of the coronary microcirculation. At the same time, atrial cardiomyopathy (ACM) defined by structural, functional, and electrical atrial remodeling has a major clinical impact due to its manifestations: atrial fibrillation (AF), atrial thrombosis, stroke, and HF symptoms. Both these pathologies share similar risk factors and have a high comorbidity burden. CMD causing INOCA and ACM frequently coexist. Thus, questions arise whether there is a potential link between these pathologies. Does CMD promote AF or the reverse? Which are the mechanisms that ultimately lead to CMD and ACM? Are both part of a systemic disease characterized by endothelial dysfunction? Lastly, which are the therapeutic strategies that can target endothelial dysfunction and improve the prognosis of patients with CMD and ACM? This review aims to address these questions by analyzing the existing body of evidence, offering further insight into the mechanisms of CMD and ACM, and discussing potential therapeutic strategies.

Diagnostic Value of Non-invasive Liver Function Tests in Liver Fibrosis and Changes in These Parameters Post-metabolic Surgery

PURPOSE

This study aimed to ascertain the diagnostic accuracy of non-invasive liver function tests in liver fibrosis and assess their changes after metabolic surgery.

MATERIALS AND METHODS

1005 individuals with severe obesity who were referred for metabolic surgery were analysed. All participants had blood samples taken for liver enzymes and lipid profile. In addition, hepatic indexes, including AAR, APRI, NFS and Fibrosis-4 (FIB4), were checked. Furthermore, all participants underwent two-dimensional shear wave elastography (2D-SWE). All investigations were repeated 6-8 months after metabolic surgery. The receiver operating characteristic (ROC) curve and the area under the ROC curve was utilised to determine the optimal cut-off values for baseline study parameters. Logistic regression was applied to predict the relationship between study parameters-as predictors-and change in 2D-SWE.

RESULTS

AST/ALT (AAR) was the most sensitive (79%) pre-operative non-invasive serological marker for detecting liver fibrosis, whereas NAFLD Fibrosis Score (NFS) was the most specific (84%). AST/upper limit of the normal AST range × 100/platelets (× 10⁹/L) (APRI) showed a positive correlation with 2D-SWE post-metabolic surgery (p-value = 0.021). Regression analysis from both adjusted and unadjusted models showed that baseline AAR was a predictor of postoperative liver status in terms of hepatic fibrosis.

CONCLUSION

AAR has a high sensitivity, whereas NFS exhibits a high specificity in diagnosing liver fibrosis. The authors recommend using both investigations in conjunction with 2D-SWE to increase the likelihood of detecting liver fibrosis.

Prior statin use and the incidence of in-hospital arrhythmia in acute coronary syndrome: A systematic review and meta-analysis

BACKGROUND

The benefit of prior statin use to reduce the incidence of arrhythmia in acute coronary syndrome (ACS) is still a matter of debate. Statins have multiple pleiotropic effects, which may reduce the incidence of in-hospital arrhythmia. A systematic review and meta-analysis were performed to evaluate prior statin use and the incidence of in-hospital arrhythmia in ACS.

METHODS

This systematic review was conducted as per the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). We performed a literature search through Pubmed, Proquest, EBSCOhost, and Clinicaltrial.gov. A random-effect model was used due to moderate heterogeneity. Quality assessment was performed using Newcastle Ottawa Scale. Sensitivity analysis was performed by using leave one or two out method. PROSPERO registration number: CRD42022336402.

RESULTS

Nine eligible studies consisting of 86,795 patients were included. A total of 22,130 (25.5%) patients were in statin use before the index ACS event. The prevalence of old myocardial infarction, heart failure, hypertension, diabetes mellitus, and chronic renal failure and concomitant treatment with aspirin, clopidogrel, and beta blocker was higher in the prior statin group compared to no previous statin. Overall, prior statin use was associated with a significantly lower incidence of in-hospital arrhythmia during ACS compared to no previous statin (OR 0.60; 95% CI 0.49-0.72; P < 0.00001; I2 = 54%, P-heterogeneity = 0.03). In subgroup analysis, previous statin use reduced the incidence of atrial fibrillation or atrial flutter (OR 0.64; 95% CI 0.43-0.95; P = 0.03; I2 = 73%, P-heterogeneity = 0.01) and ventricular tachycardia or ventricular fibrillation (OR 0.57; 95% CI 0.49-0.65; P < 0.00001; I2 = 8%, P-heterogeneity = 0.35).

CONCLUSIONS

Based on aggregate patient data, prior statin use may reduce the incidence of in-hospital arrhythmia during ACS, particularly atrial fibrillation or atrial flutter and ventricular tachycardia or ventricular fibrillation.

The Effect of Bariatric Surgery on Circulating Levels of Monocyte Chemoattractant Protein-1: A Systematic Review and Meta-Analysis

Background: MCP-1 (monocyte chemoattractant protein) plays an important role in early phases of atherogenesis as well as in plaque destabilization, which causes cardiovascular events to play an important role in low-grade inflammation. Obesity, particularly extreme obesity, is a pivotal risk factor for atherosclerosis and many other diseases. In the early stages, bariatric surgery might stop or slow atherogenesis by suppressing inflammation, but also in later stages, preventing plaque destabilization. The aim of this meta-analysis was to provide an answer as to whether bariatric surgery has a significant effect on circulating MCP-1 level or not. Methods: A systematic literature search in PubMed, Scopus, Embase, and Web of Science was performed from inception to 1 January 2022. Meta-analysis was performed using Comprehensive Meta-Analysis (CMA) V2 software. In order to heterogeneity compensation of studies in terms of study design and treatment duration, the characteristics of the studied populations random-effects model and the generic inverse variance weighting method were used. To investigate the relationship with the estimated effect size, a random-effect meta-regression model was used. To assess the exitance of publication bias in the meta-analysis, the funnel plot, Begg's rank correlation, and Egger's weighted regression tests were used. Results: Meta-analysis of 25 studies with 927 subjects included demonstrated a significant decrease of MCP-1 concentration after bariatric surgery. The data of meta-regression did not indicate any association between the alterations in body mass index (BMI) and absolute difference in MCP-1 levels, but a linear relationship between the changes in MCP-1 and length of follow-up was proven. Conclusions: Bariatric surgery significantly decreases MCP-1 concentration, but there was no association between the changes in BMI and absolute difference in MCP-1 levels before and after the surgery.

The Effect of Bariatric Surgery on Circulating Levels of Lipoprotein (a): A Meta-analysis

Background

Obesity, especially severe obesity, is associated with a higher risk of atherosclerotic cardiovascular disease (ASCVD) morbidity and mortality. Bariatric surgery is a durable and effective weight loss therapy for patients with severe obesity and weight-related comorbidities. Elevated plasma levels of lipoprotein (a) (Lp(a)) are causally associated with ASCVD. The aim of this meta-analysis was to analyze whether bariatric surgery is associated with Lp(a) concentrations.

Methods

A literature search in PubMed, Scopus, Embase, and Web of Science was performed from inception to May 1st, 2021. A random-effects model and the generic inverse variance weighting method were used to compensate for the heterogeneity of studies in terms of study design, treatment duration, and the characteristics of the studied populations. A random-effects metaregression model was used to explore the association with an estimated effect size. Evaluation of funnel plot, Begg's rank correlation, and Egger's weighted regression tests were used to assess the presence of publication bias in the meta-analysis.

Results

Meta-analysis of 13 studies including 1551 patients showed a significant decrease of circulating Lp(a) after bariatric surgery (SMD: -0.438, 95% CI: -0.702, -0.174, p < 0.001, I²: 94.05%). The results of the metaregression did not indicate any significant association between the changes in Lp(a) and duration of follow-up after surgery, reduction in body mass index, or baseline Lp(a) concentration. The reduction in circulating Lp(a) was robust in the leave-one-out sensitivity analysis.

Conclusion

Bariatric surgery significantly decreases circulating Lp(a) concentrations. This decrease may have a positive effect on ASCVD in obese patients.

Impact of bariatric surgery on circulating PCSK9 levels as a marker of cardiovascular disease risk: a meta-analysis

INTRODUCTION

This systematic review and meta-analysis focuses on PCSK9 changes in obese patients following bariatric surgery.

METHODS

A systematic literature search in four databases was performed. Comprehensive Meta-Analysis (CMA) V2 software used to conduct the meta-analysis. Studies were evaluated regarding heterogeneity in design, populations under investigation, and treatment duration using a random-effects model and the generic inverse variance weighting approach. A random-effect meta-regression approach was used to investigate the association with the estimated effect size.

RESULTS

The results of the meta-analysis on 4 trials including 260 individuals demonstrated a remarkable decline of PCSK9 after bariatric surgery (WMD = -57.34 ng/ml, 95% CI: -87.97, -26.71, p < 0.001; I ² = 96.25%). Consistently, a significant decrease of LDL-C after bariatric surgery (WMD = -22.57 mg/dl, 95% CI: -27.5, -17.574, p < 0.001; I ² = 86.35%) was observed.

CONCLUSIONS

PCSK9 is reduced significantly after bariatric surgery. The decrease of PCSK9 might be utilized as an independent surrogate marker of improvement of atherosclerotic cardiovascular disease risk after bariatric surgery.