Overweight status is associated with extensive signs of microvascular dysfunction and cardiovascular risk

Short-term high-intensity interval training improves micro- but not macrovascular function in hypertensive patients

INTRODUCTION

Arterial hypertension is a global health burden that affects vascular structure and function. Assessment of endothelial function can improve cardiovascular (CV) risk stratification. Exercise treatment reduces over all CV risk and improves vascular health. However, it is still not clear which part of the vascular bed is most sensitive to exercise treatment in patients with CV risk. This study aimed to investigate the effects of an 8-week walking based and supervised high-intensity interval training (HIIT) on macro- and microvascular endothelial function as add-on therapy in patients with arterial hypertension.

METHODS

Forty patients (mean age 58 ± 7 years) treated for arterial hypertension were randomized in the HIIT (3×/week) or control group (CG) receiving standard physical activity recommendations. Arteriolar (aFID) and venular (vFID) flicker light-induced dilatation for retinal microvascular and flow-mediated dilatation (FMD) for macrovascular endothelial function were assessed. In addition, standardized assessments of patients' characteristics were performed before and after 8 weeks.

RESULTS

Both groups reduced weight and body mass index but only the HIIT group reduced body fat, visceral fat, and increased peak oxygen uptake after 8 weeks. The control group reduced diastolic blood pressure. No blood pressure changes were found in the HIIT group. Arteriolar FID increased in the HIIT group independently of confounders (pre: 2.40 ± 0.98%, post: 3.19 ± 1.31%, p < 0.001) but not in the control group (pre: 3.06 ± 1.50%, post: 2.90 ± 1.46%, p = 0.280). No changes were found for FMD in either group.

CONCLUSION

Arteriolar FID was found to be a sensitive vascular biomarker to assess exercise-induced microvascular improvements even in a short time setting of an 8-week exercise therapy with HIIT. Short-term exercise training affects microvascular endothelial function but not large artery endothelial function. Thus, retinal aFID appears to be a sensitive biomarker to detect short-term exercise efficacy on a vascular level. Dynamic retinal vessel analysis as a diagnostic approach may prove to be an ideal candidate vascular biomarker to monitor treatment effects of exercise in patients with hypertension on top of standard clinical care and may support clinical decision-making in the future.

Pilot study of optical coherence tomography angiography-derived microvascular metrics in hands and feet of healthy and diabetic people

Optical coherence tomography angiography (OCTA) is a non-invasive, high-resolution imaging modality with growing application in dermatology and microvascular assessment. Accepted reference values for OCTA-derived microvascular parameters in skin do not yet exist but need to be established to drive OCTA into the clinic. In this pilot study, we assess a range of OCTA microvascular metrics at rest and after post-occlusive reactive hyperaemia (PORH) in the hands and feet of 52 healthy people and 11 people with well-controlled type 2 diabetes mellitus (T2DM). We calculate each metric, measure test-retest repeatability, and evaluate correlation with demographic risk factors. Our study delivers extremity-specific, age-dependent reference values and coefficients of repeatability of nine microvascular metrics at baseline and at the maximum of PORH. Significant differences are not seen for age-dependent microvascular metrics in hand, but they are present for several metrics in the foot. Significant differences are observed between hand and foot, both at baseline and maximum PORH, for most of the microvascular metrics with generally higher values in the hand. Despite a large variability over a range of individuals, as is expected based on heterogeneous ageing phenotypes of the population, the test-retest repeatability is 3.5% to 18% of the mean value for all metrics, which highlights the opportunities for OCTA-based studies in larger cohorts, for longitudinal monitoring, and for assessing the efficacy of interventions. Additionally, branchpoint density in the hand and foot and changes in vessel diameter in response to PORH stood out as good discriminators between healthy and T2DM groups, which indicates their potential value as biomarkers. This study, building on our previous work, represents a further step towards standardised OCTA in clinical practice and research.

Retinal Microvascular Abnormalities and Systemic Arterial Stiffness Are the First Manifestation of Cardiovascular Abnormalities in Patients with Untreated Moderate to Severe Obstructive Sleep Apnoea and with Low to Intermediate Cardiovascular Risk-A Pilot Study

This study aimed to investigate macro- and microvascular function parameters and their relationship with known markers of cardiovascular risk in patients with untreated moderate to severe obstructive sleep apnoea (OSA). Fourteen patients with moderate to severe OSA and fourteen controls were included in the present study. General assessments included BMI, systemic blood pressure (BP) and circulating markers for oxidative stress and endothelial function. Additional assessments included 24 h BP and heart rate monitoring, as well as the assessment of heart rate variability. Macro- and microvascular assessments included augmentation index, carotid intima-media thickness, brachial artery flow-mediated dilation, as well as various retinal microvascular function assessments, using the Dynamic Retinal Vessel Analyzer. All participants completed the Short Form Health Survey, Functional Outcomes of Sleep Questionnaire, and Epworth Sleepiness Scale. The results show that, in comparison to controls, BMI (p = 0.003) and AIx (p = 0.025) were significantly higher in the OSA group. There was, however, no significant difference between groups with regard to other measured systemic general, vascular and circulatory parameters (all p > 0.05). Nevertheless, the retinal microvascular function showed various alterations in the OSA patients, including a delayed reaction time in response to flicker (p = 0.047), as well as a decreased dilation amplitude (p = 0.004), dilation slope (p = 0.004), and post-flicker constriction (p = 0.015). In addition, the observed SlopeAD alterations correlated negatively with BMI values only in the OSA group (r = −0.46, p = 0.045). In conclusion, individuals with untreated moderate to severe OSA but without overt CVD, exhibit signs of increased arterial stiffness and retinal microvascular dysfunction, which can be early indicators for future vascular complications.

Hypertension and retinal microvascular dysfunction (HyperVasc): protocol of a randomised controlled exercise trial in patients with hypertension

INTRODUCTION

Hypertension is a global healthcare burden that affects the structure and function of the macrocirculation and microcirculation and induces disease-specific end-organ damage. Vascular biomarkers are essential to timely diagnose this end-organ damage to improve cardiovascular (CV) risk stratification and medical decision making. Exercise therapy is an effective means to improve vascular health and reduce overall CV risk. However, it is still not clear whether high-intensity interval training (HIIT) is recommendable for patients with hypertension to reduce blood pressure, increase cardiorespiratory fitness and ameliorate vascular health.

METHODS AND ANALYSIS

The 'Hypertension and retinal microvascular dysfunction' trial will investigate macrovascular and microvascular impairments in hypertensive patients compared with healthy controls to investigate hypertension-induced end-organ damage by using gold-standard methods as well as newly developed unique retinal microvascular biomarkers. In addition, this trial will investigate the reversibility of retinal end-organ damage by assessing the effects of an 8-week supervised and walking based HIIT on blood pressure, cardiorespiratory fitness as well as macrovascular and microvascular health, compared with a control group following standard physical activity recommendations. Primary outcome will be the arteriolar-to-venular diameter ratio. Secondary outcomes will be arteriolar and venular diameters as well as the flicker-light-induced dilation. Further outcomes will be other retinal microvascular biomarkers, flow-mediated dilation of the brachial artery as well as blood pressure, cardiorespiratory fitness, microalbuminuria, hypertensive retinopathy and classical CV risk markers. Analysis of variance and analysis of covariance will be used to investigate group differences between healthy controls and hypertensive patients and training effects in hypertensive patients, respectively.

ETHICS AND DISSEMINATION

The Ethics Committee of Northwestern and Central Switzerland approved this study (EKNZ-2021-00086). All participants will give informed consent.

TRIAL REGISTRATION NUMBER

NCT04763005.

Role of von Willebrand factor in venous thromboembolic disease

Objective

Evolving evidence of the shared risk factors and pathogenic mechanisms in arterial and venous thrombosis questions of the strict vascular dichotomy of arterial vs venous. The connection between arterial and venous thrombosis has been highlighted by common underlying inflammatory processes, a concept known as thromboinflammatory disease. Using this relationship, we can apply knowledge from arterial disease to better understand and potentially mitigate venous disease. A protein that has been extensively studied in atherothrombotic disease and inflammation is von Willebrand factor (VWF). Because many predisposing and provoking factors of venous thromboembolism (VTE) have been shown to directly modulate VWF levels, it is, perhaps, not surprising that VWF has been highlighted by several recent association studies of patients with VTE.

Methods

In the present narrative review, we investigated more deeply the effects of VWF in venous disease by synthesizing the data from clinical studies of deep vein thrombosis of the limbs, pulmonary embolism, portal and cerebral vein thrombosis, and the complications of thrombosis, including post-thrombotic syndrome, venous insufficiency, and chronic thromboembolic pulmonary hypertension. We have also discussed the findings from preclinical studies to highlight novel VWF biochemistry in thrombosis and therapeutics.

Results

Across the spectrum of venous thromboembolic disease, we consistently observed that elevated VWF levels conferred an increased risk of VTE and long-term venous complications. We have highlighted important findings from VWF molecular research and have proposed mechanisms by which VWF participates in venous disease. Emerging evidence from preclinical studies might reveal novel targets for thromboinflammatory disease, including specific VWF pathophysiology. Furthermore, we have highlighted the utility of measuring VWF to prognosticate and risk stratify for VTE and its complications.

Conclusions

As the prevalence of inflammatory processes, such as aging, obesity, and diabetes increases in our population, it is critical to understand the evolving role of VWF in venous disease to guide clinical decisions and therapeutics.

Identification of Endothelial Proteins in Plasma Associated With Cardiovascular Risk Factors

Supplemental Digital Content is available in the text.

Objective:

Endothelial cell (EC) dysfunction is a well-established response to cardiovascular disease risk factors, such as smoking and obesity. Risk factor exposure can modify EC signaling and behavior, leading to arterial and venous disease development. Here, we aimed to identify biomarker panels for the assessment of EC dysfunction, which could be useful for risk stratification or to monitor treatment response.

Approach and Results:

We used affinity proteomics to identify EC proteins circulating in plasma that were associated with cardiovascular disease risk factor exposure. Two hundred sixteen proteins, which we previously predicted to be EC-enriched across vascular beds, were measured in plasma samples (N=1005) from the population-based SCAPIS (Swedish Cardiopulmonary Bioimage Study) pilot. Thirty-eight of these proteins were associated with body mass index, total cholesterol, low-density lipoprotein, smoking, hypertension, or diabetes. Sex-specific analysis revealed that associations predominantly observed in female- or male-only samples were most frequently with the risk factors body mass index, or total cholesterol and smoking, respectively. We show a relationship between individual cardiovascular disease risk, calculated with the Framingham risk score, and the corresponding biomarker profiles.

Conclusions:

EC proteins in plasma could reflect vascular health status.

Supplemental Watermelon Juice Attenuates Acute Hyperglycemia-Induced Macro-and Microvascular Dysfunction in Healthy Adults

BACKGROUND

Acute hyperglycemia reduces NO bioavailability and causes macro- and microvascular dysfunction. Watermelon juice (WMJ) is a natural source of the amino acid citrulline, which is metabolized to form arginine for the NO cycle and may improve vascular function.

OBJECTIVES

We examined the effects of 2 weeks of WMJ compared to a calorie-matched placebo (PLA) to attenuate acute hyperglycemia-induced vascular dysfunction.

METHODS

In a randomized, placebo-controlled, double-blind, crossover trial, 6 men and 11 women (aged 21-25; BMI, 23.5 ± 3.2 kg/m2) received 2 weeks of daily WMJ (500 mL) or a PLA drink followed by an oral-glucose-tolerance test. Postprandial flow-mediated dilation (FMD) was measured by ultrasound (primary outcome), while postprandial microvascular blood flow (MVBF) and ischemic reperfusion were measured by near-infrared spectroscopy (NIRS) vascular occlusion test (VOT).

RESULTS

The postprandial FMD area AUC was higher after WMJ supplementation compared to PLA supplementation (838 ± 459% · 90 min compared with 539 ± 278% · 90 min; P = 0.03). The postprandial MVBF (AUC) was higher (P = 0.01) following WMJ supplementation (51.0 ± 29.1 mL blood · 100 mL tissue-1 · min-1 · 90 min) compared to the PLA (36.0 ± 20.5 mL blood · 100 mL tissue-1 · min-1 · 90 min; P = 0.01). There was a significant treatment effect (P = 0.048) for WMJ supplementation (71.2 ± 1.5%) to increase baseline tissue oxygen saturation (StO2%) when compared to PLA (65.9 ± 1.7%). The ischemic-reperfusion slope was not affected by WMJ treatment (P = 0.83).

CONCLUSIONS

Two weeks of daily WMJ supplementation improved FMD and some aspects of microvascular function (NIRS-VOT) during experimentally induced acute hyperglycemia in healthy adults. Preserved postprandial endothelial function and enhanced skeletal muscle StO2% are likely partially mediated by increased NO production (via citrulline conversion into arginine) and by the potential antioxidant effect of other bioactive compounds in WMJ.

Normative data and standard operating procedures for static and dynamic retinal vessel analysis as biomarker for cardiovascular risk

Retinal vessel phenotype is predictive for cardiovascular outcome. This cross-sectional population-based study aimed to quantify normative data and standard operating procedures for static and dynamic retinal vessel analysis. We analysed central retinal arteriolar (CRAE) and venular (CRVE) diameter equivalents, as well as retinal endothelial function, measured by flicker light‐induced maximal arteriolar (aFID) and venular (vFID) dilatation. Measurements were performed in 277 healthy individuals aged 20 to 82 years of the COmPLETE study. The mean range from the youngest compared to the oldest decade was 196 ± 13 to 166 ± 17 µm for CRAE, 220 ± 15 to 199 ± 16 µm for CRVE, 3.74 ± 2.17 to 3.79 ± 2.43% for aFID and 4.64 ± 1.85 to 3.86 ± 1.56% for vFID. Lower CRAE [estimate (95% CI): − 0.52 (− 0.61 to − 0.43)], CRVE [− 0.33 (− 0.43 to − 0.24)] and vFID [− 0.01 (− 0.26 to − 0.00)], but not aFID, were significantly associated with older age. Interestingly, higher blood pressure was associated with narrower CRAE [− 0.82 (− 1.00 to − 0.63)] but higher aFID [0.05 (0.03 to 0.07)]. Likewise, narrower CRAE were associated with a higher predicted aFID [− 0.02 (− 0.37 to − 0.01)]. We recommend use of defined standardized operating procedures and cardiovascular risk stratification based on normative data to allow for clinical implementation of retinal vessel analysis in a personalized medicine approach.

Evaluation of gingival microcirculation in patients with gestational diabetes mellitus

OBJECTIVE

The aim of this study was to evaluate the possible microcircularity variations at periodontal mucous level in patients with gestational diabetes mellitus (GDM).

MATERIAL AND METHODS

Overall 55 periodontally healthy and non-smoker participants were enrolled in the study by whom 30 were diagnosed with GDM (26 to 34 weeks pregnant) and 25 were systemically healthy unpregnant controls. The analysis was performed in the masticatory/gingival mucosa of maxillary anterior region and by the optical probe videocapillaroscopy technique equipped with 200× lenses. The following parameters were recorded: capillary loop visibility, capillary orientation to surface, microhemorrhages, capillary density and tortuosity.

RESULTS

The average capillary density was significantly higher in participants with GDM (27 ± 5.46 no. loops/mm²) compared to controls (21.16 ± 3 no. loops/mm²) (P = 0.035) while increased tortuosity scores was observed in controls compared with the GDM group (P = 0.017). There was not any significantly difference between study groups among the other variables (P > 0.05).

CONCLUSIONS

Capillary alterations including capillary density and tortuosity were demonstrated in gingival microcirculation of patients with GDM. These microcirculatory changes could provide us new understanding on the dynamics of the relationship between GDM and periodontal tissues.

Inflammatory Mechanisms Contributing to Endothelial Dysfunction

Maintenance of endothelial cell integrity is an important component of human health and disease since the endothelium can perform various functions including regulation of vascular tone, control of hemostasis and thrombosis, cellular adhesion, smooth muscle cell proliferation, and vascular inflammation. Endothelial dysfunction is encompassed by complex pathophysiology that is based on endothelial nitric oxide synthase uncoupling and endothelial activation following stimulation from various inflammatory mediators (molecular patterns, oxidized lipoproteins, cytokines). The downstream signaling via nuclear factor-κB leads to overexpression of adhesion molecules, selectins, and chemokines that facilitate leukocyte adhesion, rolling, and transmigration to the subendothelial space. Moreover, oscillatory shear stress leads to pro-inflammatory endothelial activation with increased monocyte adhesion and endothelial cell apoptosis, an effect that is dependent on multiple pathways and flow-sensitive microRNA regulation. Moreover, the role of neutrophil extracellular traps and NLRP3 inflammasome as inflammatory mechanisms contributing to endothelial dysfunction has recently been unveiled and is under further investigation. Consequently, and following their activation, injured endothelial cells release inflammatory mediators and enter a pro-thrombotic state through activation of coagulation pathways, downregulation of thrombomodulin, and an increase in platelet adhesion and aggregation owing to the action of von-Willebrand factor, ultimately promoting atherosclerosis progression.

Quantification of Retinal Vessel Myogenic Constriction in Response to Blood Pressure Peaks: Implications for Flicker Light-Induced Dilatation

Background/Aims

Flicker-light induced retinal vessel dilatation (FID), a marker of microvascular endothelial function, has been shown to be blunted in sedentary cardiovascular risk patients (SR) as well as healthy physically active individuals (HA). This study aimed to quantify the retinal myogenic response to blood pressure (BP) peaks and its effects on consecutive FID for differentiation of microvascular health.

Methods

Ten HA and eleven SR with a previously established restriction of arteriolar FID (aFID) (<2.2%) were invited in order to assess BP-induced myogenic constriction following a standardized handgrip task and a consecutive FID. BP was measured beat-to-beat.

Results

The complete dataset of nine HA (3 female, mean age 65 years) and nine SR (5 female, mean age 61 years) individuals was analyzed. The central retinal arteriolar diameter equivalent (CRAE) was 183 ± 11 μm for HA and 176 ± 20 μm for SR. Initial baseline aFID was 1.6 ± 0.4% in HA and 1.6 ± 0.7% in SR. Systolic (p = 0.334) and diastolic (p = 0.245) BP increase following the handgrip task was in the range of 20–30% and comparable in both groups. BP increase was followed by a significantly higher arteriolar (−2.9 ± 1.3% vs. −1.3 ± 0.6%, p < 0.01) myogenic constriction in HA compared to SR. Moreover, in the consecutive assessment of FID directly after the BP-induced vessel constriction, aFID (4.1 ± 2.0% vs. 1.6 ± 0.9%, p < 0.01) was higher in HA compared to SR.

Conclusion

Initial baseline aFID was blunted in HA and SR. Retinal myogenic constriction was impaired in SR compared to HA. The consecutive aFID after BP-induced myogenic constriction recovered in HA but remained blunted in SR. Additional assessment of retinal myogenic constriction needs to be considered to improve CV risk stratification and reduce false-positive findings of endothelial dysfunction in otherwise healthy active individuals.

Clinical Trial Registration

ClinicalTrials.gov: NCT03986892 (https://clinicaltrials.gov/ct2/show/NCT03986892).

European Society of Cardiology/European Society of Hypertension versus the American College of Cardiology/American Heart Association guidelines on the cut-off values for early hypertension: a microvascular perspective

The aim of this study was to investigate retinal and peripheral microvascular function in asymptomatic individuals that fall into different BP groups when using either the ESC/ESH or the ACC/AHA guidelines. Retinal and peripheral microvascular function was assessed in 358 participants by means of dynamic retinal vessel analysis and digital thermal monitoring, respectively. Blood pressure and lipid panel were also evaluated. Retinal vascular function measured in all groups belonging to the ACC/ASH classifications were within the normal values for age-matched normal population. Individuals classed as grade 1 hypertension according to the ESC/ESH guidelines, however, exhibited a significantly decreased artery baseline (p = 0.0004) and MC (p = 0.040), higher slope_AD (p = 0.0018) and decreased vein MC (p = 0.0446) compared to age matched normal individuals. In addition, they also had significant lower artery baseline, artery BDF, MD and MC than individuals classed as stage 1 hypertension based on the ACC/ASH guidelines (p = 0.00022, p = 0.0179, p = 0.0409 and p = 0.0329 respectively). Peripheral vascular reactivity (aTR) was lower in ESC /ESH grade I compared to those graded ACC/ASH stage I hypertension (p = 0.0122). The conclusion of this study is that microvascular dysfunctions is present at multiple levels only in individuals with ESC/ESH grade 1 hypertension. This observation could be important when deciding personalised care in individuals with early hypertensive changes.

Predictors of recurrent angina in patients with no need for secondary revascularization

BACKGROUND

Approximately 20% to 30% of patients with coronary artery disease (CAD) develop recurrent angina pectoris following successful and complete coronary revascularization utilizing percutaneous coronary intervention (PCI). We aim to investigate predictors of recurrent angina pectoris in patients who have undergone successful coronary revascularization using PCI, but on repeat coronary angiography have no need for secondary revascularization.

METHODS

The study comprised 3,837 patients with CAD, who were enrolled from January 2007 to June 2019. They had undergone successful PCI; some of them redeveloped angina pectoris within one year after the procedure, but on repeat coronary angiography had no need for revascularization. Thrombolysis in myocardial infarction (TIMI) frame count was used to evaluate the velocity of coronary blood in the follow-up angiogram. Multivariate logistic regression was used to investigate risk factors for recurrent angina pectoris. Similarly, predictors of recurrent angina according to the TIMI frame count were assessed using multivariate linear regression.

RESULTS

In this retrospective study, 53.5% of patients experienced recurrent angina pectoris. By multivariate logistic regression, the following characteristics were statistically identified as risk factors for recurrent angina pectoris: female sex, older age, current smoking, low-density lipoprotein cholesterol (LDL-C) ≥1.8 mmol/L, and an elevated TIMI frame count (P for all <0.05). Similarly, using multivariate linear regression, the statistical risk factors for TIMI frame count included: female sex, older age, diabetes, body mass index (BMI), post-procedural treatment without the inclusion of dual antiplatelet therapy.

CONCLUSIONS

Patient characteristics of female sex, older age, diabetes, and elevated BMI are associated with an increased TIMI frame count, coronary microcirculation dysfunction, and recurrent angina pectoris after initially successful PCI. In addition, current smoking and LDL-C ≥1.8 mmol/L are risk factors for recurrent angina pectoris. In contrast, the treatment with dual antiplatelet therapy is negatively correlated with a higher TIMI frame count and the risk of recurrent angina pectoris.

Endothelial function in cardiovascular medicine: a consensus paper of the European Society of Cardiology Working Groups on Atherosclerosis and Vascular Biology, Aorta and Peripheral Vascular Diseases, Coronary Pathophysiology and Microcirculation, and Thrombosis

Endothelial cells (ECs) are sentinels of cardiovascular health. Their function is reduced by the presence of cardiovascular risk factors, and is regained once pathological stimuli are removed. In this European Society for Cardiology Position Paper, we describe endothelial dysfunction as a spectrum of phenotypic states and advocate further studies to determine the role of EC subtypes in cardiovascular disease. We conclude that there is no single ideal method for measurement of endothelial function. Techniques to measure coronary epicardial and micro-vascular function are well established but they are invasive, time-consuming, and expensive. Flow-mediated dilatation (FMD) of the brachial arteries provides a non-invasive alternative but is technically challenging and requires extensive training and standardization. We, therefore, propose that a consensus methodology for FMD is universally adopted to minimize technical variation between studies, and that reference FMD values are established for different populations of healthy individuals and patient groups. Newer techniques to measure endothelial function that are relatively easy to perform, such as finger plethysmography and the retinal flicker test, have the potential for increased clinical use provided a consensus is achieved on the measurement protocol used. We recommend further clinical studies to establish reference values for these techniques and to assess their ability to improve cardiovascular risk stratification. We advocate future studies to determine whether integration of endothelial function measurements with patient-specific epigenetic data and other biomarkers can enhance the stratification of patients for differential diagnosis, disease progression, and responses to therapy.

In vivo imaging of hemodynamic redistribution and arteriogenesis across microvascular network

OBJECTIVE

Arteriogenesis is an important mechanism that contributes to restoration of oxygen supply in chronically ischemic tissues, but remains incompletely understood due to technical limitations. This study presents a novel approach for comprehensive assessment of the remodeling pattern in a complex microvascular network containing multiple collateral microvessels.

METHODS

We have developed a hardware-software integrated platform for quantitative, longitudinal, and label-free imaging of network-wide hemodynamic changes and arteriogenesis at the single-vessel level. By ligating feeding arteries in the mouse ear, we induced network-wide hemodynamic redistribution and localized arteriogenesis. The utility of this technology was demonstrated by studying the influence of obesity on microvascular arteriogenesis.

RESULTS

Simultaneously monitoring the remodeling of competing collateral arterioles revealed a new, inverse relationship between initial vascular resistance and extent of arteriogenesis. Obese mice exhibited similar remodeling responses to lean mice through the first week, including diameter increase and flow upregulation in collateral arterioles. However, these gains were subsequently lost in obese mice.

CONCLUSIONS

Capable of label-free, comprehensive, and dynamic quantification of structural and functional changes in the microvascular network in vivo, this platform opens up new opportunities to study the mechanisms of microvascular arteriogenesis, its implications in diseases, and approaches to pharmacologically rectify microvascular dysfunction.

The role of the adipocytokines vaspin and visfatin in vascular endothelial function and insulin resistance in obese children

BACKGROUND

We measured the concentrations of the adipocytokines vaspin and visfatin in obese Chinese children. Furthermore, we studied the correlation of these adipocytokines with early-onset metabolic and vascular sequelae among these children.

METHODS

A total of 244 children (160 obese and 84 lean) were included in this study. Vaspin and visfatin were detected using enzyme-linked immunosorbent assays. We also assayed other metabolic and cardiovascular parameters. The associations of serum vaspin and visfatin concentrations with metabolic and cardiovascular parameters were determined.

RESULTS

We found a significant elevation in the concentrations of vaspin and visfatin in obese children compared to the concentrations in lean children. Additionally, we found a significant positive correlation between visfatin and vaspin levels, as well as inflammatory cell infiltration and markers of endothelial activation, but these factors did not affect insulin resistance in obese children. Multiple regression analyses confirmed that vaspin is the strongest predictor of higher tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6), angiotensin-2 (Ang-2), vascular cellular adhesion molecule-1 (VCAM-1), and E-selectin levels. We also found a significant association between visfatin and Ang-2, IL-6, VCAM-1, and E-selectin levels.

CONCLUSION

The adipocytokines vaspin and visfatin are significantly interrelated, and both adipocytokines play a role in vascular endothelial function and inflammation.

The association between near-infrared spectroscopy assessment of microvascular reactivity and flow-mediated dilation is disrupted in individuals at high risk for cardiovascular disease

OBJECTIVE

This study aimed to evaluate the correlation between the NIRS-derived reperfusion slope and %FMD in the arm of healthy and at high risk for CVD individuals.

METHODS

Twelve healthy (24 ± 4 years) and twelve at high risk for cardiovascular disease (65 ± 11 years) individuals participated in the study. The individuals were submitted to a conduit artery FMD followed by a NIRS-VOT microvascular function test in the arm. Microvascular responsiveness was calculated as the forearm reperfusion slope, and macrovascular function was assessed as the percent of change in FMD (%FMD) of the brachial artery.

RESULTS

There was a significant correlation between reperfusion slope and %FMD (R = 0.61, P < 0.05) in the healthy group; however, no significant correlation between FMD and reperfusion slope (R = -0.21, P > 0.05) was found in individuals at high risk for CVD.

CONCLUSION

The correlation between NIRS-derived reperfusion slope and %FMD was disrupted in the arm of individuals at high risk for cardiovascular disease compared to healthy individuals. The findings of the present study reinforce the importance of examining vascular function at microvasculature and conduit artery level, especially in populations with risk factors for CVD.

Retinal vessel dynamic functionality in the eyes of asymptomatic patients with significant internal carotid artery stenosis

BACKGROUND

The goal of this study was to assess the retinal microvascular function in asymptomatic patients with hemodynamically significant internal carotid artery stenosis (ICAS) and to assess the potential efficacy of carotid endarterectomy (CEA) for the improvement of vessel functionality.

METHODS

Retinal vessel caliber and reactions to flicker stimulation were assessed in both eyes of 65 asymptomatic patients with unilateral hemodynamically significant ICAS and 34 healthy subjects. Subsequently, the recruited ICAS patients were referred for standard unilateral CEA procedure. The full ophthalmologic examination of both eyes and vessel analysis were performed 1 day before and 3 months after CEA.

RESULTS

The venous responses to flicker stimulation were significantly lower in the EIS (eyes ipsilateral to stenosis) and ECS (eyes contralateral to stenosis) compared with those in the controls (P<0.0001 and P<0.0001, respectively). No changes were identified in retinal vascular flicker responses after CEA in both groups of eyes compared with the baseline values. We observed a decrease in CRVE (central retinal venular equivalent) after the CEA both in eyes ipsilateral (P=0.01) and contralateral (P=0.04) to CEA. Likewise, a decrease in CRAE (central retinal arteriolar equivalent) was identified in the eyes ipsilateral to CEA (P<0.001).

CONCLUSIONS

This outcome strongly indicates that microvascular dysfunction is long-lasting despite the recovery of the flow in the carotid artery.

Near-infrared spectroscopy can detect differences in vascular responsiveness to a hyperglycaemic challenge in individuals with obesity compared to normal-weight individuals

OBJECTIVE

To examine whether the near-infrared spectroscopy combined with vascular occlusion test technique could detect differences in vascular responsiveness during hyperglycaemia between normal-weight individuals and individuals with obesity.

METHODS

A total of 16 normal-weight individuals (body mass index, 21.3 ± 1.7 kg/m²) and 13 individuals with obesity (body mass index, 34.4 ± 2.0 kg/m²) were submitted to five vascular occlusion tests (Pre, 30, 60, 90 and 120 min after glucose challenge). Vascular responsiveness was determined by the Slope 2 (Slope 2 StO₂) and the area under the curve (StO_2AUC) of oxygen saturation derived from near-infrared spectroscopy-vascular occlusion test.

RESULTS

The Slope 2 StO₂ increased from 1.07 ± 0.16%/s (Pre) to 1.53 ± 0.21%/s at 90 min ( p < 0.05) in the control group, while in obese it increased from 0.71 ± 0.09%/s (Pre) to 0.92 ± 0.14%/s at 60 min ( p < 0.05), and to 0.97 ± 0.10%/s ( p < 0.01) at 120 min after glucose ingestion. The StO_2AUC decreased from 1729 ± 214% . sec (Pre) to 1259 ± 232% . sec at 60 min ( p < 0.05) and to 1034 ± 172% . sec at 90 min ( p < 0.05) in the normal-weight group, whereas it decreased at 90 min (637 ± 98% . sec; p < 0.05) and at 120 min (590 ± 93% . sec; p < 0.01) compared to 30 min (1232 ± 197% . sec) after glucose ingestion in individuals with obesity.

CONCLUSION

Near-infrared spectroscopy-vascular occlusion test technique was capable of detecting differences in vascular responsiveness during hyperglycaemia between normal-weight individuals and individuals with obesity.

Surgery in overweight patients with insulinoma: effects on weight loss

OBJECTIVE

Weight loss induced by the complete resection of insulinoma is controversial in overweight patients. The study sought to explore postoperative weight loss and metabolic changes in overweight insulinoma patients.

METHODS

A retrospective study was conducted to review the follow-up data of insulinoma patients with a BMI ≥25kg/m² who underwent complete lesion resection between May 2010 and May 2015. Body mass index (BMI), weight loss (WL) and percentage weight loss (%WL) were main outcomes.

RESULTS

Fifty-one patients were included with a median follow-up of 28 months. The BMI at 3 months, 1 year, 2 years and 3 years postoperatively were significantly lower than the preoperative BMI values (p < .01). The WL% was 12.9% at 3 months postoperatively without significant changes throughout the 3-year follow-up. WL and the %WL were significantly higher in the high BMI group (BMI≥ 27.5 kg/m²). Multivariate analysis indicated that higher initial BMI was associated with increased weight loss (p = .001). 63.8% of patients with hypertension recovered and improved sleep quality was evident in all patients with obstructive sleep apnea syndrome within 1 year postoperatively.

CONCLUSIONS

Weight significantly decreased postoperatively in overweight insulinoma patients, which was more evident in patients with higher BMI and metabolic comorbidities were largely improved.