The short-term effect of bariatric surgery on non-invasive markers of artery function in patients with metabolic syndrome

Impact of bariatric surgery on carotid intima-media thickness, flow-mediated dilation, and nitrite-mediated dilation: a systematic review and meta-analysis

Obesity is considered one of the independent risk factors for atherosclerosis and is strongly correlated with cardiovascular morbidity and mortality. Previous studies showed carotid intima-media thickness (CIMT), flow-mediated dilation (FMD), and nitrite-mediated dilatation (NMD) are reliable non-invasive markers of arterial damage and dysfunction. The aim of this study was to evaluate the effect of bariatric surgery on CIMT, FMD, and NMD markers in patients with obesity. A systematic search was performed in the PubMed, Embase, Scopus, and Web of Science databases until May 2022. All the English-published studies on the effect of bariatric surgery on CIMT, FMD, and NMD were included. A quantitative meta-analysis was performed, as well as subgroup analyses for the type of procedure and duration of follow-up. Meta-analysis of 41 studies with 1639 patients showed CIMT was significantly reduced by .11 mm after bariatric surgery (95% CI, -.14 to -.08; P < .001; mean follow-up = 10.8 mo). The pooled analysis of 23 studies with 1106 patients showed an increase of FMD by 4.57% after bariatric surgery (95% CI, 2.69-6.44; P < .001; mean follow-up = 11.5 mo). The results of a pooled analysis of 12 studies with 346 patients showed a significant increase of NMD by 2.46% after bariatric surgery (95% CI, .99-3.94; P < .001; mean follow-up = 11.4 mo). The random effect meta-regression demonstrated that baseline CIMT and FMD significantly affect the changes in CIMT and FMD. This meta-analysis showed bariatric surgery can improve CIMT, FMD, and NMD markers in patients with obesity. These improvements show the known effect of metabolic surgery in decreasing cardiovascular risk.

Endothelial Function Assessment by Flow-Mediated Dilation Method: A Valuable Tool in the Evaluation of the Cardiovascular System

Cardiovascular diseases (CVDs) in the course of atherosclerosis are one of the most critical public health problems in the world. Endothelial cells synthesize numerous biologically active substances involved in regulating the functions of the cardiovascular system. Endothelial dysfunction is an essential element in the pathogenesis of atherosclerosis. Thus, the assessment of endothelial function in people without overt CVD allows for a more accurate estimate of the risk of developing CVD and cardiovascular events. The assessment of endothelial function is primarily used in scientific research, and to a lesser extent in clinical practice. Among the tools for assessing endothelial function, we can distinguish biochemical and physical methods, while physical methods can be divided into invasive and non-invasive methods. Flow-mediated dilation (FMD) is based on the ultrasound assessment of changes in the diameter of the brachial artery as a result of increased blood flow. FMD is a non-invasive, safe, and repeatable test, but it must be performed by qualified and experienced medical staff. The purpose of this paper is to present the literature review results on the assessment of endothelial function using the FMD method, including its methodology, applications in clinical practice and research, limitations, and future perspectives.

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

Objectives. Flow mediated vasodilation (FMD) is a marker of endothelial function and its decline is related to increased cardiovascular risk. This systematic review and meta-analysis evaluated the impact of bariatric surgery on FMD. Materials and methods. A systematic literature search in PubMed, Scopus, Embase, and Web of Science was performed to 1 May 2021. Meta-analysis was performed using Comprehensive Meta-Analysis (CMA) V2 software. All types of bariatric surgery were considered, with the inclusion that FMD had to have been tested before and after the surgical procedure. Meta-analysis was carried out using a random-effects model and the generic inverse variance approach. The leave-one-out approach was used for sensitivity analysis. To assess metabolic parameter confounders, a weighted random-effects meta-regression was used. Results. A meta-analysis and a systematic review of 23 studies (n = 891 individuals) demonstrated improvement in FMD following bariatric surgery (weighted mean difference (WMD): 5.867, 95% CI: 4.481, 7.252, p < 0.001; I2: 96.70). Iteratively removing each item in the meta-analysis did not result in a significant alteration in the pooled estimate of effect size. There was an improvement in FMD for up to 6 months following bariatric surgery in a meta-analysis from 7 trials that included 356 subjects (WMD: 5.248, 95% CI: 2.361, 8.135, p < 0.001; I2: 98.18). The meta-analysis from 9 trials (n = 414 subjects) showed an improvement in FMD 6 to 12 months after bariatric surgery (WMD: 5.451, 95% CI: 3.316, 7.587, p < 0.001; I2: 94.18). The meta-analysis from 10 trials (n = 414 subjects) demonstrated an improvement in FMD 12 months after bariatric surgery (WMD: 2.401, 95% CI: 0.944, 3.859, p = 0.001; I2: 88.35). Random-effects meta-regression did not show any association between the alteration in FMD and percent body mass index (BMI) change (slope: 0.0258; 95% CI: −0.323, 0.375; p = 0.884), or changes in blood pressure; however, there was an association between the changes in FMD and the duration of follow-up (slope: −0.106; 95% CI: −0.205, −0.008; p = 0.033) with greater changes in FMD after 12 months. Conclusions. Bariatric surgery significantly improved FMD that increased with time, and the resultant improvement in endothelial function was independent of weight loss or a reduction in blood pressure.

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.

Increase in arterial stiffness measures after bariatric surgery

BACKGROUND AND AIMS

The relationship between obesity and arterial stiffness is complex, with a potential interaction by age (inverse association at younger age and positive at older age) and conflicting reports on the effect of lifestyle-based weight loss on arterial stiffness. Little is understood about post-bariatric surgery changes in arterial stiffness. This study aimed to examine post-bariatric surgery changes in arterial stiffness and identify factors associated with greater changes in arterial stiffness.

METHODS

In 72 patients (mean age 44.5 years, 72.2% female), we evaluated two arterial stiffness measures, cardio-ankle vascular index (CAVI) and heart-ankle pulse wave velocity (haPWV), one month prior to and 6 months after bariatric surgery. Another follow-up visit was conducted 12 months after bariatric surgery in a subset of 58 participants.

RESULTS

Six months after bariatric surgery, an evident decrease was seen in body mass index, heart rate, and systolic blood pressure. In contrast, both CAVI and haPWV significantly increased at 6 months (+0.64 [0.42, 0.87] and +0.24 [0.04, 0.44] m/s, respectively). Among 58 patients with relevant data, CAVI and haPWV remained elevated 12 months after bariatric surgery (+0.80 [0.53, 1.07] and +0.40 [0.17, 0.62] m/s, respectively). Being non-diabetic and having larger decreases in post-surgery heart rate were independently associated with greater increases in post-surgical CAVI.

CONCLUSIONS

Arterial stiffness measures, CAVI and haPWV, were elevated after bariatric surgery despite other favorable cardiometabolic changes. Further studies are necessary to elucidate the underlying mechanism and prognostic implications of this elevation in arterial stiffness measures after bariatric surgery.

Short- and Long-Term Effects of Bariatric Surgery on Vascular Phenotype

BACKGROUND

Retinal microvascular diameters and large artery stiffness are valid biomarkers of cardiovascular risk. This study assessed short- and long-term micro- and macrovascular improvements after bariatric surgery (BS).

METHODS

Sixteen patients (44 ± 12 years) underwent BS in this observational study. Two weeks before as well as 6 weeks and 4 years after surgery, retinal vessel analysis and assessment of brachial-ankle pulse wave velocity (baPWV), cardio-ankle vascular index (CAVI), and anthropometry were performed. Three patients were lost to follow-up.

RESULTS

Six weeks after BS, retinal arteriolar diameters (CRAE) were wider (180.1 μm vs. 188.1 μm; p = 0.001), and the arteriolar-to-venular diameter ratio (AVR) was higher (0.82 vs. 0.86; p < 0.001) compared to baseline levels. During the 4 years of follow-up, the retinal changes sustained but further improvements did not occur. Both indices of large artery stiffness, baPWV and CAVI, remained unchanged 6 weeks and 4 years after surgery.

CONCLUSIONS

Retinal microvascular phenotype improved 6 weeks after BS. The improvements in microvascular health were maintained during 4 years of follow-up but, despite significant further reductions in body mass index, did not improve further long-term. baPWV and CAVI were unaffected after surgery indicating that BS primarily affects microvascular phenotype rather than large artery stiffness. Retinal vessel imaging seems to be a feasible diagnostic tool to monitor microvascular health after BS. Normalization of BMI and blood pressure may be necessary to achieve long-term improvement of large artery phenotype after BS.

EFFECTS OF BODY WEIGHT REDUCTION ON ARTERIAL STIFFNESS AND ENDOTHELIAL FUNCTION AFTER BARIATRIC SURGERY IN MORBIDLY OBESE PATIENTS: A 4-YEAR CLINICAL STUDY

OBJECTIVE

To determine the long-term effect of weight loss on arterial stiffness, metabolic parameters in morbidly obese patients who underwent laparoscopic adjustable gastric banding (LAGB).

SUBJECTS

Forty-eight morbidly obese Caucasian subjects underwent LAGB from January 2009 to January 2010 and completed 4 years follow-up.

MEASUREMENTS

Patients were evaluated for body mass index (BMI), waist circumference, arterial blood pressure (BP), metabolic factors: leptin, adiponectin, glucose, glycated haemoglobin (HbA1c), insulin. Endothelial function - evaluated as reactive hyperemic index (RHI). Arterial stiffness - determined by cardio - ankle vascular index (CAVI).

RESULTS

Average BMI decreased from 46.48±7.06 kg/m2 to 39.78±7.36 kg/m2 (1year, p<0.001) and 37.29±7.49 kg/m2 (4years, p=0.012). The systolic BP and heart rate reduction were observed after the 4 years. Changes in cardiovascular parameters were accompanied by waist circumference reduction and improvement of glucose metabolism,reduction of insulin, HbA1c, leptin, C-reactive protein values. However, there were statistically significant increases in CAVI 6.58±1.77m/s vs. 7.03±2.00 m/s (p=0.014) at 1 year, but not significant 7.12±2.19 (p=0.153) after 4 years. Endothelial changes were observed only in diabetic patients one year after LAGB 2.18±0.57 vs. 1.86±0.34 (p=0.021) vs. 2.05±0.42 (p=0.086).

CONCLUSION

Weight reduction induced by LAGB was associated with changes in body weight and metabolic parameters, but it was no improvement on endothelial function and arterial stiffness.

Long-Term Improvement in Aortic Pulse Wave Velocity After Weight Loss Can Be Predicted by White Adipose Tissue Factors

BACKGROUND

Arterial stiffness, measured by pulse wave velocity (PWV), is linked to obesity, cardiovascular disease, and all-cause mortality. Short-term weight loss improves PWV, but the long-term effects are unknown. We investigated the effect of pronounced long-term weight loss on PWV and whether anthropometric/metabolic parameters and/or white adipose tissue (WAT) phenotype could predict this change in PWV.

METHODS

Eighty-two obese subjects were examined before and 2 years after Roux-en-Y gastric bypass. Analyses included anthropometrics, routine clinical chemistry, and hyperinsulinemic-euglycemic clamp. Arterial stiffness was measured as aortic PWV (aPWV) using the Arteriograph device. WAT mass and distribution were assessed by dual-X-ray absorptiometry. Baseline visceral and subcutaneous WAT samples were obtained to measure adipocyte cell size. Transcriptomic profiling of subcutaneous WAT was performed in a subset of subjects (n = 30).

RESULTS

At the 2-year follow-up, there were significant decreases in body mass index (39.4 ± 3.5 kg/m2 vs. 26.6 ± 3.4 kg/m2; P < 0.0001) and aPWV (7.8 ± 1.5 m/s vs. 7.2 ± 1.4 m/s; P = 0.006). Multiple regression analyses showed that baseline subcutaneous adipocyte volume was associated with a reduction in aPWV (P = 0.014), after adjusting for confounders. Expression analyses of 52 genes implicated in arterial stiffness showed that only one, COL4A1, independently predicted improvements in aPWV after adjusting for confounders (P = 0.006).

CONCLUSIONS

Bariatric surgery leads to long-term reduction in aPWV. This improvement can be independently predicted by subcutaneous adipocyte volume and WAT COL4A1 expression, which suggests that subcutaneous WAT has a role in regulating aPWV.

CLINICAL TRIALS REGISTRATION

Trial Number NCT01727245 (clinicaltrials.gov).

The Role of Sleeve Gastrectomy in Reducing Cardiovascular Risk

BACKGROUND

Obesity is an independent cardiovascular risk factor and a catalyst of other cardiovascular risk factors, such as hypertension, dyslipidemia, type 2 diabetes mellitus (DM2) and metabolic syndrome.

METHODS

We analyzed cardiovascular risk in obese patients before and after sleeve gastrectomy (SG). To this end, we studied changes in body mass index (BMI), blood chemistry parameters that characterize the risk of atherosclerosis and instrumental parameters (objective markers of this risk), namely intima-media thickness (IMT) and flow-mediated dilation (FMD), the latter reflecting endothelial function. We also considered purely cardiac parameters-mitral annular plane systolic excursion (MAPSE) and tricuspid annular plane systolic excursion (TAPSE)-which describe cardiac risk more specifically than the ejection fraction. Alteration of one or more of these parameters determines an increase in cardiovascular morbidity and mortality.

RESULTS

The results showed that weight loss, in patients undergoing SG, is accompanied by a reduced BMI and a marked improvement in blood chemistry, confirming what has already been shown in many other studies, but the most interesting finding was the effect of SG on the instrumental markers of atherosclerosis. In particular, carotid IMT was significantly reduced (p < 0.001) and FMD significantly improved. MAPSE and TAPSE also improved significantly at both follow-up assessments (p < 0.001).

CONCLUSIONS

This study suggests that SG should be considered from a broader perspective, i.e. as a weight loss treatment that also improves obesity-related morbidity and mortality, benefitting both the patient and, in an economic sense, the society as a whole.

Perfil farmacoterapêutico de pacientes obesos no pós-operatório de cirurgia bariátrica

Contexto

A obesidade pode estar relacionada a doenças como diabetes, hipertensão arterial e dislipidemia. A cirurgia bariátrica é um dos tratamentos mais eficazes, levando à diminuição de peso e comorbidades.

Objetivo

Avaliar o perfil metabólico e farmacoterapêutico de pacientes obesos após cirurgia bariátrica.

Métodos

Trata-se de um estudo observacional transversal retrospectivo, realizado em um hospital localizado na cidade de Porto Alegre, RS, Brasil. Foram avaliados 70 prontuários de pacientes que realizaram cirurgia bariátrica, nos períodos de antes de 2 meses e mais de 6 meses após a cirurgia bariátrica. A análise estatística foi realizada no programa SPSS 17.0®.

Resultados

A pressão arterial inicial foi de 130/85 mmHg, passando para 120/80 mmHg (p < 0,01). Com relação ao perfil metabólico antes de dois meses, o HDL foi de 34 mg/dL, o colesterol total foi de 195,07 ± 40,17 mg/dL, o LDL foi de 118,22 ± 41,28 mg/dL, os triglicerídeos foram de 141,09 ± 43,39 mg/dL, e a glicemia de jejum foi de 90 mg/dL. Após 6 meses de cirurgia, os valores passaram para 43 mg/dL, 133,67 ± 28,14 mg/dL, 65,53 ± 24,3 mg/dL, 104,41 ± 29,6 mg/dL, e 77 mg/dL, respectivamente (p < 0,01). Com relação ao uso de medicamentos, 41% utilizaram anti-hipertensivos, 39% utilizaram hipolipemiantes, 10% utilizaram hipoglicemiantes orais e 97% utilizaram suplementos antes dos 2 meses de cirurgia. Após os 6 meses, os percentuais foram alterados para 21%, 19%, 9% e 99%, respectivamente.

Conclusões

O estudo mostra o sucesso da cirurgia bariátrica em pacientes obesos com comorbidades, revelando melhora no perfil metabólico e redução na utilização de medicamentos para tratamento de comorbidades.