Effect of bariatric surgery on peripheral flow-mediated dilation and coronary microvascular function

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.

Comprehensive Management of ANOCA, Part 2-Program Development, Treatment, and Research Initiatives: JACC State-of-the-Art Review

Centers specializing in coronary function testing are critical to ensure a systematic approach to the diagnosis and treatment of angina with nonobstructive coronary arteries (ANOCA). Management leveraging lifestyle, pharmacology, and device-based therapeutic options for ANOCA can improve angina burden and quality of life in affected patients. Multidisciplinary care teams that can tailor and titrate therapies based on individual patient needs are critical to the success of comprehensive programs. As coronary function testing for ANOCA is more widely adopted, collaborative research initiatives will be fundamental to improve ANOCA care. These efforts will require standardized symptom assessments and data collection, which will propel future large-scale clinical trials.

Coronary microvascular dysfunction and cardiovascular disease: Pathogenesis, associations and treatment strategies

Coronary microvascular dysfunction (CMD) is a high-risk factor for a variety of cardiovascular events. Due to its complex aetiology and concealability, knowledge of the pathophysiological mechanism of CMD is still limited at present, which greatly restricts its clinical diagnosis and treatment. Studies have shown that CMD is closely related to a variety of cardiovascular diseases, can aggravate the occurrence and development of cardiovascular diseases, and is closely related to a poor prognosis in patients with cardiovascular diseases. Improving coronary microvascular remodelling and increasing myocardial perfusion might be promising strategies for the treatment of cardiovascular diseases. In this paper, the pathogenesis and functional assessment of CMD are reviewed first, along with the relationship of CMD with cardiovascular diseases. Then, the latest strategies for the treatment of CMD and cardiovascular diseases are summarized. Finally, urgent scientific problems in CMD and cardiovascular diseases are highlighted and future research directions are proposed to provide prospective insights for the prevention and treatment of CMD and cardiovascular diseases in the future.

New Insights into the Use of Liraglutide-Impact on Cardiovascular Risk and Microvascular Outcomes

Despite the availability of many glucose-lowering drugs, patients with type 2 diabetes mellitus (T2DM) often do not achieve the desired effect, and cardiovascular complications remain the leading cause of death in this group of patients. Recently, more and more attention has been paid to the properties of drugs, with particular emphasis on the possibility of reducing cardiovascular risk. One of them is liraglutide, which belongs to long-acting analogs of glucagon-like peptides-1 (GLP-1); it imitates incretins and causes an increase in insulin secretion. The current study focused on analyzing the efficacy and safety of liraglutide, as well as its impact on microvascular and cardiovascular outcomes in the treatment of patients with T2DM. Hyperglycemia-induced endothelial dysfunction, which is known to play a key role in maintaining cardiovascular homeostasis, is common in diabetes. Liraglutide reduces endothelial dysfunction by reversing damage to endothelial cells. By reducing the generation of reactive oxygen species (ROS), thereby affecting Bax, Bcl-2 protein levels, and restoring signaling pathways, Liraglutide reduces oxidative stress, inflammation, and prevents endothelial cell apoptosis. Liraglutide has beneficial effects on the cardiovascular system; patients with high cardiovascular risk particularly benefit from treatment, as it reduces their major adverse cardiovascular event (MACE) rate, which takes into account cardiovascular death, stroke, and non-fatal myocardial infarction. Liraglutide reduces the occurrence and progression of nephropathy, which is one of the most common microvascular complications of diabetes.

Sleeve gastrectomy improved microvascular phenotypes from obesity cohort, detected with optical coherence tomography angiography

AIMS

To examine how metabolic status is associated with microvascular phenotype and to identify variables associated with vascular remodeling after bariatric surgery, using noninvasive optical coherence tomography angiography (OCTA).

METHODS

The study included 136 obese subjects scheduled for bariatric surgery and 52 normal-weight controls. Patients with obesity were divided into metabolically healthy obesity (MHO) and metabolic syndrome (MetS) groups according to the diagnosis criteria of the Chinese Diabetes Society. Retinal microvascular parameters were measured by OCTA, including superficial capillary plexus (SCP) and deep capillary plexus (DCP) vessel densities. Follow-ups were performed at the baseline and 6 months after bariatric surgery.

RESULTS

Fovea SCP, average DCP, fovea DCP, parafovea DCP, and perifovea DCP vessel densities were significantly lower in the MetS group, compared to controls (19.91% vs. 22.49%, 51.60% vs. 54.20%, 36.64% vs. 39.14%, 56.24% vs. 57.65% and 52.59% vs. 55.58%, respectively, all p < .05). Parafovea SCP, average DCP, parafovea DCP, and perifovea DCP vessel densities significantly improved in patients with obesity 6 months after surgery, compared to baseline (54.21% vs. 52.97%, 54.43% vs. 50.95%, 58.29% vs. 55.54% and 55.76% vs. 51.82%, respectively, all p < .05). Multivariable analyses showed that baseline blood pressure and insulin were independent predictors of vessel density changes 6 months after surgery.

CONCLUSIONS

Retinal microvascular impairment occurred mainly in MetS rather than MHO patients. Retinal microvascular phenotype improved 6 months after bariatric surgery and baseline blood pressure and insulin status may be key determinants. OCTA may be a reliable method to evaluate the microvascular complications associated with obesity.

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.

Association of vascular endothelial function and quality of life in patients with ischemia and non-obstructive coronary artery disease

Improvements are required in the quality of life (QoL) of patients with ischemia and non-obstructive coronary artery disease (INOCA). Several patients with INOCA experience vascular endothelial dysfunction. However, the relationship between endothelial function and QoL remains unelucidated. This study aimed to initially investigate the relationship between endothelial function and QoL in patients with INOCA. This prospective observational study included 121 patients with INOCA (aged 31-85 years). Vascular endothelial function was assessed by flow-mediated dilatation (FMD) of the peripheral brachial artery. QoL was evaluated using the 36-Item Short-Form Health Survey (SF-36). Patients with INOCA were divided into two groups according to the median FMD change during the 1-year follow-up (group A, ≥ median FMD change cut-off; group B, < median FMD change cut-off). The median change in FMD was 0.92%. The mean baseline SF-36 scores were comparable between the two groups (53.95 ± 6.46 vs. 53.92 ± 4.29, p = 0.98). The QoL at follow-up was better in group A than in group B (56.61 ± 5.50 vs. 53.32 ± 5.58, p = 0.002). The change in FMD (r = 0.34, p < 0.01), rather than FMD at baseline (r = - 0.01, p = 0.89) or follow-up (r = 0.13, p = 0.15), was related to the follow-up SF-36 scores. FMD improvement was an independent predictor of increased QoL (odds ratio, 3.90; 95% confidence interval: 1.59-9.53, p = 0.003). Endothelial function change is associated with QoL, and patients with improved endothelial function have a better QoL than those without.

Assessment of Endothelial Function in Iranian Healthy Obese Patients after Bariatric Surgery

Background

Endothelial function plays a critical role in cardiovascular homeostasis. Morbid obesity is associated with an enhanced risk of atherosclerosis and chronic inflammation. Bariatric surgery (BS) is a promising method used recently for weight loss; however, the number of studies that have examined the effect of BS on endothelial function is limited. This study aimed to investigate the association between endothelial function evaluated by flow-mediated dilation (FMD) and weight loss after BS.

Materials and Methods

This is a cross-sectional study conducted in Isfahan, Iran, and included 40 healthy obese individuals who underwent BS as an intervention group and 40 healthy obese patients who did not undergo BS as a control group in a 6-month follow-up duration period. FMD as an indicator of endothelial function was evaluated in these participants. FMD <7.1% is considered abnormal.

Results

There was no significant difference between control and BS groups in terms of age and body mass index (BMI) at baseline. The mean ± standard deviation (SD) of FMD in the BS group pre- and post-intervention were 12.95 ± 6.90 and 37.65 ± 13.52 respectively and the mean ± SD of FMD in the control group were 15.88 ± 6.85 and 15.85 ± 5.83. The association between significant weight loss after BS and FMD was strongly significant (P < 0.001).

Conclusions

According to the results of this study, it can be concluded that BS has been effective in terms of improving the FMD as an indicator of endothelial function.

The metabolic phenotype of the patient influences the reduction in carotid intima-media thickness achieved following metabolic surgery

Objectives

To determine whether metabolic phenotype is associated with the change in carotid intima-media thickness (CIMT) in patients undergoing bariatric /metabolic surgery (BMS).

Methods

We performed a case-control study of BMS candidates who had metabolically unhealthy obesity (MUO) or metabolically healthy obesity (MHO). We measured the change in CIMT during the 9 months following BMS. The plasma tumor necrosis factor-α, interleukin-1β, adiponectin, leptin, nitric oxide (NO), vascular endothelial growth factor A (VEGF-A), and malondialdehyde concentrations were determined, adipocyte area was measured histologically, and adipose tissue area was estimated using computed tomography.

Results

Fifty-six patients (mean age 44.5 years, mean body mass index 44.9 kg/m2, 53% women, and 53% had MUO) were studied. Nine months following BMS, the MUO phenotype was not associated with a significant reduction in CIMT, and that of the MHO group was larger. In addition, fewer participants achieved a 10% reduction in CIMT in the MUO group. A CIMT reduction was associated with lower VEGF-A and NO in the MUO group, while that in the MHO group was associated with a higher NO concentration.

Conclusion

The metabolic phenotype of patients may influence their change in CIMT following BMS, probably through circulating vasodilatory and pro-inflammatory molecules.

Coronary Microvascular Dysfunction in Diabetes Mellitus: Pathogenetic Mechanisms and Potential Therapeutic Options

Diabetic patients are frequently affected by coronary microvascular dysfunction (CMD), a condition consisting of a combination of altered vasomotion and long-term structural change to coronary arterioles leading to impaired regulation of blood flow in response to changing cardiomyocyte oxygen requirements. The pathogenesis of this microvascular complication is complex and not completely known, involving several alterations among which hyperglycemia and insulin resistance play particularly central roles leading to oxidative stress, inflammatory activation and altered barrier function of endothelium. CMD significantly contributes to cardiac events such as angina or infarction without obstructive coronary artery disease, as well as heart failure, especially the phenotype associated with preserved ejection fraction, which greatly impact cardiovascular (CV) prognosis. To date, no treatments specifically target this vascular damage, but recent experimental studies and some clinical investigations have produced data in favor of potential beneficial effects on coronary micro vessels caused by two classes of glucose-lowering drugs: glucagon-like peptide 1 (GLP-1)-based therapy and inhibitors of sodium-glucose cotransporter-2 (SGLT2). The purpose of this review is to describe pathophysiological mechanisms, clinical manifestations of CMD with particular reference to diabetes, and to summarize the protective effects of antidiabetic drugs on the myocardial microvascular compartment.

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.

Relation of endothelial and cardiac autonomic function with left ventricle diastolic function in patients with type 2 diabetes mellitus

BACKGROUND AND AIMS

Diabetes mellitus (DM) is a risk factor for left ventricle (LV) diastolic dysfunction. Aim of this study was to investigate whether endothelial and/or autonomic dysfunction are associated with LV diastolic dysfunction in DM patients.

METHODS

We studied 84 non-insulin-dependent type 2 DM (T2DM) patients with no heart disease by assessing: 1) LV diastolic function by echocardiography; 2) peripheral vasodilator function, by measuring flow-mediated dilation (FMD) and nitrate-mediate dilation (NMD); 3) heart rate variability (HRV) on 24-h Holter electrocardiographic monitoring.

RESULTS

Twenty-five patients (29.8%) had normal LV diastolic function, while 47 (55.9%) and 12 (14.3%) showed a mild and moderate/severe diastolic dysfunction, respectively. FMD in these 3 groups was 5.25 ± 2.0, 4.95 ± 1.6 and 4.43 ± 1.8% (p = 0.42), whereas NMD was 10.8 ± 2.3, 8.98 ± 3.0 and 8.82 ± 3.2%, respectively (p = 0.02). HRV variables did not differ among groups. However, the triangular index tended to be lower in patients with moderate/severe diastolic dysfunction (p = 0.09) and a significant correlation was found between the E/e' ratio and both the triangular index (r = -0.26; p = 0.022) and LF amplitude (r = -0.29; p = 0.011).

CONCLUSIONS

In T2DM patients an impairment of endothelium-independent, but not endothelium-dependent, dilatation seems associated with LV diastolic dysfunction. The possible role of cardiac autonomic dysfunction in diastolic dysfunction deserves investigation in larger populations of patients.

Comprehensive treatment of microvascular angina in overweight women - a randomized controlled pilot trial

AIMS

Coronary microvascular dysfunction (CMD) carries a poor cardiovascular prognosis and may explain angina in women without obstructive coronary artery disease (CAD). Currently, no evidence-based treatment for CMD exists. We investigated whether reducing cardiovascular risk factors improves symptoms and microvascular function in women with non-endothelial dependent CMD and no obstructive CAD.

METHODS

We randomized 62 women aged 40-75, with body mass index (BMI) >25 kg/m2, angina ≥monthly, and coronary flow velocity reserve (CFVR) ≤2.5 to a 24-week intervention comprising low energy diet, exercise training, and optimized treatment of hypertension, dyslipidemia and diabetes or to control. Patients were assessed before randomization and after 24 weeks. Primary outcomes were CFVR assessed by transthoracic Doppler stress-echocardiography and angina burden by Seattle Angina Questionnaire (SAQ). Secondary outcomes were exercise capacity, body composition, glycemic control, myocardial function, and anxiety and depression symptoms.

RESULTS

Fifty-six participants (90%) completed the study. Median (IQR) age was 65.2 (57.1;70.7) years, BMI was 30.1 (28.4;32.7) kg/m2. The intervention resulted in relevant improvement in angina symptoms (9-21-point increase on SAQ-scales (all p<0.01)) but had no effect on CFVR (p = 0.468). Mean (CI) weight loss was 9.6 (7.80;11.48) kg, (p<0.0001). There was a significant mean (CI) decrease in depression symptoms = 1.16 (0.22;2.12), triglycerides = 0.52 (0.25;0.78) mmol/L, total cholesterol = 0.55 (0.12;0.98) mmol/L, and HbA1c in diabetics = 27.1 (1.60;52.6) mmol/mol but no effect on other secondary outcomes.

CONCLUSION

A major weight loss and intensified risk factor control resulted in significantly improved angina burden but no improvement of coronary microvascular function among women with microvascular angina.

Cardiac Rehabilitation and Endothelial Function

Endothelial dysfunction is an early abnormality in the process of atherosclerosis and cardiovascular disease and has been associated with worse clinical outcome. Cardiac rehabilitation (CR) has been reported to be helpful to reduce cardiovascular events in various types of cardiac disease, but the mechanisms of its beneficial effects remain only partially known. In this article, we review the studies that assessed the effect of CR on endothelial function in patients with various cardiac conditions. Available data show that CR significantly improves impaired endothelial function in these patients, which may contribute to the beneficial effects of CR on clinical outcome.

Effect of Chinese medicine for promoting blood circulation on microvascular angina: A systematic review and meta-analysis

BACKGROUND

Blood-activating drugs (BADs) are widely used to treat microvascular angina in China. This study aims to summarize relevant evidence from randomized controlled trials (RCTs) to assess the efficacy and safety of BADs in the treatment of microvascular angina.

METHODS

We searched for relevant studies before June 2019 from seven databases. Twenty-four studies were included of 1903 patients with microvascular angina. All studies compared the use of traditional Chinese medicine for activating blood circulation (BADs) and Western medicine (WM) with the use of Western medicine alone.

RESULTS

In all, 15 trials reported a significant effect of BADs on improving clinical symptoms compared with the control treatment (P < .00001), and 8 trials reported significant effects of BADs on reducing the frequency of angina pectoris attacks compared with Western medicine treatment (P < .00001). The pooled results also demonstrated that BADs provided a significant benefit in reducing the dosage of nitroglycerin required (P = .02), the maximum range of ST-segment depression (P = .003) and the descending degree of the ST-T segment of ECG (P = .0002); prolonging the total time of treadmill exercise (P < .00001) and the time of ST-segment depression of 1 mm (P = .002); enhancing the total effective rate of Traditional Chinese Medicine (TCM) syndromes (P < .00001); improving endothelial function (P < .00001); and reducing the levels of high-sensitivity C-reactive protein (hs-CRP) (P < .00001). BAD treatment showed no statistically significant effect on the levels of TNF-a (P = .8) or IL-6 (P = .13). No severe adverse events were reported.

CONCLUSION

This meta-analysis shows that BADs are effective for the treatment of microvascular angina. Although concerns regarding selective bias and low methodological quality were raised, our findings suggest that BADs are beneficial for patients with microvascular angina and should be given priority for future clinical studies.

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.

Impact of bariatric surgery on cerebral vascular reactivity and cognitive function: a non-randomized pilot study

Background

Bariatric surgery is an effective long-term weight loss strategy yielding improvements in neurocognitive function; however, the mechanism(s) responsible for these improvements remains unclear. Here, we assessed the feasibility of using magnetic resonance imaging (MRI) to evaluate whether cerebral vascular reactivity (CVR) is impaired in severely obese bariatric surgery candidates compared with normal weight healthy controls and whether CVR improves following bariatric surgery. We also investigated whether changes in CVR were associated with changes in cognitive function.

Methods

Bariatric surgery candidates (n = 6) were compared with normal weight healthy controls of a similar age (n = 10) at baseline, and then reassessed 2 weeks and 14 weeks following sleeve gastrectomy bariatric surgery. Young reference controls (n = 7) were also studied at baseline to establish the range of normal for each outcome measure. Microvascular and macrovascular CVR to hypercapnia (5% CO₂) were assessed using blood-oxygen-level-dependent (BOLD) MRI, and changes in the middle cerebral artery (MCA) cross-sectional area, respectively. Cognitive function was assessed using a validated neurocognitive software.

Results

Compliance with the CVR protocol was high. Both macro- and micro-cerebrovascular function were highest in the young reference controls. Cognitive function was lower in obese bariatric surgery candidates compared with normal weight controls, and improved by 17% at 2 weeks and 21% by 14 weeks following bariatric surgery. To our surprise, whole-brain CVR BOLD did not differ between obese bariatric surgery candidates and normal weight controls of similar age (0.184 ± 0.101 vs. 0.192 ± 0.034 %BOLD/mmHgCO₂), and did not change after bariatric surgery. In contrast, we observed vasoconstriction of the MCA during hypercapnia in 60% of the obese patients prior to surgery, which appeared to be abolished following bariatric surgery. Improvements in cognitive function were not associated with improvements in either CVR BOLD or MCA vasodilation after bariatric surgery.

Conclusions

Assessing CVR responses to a hypercapnic challenge with MRI was feasible in severely obese bariatric patients. However, no changes in whole-brain BOLD CVR were observed following bariatric surgery despite improvements in cognitive function. We recommend that future large trials assess CVR responses to cognitive tasks (rather than hypercapnia) to better define the mechanisms responsible for cognitive function improvements following 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.

Improvement in arterial stiffness (pOpmètre®) after bariatric surgery. Results from a prospective study

BACKGROUND

Arterial stiffness (AS) is an independent predictor of cardiovascular risk, and could be used as a surrogate marker of improvement in cardiovascular risk following bariatric surgery. The aim of this study was to compare AS before and after surgery.

METHODS

One hundred and thirty-four patients undergoing bariatric surgery between May 2016 and January 2019 were prospectively included. AS was measured on pulse wave velocity (PWV) with the pOpmètre® device pre- and postoperatively. The main endpoint was change in PWV between baseline and 3 months post-surgery.

RESULTS

Overall, mean PWV was 6.87m/s preoperatively and 6.71m/s at 3 months (P=0.7148). Patients with pathologic PWV (>2 standard deviations from expected value for age) showed significant improvement at 3 months (31 patients; 10.1m/s preoperatively vs 7.5m/s at 3 months; P=0.007). These results did not correlate with improvement in other clinical or biological parameters following surgery (excess weight loss, mean blood pressure, fasting blood glucose, waist circumference, body composition).

CONCLUSION

These results suggest that pathological arterial stiffness may resolve following bariatric surgery independently of the other factors influencing cardiovascular risk in obesity.

Endothelial dysfunction and cardiovascular outcome in asymptomatic patients with type 2 diabetes: A pilot study

BACKGROUND

Type 2 diabetes mellitus (T2DM) is associated with an increased risk of cardiovascular events, but risk stratification of asymptomatic T2DM patients remains a challenging issue. We conducted a pilot study to assess whether endothelial dysfunction might help identify, among asymptomatic T2DM patients, those at increased risk of cardiovascular events.

METHODS

We studied 61 consecutive T2DM patients with no evidence of cardiovascular disease and no insulin therapy. Endothelial function was assessed by flow-mediated dilation (FMD) of the right brachial artery. The primary endpoint was a combination of major cardiovascular events (MACE: cardiovascular death, acute coronary events, coronary interventions, and acute cerebrovascular accidents). FMD was repeated at follow-up in 48 patients (79%).

RESULTS

A total of 10 MACE (16.4%) occurred during a mean follow-up of 48 months, including three acute myocardial infarctions, five coronary revascularizations for stable angina, and two acute ischaemic strokes. FMD at enrolment was lower in patients with compared with patients without MACE (3.78 ± 0.97% vs 4.70 ± 1.33%, respectively; P = .04). No other clinical or laboratory variables (age, diabetes duration, glycated haemoglobin, cardiovascular risk factors, drug therapy, and nitrate-mediated dilation) were associated with MACE. FMD at follow-up was also lower in patients with (n = 10) compared with those without (n = 38) MACE (3.66 ± 1.29 vs 4.85 ± 1.92; P = .006).

CONCLUSIONS

Our data suggest that assessment of FMD might be helpful to identify patients at increased risk of MACE among individuals with asymptomatic T2DM; accordingly, a large study is warranted to adequately define the clinical utility of FMD assessment in the management of T2DM patients.

Endothelial Function in Obese Patients Treated with Bariatric Surgery

PURPOSE

Bariatric surgery (BS) is becoming an increasingly frequent treatment option especially in people with morbid obesity, demonstrating that it is able to reduce total mortality and cardiovascular (CV) risk. Despite endothelial dysfunction is an essential requisite contributing to atherosclerosis and predicting CV events, only some studies have investigated the effects of BS on endothelial function with controversial results. In this study, the effects of weight loss on endothelial function were investigated in obese patients after BS and compared with patients after medical nutrition treatment (MNT).

PATIENTS AND METHODS

Seventeen obese patients who underwent BS procedures (9 adjustable gastric bands, 3 gastric by-passes and 5 biliopancreatic diversions) were included in the study and compared with 18 obese individuals who underwent MNT. Endothelial function was investigated by flow-mediated dilation (FMD) of the brachial artery. Also, carotid intima-media thickness (c-IMT) was measured as a marker of subclinical atherosclerosis.

RESULTS

At the end of follow-up, the mean weight loss was 18.8% in the BS group and 7.0% in the MNT group. After treatment, FMD significantly decreased in the BS group (mean ± SD before: 9.0 ± 4.7; after: 6.1 ± 2.9%; P= 0.04); however, no significant change was observed in the MNT group (before: 9.4 ± 5.8; after: 8.3 ± 5.3; P= 0.41). The modification of endothelial function was negatively correlated with c-IMT change in the BS group (r= -0.63; P <0.007).

CONCLUSION

A significant endothelial dysfunction occurred following BS but not after MNT. Furthermore, the decline of endothelial function observed in the BS group might have contributed to atherosclerosis.

Treatment strategies in coronary microvascular dysfunction: A systematic review of interventional studies

CMD has been associated with a wide spectrum of diseases and conditions, and it has proven to be a strong prognostic marker of morbidity and mortality. Despite increased attention, guideline-based treatment recommendations are lacking. We performed a systematic review of pharmacological and nonpharmacological interventions to improve coronary perfusion, assessed by IC Doppler, TTDE, PET, CMRI, transthoracic contrast perfusion echocardiography, and dilution techniques. No restrictions were made regarding the study design (randomized, placebo-controlled/randomized with active comparators/nonrandomized with or without a control group), the cardiac condition studied, or the coronary microvascular function at baseline. An electronic database search yielded 4485 records of which 80 studies met our inclusion criteria. Included studies were sorted according to intervention and study design. Studies were small and heterogeneous in methodology, and only few were placebo-controlled. Although some treatments looked promising, we found that no specific treatment was sufficiently well documented to be recommended in any patient groups. There is a need for larger well-designed clinical trials, and we suggest that future studies stratify study populations according to pathogenic mechanisms, thereby investigating whether an individualized treatment approach would be more successful.

Effect of liraglutide on body weight and microvascular function in non-diabetic overweight women with coronary microvascular dysfunction

BACKGROUND

Coronary microvascular dysfunction (CMD) is associated with adverse cardiovascular outcomes and CMD is a hallmark of type 2 diabetes. Liraglutide improves cardiovascular prognosis through partly unknown mechanisms. We hypothesized that treatment with liraglutide improves CMD and symptoms through weight loss, in non-diabetic overweight patients with angina and no obstructive coronary artery disease (CAD).

METHODS

We included 33 non-diabetic overweight women (BMI > 25) with CMD (Coronary flow velocity reserve (CFVR) ≤2.5), angina symptoms and no obstructive CAD, in an open-label proof-of-concept study. The protocol included a control period of 5 weeks followed by an intervention period with liraglutide aiming at 3 mg daily for 12 weeks. Participants were investigated before and after the control period and again 1-2 weeks after last liraglutide dose. Primary outcomes were change in CFVR and change in angina symptoms measured by the Seattle Angina Questionnaire (SAQ) in the intervention period compared with the control period. (clinicaltrials.gov, NCT02602600, and ethically approved).

RESULTS

Twenty-nine participants completed the study. Liraglutide treatment led to a significant weight loss (mean 6.03 kg (95%CI: 5.22;6.84)) and decrease in systolic blood pressure (mean 10.95 mm Hg (95%CI: 4.60;17.30)). Baseline median CFVR was 2.30 (IQR 1.91;2.51) and remained unchanged after liraglutide treatment (mean change 0.07 (95%CI: -0.07;0.21)). There were no effects on symptoms measured by SAQ or parameters of left ventricular systolic as well as diastolic function.

CONCLUSIONS

Treatment with liraglutide led to significant weight loss and lowering of blood pressure with no concomitant symptoms alleviation during treatment and no improvement in coronary microvascular function.

The effect of DPP-4-protected GLP-1 (7-36) on coronary microvascular function in obese adults

Objective

Glucagon-like-peptide-1 (GLP-1) receptor analogues have been shown to reduce cardiovascular events in patients with type 2 diabetes. However, the mechanism behind is still unknown. The aim of the study was to investigate the effect of intact GLP-1 (7-36) on coronary microcirculation in overweight adults.

Design and methods

A double-blinded randomized cross-over study was performed, with 12 overweight participants. Effects of intact GLP-1 (7-36) infusion were compared with a saline infusion on separate days. A DPP-4 inhibitor was administered to block degradation of intact GLP-1 (7-36) to the GLP-1 metabolite (9-36). Coronary microcirculation was assessed by Doppler coronary flow velocity reserve (CFVR) before and after 2 h of infusion. Peripheral endothelial function was assessed by flow mediated dilation (FMD) before and after one hour of infusion.

Results

CFVR was 3.77 ± 1.25 during GLP-1 infusion and 3.85 ± 1.32 during saline infusion, endothelial function was 16.3 ± 15.5 % during GLP-1 infusion and 7.85 ± 7.76 % during saline infusion. When adjusting for baseline values no significant differences in CFVR (ΔCFVR 0.38 ± 0.92 vs. ΔCFVR 0.71 ± 1.03, p = 0.43) and no difference in peripheral endothelial function (ΔFMD 7.34 ± 11.5 % vs. ΔFMD -1.25 ± 9.23%, p = 0.14) was found.

Conclusions

We found no effect of intact GLP-1 (7-36), protected from DPP4 mediated degradation on coronary microcirculation in overweight adults.

Coronary microvascular dysfunction in diabetes mellitus

The significance, mechanisms and consequences of coronary microvascular dysfunction associated with diabetes mellitus are topics into which we have insufficient insight at this time. It is widely recognized that endothelial dysfunction that is caused by diabetes in various vascular beds contributes to a wide range of complications and exerts unfavorable effects on microcirculatory regulation. The coronary microcirculation is precisely regulated through a number of interconnected physiological processes with the purpose of matching local blood flow to myocardial metabolic demands. Dysregulation of this network might contribute to varying degrees of pathological consequences. This review discusses the most important findings regarding coronary microvascular dysfunction in diabetes from pre-clinical and clinical perspectives.

Gastric Bypass Surgery Produces a Durable Reduction in Cardiovascular Disease Risk Factors and Reduces the Long-Term Risks of Congestive Heart Failure

Background

Obesity and its association with reduced life expectancy are well established, with cardiovascular disease as one of the major causes of fatality. Metabolic surgery is a powerful intervention for severe obesity, resulting in improvement in comorbid diseases and in cardiovascular risk factors. This study investigates the relationship between metabolic surgery and long‐term cardiovascular events.

Methods and Results

A cohort of Roux‐en‐Y gastric bypass surgery (RYGB) patients was tightly matched by age, body mass index, sex, Framingham Risk Score, smoking history, use of antihypertension medication, diabetes mellitus status, and calendar year with a concurrent cohort of nonoperated control patients. The primary study end points of major cardiovascular events (myocardial infarction, stroke, and congestive heart failure) were evaluated using Cox regression. Secondary end points of longitudinal cardiovascular risk factors were evaluated using repeated‐measures regression. The RYGB and matched controls (N=1724 in each cohort) were followed for up to 12 years after surgery (overall median of 6.3 years). Kaplan–Meier analysis revealed a statistically significant reduction in incident major composite cardiovascular events (P=0.017) and congestive heart failure (0.0077) for the RYGB cohort. Adjusted Cox regression models confirmed the reductions in severe composite cardiovascular events in the RYGB cohort (hazard ratio=0.58, 95% CI=0.42–0.82). Improvements of cardiovascular risk factors (eg, 10‐year cardiovascular risk score, total cholesterol, high‐density lipoprotein, systolic blood pressure, and diabetes mellitus) were observed within the RYGB cohort after surgery.

Conclusions

Gastric bypass is associated with a reduced risk of major cardiovascular events and the development of congestive heart failure.

Long-term effects of bariatric surgery on peripheral endothelial function and coronary microvascular function

BACKGROUND

We previously demonstrated that bariatric surgery (BS) leads to a short-term significant improvement of endothelial function and coronary microvascular function. In this study we assessed whether BS maintains its beneficial effect at long-term follow up.

DESIGN

We studied 19 morbidly obese patients (age 43±9years, 12 women) without any evidence of cardiovascular disease who underwent BS. Patients were studied before BS, at 3 months and at 4.0±1.5years follow up.

METHODS

Peripheral vascular function was assessed by flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD), i.e., brachial artery diameter changes in response to post-ischemic forearm hyperhaemia and to nitroglycerin administration, respectively. Coronary microvascular function was assessed by measuring coronary blood flow (CBF) response to intravenous adenosine and to cold pressor test (CPT) in the left anterior descending coronary artery.

RESULTS

Together with improvement of anthropometric and metabolic profile, at long-term follow-up patients showed a significant improvement of FMD (6.43±2.88 vs. 8.21±1.73%, p=0.018), and CBF response to both adenosine (1.73±0.48 vs. 2.58±0.54; p<0.01) and CPT (1.43±0.30 vs. 2.23±0.48; p<0.01), compared to basal values. No differences in vascular end-points were shown at 3-month and 4-year follow-up after BS.

CONCLUSIONS

Our data show that, in morbidly obese patients, BS exerts beneficial and long lasting effects on peripheral endothelial function and on coronary microvascular dilator function.

Weight loss improves biomarkers endothelial function and systemic inflammation in obese postmenopausal Saudi women

BACKGROUND

Although postmenopausal associated disorders are important public health problems worldwide, to date limited studies evaluated the endothelial function and systemic inflammation response to weight loss in obese postmenopausal women.

OBJECTIVE

This study was done to evaluate the endothelial function and systemic inflammation response to weight loss in obese postmenopausal Saudi women.

MATERIAL AND METHODS

Eighty postmenopausal obese Saudi women (mean age 52.64±6.13 year) participated in two groups: Group (A) received aerobic exercise on treadmill and diet whereas, group (B) received no intervention. Markers of inflammation and endothelial function were measured before and after 3 months at the end of the study.

RESULTS

The values of body mass index(BMI), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), inter-cellular adhesion molecule (ICAM-1), vascular cell adhesion molecule (VCAM-1) and plasminogen activator inhibitor-1 activity (PAI-1:Ac) were significantly decreased in group (A), while changes were not significant in group (B). Also, there were significant differences between mean levels of the investigated parameters in group (A) and group (B) after treatment.

CONCLUSION

Weight loss ameliorates inflammatory cytokines and markers of endothelial function in obese postmenopausal Saudi women.

Leptin relates to prolonged cardiovascular recovery after acute stress in Africans: The SABPA study

BACKGROUND AND AIMS

Heightened cardiovascular reactivity and delayed recovery to stress are associated with an increased risk of cardiovascular disease. Africans, who are more prone to develop hypertension, show greater cardiovascular reactivity to stress. However, causal factors underlying individual and ethnic differences in stress reactivity and recovery remain largely unexplored. Leptin, which is known for its sympatho-activating effects, is higher in Africans compared to Caucasians for any given body mass index. We compared how cardiovascular reactivity and recovery relate to leptin in African (n = 200) and Caucasian (n = 209) teachers.

METHODS AND RESULTS

We measured leptin in serum and cardiovascular baseline and reactivity continuously with the Finometer device during the cold pressor test for 1 min, and recovery at intervals of 1, 3 and 5 min. Africans had higher body mass index, leptin and blood pressure (all P < 0.001). After full adjustment in multiple regression analyses, associations were seen mainly at the 5 min recovery interval. In Africans, cardiac output reactivity (β = -0.335; P = 0.0018) and arterial compliance- (β = -0.241; P = 0.048) associated negatively and total peripheral resistance- (β = 0.227; P = 0.047) positively with leptin. In Caucasians, diastolic blood pressure correlated positively with leptin (β = 0.200; P = 0.015).

CONCLUSION

In Africans, higher circulating leptin levels associated with prolonged cardiovascular recovery after exposure to stress which could explain their increased vulnerability to hypertension development.

Coronary microvascular dysfunction, microvascular angina, and treatment strategies

Angina without coronary artery disease (CAD) has substantial morbidity and is present in 10% to 30% of patients undergoing angiography. Coronary microvascular dysfunction (CMD) is present in 50% to 65% of these patients. The optimal treatment of this cohort is undefined. We performed a systematic review to evaluate treatment strategies for objectively-defined CMD in the absence of CAD. We included studies assessing therapy in human subjects with angina and coronary flow reserve or myocardial perfusion reserve <2.5 by positron emission tomography, cardiac magnetic resonance imaging, dilution methods, or intracoronary Doppler in the absence of coronary artery stenosis ≥50% or structural heart disease. Only 8 papers met the strict inclusion criteria. The papers were heterogeneous, using different treatments, endpoints, and definitions of CMD. The small sample sizes severely limit the power of these studies, with an average of 11 patients per analysis. Studies evaluating sildenafil, quinapril, estrogen, and transcutaneous electrical nerve stimulation application demonstrated benefits in their respective endpoints. No benefit was found with L-arginine, doxazosin, pravastatin, and diltiazem. Our systematic review highlights that there is little data to support therapies for CMD. We assess the data meeting rigorous inclusion criteria and review the related but excluded published data. We additionally describe the next steps needed to address this research gap, including a standardized definition of CMD, routine assessment of CMD in studies of chest pain without obstructive CAD, and specific therapy assessment in the population with confirmed CMD.

Inhibition of inflammation may enhance nitric oxide availability in patients undergoing bariatric surgery for weight loss

BACKGROUND

Weight loss surgery is the most effective treatment for morbid obesity. The mechanisms underlying the beneficial cardiovascular effects are poorly understood, although inhibition of inflammatory markers has been demonstrated. We hypothesized that anti-inflammatory and antioxidative stress reactions are responsible for the beneficial effects of bariatric surgery that have been shown in clinical trials.

METHODS

The inflammatory system was studied by measuring mRNA levels of E-selectin, tumour necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and in a cell line (HUVEC-CS) of human umbilical vein endothelial cells that were incubated for 4 h with pools of serum, collected before and 3 months after surgery, from 20 women who underwent bariatric surgery for weight loss. The oxidative stress pathway was examined by mRNA expression of NADPH oxidase (P22(phox) ), paraoxonase (PON2), superoxide dismutase 2 (SOD2), glutathione peroxidase (GPx) and catalase following incubation of the cells for 4 h with serum pools. The nitric oxide (NO) pathway was studied by measuring mRNA levels of inducible NOS and endothelial NOS and by determining nitrite and nitrate levels. To study the functional behaviour of endothelial cells under stress, primary human umbilical vein endothelial cells (PECs) were incubated with the serum pools for 48 h, with lipopolysaccharide (LPS) for the last 4 h.

RESULTS

The inflammatory system: incubation of HUVEC-CS cells with serum from women who underwent bariatric surgery led to a significant decrease in mRNA expression of E-selectin and IL-6 postsurgery. Stimulation of PECs with LPS in the presence of serum from women who underwent bariatric surgery caused a more significant difference in E-selectin and TNF-α mRNA expression before and after surgery. The antioxidant system: incubation of HUVEC-CS cells with serum from women who underwent bariatric surgery did not lead to any difference in mRNA expression of P22(phox) , PON2, SOD2, GPx or catalase. Stimulation of PECs with LPS showed that obese women had higher levels of P22(phox) , PON2 and the antioxidant enzymes SOD2, GPx and catalase before and after surgery, compared to the control group. The NO pathway: HUVEC-CS cells incubated with serum from women who underwent bariatric surgery secreted higher nitrite/nitrate levels compared to presurgery serum (P = 0.04).

CONCLUSIONS

Inhibition of inflammation and enhanced availability of NO 3 months after bariatric surgery could partly explain the beneficial effects of surgery for weight loss.

Effects of bariatric surgery on markers of subclinical atherosclerosis and endothelial function: a meta-analysis of literature studies

BACKGROUND/OBJECTIVES

Several studies confirmed a significantly increased carotid intima-media thickness (IMT) and impaired flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD) in obese subjects, but few data are available on the effects of bariatric surgery on these markers of cardiovascular (CV) risk. We performed a meta-analysis of studies evaluating changes in IMT, FMD and NMD in obese patients after bariatric surgery.

METHODS

A systematic search was performed in the PubMed, Web of Science, Scopus and EMBASE databases without any language or publication year restriction. The last search was performed in January 2015. In addition, the reference lists of all retrieved articles were manually reviewed. Prospective studies evaluating the impact of bariatric surgery on the markers of CV risk were included. Changes in IMT, FMD and NMD after bariatric surgery were expressed as mean differences (MD) with pertinent 95% confidence intervals (95% CIs). IMT has been expressed in millimeters (mm); FMD and NMD as percentage (%). Impact of clinical and demographic features on effect size was assessed by meta-regression.

RESULTS

Ten articles (314 obese patients) were included in the analysis. Six studies contained data on IMT (7 data sets; 206 patients), 8 studies on FMD (9 data sets; 269 patients) and 4 on NMD (4 data sets; 149 patients). After bariatric surgery, there was a significant reduction of IMT (MD: -0.17 mm; 95% CI: -0.290, -0.049; P=0.006) and a significant improvement in FMD (MD: 5.65%; 95% CI: 2.87, 8.03; P<0.001), whereas NMD did not change (MD: 2.173%; 95% CI: -0.796, 5.142; P=0.151). Interestingly, percentage of changes in the body mass index were associated with changes in IMT (Z=11.52, P<0.001), FMD (Z=-4.26, P<0.001) and NMD (Z=-3.81, P<0.001).

CONCLUSIONS

Despite heterogeneity among studies, bariatric surgery is associated with improvement of subclinical atherosclerosis and endothelial function. These effects may significantly contribute to the reduction of the CV risk after bariatric surgery.

A randomised trial comparing the effect of exercise training and weight loss on microvascular function in coronary artery disease

BACKGROUND

Coronary microvascular function is associated with outcome and is reduced in coronary artery disease (CAD) and obesity. We compared the effect of aerobic interval training (AIT) and weight loss on coronary flow reserve (CFR) and peripheral vascular function in revascularised obese CAD patients.

METHODS AND RESULTS

Seventy non-diabetic patients (BMI 28-40 kg × m(-2), age 45-75 years) were randomised to 12 weeks' AIT (three weekly sessions lasting 38 min with ≈ 16 min at 85-90% of VO2peak) or low energy diet (LED, 800-1000 kcal/day). Per protocol adherence was defined by training-attendance ≥ 60% and weight loss ≥ 5%, respectively. CFR was assessed by Doppler echocardiography of the LAD. Peripheral vascular function was assessed by arterial tonometry as reactive hyperaemia index (RHI) and augmentation index. Most participants had impaired CFR with a mean CFR of 2.38 (SD 0.59). Twenty-six AIT and 24 LED participants completed the study per protocol with valid CFR measurements. AIT resulted in a 10.4% improvement in VO2peak and LED in a 10.6% weight loss (between group differences both P<0.001). CFR increased by 0.26 (95%CI 0.04;0.48) after AIT and by 0.39 (95%CI 0.13;0.65) after LED without significant between-group difference (-0.13 (95%CI -0.45;0.20)). RHI and augmentation index remained unchanged after both interventions (P>0.50). Intention-to-treat analyses showed similar results.

CONCLUSIONS

12 weeks' AIT and LED increased CFR by comparable magnitude; thus both interventions might impact prognosis of CAD through improvement of coronary microvascular function.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01724567.

Coronary Microvascular Function and Beyond: The Crosstalk between Hormones, Cytokines, and Neurotransmitters

Beyond its hemodynamic function, the heart also acts as a neuroendocrine and immunoregulatory organ. A dynamic communication between the heart and other organs takes place constantly to maintain cardiovascular homeostasis. The current understanding highlights the importance of the endocrine, immune, and nervous factors to fine-tune the crosstalk of the cardiovascular system with the entire body. Once disrupted, this complex interorgan communication may promote the onset and the progression of cardiovascular diseases. Thus, expanding our knowledge on how these factors influence the cardiovascular system can lead to novel therapeutic strategies to improve patient care. In the present paper, we review novel concepts on the role of endocrine, immune, and nervous factors in the modulation of microvascular coronary function.

Systemic inflammation is related to coronary microvascular dysfunction in obese patients without obstructive coronary disease

BACKGROUND AND AIMS

Obesity, systemic inflammation and changes in the heart functions are associated with increased cardiovascular risk. This study aimed to investigate coronary microvascular dysfunction as an early marker of atherosclerosis in obese patients without any evidence of cardiovascular disease.

METHODS AND RESULTS

86 obese subjects (aged 44 ± 12 years, body mass index (BMI) 41 ± 8 kg m(-2)), without evidence of heart disease, and 48 lean controls were studied using transthoracic Doppler echocardiography for detecting coronary flow reserve (CFR). A value of CFR ≤ 2.5 was considered abnormal. We measured interleukin-6 (IL-6), tumour necrosis factor-α (TNF-α) and adiponectin in all patients. Patients with abnormal CFR underwent coronary multislice computed tomography (MSCT) in order to exclude an epicardial stenosis. CFR in obese subjects was lower than in lean subjects (3.2 ± 0.8 vs. 3.7 ± 0.7, p = 0.02) and was abnormal in 27 (31%) obese patients and in one (2%) control (p < 0.0001). All subjects with abnormal CFR showed no coronary stenosis at MSCT. At multivariable analysis, IL-6 and TNF-α were the only determinants of CFR (p < 0.02 and p < 0.02, respectively). At multivariable logistic regression analysis, IL-6 and TNF-α were the only determinants of CFR ≤ 2.5 (p < 0.03 and p < 0.03, respectively).

CONCLUSIONS

CFR is often reduced in obese subjects without clinical evidence of heart disease, suggesting a coronary microvascular impairment. This microvascular dysfunction seems to be related to a chronic inflammation mediated by adipocytokines. Our findings may explain the increased cardiovascular risk in obesity, independently of BMI.

Impaired HDL function in obese adolescents: impact of lifestyle intervention and bariatric surgery

OBJECTIVE

HDL regulates endothelial function via stimulation of nitric oxide production. It is documented that endothelial function is impaired in obese adolescents, and improved by lifestyle interventions (LI).

DESIGN AND METHODS

HDL function in obese adolescents and the impact of LI or Roux-en-Y gastric bypass surgery (RYGB) was assessed. HDL was isolated from 14 adolescents with normal body mass index (HDLcontrol ), 10 obese (HDLobese ) before and after 6 month LI, and five severe obese adolescents before and one year after RYGB. HDL-mediated phosphorylation of endothelial nitric oxide synthase (eNOS)-Ser(1177) , eNOS-Thr(495) , and PKC-ßII was evaluated. In addition the HDL proteome was analyzed.

RESULTS

HDLobese -mediated eNOS-Ser(1177) phosphorylation was reduced, whereas eNOS-Thr(495) phosphorylation increased significantly when compared to HDLcontrol . No impact of obesity was observed on PKC-ßII phosphorylation. LI and RYGB had no impact on HDL-mediated phosphorylation of eNOS and PKC-ßII. A principle component plot analysis of the HDL particle separated controls and severe obese, whereas the interventions did not trigger sufficient differences to the HDL proteome to permit distinction.

CONCLUSION

These results demonstrated that HDL-function is impaired in obese adolescents, and that LI or RYGB did not correct this dysfunction. This might be an argument for developing earlier prevention strategies in obese adolescents to avoid HDL dysfunction.

Endothelial and platelet function in children with previous Kawasaki disease

We investigated whether children with a previous Kawasaki disease (KD) have evidence of abnormal vascular and/or platelet function. We included 14 patients with previous KD and 14 matched controls. We assessed endothelial function by flow-mediated dilation (FMD), carotid intima-media thickness (cIMT), coronary microvascular function by coronary blood flow response (CBFR) to cold pressor test, and platelet reactivity by measuring monocyte-platelet aggregates (MPAs) and CD41-platelet expression by flow cytometry. No differences were found between the groups in FMD, cIMT, or CBFR to cold pressor test. The MPAs were similar in patients with KD and controls. CD41-platelet expression, however, was significantly increased in patients with KD compared with controls, both at rest (14.3 ± 1.9 vs 12.4 ± 1.9 mean fluorescence intensity [mfi], P = .01) and after adenosine diphosphate stimulation (19.3 ± 1.3 vs 17 ± 1.7 mfi, P < .001). In conclusion, children with a previous episode of KD showed increased platelet activation, compared with healthy participants despite no apparent vascular abnormality at follow-up.

Insulin resistance and not BMI is the major determinant of early vascular impairment in patients with morbid obesity

AIM

Several factors contribute to the development of atherogenesis in patients with obesity. The aim of our study was to evaluate the different roles of insulin resistance, strictly correlated to visceral adiposity, and the body mass index (BMI), an estimate of overall adiposity, on early vascular impairment in patients with morbid obesity.

METHODS

We enrolled 65 morbidly obese subjects (BMI 44.6 ± 7 kg/m(2)) who were free of previous cardiovascular events and 28 nonobese subjects (control group) in a cross-sectional study. The presence of glycemia and insulinemia, the levels of lipids and liver parameter and the ultrasonographic assessment of the flow-mediated dilatation (FMD), carotid intima-media thickness (IMT) and visceral fat area (VFA) were evaluated in all subjects.

RESULTS

In the obese patients with a median HOMA value of ≥ 3.5, the FMD was significantly lower (p < .05) and the left carotid maximum-IMT was significantly higher (p < .05) than those observed in the group with lower HOMA values. No vascular differences were found between the two groups that were subdivided according to the BMI median value. Both the left max-IMT and FMD exhibited a significant correlation with HOMA-IR ("ρ" .292, p=0.02 , "ρ"-.292, p=0.02 respectively) but not with BMI. According to a multivariate analysis, the VFA was an independent predictor of a reduced FMD (β - .541, p.002; p of the model .002), while age (β .611 p < .0001) and HOMA-IR (β .399 p < .001) were independent predictors of the left max-IMT (p of the model .002).

CONCLUSIONS

The HOMA-IR, which is strictly related to visceral fat and is an index of metabolic impairment, and not BMI, which reflects of global adiposity, can be used to identify early vascular impairment in patients with morbid obesity.

Impact of bariatric surgery on comorbidities

Published data show that bariatric surgery not only leads to significant and sustained weight loss but also resolves or improves multiple comorbidities associated with morbid obesity. Evidence suggests that the earlier the intervention the better the resolution of comorbidities. Patients with metabolic syndrome and comorbidities associated with morbid obesity should be promptly referred for consideration for bariatric surgery earlier in the disease process.

Bariatric surgery reduces visceral adipose inflammation and improves endothelial function in type 2 diabetic mice

OBJECTIVE

Bariatric surgery is emerging as an effective method to alleviate a multitude of medical conditions associated with morbid obesity and type 2 diabetes. However, little is known about the effects and mechanisms of bariatric surgery on visceral fat inflammation and endothelial dysfunction in type 2 diabetes. We hypothesize that bariatric surgery ameliorates interferon-γ-mediated adipose tissue inflammation/oxidative stress and improves endothelial function in type 2 diabetic mice.

METHODS AND RESULTS

Control mice (m Lepr(db)) and diabetic mice (Lepr(db)) were treated with either sham surgery or improved gastric bypass surgery and then were evaluated at 5, 10, 20, and 30 days to assess postsurgical effects. Surgery reduced body weight, abdominal adiposity, blood glucose level, and food intake in Lepr(db). The surgery-induced decrease in visceral adiposity was accompanied by amelioration of T-lymphocytes and macrophage infiltration, as well as reduction in the expression of interferon-γ and other inflammatory cytokines in the mesenteric adipose tissue (MAT) of Lepr(db) mice. Furthermore, surgery improved endothelium-dependent, but not endothelium-independent, vasorelaxation in small mesenteric arteries (SMA) of Lepr(db) mice. The improvement in endothelial function was largely attenuated by nitric oxide synthase inhibitor (L-NAME) incubation. Interferon-γ treatment increased the mRNA expression of tumor necrosis factor-α in the MAT of control mice and incubation of SMA of control mice with tumor necrosis factor-α caused impairment of endothelial function. Superoxide production in MAT/SMA and nitrotyrosine protein level in SMA were elevated in diabetic mice. Surgery reduced MAT/SMA oxidative stress in Lepr(db) mice.

CONCLUSIONS

The amelioration of adipose tissue inflammation and the improvement of endothelial function may represent important mechanisms that result in cardiovascular benefits after bariatric surgery.