Assessment of peripheral vascular endothelial function with finger arterial pulse wave amplitude

Effects of roflumilast on arterial stiffness in COPD (ELASTIC): A randomized trial

BACKGROUND AND OBJECTIVE

Cardiovascular risk is substantially increased in patients with COPD and can be quantified via arterial stiffness. The PDE-IV inhibitor roflumilast revealed a potential reduction of COPD-related cardiovascular risk. We aimed to investigate the effects of roflumilast on arterial stiffness by quantification of pulse wave velocity (PWV) in stable COPD.

METHODS

In this randomized placebo-controlled trial, 80 COPD patients received roflumilast or placebo for 24 weeks. The primary outcome was the change in cf-PWV. Secondary outcomes comprised markers of vascular function (e.g. Aix and RHI), systemic inflammation (e.g. IL-6 and TNF-α) and clinical characteristics of COPD (e.g. CAT and 6MWT).

RESULTS

A total of 33 and 34 patients completed the roflumilast and placebo arm, respectively (age, median (IQR): 64.5 (61-69.5) vs 64.5 (56-72) years; FEV₁ , median (IQR): 34.5 (25.5-48.6) vs 35.3 (27-46.8) % predicted; 6MWT, median (IQR): 428 (340-558) vs 456 (364-570) m). Change from baseline PWV did not show a significant difference between roflumilast and placebo (+5.0 (95% CI: -2.0 to +13.0) vs 0.0 (95% CI: -7.0 to +7.0)%, P = 0.268). Roflumilast did not improve markers of vascular function or systemic inflammation. We observed a significant improvement in change from baseline 6MWT with roflumilast versus placebo (+53.0 (95% CI: +19.1 to +86.9) vs -0.92 (95% CI: -35.1 to +33.3) m, P = 0.026).

CONCLUSION

Our study revealed no beneficial effects of roflumilast on arterial stiffness. Further studies are needed to test a potential improvement of exercise capacity with roflumilast in COPD.

Improvement in renal and endothelial function after catheter ablation in patients with persistent atrial fibrillation

BACKGROUND

Cardiovascular events in patients with atrial fibrillation (AF) can be lowered by catheter ablation. We hypothesized the underlying mechanism was improvement in renal and endothelial function corresponding to AF burden, and investigated whether restoration of sinus rhythm (SR) after ablation affected these functions according to AF type.

METHODS AND RESULTS

We prospectively measured estimated glomerular filtration rate (eGFR), urinary albumin-to-creatinine ratio (UACR), and reactive hyperemia index (RHI) in 358 consecutive patients with AF before and 6 and 12 months after the ablation. For each AF type [paroxysmal AF (PAF), n = 229, and persistent AF (PeAF), n = 129], we evaluated changes in these markers and influence of chronic kidney disease (CKD). The eGFR and natural logarithm-transformed (ln) UACR improved at 6 months in the PeAF group (68.7 ± 18.7-71.8 ± 18.9 mL/min/1.73 m², p = 0.003 and 3.1±1.6 to 2.8±1.5, p < 0.001, respectively) and remained unchanged in the PAF group. Among the PeAF patients, recurrent AF was identified in 41, but only transiently in 38 patients. PeAF at baseline independently predicted increased eGFR [odds ratio (OR)=2.13, 95 % confidence interval (CI) 1.35-3.40, p = 0.001] and decreased UACR (OR=1.94, 95 % CI 1.05-3.58, p = 0.033). In the PeAF patients with CKD, ln-RHI significantly increased at 6 months after the ablation, and the change (Δ) in ln-RHI was significantly correlated with the ΔeGFR (r=0.35, p = 0.03).

CONCLUSIONS

SR restoration after ablation was associated with an improved eGFR and UACR in PeAF patients, but not PAF patients. In PeAF patients with CKD, an improved endothelial function after ablation was associated with an improved renal function.

From short-term blood pressure variability to atherosclerosis: Relative roles of vascular stiffness and endothelial dysfunction

Both arterial blood pressure (BP) average levels and short-term BP variability (BPV) relate to hypertension-mediated organ damage, in particular increased carotid artery intima-media thickness (IMT) and carotid-femoral pulse wave velocity (PWV). Endothelial dysfunction possibly mediates such damage. The authors aimed at further investigating such role in hypertensive patients. In 189 recently diagnosed, untreated hypertensive patients the authors evaluated, in a cross-sectional design, the relationships of BP average levels and short-term systolic (S) BPV (standard deviation of awake SBP or of 24-hour-weighted SBP) with IMT and PWV, and how much these relationships are explained by endothelial function parameters-brachial artery flow-mediated dilation (FMD) and digital reactive hyperemia index (RHI). Multivariable models assessed the strength of these relationships to derive a plausible pathogenetic sequence. Both average SBP values and our measures of SBPV were significantly related to IMT (24-hour mean SBP: r = .156, P = .034; 24-hour-weighted SBPV: r = .157, P = .033) and to PWV (24-hour mean SBP: r = .179, P = .015; 24-hour-weighted SBPV: r = .175; P = .018), but only poorly related to FMD or RHI (P > .05 for all). At univariable regression analysis, FMD and RHI were both related to IMT, (P < .001), but not to PWV. When FMD and RHI were added to average SBP and SBPV parameters in a multivariable model, both significantly (P < .005) contributed to predict IMT, but not PWV. Thus, endothelial dysfunction relates to IMT independently of BP parameters, but appears to play a minor role in the association between BP variability-related variables and arterial stiffening.

SAFETY AND EFFECTS OF CRATAEGUS EXTRACT WS 1442 AND NORDIC WALKING ON LIPID PROFILE AND ENDOTHELIAL FUNCTION: A RANDOMIZED, PARTIALLY BLINDED PILOT STUDY IN OVERWEIGHT VOLUNTEERS

Overweight and physical inactivity adversely affect endothelial function and are risk factors for atherosclerosis and cardiovascular disease. Both Crataegus extract WS 1442 and physical exercise exert beneficial effects on endothelial function. We investigated whether WS 1442 and Nordic walking (NW) had comparable effects on endothelial function and lipid profile in overweight subjects. In this partially blinded pilot study, overweight, otherwise healthy volunteers aged 45-75 years were randomized into four groups as follows: WS 1442 2x450 mg/day (WS-standard), WS 1442 2x900 mg/day (WS-double), exercise 2x30 minutes/week (NW-low), and exercise 4x45 minutes/week (NW-high) for 12 weeks. Safety was assessed based on adverse events. Endothelial function testing (EndoPAT^®), assessment of endothelial progenitor cells, lipid profiles, and treadmill testing were performed. Sixty subjects participated in the study. At baseline, subjects in WS-standard/-double groups had higher lipid levels and greater impairment of endothelial function. Subjects with impaired endothelial function showed improvement regardless of the type of intervention. Subjects in WS-standard and WS-double groups showed a trend towards modest decrease in triglycerides and modest increase in HDL-cholesterol; most changes were within the normal limits. In NW-low/-high groups, values also remained within the normal range. Exercise capacity improved in both NW groups. WS-double showed no additional benefits over WS-standard. All adverse events were unrelated or improbably related to treatment. In conclusion, WS 1442 and exercise training were safe and showed beneficial effects on endothelial function and lipid profile in overweight but otherwise healthy volunteers; exercise capacity improved only by Nordic walking.

Secondary analyses to assess the profound effects of empagliflozin on endothelial function in patients with type 2 diabetes and established cardiovascular diseases: The placebo-controlled double-blind randomized effect of empagliflozin on endothelial function in cardiovascular high risk diabetes mellitus: Multi-center placebo-controlled double-blind randomized trial

Aims/Introduction

Recent clinical trials on sodium–glucose cotransporter 2 inhibitors showed improved outcomes in patients with type 2 diabetes at a high risk of cardiovascular events. However, the underlying effects on endothelial function remain unclear.

Materials and Methods

The effect of empagliflozin on endothelial function in cardiovascular high risk diabetes mellitus: Multi‐center placebo‐controlled double‐blind randomized (EMBLEM) trial in patients with type 2 diabetes and cardiovascular disease showed empagliflozin treatment for 24 weeks had no effect on peripheral endothelial function measured by reactive hyperemia peripheral arterial tonometry. This post‐hoc analysis of the EMBLEM trial included a detailed evaluation of the effects of empagliflozin on peripheral endothelial function in order to elucidate the clinical characteristics of responders or non‐responders to treatment.

Results

Of the 47 patients randomized into the empagliflozin group, 21 (44.7%) showed an increase in the reactive hyperemia index (RHI) after 24 weeks of intervention, with no apparent difference in the clinical characteristics between patients whose RHI either increased (at least >0) or did not increase. There was also no obvious difference between the treatment groups in the proportion of patients who had a clinically meaningful change (≥15%) in log‐transformed RHI. No correlation was found between changes in RHI and clinical variables, such as vital signs and laboratory parameters.

Conclusions

Treatment with empagliflozin for 24 weeks in patients with type 2 diabetes and cardiovascular disease did not affect peripheral endothelial function, and was not related to changes in clinical variables, including glycemic parameters. These findings suggest that the actions of sodium–glucose cotransporter 2 inhibitors other than direct improvement in peripheral endothelial function were responsible, at least in the early phase, for the clinical benefits found in recent cardiovascular outcome trials.

Rationale and design of an investigator-initiated, multicenter, prospective open-label, randomized trial to evaluate the effect of ipragliflozin on endothelial dysfunction in type 2 diabetes and chronic kidney disease: the PROCEED trial

Background

Type 2 diabetes (T2D) is associated with renal impairment and vascular endothelial dysfunction. Therefore, this pathological connection is an important therapeutic target. Recent cardiovascular and renal outcome trials demonstrated that sodium glucose cotransporter 2 inhibitors (SGLT2is) consistently reduced the risks of cardiovascular and renal events and mortality in patients with T2D and various other background risks including chronic kidney disease (CKD). However, the precise mechanisms by which SGLT2is accords these therapeutic benefits remain uncertain. It is also unknown whether these SGLT2is-associated benefits are associated with the amelioration of endothelial dysfunction in patients with T2D and CKD.

Methods

The PROCEED trial is an investigator-initiated, prospective, multicenter, open-label, randomized-controlled trial. The target sample size is 110 subjects. After they furnish informed consent and their endothelial dysfunction is confirmed from their decreased reactive hyperemia indices (RHI), eligible participants with T2D (HbA1c, 6.0–9.0%) and established CKD (30 mL/min/1.73 m² ≤ estimated glomerular filtration ratio [eGFR] < 60 and/or ≥ urine albumin-to-creatinine ratio 30 mg/g Cr) will be randomized (1:1) to receive either 50 mg ipragliflozin daily or continuation of background treatment (non-SGLT2i). The primary endpoint is the change in RHI from baseline after 24 weeks. To compare the treatment effects between groups, the baseline-adjusted means and their 95% confidence intervals will be estimated by analysis of covariance adjusted for HbA1c (< 7.0% or ≥ 7.0%), age (< 70 y or ≥ 70 y), RHI (< 1.67 or ≥ 1.67), eGFR (< 45 mL/min/1.73 m² or ≥ 45 mL/min/1.73 m²), and smoking status. Prespecified responder analyses will be also conducted to determine the proportions of patients with clinically meaningful changes in RHI at 24 weeks.

Discussion

PROCEED is the first trial to examine the effects of ipragliflozin on endothelial dysfunction in patients with T2D and CKD. This ongoing trial will establish whether endothelial dysfunction is a therapeutic target of SGLT2is in this population. It will also provide deep insights into the potential mechanisms by which SGLT2is reduced the risks of cardiovascular and renal events in recent outcome trials.

Trial registration Unique Trial Number, jRCTs071190054 (https://jrct.niph.go.jp/en-latest-detail/jRCTs071190054).

Peripheral arterial endothelial dysfunction predicts future cardiovascular events in diabetic patients with albuminuria: a prospective cohort study

Background

Reactive hyperemia-peripheral arterial tonometry (RH-PAT) is a noninvasive and simple test for evaluating the endothelial function. There has been sparse evidence on the usefulness of the RH-PAT index (RHI) in predicting future cardiovascular diseases among diabetic patients.

Methods

Asymptomatic diabetic patients with albuminuria were selected; their medical history and laboratory findings were evaluated every 3 to 4 months, respectively. The primary outcome was a composite of three-point major adverse cardiovascular events (3-point MACE): death from cardiovascular causes, acute coronary events, or nonfatal stroke. On the contrary, secondary outcomes included a composite of 3-point MACE, hospitalization for heart failure, or chronic kidney disease (CKD) progression. RHI was measured using the Endo-PAT2000 at the baseline. RHI < 1.67 was considered to indicate peripheral endothelial dysfunction (PED).

Results

In total, 149 subjects were included (mean age, 61.8 ± 9.2 years; duration of diabetes was 12 years). During the follow-up period (median, 49.7 months), of the 149 subjects, primary outcomes were detected in 12 (1 [2.3%] and 11 [10.5%] of those without and with PED, respectively). The presence of PED in baseline measurements significantly increased both primary and secondary outcomes, following adjustment for age, sex, hypertension, glycated hemoglobin, low-density lipoprotein cholesterol, triglyceride, systolic blood pressure, baseline estimated glomerular filtration rate, overt proteinuria, duration of diabetes, premedical history of ischemic events, anti-platelet agents, and smoking history (hazard ratio [HR]: 10.95; 95% confidence interval CI 1.00–119.91 for the primary outcome; HR, 4.12; 95% CI 1.37–12.41 for secondary outcome). In addition, PED could predict secondary outcomes independent of the risk score according to the American College of Cardiology/American Heart Association (HR: 3.24; 95% CI 1.14–9.17).

Conclusions

PED can independently predict future cardiovascular events among diabetic patients with albuminuria.

Nocturnal blood pressure dipping as a marker of endothelial function and subclinical atherosclerosis in pediatric-onset systemic lupus erythematosus

Background

Loss of the normal nocturnal decline in blood pressure (BP), known as non-dipping, is a potential measure of cardiovascular risk identified by ambulatory blood pressure monitoring (ABPM). We sought to determine whether non-dipping is a useful marker of abnormal vascular function and subclinical atherosclerosis in pediatric-onset systemic lupus erythematosus (pSLE).

Methods

Twenty subjects 9–19 years of age with pSLE underwent ABPM, peripheral endothelial function testing, carotid-femoral pulse wave velocity/analysis for aortic stiffness, and carotid intima-media thickness. We assessed the prevalence of non-dipping and other ABPM abnormalities. Pearson or Spearman rank correlation tests were used to evaluate relationships between nocturnal BP dipping, BP load (% of abnormally elevated BPs over 24-h), and vascular outcome measures.

Results

The majority (75%) of subjects had inactive disease, with mean disease duration of 3.2 years (± 2.1). The prevalence of non-dipping was 50%, which occurred even in the absence of nocturnal or daytime hypertension. Reduced diastolic BP dipping was associated with poorer endothelial function (r 0.5, p = 0.04). Intima-media thickness was significantly greater in subjects with non-dipping (mean standard deviation score of 3.0 vs 1.6, p = 0.02). In contrast, higher systolic and diastolic BP load were associated with increased aortic stiffness (ρ 0.6, p = 0.01 and ρ 0.7, p < 0.01, respectively), but not with endothelial function or intima-media thickness.

Conclusion

In a pSLE cohort with low disease activity, isolated nocturnal BP non-dipping is prevalent and associated with endothelial dysfunction and atherosclerotic changes. In addition to hypertension assessment, ABPM has a promising role in risk stratification and understanding heterogeneous mechanisms of cardiovascular disease in pSLE.

Reactive Hyperemia Index Associated With Atherosclerotic Cardiovascular Disease Under Treatment for Lifestyle Diseases

Background

Endothelial dysfunction is an early phase of atherosclerosis and causes atherosclerotic cardiovascular disease (ASCVD), but the cutoff reactive hyperemia index (RHI) for identifying ASCVD patients under treatment for lifestyle diseases is unknown.

Methods

Patients who visited Cardiology Section, Izumi General Medical Center, Kagoshima, Japan and were measured RHI using Endo-PAT 2000 during May 2014 and March 2016 were enrolled. We divided them into ASCVD and non-ASCVD groups and investigated the association with RHI between the groups.

Results

ASCVD group included 195 patients and non-ASCVD group included 288 patients. Age, body mass index and the rate of male, hypertension, diabetes, dyslipidemia and chronic kidney disease in the ASCVD group were significantly higher than those in non-ASCVD group. RHI in the ASCVD group (1.65 (1.40 - 1.92)) was significantly lower than that in the non-ASCVD group (1.73 (1.45 - 2.24)) (P < 0.05). In multi-regression analysis, RHI (odds ratio: 0.67, 95% confidence interval: 0.45 - 0.99, P = 0.04) was independently associated with ASCVD after adjusted by age, sex, body mass index, smoking, hypertension, diabetes, dyslipidemia and chronic kidney disease. The cutoff RHI value between the groups was 1.80.

Conclusion

RHI was significantly associated with ASCVD under treatment for lifestyle diseases and the cutoff value was 1.80.

Profiling the endothelial function using both peripheral artery tonometry (EndoPAT) and Laser Doppler Flowmetry (LD) - Complementary studies or waste of time?

Endothelial dysfunction (ED) plays a key role in developing of cardiovascular diseases and is an important predictor of future cardiovascular events. Nevertheless, there is no established method assessing endothelial function in general population. The most popular protocol includes the ultrasound-flow-mediated-dilation, but its repeatability is operator-dependent. We intended to compare the two other operator-independent methods assessing endothelial function - the EndoPAT and Laser Doppler flowmetry (LD), and we endeavored to place them on current individual profile of biochemical cardiovascular risk and endothelial function. A total of 61 clinically healthy subjects (aged 29 ± 1y) were investigated. The blood was collected for conventional cardiovascular risk markers, the NO-pathway metabolites (ADMA, L-arginine, SDMA), oxidative-stress-markers (MDA, thiol-index) as well as endothelial and platelet activation markers (sICAM1, sVCAM1, PAI-1, sE-selectin, sP-selectin, VEGF). Subsequently, all participants underwent examination by both EndoPAT and LD. There was a poor correlation between EndoPAT and LD results. No significant differences between participants with preserved and impaired endothelial function regarding endothelial activation nor cardiovascular risk markers were observed. Both methods assess endothelial function independently from the profile of endothelial pro/anti-inflammatory status and conventional risk factors, therefore further prospective studies are needed in order to verify their additional value in the cardiovascular risk stratification.

Endothelial dysfunction is not a predictor of outcome in chronic obstructive pulmonary disease

Background

Local airway inflammation may cause systemic changes which result in endothelial dysfunction. Only a few studies have used reactive hyperemia peripheral arterial tonometry (RH-PAT) in patients with chronic obstructive pulmonary disease (COPD) in order to measure their endothelial dysfunction.

Objective

To determine the efficacy of endothelial dysfunction, measured by RH-PAT, in assessing disease severity and systemic burden in a cohort of COPD patients.

Methods

In this prospective, monocentric study, 157 patients with moderate to very severe COPD (GOLD class II-IV) were examined for endothelial dysfunction using RH-PAT (Itamar medical Ltd., Caesarea, Israel). In a nested-cohort, examination was repeated at exacerbation. The association between reactive hyperemia index (RHI), augmentation index (AI) and disease severity and outcome parameters was analysed.

Results

57% of the COPD patients had a dysfunctional endothelium and the median (IQR) RHI was 1.42 (1.27–1.53). Exacerbation of COPD was not associated with a significant change in RHI (p = 0.625) or ΑΙ (p = 0.530). None of the diagnostic or clinical outcomes of COPD was associated with RHI or arterial stiffness.

Conclusion

Endothelial dysfunction is common in COPD. However, it does not seem to be a predictor neither of disease severity, nor of outcome and does not change during exacerbations of the disease.

Clinical significance of endothelial vasodilatory function evaluated by EndoPAT in patients with systemic sclerosis

Endothelial dysfunction is a hallmark of vasculopathy associated with systemic sclerosis (SSc). Reactive hyperemia peripheral arterial tonometry is a rapid and non-invasive technique to assess peripheral microvascular endothelial function by measuring changes in digital pulse volume during reactive hyperemia. Low scores of the reactive hyperemia index (RHI) imply an impaired vasodilatory response and, accordingly, impaired endothelial and vascular health. To investigate the clinical significance of the RHI in SSc patients, RHI values were measured in 43 SSc patients and 10 healthy controls. In diffuse cutaneous SSc (dcSSc) patients, RHI values were significantly decreased compared with healthy controls, and inversely correlated with disease duration. In total SSc patients, there was a significant inverse correlation between RHI values and skin score, and interstitial lung disease was associated with the decrease in RHI values. Among vascular symptoms, the current and past history of digital ulcers was seen more frequently in patients with decreased RHI values than in those with normal RHI values. Although no SSc patients had pulmonary arterial hypertension, an inverse correlation was evident between RHI values and mean pulmonary arterial pressure measured by right heart catheterization. These results indicate that the decrease in RHI values is associated with skin fibrosis, interstitial lung disease, digital ulcers and pulmonary vascular involvement leading to pulmonary arterial hypertension, supporting the canonical idea that endothelial dysfunction is a critical event underlying the development of tissue fibrosis and vascular complications in SSc.

Assessment of traditional and non-traditional risk factors for premature atherosclerosis in children with juvenile dermatomyositis and pediatric controls

BACKGROUND

Children with juvenile dermatomyositis (JDM), the most common inflammatory myopathy of childhood, may be at increased risk of premature atherosclerosis given a host of traditional and non-traditional risk factors. The primary aim of this study was to determine the underlying frequency of premature atherosclerosis in children with JDM compared to pediatric controls using flow-mediated dilation as a measure of endothelial function.

METHODS

Children and adolescents with and without JDM were evaluated for traditional atherosclerotic risk factors and assessment of endothelial function, using Endothelial Pulse Amplitude Testing (Endo-PAT).

RESULTS

In this study, 75% of pediatric controls were of Black or Hispanic descent (compared to 55% in the JDM group) and 70% were found to live in a household with a medium income less than $50,000/year (compared to 45% in the JDM group). Among traditional atherogenic risk factors, lipoprotein A appeared to be different between controls and JDM patients (66 nmol/L and 16.5 nmol/L, respectively). Using a reactive hyperemia index (RHI) < 1.67 as evidence of endothelial dysfunction, 75% of controls were defined as having endothelial dysfunction compared to 50% in JDM group. When controlled for lipoprotein A as an atherogenic confounder, JDM patients were found to have a 41% increase in RHI, thus indicating less endothelial dysfunction compared to controls.

CONCLUSIONS

In this study, we have shown that atherogenic risk factors are present in the pediatric population and may be associated with endothelial dysfunction, even at very young ages. Despite increasing concerns that children with rheumatologic disorders may be at increased risk of developing premature atherosclerosis, traditional and sociodemographic features may play a greater role in the ultimate development of cardiovascular disease.

Peripheral endothelial dysfunction in myalgic encephalomyelitis/chronic fatigue syndrome

AIMS

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex multisystem disease. Evidence for disturbed vascular regulation comes from various studies showing cerebral hypoperfusion and orthostatic intolerance. The peripheral endothelial dysfunction (ED) has not been sufficiently investigated in patients with ME/CFS. The aim of the present study was to examine peripheral endothelial function in patients with ME/CFS.

METHODS AND RESULTS

Thirty-five patients [median age 40 (range 18-70) years, mean body mass index 23.8 ± 4.2 kg/m² , 31% male] with ME/CFS were studied for peripheral endothelial function assessed by peripheral arterial tonometry (EndoPAT2000). Clinical diagnosis of ME/CFS was based on Canadian Criteria. Nine of these patients with elevated antibodies against β2-adrenergic receptor underwent immunoadsorption, and endothelial function was measured at baseline and 3, 6, and 12 months follow-up. ED was defined by reactive hyperaemia index ≤1.81. Twenty healthy subjects of similar age and body mass index were used as a control group. Peripheral ED was found in 18 of 35 patients (51%) with ME/CFS and in 4 healthy subjects (20%, P < 0.05). Patients with ED, in contrast to patients with normal endothelial function, reported more severe disease according to Bell score (31 ± 12 vs. 40 ± 16, P = 0.04), as well as more severe fatigue-related symptoms (8.62 ± 0.87 vs. 7.75 ± 1.40, P = 0.04) including a higher demand for breaks [9.0 (interquartile range 7.0-10.0) vs. 7.5 (interquartile range 6.0-9.25), P = 0.04]. Peripheral ED showed correlations with more severe immune-associated symptoms (r = -0.41, P = 0.026), such as sore throat (r = -0.38, P = 0.038) and painful lymph nodes (r = -0.37, P = 0.042), as well as more severe disease according to Bell score (r = 0.41, P = 0.008) and symptom score (r = -0.59, P = 0.005). There were no differences between the patient group with ED and the patient group with normal endothelial function regarding demographic, metabolic, and laboratory parameters. Further, there was no difference in soluble vascular cell adhesion molecule and soluble intercellular adhesion molecule levels. At baseline, peripheral ED was observed in six patients who underwent immunoadsorption. After 12 months, endothelial function had improved in five of these six patients (reactive hyperaemia index 1.58 ± 0.15 vs. 2.02 ± 0.46, P = 0.06).

CONCLUSIONS

Peripheral ED is frequent in patients with ME/CFS and associated with disease severity and severity of immune symptoms. As ED is a risk factor for cardiovascular disease, it is important to elucidate if peripheral ED is associated with increased cardiovascular morbidity and mortality in ME/CFS.

Endothelial Dysfunction and the Effect of Arginine and Citrulline Supplementation in Children and Adolescents With Mitochondrial Diseases

BACKGROUND

In addition to the reduced energy production, characteristic of mitochondrial disorders, nitric oxide (NO) deficiency can occur as well. The NO produced by vascular endothelial cells relaxes vascular smooth muscles, resulting in vasodilation that maintains the patency of small blood vessels and promotes blood flow through microvasculature. Endothelial dysfunction due to inability of vascular endothelium to generate enough NO to maintain adequate vasodilation can result in decreased perfusion in the microvasculature of various tissues, contributing to many complications seen in individuals with mitochondrial diseases. The amino acids arginine and citrulline are NO precursors: increasing their concentrations could potentially restore NO production.

METHODS

In this study, we assessed endothelial dysfunction in children and adolescents with mitochondrial diseases. We also investigated the effect of arginine and citrulline supplementation on endothelial dysfunction in these individuals. We used peripheral arterial tonometry to measure the reactive hyperemic index (RHI), which is low when there is endothelial dysfunction.

RESULTS

The results demonstrated low RHI in individuals with mitochondrial diseases, indicating endothelial dysfunction. RHI increased with arginine or citrulline supplementation suggesting that supplementation with NO precursors can improve endothelial dysfunction by enhancing NO production.

CONCLUSIONS

This study is the first one to use peripheral arterial tonometry methodology in mitochondrial diseases. The results of this study provide evidence for endothelial dysfunction in mitochondrial diseases and demonstrate that arginine or citrulline supplementation can alleviate the endothelial dysfunction, providing more evidence for the potential therapeutic utility of these amino acids in mitochondrial diseases.

Tadalafil may improve cerebral perfusion in small-vessel occlusion stroke-a pilot study

New treatments for cerebral small-vessel disease are needed to reduce the risk of small-vessel occlusion stroke and vascular cognitive impairment. We investigated an approach targeted to the signalling molecule cyclic guanosine monophosphate, using the phosphodiesterase 5 inhibitor tadalafil, to explore if it improves cerebral blood flow and endothelial function in patients with cerebral small-vessel disease and stroke. In a randomized, double-blinded, placebo-controlled, cross-over pilot trial (NCT02801032), we included patients who had a previous (>6 months) small-vessel occlusion stroke. They received a single dose of either 20 mg tadalafil or placebo on 2 separate days at least 1 week apart. We measured the following: baseline MRI for lesion load, repeated measurements of blood flow velocity in the middle cerebral artery by transcranial Doppler, blood oxygen saturation in the cortical microvasculature by near-infrared spectroscopy, peripheral endothelial response by EndoPAT and endothelial-specific blood biomarkers. Twenty patients with cerebral small-vessel disease stroke (3 women, 17 men), mean age 67.1 ± 9.6, were included. The baseline mean values ± standard deviations were as follows: blood flow velocity in the middle cerebral artery, 57.4 ± 10.8 cm/s; blood oxygen saturation in the cortical microvasculature, 67.0 ± 8.2%; systolic blood pressure, 145.8 ± 19.5 mmHg; and diastolic blood pressure, 81.3 ± 9.1 mmHg. We found that tadalafil significantly increased blood oxygen saturation in the cortical microvasculature at 180 min post-administration with a mean difference of 1.57 ± 3.02%. However, we saw no significant differences in transcranial Doppler measurements over time. Tadalafil had no effects on peripheral endothelial function assessed by EndoPAT and endothelial biomarker results conflicted. Our findings suggest that tadalafil may improve vascular parameters in patients with cerebral small-vessel disease stroke, although the effect size was small. Increased oxygenation of cerebral microvasculature during tadalafil treatment indicated improved perfusion in the cerebral microvasculature, theoretically presenting an attractive new therapeutic target in cerebral small-vessel disease. Future studies of the effect of long-term tadalafil treatment on cerebrovascular reactivity and endothelial function are needed to evaluate general microvascular changes and effects in cerebral small-vessel disease and stroke.

Preclinical vascular alterations in obese adolescents detected by Laser-Doppler Flowmetry technique

BACKGROUND AND AIMS

Childhood obesity promotes adverse changes in cardiovascular structure and function. This study evaluated whether alterations in skin microcirculation were already present in obese adolescents in a pre-clinical phase of cardiovascular disease.

METHODS AND RESULTS

After an overnight fasting 22 obese adolescents and 24 normal-weight controls of similar age and gender distribution underwent clinical and blood examination and assessment of microvascular function by using two non-invasive techniques such as Peripheral Artery Tonometry (PAT) and Laser-Doppler Flowmetry (LDF). As compared to normal weight subjects, obese children had higher blood pressure, were significantly more hyper-insulinemic and insulin resistant, showing significantly higher plasma total cholesterol, LDL cholesterol, triglycerides and alanine aminotransferase (ALT). LDF showed lower pre- and post-occlusion forearm skin perfusion (perfusion units/second (PU/sec); median [IQR]) in obese than in normal weight subjects (pre-occlusion: 1633.8 [1023.5] vs. 2281.1 [1344.2]; p = 0.015. Post-occlusion: 4811.3 [4068.9] vs. 7072.8 [7298.8]; p = 0.021), while PAT revealed similar values of reactive hyperemia index (RHI). In entire population, fat mass % (FM%) was an independent determinant of both pre-and post-occlusion skin perfusion. Finally, being obese was associated with a higher risk to have a reduction of both pre- and post-occlusion skin perfusion (OR = 5,82 and 9,27, respectively).

CONCLUSION

LDF showed very early, pre-clinical, vascular involvement in obese adolescents, characterized by impaired skin microcirculation, possibly reflecting a more diffuse microvascular dysfunction to other body tissues. Whether changing life style and improving weight may reverse such pre-clinical alterations remains to be established.

Reactive hyperemia: a review of methods, mechanisms, and considerations

Reactive hyperemia is a well-established technique for noninvasive assessment of peripheral microvascular function and a predictor of all-cause and cardiovascular morbidity and mortality. In its simplest form, reactive hyperemia represents the magnitude of limb reperfusion following a brief period of ischemia induced by arterial occlusion. Over the past two decades, investigators have employed a variety of methods, including brachial artery velocity by Doppler ultrasound, tissue reperfusion by near-infrared spectroscopy, limb distension by venous occlusion plethysmography, and peripheral artery tonometry, to measure reactive hyperemia. Regardless of the technique used to measure reactive hyperemia, blunted reactive hyperemia is believed to reflect impaired microvascular function. With the advent of several technological advancements, together with an increased interest in the microcirculation, reactive hyperemia is becoming more common as a research tool and is widely used across multiple disciplines. With this in mind, we sought to review the various methodologies commonly used to assess reactive hyperemia and current mechanistic pathways believed to contribute to reactive hyperemia and reflect on several methodological considerations.

Endothelial dysfunction and arterial stiffness in patients with systemic lupus erythematosus: A systematic review and meta-analysis

BACKGROUND AND AIMS

Non-invasive surrogates of cardiovascular (CV) disease such as endothelial dysfunction (ED) and peripheral arterial stiffness (AS) have been evaluated in systemic lupus erythematosus (SLE) patients. The aim of this study was to systematically review and meta-analyze reports of cardiovascular disease (CVD) in SLE patients, as measured by ED and AS.

METHODS

Studies analyzing the relationship of SLE with ED (flow-mediated dilatation [FMD], nitroglycerin-mediated dilatation [NMD] and peripheral arterial tonometry [PAT]) and AS (augmentation index [AIx], pulse wave velocity [PWV]) were systematically searched for in PubMed, Cochrane library, EMBASE, VHL, SciELO and Web of Science databases. Inclusion criteria included peer-review and English language. Mean differences (MD) and 95% confidence intervals (CIs) were estimated using the random effect model. The study was registered with PROSPERO, number CRD42019121068.

RESULTS

The meta-analysis included 49 studies. FMD data from 18 studies including 943 SLE subjects (mean age = 38.71 [95%CI 36.21, 41.21] years) and 644 unaffected controls (mean age = 38.63 [95%CI 36.11, 41.15] years) were included. When compared with unaffected controls, FMD in SLE subjects was decreased by 4.3% (95%CI: -6.13%, -2.47%): p < 0.001). However, NMD did not significantly differ between SLE patients and controls (MD = - 2.68%; 95% CI -6.00, 0.62; p = 0.11). A significantly increased AS between SLE patients and controls according to overall PWV (MD = 1.12 m/s; 95% CI 0.72-1.52; p < 0.001) was observed, but not for the brachial-ankle PWV. AIx was also increased in SLE patients compared with healthy controls (MD = 4.55%; 95% CI 1.48-7.63; p = 0.003).

CONCLUSIONS

Overall, SLE patients showed impaired FMD, an independent predictor of CV events. There was a higher degree of AS in SLE patients compared with controls. ED and AS in SLE should be considered when planning preventive strategies and therapies.

Influencing factors of vascular endothelial function in patients with non-obstructive coronary atherosclerosis: a 1-year observational study

BACKGROUND

Endothelial dysfunction may play a key role in non-obstructive coronary artery atherosclerosis. Our study aimed to evaluate the vascular endothelial function and its influencing factors in patients with non-obstructive coronary artery atherosclerosis.

METHODS

A total of 131 consecutive patients with non-obstructive coronary artery atherosclerosis were enrolled. Flow-mediated dilatation (FMD) was measured at baseline and 1-year follow-up. Endothelial progenitor cells (EPCs) were counted by staining the fasting venous blood with antibodies against CD34 and vascular endothelial growth factor receptor 2.

RESULTS

Systolic blood pressure, pulse pressure and the levels of HbA1c in participants with baseline FMD < 6% (n = 65) were significantly higher than those with baseline FMD ≥ 6% (n = 66). Baseline FMD was negatively associated with EPC counts (r = - 0.199, P < 0.05) and systolic blood pressure (r = - 0.315, P < 0.01). The 1-year FMD was significantly increased compared to the baseline FMD [(9.31 ± 5.62) % vs (7.31 ± 5.26) %, P < 0.001]. Independent predictors of FMD improvement included elevated EPC counts (OR = 1.104, 95% CI: 1.047-1.165, P < 0.001) and decreased levels of serum creatinine (OR = 0.915, 95% CI: 0.843-0.993, P = 0.034).

CONCLUSIONS

Family history of premature cardiovascular diseases, hypertension, elevated systolic pressure, and HbA1c > 6.5% are independent risk factors for endothelial dysfunction in non-obstructive atherosclerotic patients. Elevated peripheral blood EPC counts and decreased levels of serum creatinine are independent predictors of endothelial function improvement.

Systemic Lupus Erythematosus and Endothelial Dysfunction: A Close Relationship

BACKGROUND

Accelerated atherosclerosis, responsible for premature cardiovascular disease, has been estimated to develop or progress in 10% of systemic lupus erythematosus (SLE) patients each year and to be 6-fold more frequent in SLE compared with the general population. The mechanisms underlying accelerated atherosclerosis in SLE are complex and involve classical and "non-classical" cardiovascular risk factors. Subclinical and disseminated atherosclerosis is associated with endothelial dysfunction and arterial stiffness.

OBJECTIVE

The aim of this review is to analyze the association between SLE and endothelial dysfunction.

RESULTS AND CONCLUSION

Different mechanisms have been proposed to explain the prevalence of endothelial dysfunction in SLE, which are briefly reported in this review: impaired clearance of apoptotic cells, oxidative stress markers, B cell activation with different circulating autoantibodies, different subtypes of T lymphocytes, cytokine cascade. Several studies and meta-analyses show a significant trend towards a prevalence of subclinical accelerated atherosclerosis in patients with SLE compared with healthy controls, since childhood. Based on general considerations, we suggest a multidisciplinary management to assess endothelial dysfunction at the diagnosis of the disease and to periodically search for and treat the traditional cardiovascular risk factors. Prospective studies are needed to confirm the benefits of this management.

Evaluation of Vascular Endothelial Function in Young and Middle-Aged Women with Respect to a History of Pregnancy, Pregnancy-Related Complications, Classical Cardiovascular Risk Factors, and Epigenetics

The aim of the study was to examine the effect of previous pregnancies and classical cardiovascular risk factors on vascular endothelial function in a group of 264 young and middle-aged women 3 to 11 years postpartum. We examined microvascular functions by peripheral arterial tonometry and EndoPAT 2000 device with respect to a history of gestational hypertension, preeclampsia, fetal growth restriction, the severity of the disease with regard to the degree of clinical signs and delivery date. Besides, we compared Reactive Hyperemia Index (RHI) values and the prevalence of vascular endothelial dysfunction among the groups of women with normal and abnormal values of BMI, waist circumference, systolic and diastolic blood pressures, heart rate, total serum cholesterol levels, serum high-density lipoprotein cholesterol levels, serum low-density lipoprotein cholesterol levels, serum triglycerides levels, serum lipoprotein A levels, serum C-reactive protein levels, serum uric acid levels, and plasma homocysteine levels. Furthermore, we determined the effect of total number of pregnancies and total parity per woman, infertility and blood pressure treatment, presence of trombophilic gene mutations, current smoking of cigarettes, and current hormonal contraceptive use on the vascular endothelial function. We also examined the association between the vascular endothelial function and postpartum whole peripheral blood expression of microRNAs involved in pathogenesis of cardiovascular/cerebrovascular diseases (miR-1-3p, miR-16-5p, miR-17-5p, miR-20a-5p, miR-20b-5p, miR-21-5p, miR-23a-3p, miR-24-3p, miR-26a-5p, miR-29a-3p, miR-92a-3p, miR-100-5p, miR-103a-3p, miR-125b-5p, miR-126-3p, miR-130b-3p, miR-133a-3p, miR-143-3p, miR-145-5p, miR-146a-5p, miR-155-5p, miR-181a-5p, miR-195-5p, miR-199a-5p, miR-210-3p, miR-221-3p, miR-342-3p, miR-499a-5p, and miR-574-3p). A proportion of overweight women (17.94% and 20.59%) and women with central obesity (18.64% and 21.19%) had significantly lower RHI values at 10.0% false positive rate (FPR) both before and after adjustment of the data for the age of patients. At 10.0% FPR, a proportion of women with vascular endothelial dysfunction (RHI ≤ 1.67) was identified to have up-regulated expression profile of miR-1-3p (11.76%), miR-23a-3p (17.65%), and miR-499a-5p (18.82%) in whole peripheral blood. RHI values also negatively correlated with expression of miR-1-3p, miR-23a-3p, and miR-499a-5p in whole peripheral blood. Otherwise, no significant impact of other studied factors on vascular endothelial function was found. We suppose that screening of these particular microRNAs associated with vascular endothelial dysfunction may help to stratify a highly risky group of young and middle-aged women that would benefit from early implementation of primary prevention strategies. Nevertheless, it is obvious, that vascular endothelial dysfunction is just one out of multiple cardiovascular risk factors which has only a partial impact on abnormal expression of cardiovascular and cerebrovascular disease associated microRNAs in whole peripheral blood of young and middle-aged women.

Baseline Results: The Association Between Cardiovascular Risk and Preclinical Alzheimer's Disease Pathology (ASCEND) Study

BACKGROUND

The rate of AD for African Americans (AAs) is 64% higher than for non-Hispanic White Americans (Whites). It is hypothesized that poor peripheral vascular function, in combination with genetics, stress, and inflammation may directly contribute to the accumulation of AD pathologic biomarkers. These risk factors may disproportionately affect AAs.

OBJECTIVE

Our objective was to determine if in a healthy middle-aged cohort at risk for AD (1) AD biomarkers in CSF differ by race, (2) peripheral vascular dysfunction and cognition are related to a higher burden of CSF AD biomarkers, and (3) these relationships differ by race.

METHODS

We enrolled 82 cognitively normal, middle-aged (45 and older) adults including AAs and Whites at high risk for AD due to parental history. Study procedures included lumbar puncture, vascular ultrasound, and cognitive testing.

RESULTS

While participants were in overall good health, AAs exhibited poorer indices of preclinical vascular health, including higher central SBP, central MAP, and EndoPAT AI, a marker of arterial stiffness. AAs also had significantly less cerebrospinal fluid tau burden than Whites. After polynomial regression analysis, adjusted for age, gender, education, and ApoE4 status, race significantly modified the relationship between total tau, phospho-tau, and Trails B, a marker of executive function. Small differences in tau correlated with poorer cognition in AAs.

CONCLUSION

In a healthy middle-aged cohort at risk for AD, AAs had worse peripheral vascular health and worse cognition than Whites. Despite lower tau burden overall, race modified the relationship between tau and cognition, such that small differences in tau between AAs was related to worse cognition when compared to Whites.

Dynamics of Soluble Thrombomodulin and Circulating miRNAs in Patients with Atrial Fibrillation Undergoing Radiofrequency Catheter Ablation

Atrial fibrillation (AF) is the most common cardiac arrhythmia in the world and has a high risk of thromboembolism. The most effective approach, catheter ablation, requires evaluation by electrocardiography. The aim of our study was to investigate novel clinical markers that predict restoration of sinus rhythm (SR) after catheter ablation. Seventy-eight consecutive patients with AF underwent catheter ablation and were separated into 2 groups: restored SR and recurrent AF. The levels of 4 blood proteins (serum or plasma) and 3 mature microRNAs (miRNAs) and their primary miRNAs (pri-miRNAs) in serum were measured before and after ablation, and the associations between each parameter were analyzed statistically. Soluble thrombomodulin (s-TM) and plasminogen activator inhibitor-1 (PAI-1) levels increased above baseline after ablation in both the restored SR (s-TM 11.55 [2.92] vs 13.75 [3.38], P < .001; PAI-1 25.74 [15.25] vs 37.79 [19.56], P < .001) and recurrent AF (s-TM 10.28 [2.78] vs 11.67 [3.37], P < .001; PAI-1 26.16 [15.70] vs 40.74 [22.55], P < .001) groups. Levels of C-reactive protein and asymmetric dimethylarginine were not significantly changed. Pri-miR-126 levels significantly decreased after ablation in the recurrent AF group, but the other miRNAs and pri-miRNAs did not. The measurement of s-TM and pri-miR-126 in blood was a useful tool to reflect the condition of AF patients with catheter ablation.

In vivo assessment of endothelial function in small animals using an infrared pulse detector

Objective

Endothelial dysfunction is the earliest change in atherosclerosis. Flow-mediated dilatation (FMD) is used to assess endothelial function in humans. However, this assessment is not easy in small animals. This study demonstrated the reliability and reproducibility of a proposed instrument for in vivo assessment of FMD in a rodent model using infrared pulse sensors.

Materials and Methods

We used 24 adult male Wistar Kyoto rats randomly divided into three groups. FMD was measured under continuous infusion of normal saline followed by intra-arterial infusion of acetylcholine (Ach; n = 8), sodium nitroprusside (SNP; n = 8), or N^ω-nitro-_L-arginine methyl ester (_L-NAME; n = 8).

Results

The dilatation indices (DIs) of all three groups were similar before application of the vasoactive agents (1.82 ± 0.46, 1.81 ± 0.44, and 1.93 ± 0.40, P = 0.877, by one-way analysis of variance). The DI was significantly increased during infusion of Ach (2.97 ± 1.03 vs. 1.82 ± 0.46, P = 0.015), unchanged during infusion of SNP (1.81 ± 0.44 vs. 1.98 ± 0.40, P = 0.574), and attenuated during infusion of _L-NAME (1.91 ± 0.40 vs. 1.42 ± 0.35; P = 0.028).

Conclusion

The results of this study correlated well with those of human studies, suggesting that this method can be used for in vivo evaluation of endothelial function in small animals.

EVALUATION INDEX OF ADULT MALE BLOOD VESSEL AGE-BASED ON PULSE WAVE WAVEFORM CHARACTERISTIC PARAMETERS

The aim of this study was to find a non-invasive pulse wave waveform index that was highly correlated with cardiovascular disease and to establish an effective model for cardiovascular health assessment in middle-aged men to provide early warning of possible cardiovascular and cerebrovascular diseases. Considering the characteristics of pulse wave easy to detect and rich physiological information, the paper collected pulse waves of healthy males at six age groups, and collected 50 samples per age group. The pulse wave waveform parameters of each sample were extracted, including inflow time, outflow time, total beat time, fast inflow time, inflow time ratio and waveform coefficient [Formula: see text] value, the differences of which in different age groups were analyzed. Stepwise regression analysis was used to establish the relationship between age and pulse waveform parameters. The results show that the indicators of inflow time, inflow time ratio and fast inflow time have obvious differences with age, and with the increase of age, these three indicators show a steady upward trend. The indicators of outflow time, total beat time, and waveform coefficient are not sensitive to age changes. A predictive model of vessel age was established: [Formula: see text] time ([Formula: see text]). The pulse wave inflow time of hypertensive patients was substituted into the above-mentioned model, and the calculated blood vessel age was greater than the actual age. The age difference is greater than 5 years old. This study suggests that the pulse wave parameters of inflow time, fast inflow time and inflow time ratio has a significant and stable trend with age, indicating that they are closely related to vascular elasticity, compliance and stiffness, and can be used as predictors of cardiovascular disease.

Application of Non-invasive Imaging in Inflammatory Disease Conditions to Evaluate Subclinical Coronary Artery Disease

PURPOSE OF REVIEW

Traditional risk models, such as the Framingham risk score, fail to capture the increased cardiovascular disease risk seen in patients with chronic inflammatory diseases. This review will cover imaging modalities and their emerging applications in assessing subclinical cardiovascular disease for both research and clinical care in patients with chronic inflammatory diseases.

RECENT FINDINGS

Multiple imaging modalities have been studied to assess for subclinical cardiovascular disease via functional/physiologic, inflammatory, and anatomic assessment in patients with chronic inflammatory diseases. The use of imaging to evaluate subclinical cardiovascular disease in patients with chronic inflammatory diseases has the potential to capture early sub-clinical atherosclerosis, to improve risk stratification of future cardiovascular events, and to guide effective disease management.

Establishing a Differential Marker Profile for Pregnancy Complications Near Delivery

OBJECTIVE

The aim of this work was to define a differential marker profile for pregnancy complications near delivery.

METHODS

We enrolled pregnant women who were referred to the outpatient pregnancy clinic of the University Medical Center, Ljubljana, Slovenia, due to symptoms of pregnancy complications and women with a history of pregnancy complications attending the high-risk hospital clinic for close surveillance. They were evaluated for prior risk and were tested for biophysical and biochemical markers at the time of enrolment. Biochemical markers included the pro- and anti-angiogenic markers, along with additional previously reported markers of potential value, all tested by various formats of immuno-diagnostics. Biophysical markers included blood pressure, sonographic markers, and EndoPAT. Statistical differences were determined with Kruskal-Wallis and Mann-Whitney tests for continuous parameters, and Pearson χ2 for categorical values. p < 0.05 was considered significant.

RESULTS

The cohort included 125 pregnant patients, 31 developed preeclampsia (PE) alone (13 were <34 weeks' gestation), 16 had intrauterine growth restriction (IUGR) alone (12 were <34 weeks), 42 had both IUGR and PE (22 were <34 weeks), and 15 had an iatrogenic preterm delivery (PTD; 6 were <34 weeks). Twenty-one were unaffected and delivered a healthy baby at term. Mean arterial blood pressure and proteinuria were significantly higher in PE and PE+IUGR but not in pure IUGR or PTD. In PE, IUGR, and PE+IUGR, the levels of soluble fms-like tyrosine kinase 1 (sFlt-1) and soluble endoglin (sEng) were significantly higher, while placental growth factor (PlGF) was very low compared to unaffected controls and PTD. PE, IUGR, and PE+IUGR also had a high anti-angiogenic ratio (sFlt-1/PlGF) and a low proangiogenic ratio of PlGF/(sFlt-1+Eng). Levels of inhibin A were significantly higher in pure PE across subgroups but had many extreme values, which made it a poor differentiator. Higher uterine artery Doppler pulsatility indexes were detected in PE, IUGR, and PE+IUGR, with similar resistance indexes and peaks of systolic velocity. A significantly different marker level between PE and IUGR was found using arterial stiffness that was 10 times higher in PE; concurrently with an increase of the reactive hyperemia index, both were accompanied by a slight increase in placental protein 13. Higher tumor necrosis factor alpha (TNFα) differentially identified iatrogenic very early PTD (<34 weeks).

CONCLUSION

Arterial stiffness can serve as a major marker to differentiate PE (with/without IUGR) from pure IUGR near delivery. TNFα can differentiate iatrogenic early PTD from other complications of pregnancy and term IUGR.

Vascular Health of Children Conceived via In Vitro Fertilization

OBJECTIVE

To evaluate whether in vitro fertilization (IVF) has an effect on the cardiovascular health of offspring.

STUDY DESIGN

This was a cross-sectional pilot study. We performed vascular health assessment for 17 children aged 10-14 years who were conceived via IVF with autologous oocytes at Stanford University. Carotid artery ultrasound evaluated intima-media thickness and stiffness, carotid-femoral pulse wave velocity determined segmental arterial stiffness, and endothelial pulse amplitude testing assessed endothelial function. We compared IVF offspring with control adolescents assessed in the same laboratory, with all comparisons adjusted for age, sex, and race/ethnicity.

RESULTS

All participants had normal body mass index and blood pressure. Compared with controls, IVF children had thicker common carotid artery intima-media thickness (0.44 ± 0.03 mm vs 0.38 ± 0.03 mm; P < .01), higher elastic modulus (395.29 ± 185.33 mm Hg vs 242.79 ± 37.69 mm Hg; P = .01), higher βstiffness (2.65 ± 0.38 vs 2.28 ± 0.23; P < .01), and higher peak velocity (142.29 ± 31.62 cm/s vs 117.71 ± 32.69 cm/s; P = .04). The mean endothelial pulse amplitude testing reactive hyperemia index was not significantly different between IVF and controls. The mean pulse wave velocity was 4.69 ± 0.51 m/s compared with the controls 4.60 ± 0.57 m/s (P = .11), with 8 (47%) having abnormal values.

CONCLUSION

In an assessment of endothelial function and arterial properties of children conceived via IVF, we found that children conceived via IVF seem to have evidence of abnormal vascular health. Further studies with larger sample size and long-term follow-up are warranted.

Arterial Stiffness and Endothelial Function in Young Obese Patients - Vascular Resistance Matters

AIM

Motivated by the paradoxical and differing results of the early atherosclerosis related indices - Cardio-Ankle Vascular Index (CAVI) reflecting arterial stiffness and Reactive Hyperemia Index (RHI) evaluating endothelium dependent flow-induced vasodilation - in obesity, we aimed to assess CAVI and RHI in obese adolescents and young adults in the context of differences in systemic vascular resistance (SVR).

METHODS

We examined 29 obese (14f, 15.4 [12.3-18.5] y; BMI: 33.2±4.4 kg.m-2) and 29 non-obese gender and age matched adolescents and young adults (BMI: 21.02±2.3 kg.m-2). CAVI and RHI were measured using VaSera VS-1500 (Fukuda Denshi, Japan) and Endo-PAT 2000 (Itamar Medical, Israel), respectively. Hemodynamic measures were recorded using volume-clamp plethysmography (Finometer Pro, FMS, Netherlands) and impedance cardiography (CardioScreen 2000, Medis GmbH, Germany). SVR and sympathetic activity related indices - Velocity Index (VI) and Heather Index (HI), and LFSAP (spectral power in low frequency band of systolic blood pressure oscillations) were determined.

RESULTS

In obese group, CAVI (4.59±0.88 vs. 5.18±0.63, p=0.002) and its refined version CAVI0 (6.46±1.39 vs.7.33±0.99, p=0.002) were significantly lower. No significant difference in RHI was found. SVR and sympathetic activity indices were all significantly lower in the obese group than in the non-obese group. RHI correlated positively with SVR (r=0.390, p=0.044) in obese subjects.

CONCLUSION

Our results indicate that both indices used for the detection of early atherosclerotic changes are influenced by vascular tone. Vascular resistance could influence CAVI and RHI results impairing their interpretation.

Effects of Dapagliflozin on Endothelial Function, Renal Injury Markers, and Glycemic Control in Drug-Naïve Patients with Type 2 Diabetes Mellitus

BACKGROUND

The study aimed to evaluate the effects of dapagliflozin and metformin on vascular endothelial function and renal injury markers.

METHODS

This prospective, randomized, open-label, crossover study included drug-naïve patients with type 2 diabetes mellitus, who were randomized to receive 8 weeks of initial treatment using metformin or dapagliflozin and crossed over for another 8 weeks of treatment after a 1-week washout period. Systemic endothelial function was evaluated via the reactive hyperemic index (RHI).

RESULTS

The 22 participants included 10 males (45.5%) and had a median age of 58 years. The RHI values were not significantly changed during both 8-week treatment periods and there was no significant difference between the treatments. Relative to the metformin group, 8 weeks of dapagliflozin treatment produced significantly higher median N-acetyl-beta-D-glucosaminidase levels (10.0 ng/mL [interquartile range (IQR), 6.8 to 12.1 ng/mL] vs. 5.6 ng/mL [IQR, 3.8 to 8.0 ng/mL], P=0.013). Only the dapagliflozin group exhibited improved homeostatic model assessment of insulin resistance and body weight, while serum ketone and β-hydroxybutyrate levels increased.

CONCLUSION

Dapagliflozin treatment did not affect systemic endothelial function or renal injury markers except N-acetyl-beta-D-glucosaminidase.

The effect of curing hepatitis C with direct-acting antiviral treatment on endothelial function

BACKGROUND

Epidemiological data suggest that chronic HCV infection (CHC) is associated with increased cardiovascular risk, but it is unknown if it is associated with endothelial dysfunction. We aimed to assess the effect of antiviral treatment on endothelial function in non-cirrhotic adults with CHC.

METHODS

Self-controlled before and after study. All patients had genotype-1 CHC and were treated with 12 weeks of paritaprevir/ritonavir, ombitasvir and dasabuvir (PrOD), with ribavirin added for those with genotype-1a infection. Endothelial function was assessed at three time points before antiviral treatment, at treatment weeks 1, 4, 8 and 12, and 12 weeks after the end of treatment. The main assessment tools were reactive hyperaemia peripheral arterial tonometry (RHPAT) and serum concentrations of angiopoietin-2 (Ang-2) and E-selectin.

RESULTS

A total of 16 patients were enrolled. Mean (sd) age was 51.4 (6.9) years and 11 participants (69%) were male. All 16 patients achieved a sustained virological response. The mean (sd) baseline RHPAT index was 2.05 (0.48), and there was no significant change during treatment (mean within-patient change from baseline to end of treatment =-0.23 [0.45]; P= not significant). There was a significant improvement in both mean Ang-2 (baseline 2.44 [0.79] ng/ml, within-patient change -0.60 [0.44]; P<0.001) and E-selectin (baseline 48.7 [21.5] ng/ml, within-patient change -14.4 [13.0]; P<0.001).

CONCLUSIONS

Removing HCV viraemia is associated with a significant improvement in endothelial function as measured by serum markers, but not in bedside microvascular reactivity. Chronic HCV viraemia may be associated with endothelial cell dysfunction and therefore long-term cardiovascular risk.

Android Fat Deposition and Its Association With Cardiovascular Risk Factors in Overweight Young Males

Objective

Excess adiposity increases the risk of type-2 diabetes and cardiovascular disease development. Beyond the simple level of adiposity, the pattern of fat distribution may influence these risks. We sought to examine if higher android fat distribution was associated with different hemodynamic, metabolic or vascular profile compared to a lower accumulation of android fat deposits in young overweight males.

Methods

Forty-six participants underwent dual-energy X-ray absorptiometry and were stratified into two groups. Group 1: low level of android fat (<9.5%) and group 2: high level of android fat (>9.5%). Assessments comprised measures of plasma lipid and glucose profile, blood pressure, endothelial function [reactive hyperemia index (RHI)] and muscle sympathetic nerve activity (MSNA).

Results

There were no differences in weight, BMI, total body fat and lean mass between the two groups. Glucose tolerance and insulin resistance (fasting plasma insulin) were impaired in group 2 (p < 0.05). Levels of plasma triglycerides and 5 lipid species were higher in group 2 (p < 0.05). Endothelial function was less in group 2 (RHI: 1.64 vs. 2.26, p = 0.003) and heart rate was higher (76 vs. 67 bpm, p = 0.004). No difference occurred in MSNA nor blood pressure between the 2 groups.

Conclusion

Preferential fat accumulation in the android compartment is associated with increased cardiovascular and metabolic risk via alteration of endothelial function.

The Role of Inflammation in the Endothelial Dysfunction in a Cohort of Pediatric Patients With Inflammatory Bowel Disease

OBJECTIVES

Chronic inflammation plays a central role in the etiology of endothelial damage. Endothelial dysfunction (ED) is the inability of the artery to dilate in response to an endothelial stimulus. We assessed the ED by measuring the reactive hyperaemia index (RHI) and the flow-mediated dilation (FMD) in a cohort of pediatric patients affected by inflammatory bowel disease (IBD) and comparing these parameters to a group of healthy controls (HC).

METHODS

Forty-one patients were consecutive enrolled. ED was evaluated by both the plethysmographic RHI method and the measurement of the FMD of brachial artery after occlusion of the blood flow. Differences between patients and controls were assessed by the Mann-Whitney test. In each patient with IBD, the main inflammation markers were detected and correlated to RHI and FMD by a linear regression test.

RESULTS

We enrolled 26 (59%) patients with IBD and 18 (41%) HC. When comparing FMD value at diagnosis it was significantly lower in IBD patients than in HC (P = 0.04). This result was confirmed at follow-up, when this difference became even more significant (P = 0.004). A significant indirect correlation was found between FMD and fecal calprotectin (r: 0.17; P = 0.04). No differences were found when comparing RHI.

CONCLUSIONS

Our results suggest that inflammation could lead to ED assessed by ultrasound FMD. These data were not confirmed by RHI; however, this could be due to the lack of a standardized pediatric cut-off. More studies are necessary to confirm our data.

Physiological Impact and Clinical Relevance of Passive Exercise/Movement

Passive exercise/movement has a long history in both medicine and physiology. Early clinical applications of passive exercise/movement utilized pneumatic and direct limb compression to stimulate the vasculature and evoke changes in blood flow to avoid complications brought about by stasis and vascular disease. Over the last 50 years, passive exercise/movement has continued to progress and has provided physiologists with a reductionist approach to mechanistically examine the cardiorespiratory, hyperemic, and afferent responses to movement without the confounding influence of metabolism that accompanies active exercise. This review, in addition to providing an historical perspective, focuses on the recent advancements utilizing passive leg movement, and how the hyperemic response at the onset of this passive movement has evolved from a method to evaluate the central and peripheral regulation of blood flow during exercise to an innovative and promising tool to assess vascular function. As an assessment of vascular function, passive leg movement is relatively simple to perform and provides a nitric oxide-dependent evaluation of endothelial function across the lifespan that is sensitive to changes in activity/fitness and disease state (heart failure, peripheral artery disease, sepsis). The continual refinement and characterization of passive leg movement are aimed at improving our understanding of blood flow regulation and the development of a clinically ready approach to predict and monitor the progression of cardiovascular disease.

Iatrogenic Hyperinsulinemia, Not Hyperglycemia, Drives Insulin Resistance in Type 1 Diabetes as Revealed by Comparison With GCK-MODY (MODY2)

Although insulin resistance consistently occurs with type 1 diabetes, its predominant driver is uncertain. We therefore determined the relative contributions of hyperglycemia and iatrogenic hyperinsulinemia to insulin resistance using hyperinsulinemic-euglycemic clamps in three participant groups (n = 10/group) with differing insulinemia and glycemia: healthy control subjects (euinsulinemia and euglycemia), glucokinase-maturity-onset diabetes of the young (GCK-MODY; euinsulinemia and hyperglycemia), and type 1 diabetes (hyperinsulinemia and hyperglycemia matching GCK-MODY). We assessed the contribution of hyperglycemia by comparing insulin sensitivity in control and GCK-MODY and the contribution of hyperinsulinemia by comparing GCK-MODY and type 1 diabetes. Hemoglobin A1c was normal in control subjects and similarly elevated for type 1 diabetes and GCK-MODY. Basal insulin levels in control subjects and GCK-MODY were nearly equal but were 2.5-fold higher in type 1 diabetes. Low-dose insulin infusion suppressed endogenous glucose production similarly in all groups and suppressed nonesterified fatty acids similarly between control subjects and GCK-MODY, but to a lesser extent for type 1 diabetes. High-dose insulin infusion stimulated glucose disposal similarly in control subjects and GCK-MODY but was 29% and 22% less effective in type 1 diabetes, respectively. Multivariable linear regression showed that insulinemia-but not glycemia-was significantly associated with muscle insulin sensitivity. These data suggest that iatrogenic hyperinsulinemia predominates in driving insulin resistance in type 1 diabetes.

Elevated serum uric acid is associated with peripheral endothelial dysfunction in women

BACKGROUND AND AIMS

Both elevated serum uric acid (SUA) and peripheral endothelial dysfunction (PED) are associated independently with cardiovascular disease (CVD). However, the association between SUA and PED is yet to be established. We hypothesized that high normal range of SUA is associated with PED.

METHODS

We performed a retrospective cross-sectional analysis of patients who were referred to Mayo Clinic between 2006 and 2014 for routine cardiovascular evaluation and who underwent evaluation of Reactive Hyperemia Peripheral Arterial Tonometry (index <2 consistent with PED). A high UA was defined as ≥5 mg/dL, in keeping with previous studies evaluating the link between SUA and CVD outcomes.

RESULTS

One hundred forty patients were included (mean age 50.7 ± 12.9 years, 86 (61.4%) female). Twenty four patients (17.1%) had pre-existing CVD (8 (9.3%) in females). Thirty patients (21.6%) had a Framingham score > 10% (8 (9.4%) in females). Fifty eight (41.4%) had PED and 77 (55.0%) had an elevated SUA. SUA levels were higher in patients with PED compared to those without (5.5 ± 1.4 vs 4.8 ± 1.2 mg/dL; p = 0.004). In an univariate analysis, elevated SUA levels were associated with PED (Odds Ratio (OR): 2.7; 95% confidence interval [CI] 1.33-5.48; p = 0.005). In a multivariate analysis adjusting for age, sex, presence of obstructive CVD and Framingham score>10, elevated SUA levels were associated with PED (OR 2.45; 95% CI 1.08-5.52; p = 0.031). After stratifying by sex, this association persisted in females only.

CONCLUSIONS

High normal SUA levels are associated with PED in women who are otherwise at low risk for CVD. Thus, SUA is a promising circulating biomarker that could be used to assist in risk stratification in female patients with chest pain and/or those undergoing evaluation of CVD risk.

Assessment of endothelium-independent vasodilation: from methodology to clinical perspectives

: Vascular response to exogenously administered nitroglycerine, an index of endothelium-independent vasodilation, has been used as a control test for the assessment of endothelium-dependent vasodilation (endothelial function) in humans. However, evidence has been accumulating that not only endothelium-dependent vasodilation but also endothelium-independent vasodilation per se is impaired in individuals with cardiovascular risk factors and cardiovascular disease. Impaired endothelium-independent vasodilation is associated with structural vascular alterations and alterations in vascular smooth muscle cells. Several methods, including assessment of vascular responses to vasoactive agents using angiography in a coronary artery and vascular responses to vasoactive agents using venous occlusion plethysmography and ultrasonography in a peripheral artery, are used to assess endothelium-independent vasodilation in humans. Measurement of endothelium-independent vasodilation is also useful for assessment of atherosclerosis and may be a predictor of future cardiovascular events. In this review, we focus on assessment of endothelium-independent vasodilation from methodology aspects to clinical perspectives.

Association between reactive hyperemia peripheral arterial tonometry index and atrial fibrillation recurrence after catheter ablation

Background

Vascular endothelial function has recently been recognized as an independent predictor of cardiovascular events. However, studies investigating its association with atrial fibrillation (AF) are lacking. This study aimed to examine association with AF recurrence and vascular endothelial function as assessed using natural logarithmic transformation of reactive hyperemia peripheral arterial tonometry index (LnRHI).

Methods

Ninety-nine consecutive AF patients who underwent catheter ablation (CA) at Shinshu University Hospital between September 2015 and April 2017 were enrolled. LnRHI was measured 48 to 72 h before CA using the EndoPAT system. The primary outcome was AF recurrence beyond 3 months post-ablation.

Results

A total of 30 (30.3%) patients experienced AF recurrence after CA over a median follow-up period of 210 days (range: 93–764 days). Female sex and low LnRHI were significantly associated with AF recurrence. In multivariate analysis, LnRHI was an independent predictor of AF recurrence (hazard ratio: 0.087, 95% confidence interval 0.015–0.51, p = 0.007). In comparison in Kaplan-Meier analysis of high LnRHI (LnRHI ≥0.52, n = 52) and low LnRHI (LnRHI ≪0.52, n = 47) groups, AF recurrence rate was significantly higher in the low LnRHI group (log-rank test, p = 0.043). A negative correlation was observed between LnRHI and AF duration, whereby LnRHI was significantly decreased when the duration of AF events exceeded 1 year.

Conclusion

Decreased LnRHI was associated with AF recurrence after CA and prolonged AF duration.

Effects of Hypobaric Hypoxia on Endothelial Function and Adiponectin Levels in Airforce Aviators

Background: Hypobaric hypoxia (HH) increases the risk of high altitude-related illnesses (HARI). The pathophysiological mechanism(s) involved are still partially unknown. Altered vascular reactivity as consequence of endothelial dysfunction during HH might play a role in this phenomenon. Adiponectin exerts protective effect on cardiovascular system since it modulates NO release, antagonizing endothelial dysfunction. Aims of this study, performed in a selected population of airforce aviators, were (1) to investigate whether exposure to acute HH might be associated with endothelial dysfunction and (2) to evaluate whether adiponectin might be involved in modulating this phenomenon. Methods: Twenty aviators were exposed to acute HH in a hypobaric chamber by simulating altitude of 8000 and then 6000 m for 2 hours. Vascular reactivity was evaluated by the EndoPAT test immediately before and after the HH; salivary and blood adiponectin levels were measured. Results: EndoPAT performed immediately after HH divided pilots in two groups: 12 pilots with preserved vascular reactivity and 8 pilots with reduction of vascular reactivity, indicating that HH exposure might cause endothelial dysfunction. Salivary and blood adiponectin levels increased post-HH in a time-dependent manner in all aviators, but the significant increase was observed only in those with preserved vascular reactivity suggesting that HH stimulated release of adiponectin that, in turn, by exerting a protective effect, might reduce endothelial dysfunction. Conclusions: Acute HH may cause endothelial dysfunction due, at least in part, to reduced release of adiponectin. This phenomenon might be involved in pathophysiology of HARI.

Advanced Glycation End Products Are Associated With Inflammation and Endothelial Dysfunction in HIV

OBJECTIVE

To compare levels of advanced glycation end products (AGEs) between HIV-infected patients and uninfected controls and assess the relationship between AGEs, HIV, inflammation, and endothelial dysfunction.

DESIGN

Cross-sectional study involving 90 individuals (68 HIV+ and 22 healthy controls matched by age and sex).

METHODS

AGE levels were assessed using 3 different modalities: free AGEs were measured in the serum, skin autofluorescence (AF) was determined with a noninvasive reader, and dietary AGEs were estimated using 24-hour dietary recalls. Markers of inflammation, immune activation, and endothelial dysfunction were also measured. Wilcoxon rank-sum and χ tests were used to compare AGEs between groups. Spearman correlations were used to explore relationships between variables while adjusting for different covariates.

RESULTS

Overall, 71% were men and 68% were African American, with a median age of 53 years. Among HIV-infected individuals, all participants were on antiretroviral therapy by design, and most participants (78%) had an undetectable HIV-1 RNA level (≤20 copies/mL). Skin AF and serum AGEs were significantly higher in HIV-infected participants compared with uninfected controls (P < 0.01), whereas no differences in dietary AGEs were found between groups (P = 0.2). In the HIV-infected group, but not in controls, skin AF and circulating AGEs were significantly associated with inflammatory and oxidative markers, and with markers of endothelial dysfunction.

CONCLUSIONS

These results suggest intrinsic production of AGE in HIV-infected individuals. The relationship between serum/skin AGE and inflammatory, oxidative, and cardiovascular markers highlights the potential implications of AGEs in chronic inflammation and endothelial dysfunction in HIV, suggesting a new potential target for HIV-associated heightened inflammation and cardiovascular risk.

Application of non-invasive detection of peripheral vascular dysfunction in ovarian hyperstimulation syndrome (OHSS): A pilot study of clinical relevance

OBJECTIVE

The current study tested the hypothesis that vascular endothelial function, as reflected by the reactive hyperemia index (RHI), and biochemical factors, including VEGF, TNFα, CRP, inhibin A, and inhibin B, were involved in the pathogenesis of ovarian hyperstimulation syndrome (OHSS).

MATERIALS AND METHODS

This study was conducted between June 2010 and June 2012, enrolling 15 patients with OHSS and 6 healthy control subjects <45 years of age. Detailed clinical parameters were reviewed, including serum VEGF, TNFα, CRP, inhibin A, inhibin B, and hematocrit. RHI assessed by novel automatic peripheral arterial tonography was used to evaluate the vascular endothelial function.

RESULTS

Twenty-one subjects were evaluated. There was no significant difference between patients with OHSS and control subjects with respect to VEGF, TNFα, CRP, inhibin A and inhibin B. The RHI was not significantly different between patients with OHSS and control subjects (mean, 1.8 ± 0.4 vs. 1.7 ± 0.2). The hematocrit was significantly different between patients with OHSS and control subjects.

CONCLUSIONS

Our preliminary data did not reveal direct evidence of vascular endothelial dysfunction in patients with OHSS. To identify whether RHI could reflect vascular endothelial dysfunction in patients with OHSS, more cases with different severities of OHSS should be recruited in the future study.

Low plasma concentrations of apolipoprotein M are associated with disease activity and endothelial dysfunction in systemic lupus erythematosus

BACKGROUND

Apolipoprotein M (apoM) is a 25-kDa apolipoprotein present in 5% of high-density lipoprotein (HDL) particles. It is suggested to be anti-atherogenic and to play a key role in sustaining endothelial barrier integrity. SLE patients have increased cardiovascular disease risk, and we aimed to investigate if apoM levels reflect endothelial function in SLE. Since apoM plasma levels decrease during inflammatory conditions, our aim was also to determine the impact of SLE disease activity on apoM plasma levels.

METHODS

Plasma concentrations of apoM were measured by ELISA in two patient groups with systemic lupus erythematosus (SLE) and in 79 healthy control individuals. In patient group I (n = 84), evaluation time points were selected with the objective to include a wide range of clinical and laboratory variables reflecting disease activity which was measured as SLEDAI. In patient group II consisting of 140 consecutive patients, endothelial function was measured by a finger plethysmograph. A low Reactive Hyperemia Index (RHI) value indicates endothelial dysfunction.

RESULTS

SLE patients had decreased levels of apoM compared to healthy controls (p < 0.01), with apoM levels correlating inversely with SLEDAI (r = - 0.31, p < 0.01) as well as with levels of CRP (r = - 0.26, p = 0.02) and positively with levels of C3 (r = 0.29, p < 0.01). ApoM levels were particularly low in patients with active disease from the kidney and skin and in patients with leukopenia or positive anti-dsDNA antibody test (p < 0.05). ApoM levels correlated with RHI values in young SLE patients (r = 0.32, p = 0.01), consistent with the important role of apoM in regulating endothelial integrity.

CONCLUSIONS

ApoM levels may be regulated by SLE-related inflammatory processes and could be a marker of disease activity and endothelial dysfunction, in particular in young SLE patients. Further studies are needed to investigate the predictive value of apoM in the development of a cardiovascular disease.

Measurement of Microvascular Function in Pediatric Inflammatory Bowel Disease

BACKGROUND AND AIMS

Altered vascular flow is known to both play a role in the pathogenesis and influence the severity of inflammatory bowel disease (IBD). This phenomenon has been described in other systemic conditions and contributes to disease progression by facilitating inflammation and thrombosis. Microvascular dysfunction may represent an early sign of generalized vascular disease (VD). It manifests by failure to achieve a normal response of vasodilation and increased blood flow following a period of vaso-occlusion. Although thromboembolic complications are well described in IBD, their pathogenesis is not fully understood. This study sought to assess microvascular responsiveness in pediatric subjects with IBD, by recording postocclusion peripheral arterial pulsatile volume changes.

PATIENTS AND METHODS

A total of 32 pediatric subjects were studied, including 16 with IBD and 16 age-matched controls. All patients with IBD were in clinical remission, and none had known VD. Vascular reactivity was evaluated using the Itamar Medical EndoPAT2000, a noninvasive device utilizing plethysmography to measure microvascular flow. Results were reported as the reactive hyperemia index (RHI), indicating post- to preocclusion pulsatile volume changes.

RESULTS

Baseline characteristics, including body mass index, plasma lipid levels, hemoglobin, and serum albumin, were similar in both study groups. All patients with IBD were in clinical remission, assessed by standard disease activity scoring methods. Measurements of microvascular function indicated patients with IBD exhibited a mean RHI both within the range associated with VD risk in adults (≤1.67) and significantly lower than that in controls (IBD vs control = 1.66 vs 2.02, P = 0.036).

CONCLUSIONS

Microvascular plethysmography is a safe and noninvasive method for assessing microvascular function in children with IBD. Patients with IBD in clinical remission demonstrate an attenuated, postocclusion microvascular hyperemic response, compared with the normal response in controls. These findings suggest pediatric IBD subjects with a mean RHI within the VD "at risk" range should be monitored for thromboembolic phenomena. Further studies in a larger patient population and over longer periods should be conducted to validate our findings and to determine the importance of these measurements in guiding IBD management.

Utility of the cold pressor test to predict future cardiovascular events

INTRODUCTION

The cold pressor test (CPT) is a common and extensively validated test, which induces systemic stress involving immersion of an individual's hand in ice water (normally temperature between 0 and 5 degrees Celsius) for a period of time. CPT has been used in various fields, like examining effects of stress on memory, decision-making, pain and cardiovascular health. Areas covered: In terms of cardiovascular health, current research is mainly interested in predicting the occurrence of cardiovascular (CV) events. The objective of this review is to give an overview of the history and methodology of the CPT, and clinical utility in possibly predicting CV events in CAD and other atherosclerotic diseases. Secondly, we will discuss possible future applications of the CPT in clinical care. Expert opinion: An important issue to address is the fact that the physiology of the CPT is not fully understood at this moment. As pointed out multiple mechanisms might be responsible for contributing to either coronary vasodilatation or coronary vasoconstriction. Regarding the physiological mechanism of the CPT and its effect on the measurements of the carotid artery reactivity even less is known.