Effect of bariatric surgery on inflammation and endothelial dysfunction as processes underlying subclinical atherosclerosis in morbid obesity

Effect of bariatric surgery on atherogenicity and insulin resistance in patients with obesity class II: a prospective study

OBJECTIVE

Enormous efforts have been made to evaluate reliable, simple and practical indicators for predicting patients at risk of progression of cardiovascular disease events, whereby bariatric surgery has remained understudied. Thus, we performed this study to assess the effect of bariatric surgery procedures on atherogenicity and insulin resistance indicators.

DESIGN

Cohort study.

SETTING, PARTICIPANTS AND OUTCOME MEASURES

Four hundred and forty-three class II obese (severely obese) patients who underwent sleeve gastrectomy, Roux-en-Y gastric bypass, or one anastomosis gastric bypass were followed up for 12 months after surgery. Atherosclerosis-related indicators were evaluated at baseline, as well as 6 and 12 months after surgery.

RESULTS

Atherogenic index of plasma, lipoprotein combine index, atherogenic coefficient, cholesterol index, Castelli's risk indices I and II, and triglyceride to high-density lipoprotein-cholesterol ratio (p<0.01) improved after 12 months. Additionally, bariatric surgery yielded a significantly reduced triglyceride glucose index. There was no significant difference between procedures in terms of indicators. The Spearman correlation test showed a significant inverse correlation between weight plus fat mass and atherosclerosis-related indicators as well as a positive correlation between percentage of excess weight loss and these indicators.

CONCLUSIONS

This study demonstrated three bariatric surgery procedures' ability to improve atherogenicity and insulin resistance in patients with obesity class II. The anti-atherogenicity effects can be partly assigned to the reduction of body weight and adipose tissue. Nevertheless, further studies with larger sample sizes and longer follow-ups are required to confirm our results.

Irisin as a Novel Biomarker of Subclinical Atherosclerosis in Severe Obesity

Severe obesity (SO) can accelerate atherosclerosis and the onset of acute cardiovascular events. The diagnosis of atherosclerosis in the context of a high body mass index (BMI) can be challenging, making the identification of biomarkers clinically relevant. We aimed to assess the usefulness of irisin as a biomarker for subclinical atherosclerosis in participants with SO. This prospective observational study included 61 participants undergoing bariatric surgery for SO, defined as a BMI >40 kg/m² or >35 kg/m² with at least one comorbidity. Atherosclerotic plaques were detected by ultrasound. Plasma samples were obtained 1 month before and at 6 and 12 months after bariatric surgery to measure irisin by ELISA. Additionally, subcutaneous samples of adipose tissue were taken and genotyped to identify irisin polymorphism rs3480. Irisin levels were positively correlated with BMI (r = 0.23, p = 0.0064), negatively correlated with atheroma-related parameters (e.g., carotid intima-media thickness), and lower in subjects with atheroma (p < 0.0002). Irisin also showed good overall accuracy for discriminating plaque presence (AUC, 0.81; 95% CI, 0.6956-0.9156). However, the rs3480 polymorphism correlated with neither the irisin levels nor the presence of atheromas. Iirisin could identify subclinical atherosclerosis in SO and might facilitate clinical diagnosis.

Change in Adipokines and Gastrointestinal Hormones After Bariatric Surgery: a Meta-analysis

PURPOSE

The study aimed to perform a meta-analysis about the change in adipokines and gastrointestinal hormones after bariatric surgery in patients with obesity.

MATERIALS AND METHODS

We searched the Cochrane Central Register of Controlled Trials, EMBASE, and PubMed for related articles and used Review Manager 5.4 for data aggregation. Sensitivity and subgroup analysis were also conducted when feasible.

RESULTS

As a result, 95 articles involving 6232 patients were included in the meta-analysis. After bariatric surgery, the levels of leptin, ghrelin, C-reactive protein (CRP), interleukin-6 (IL-6), high-sensitivity C-reactive protein (Hs-CRP), tumor necrosis, factor-α (TNF-α), and interleukin-1β (IL-1β) reduced, while adiponectin, glucagon-like peptide-1 (GLP-1), and peptide YY (PYY) levels increased significantly. Subgroup analysis indicated that there was a more significant reduction in leptin level with a longer follow-up time. OAGB had a greater effect on increasing adiponectin level compared with other procedures. SG procedure would bring about reduced ghrelin, while BPD resulted in increased ghrelin. Meta-regression analysis found that publication year, study design, number of patients, preoperative age, preoperative BMI, and quality assessment score were not significantly related to change in leptin, adiponectin, and ghrelin levels.

CONCLUSION

Bariatric surgery was associated with a significant decrease in leptin, ghrelin, CRP, IL-6, Hs-CRP, TNF-α, and IL-1β, as well as increase in adiponectin, GLP-1, and PYY levels.

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 Laparoscopic Sleeve Gastrectomy on Thrombomodulin Concentration and Early Markers of Atherosclerosis

Background

Thrombomodulin, an integral membrane protein functioning as a cofactor in the anticoagulant pathways, has recently emerged as a marker of endothelial dysfunction. This study aimed to investigate the impact of laparoscopic sleeve gastrectomy (LSG) on thrombomodulin concentration and early markers of atherosclerosis.

Methods

Forty-four subjects undergoing LSG were prospectively examined. The change in thrombomodulin concentration from baseline (preoperative) to the sixth postoperative month following the LSG and the relationship between the change in thrombomodulin concentration and BMI, CIMT, ABI, and blood lipids were examined.

Results

The medical records were available for 44 patients (mean age: 37.2 ± 10.9 years, 65.9% male). LSG led to significant reductions in total body weight and body mass index (BMI) at postoperative six months (37.0 ± 5.6 kg/m² vs. 47.1 ± 5.8 kg/m², p < 0.001). Markers of early atherosclerotic events, including carotid intima-media thickness (CIMT) and ABI, improved. The change in thrombomodulin concentration (Δ TMD) was significantly correlated with the change in Δ BMI (r = 0.500, p=0.011), Δ LDL (r = 0.389, p=0.032), Δ systolic blood pressure (r = 0.384, p=0.012), and Δ CIMT (r = 0.327, p=0.012) and was negatively correlated with Δ HDL (r = −0.344, p=0.020) and Δ ABI (r = −0.357, p=0.020).

Conclusion

LSG leads to significant improvements in blood lipids, systolic and diastolic blood pressure, and in surrogate markers of atherosclerotic burden and endothelial function, including thrombomodulin, ABI, and CIMT, at postoperative six months. LSG might prevent or reduce atherogenesis in the early stages by stopping endothelial dysfunction.

Surgery for Obesity and Weight-Related Diseases Changes the Inflammatory Profile in Women with Severe Obesity: a Randomized Controlled Clinical Trial

INTRODUCTION/PURPOSE

Obesity increases significantly every year worldwide. Since 1980, the prevalence of individuals with obesity has practically doubled. Obesity plays an important role in the pathophysiology of diseases that arise from a complex interaction of nutritional, genetic, and metabolic factors, characterizing a chronic inflammatory state. This study aimed to verify the systemic inflammatory response through the analysis of IGF-1, IL-23, and resistin levels and the lipid profile in severely obese women undergoing surgery for obesity and weight-related diseases.

MATERIALS AND METHODS

This randomized controlled clinical trial includes female patients clinically diagnosed with severe obesity with an indication for bariatric surgery.

RESULTS

In the initial evaluation, no significant difference was observed between the control (CG) and bariatric surgery (BSG) groups. The weight, BMI, systolic and diastolic blood pressures, total cholesterol, LDL, HDL, total non-HDL cholesterol, and glucose in BSG patients showed a significant change after surgery. Pre- and post-surgery levels of resistin, IGF-1, and IL-23 showed a significant difference in the BSG group, but only IL-23 was changed after 6 months in the CG.

CONCLUSION

The results of this study confirmed that weight loss induced by surgery for obesity and weight-related diseases improved the lipid profile and reduced the chronic inflammatory status in women with severe obesity.

Impact of Bariatric Surgery on Pulse Wave Velocity as a Measure of Arterial Stiffness: a Systematic Review and Meta-analysis

PURPOSE

Weight loss during post-bariatric surgery period has been linked to both reduced ASCVD mortality and overall mortality. Atherosclerosis causes arteries to lose their elasticity and become more stiff resulting in increased pulse wave velocity (PWV). It has been revealed that PWV favorably predicts subsequent ASCVDs. The goal of this systematic review and meta-analysis was to see how bariatric surgery affected PWV, an index of arterial stiffness.

MATERIALS AND METHODS

A systematic literature search in four databases was performed. Also, Cochrane guidelines were reviewed to determine bias possibility in the related studies. Comprehensive Meta-Analysis (CMA) V2 software is used to conduct the meta-analysis. Studies were evaluated regarding heterogeneity in design, populations under investigation, and treatment duration using 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. Evaluation of funnel plot, Egger's weighted regression, and Begg's rank correlation tests were utilized to estimate the presence of publication bias in the meta-analysis.

RESULTS

The results of meta-analysis on 13 trials including 1426 individuals demonstrated a remarkable decline of PWV after bariatric surgery (WMD: -0.652, 95% CI: -1.004, -0.301, p<0.001). The random-effects meta-regression revealed no evidence of significant correlation between the changes in PWV and initial BMI, BMI changes, or duration of follow-up.

CONCLUSION

The decrease of PWV might be utilized as an independent surrogate marker of improvement of ASCVD risk after bariatric surgery.

Long-Term Improvement of Chronic Low-Grade Inflammation After Bariatric Surgery

PURPOSE

Bariatric surgery (BS) was shown to improve inflammatory markers in previous short-term follow-up studies. The aim of the present study was to assess the long-term effects of BS on chronic low-grade inflammation markers related to severe obesity. Moreover, the meaning of the type of BS procedure as well as the remission of type 2 diabetes (T2D) for inflammatory status up to 4 years after BS was analyzed.

MATERIALS AND METHODS

In a retrospective cohort study including 163 patients at baseline, inflammatory and metabolic parameters were assessed at 4 time points: before surgery (baseline), 6 months after surgery (visit 1), 2 years after surgery (visit 2), and 4 years after surgery (visit 3). Univariate regression analysis was used to identify variables that were thought to determine change in inflammatory parameters.

RESULTS

CRP, hs-CRP, leucocytes, and ferritin significantly declined in the mid- and long-term according to the U-shaped curve of weight loss (p<0.001). Change in body mass index (BMI) at long-time follow-up showed a significant linear effect on change in leucocytes (B=0.082; p<0.001) and change in hs-CRP (B=0.03; p<0.05). There was a strong, positive correlation between T2D and hs-CRP at visit 2 (r_s=0.195; p<0.05) and visit 3 (r_s=0.36; p=0.001). With regard to type of surgery and gender, there were no significant differences in inflammatory parameters.

CONCLUSION

BS is able to reduce obesity-related chronic low-grade inflammation up to 4 years after surgical intervention. The improvement in metaflammation is related to the change in BMI and remission of T2D in the long-term.