Endothelial Function In Healthy Subjects Research Articles

Evaluation of the effect of a dietary supplementation with a red yeast rice and fish oil-containing nutraceutical on lipid pattern, high sensitivity C-reactive protein, and endothelial function in moderately hypercholesterolaemic subjects: a double-blind, placebo-controlled, randomized clinical trial.

Red yeast rice and omega-3 polyunsaturated fatty acids (PUFAs) are dietary supplements with well-known lipid-lowering, anti-inflammatory, and vascular health improving effects. However, they have rarely been tested in combination. The aim of our study was to test the short-term effect of a combined nutraceutical including red yeast rice and PUFAs on plasma lipids, jigh-sensitive C-reactive protein (hsCRP), and endothelial function in healthy subjects. We carried out a double-blind, randomized, placebo-controlled clinical trial with parallel groups testing the effect of 8 weeks of supplementation with softgels containing red yeast rice (2.8 mg monacolins) and PUFAs (588 mg of fish oil, standardized in PUFAs: 350 EPA, 45 mg DHA) versus placebo. A full lipid panel, hsCRP, and endothelial reactivity were measured at the baseline and after 8 weeks of treatment. The tested combined nutraceutical was very well tolerated, and after 8 weeks of supplementation it was associated with a 17.3 ±3.4% reduction of lipid-density lipoprotein-cholesterol (LDL-C), a 12.1 ±2.2% reduction of total cholesterol (TC), a 22.3 ±4.3% reduction of apoB, and a -14.9 ±1.8% reduction of hsCRP, as well as a significant improvement of pulse volume change by 5.0 ±0.9%. The tested combined dietary supplement containing red yeast rice and PUFAs was very well tolerated and significantly improved LDL-C, TC, apoB, hsCRP and endothelial function in healthy subjects with suboptimal LDL-cholesterolaemia.

A systematic review and meta-analysis of effect of yoga and meditation on endothelial system

Abstract Background/Introduction Endothelial dysfunction plays an important role in the pathophysiology of cardiovascular diseases and diabetes. Studies reported either an improvement in endothelial function by yoga and meditation or no significant effect. A systematic review and meta-analysis of effect of yoga on endothelial function is not available. Purpose The aim of this systematic review and meta-analysis is to determine the effectiveness of yoga and meditation on endothelial function in healthy subjects or patients of any age or gender. Methods Authors performed a systematic search for relevant research studies as per the PRISMA guidelines. The Pubmed, Scopus, Google Scholar and Cochrane controlled register of trials (CENTRAL) were screened from inception to November 2020. The search strategy was constructed around yoga based techniques, meditation and endothelial function. All the yoga-based interventional studies on endothelial function: controlled, uncontrolled, randomized, non-randomized and cross-over were included for this review. A narrative synthesis and descriptive analysis was done due to diverse methodology of all selected studies. We carried out a formal meta-analysis of controlled trials that assessed flow-mediated dilatation (FMD) which is a gold-standard measure of endothelial function.The quality of the studies was assessed using Cochrane risk of bias (RoB) tool. Results A total of 18 studies were included for review involving 1024 participants. Of these, 10 were RCT, one randomized cross-over study, 4 non-randomized studies and three single-group (before-after) studies. The total duration of yoga intervention ranged from 10 days to 52 weeks. Among the 18 selected studies, yoga training showed a significant favorable change in the measures of endothelial function in 12 studies (involving either healthy individuals or patients with coronary heart disease, myocardial infarction, metabolic syndrome, hypertension, migraine and dysmenorrhea) while 6 studies did not find any significant effect. Among the 15 controlled trials, 7 assessed FMD while the remaining evaluated different biomarkers of endothelial function such as circulating endothelial microparticles, asymmetric dimethyl arginine, nitric oxide or endothelin-1. Hence the results of 7 controlled trials assessing FMD were included for meta-analysis (n=384 participants) which showed a significant increase in brachial FMD by yoga practice (Mean difference = −2.02%, 95% CI: −3.72, −0.32, p=0.02). The heterogeneity between the studies was 76% (τ2=3.31, χ2=25.28) (Fig. 1). Conclusions Yoga and meditation can significantly improve endothelial function in healthy individuals and patients with cardiovascular disease or risk factors. Yoga and meditation can be applied clinically as a lifestyle modality for endothelial protection and cardiovascular prevention and rehabilitation. Funding Acknowledgement Type of funding sources: None.

Combined oral contraceptives modify the effect of smoking on inflammatory cellular indexes and endothelial function in healthy subjects

Little information is available on the influence of sex in combination with smoking habits and combined oral contraceptives (COC) use on cellular inflammatory indexes such as neutrophil/lymphocyte ratio (NLR), derived NRL (dNLR), platelet/lymphocyte ratio (PLR), monocyte/lymphocyte ratio (MLR), mean platelet volume/platelet count (MPV/PLT), aggregate inflammation systemic index (AISI), and systemic inflammation response index (SIRI), which are cost-effective biomarkers to assessing inflammation.Therefore, the effect of COC was studied alone or in association with smoking and compared with results from healthy COC-free women and men. Furthermore, the association of cellular inflammatory indexes with endothelial function (arginine (Arg), asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA) and lipid peroxidation (malondialdehyde MDA) biomarkers was evaluated.Blood was collected for hematological and biochemical analysis, which were used to calculate PLR, NLR, dNLR, MLR, MPV/PLT, AISI, and SIRI. Serum samples were assayed for Arg, ADMA, SDMA, and MDA.Monocytes, MLR, SIRI, and MPV/PLT were higher in men, while PLT count was higher in women. COC use increased lymphocytes and lowered PLR and MLR. Smoking reduced sexually divergent parameters, especially in COC users: smoking and non-smoking COC-free women displayed six divergent parameters, while COC users displayed only two (monocytes and MPV). In addition, COC affected endothelial function, reducing ADMA and Arg. Moreover, COC-free women had lower Arg levels than men.In conclusion, COC use strongly influence the effects of tobacco smoking, which are sex and parameter specific. Further, these data stress that COC use and smoking attitude select different cohorts indicating that sex and gender studies need intersectionality.

Endothelial Function is improved by Inducing Microbial Polyamine Production in the Gut: A Randomized Placebo-Controlled Trial.

Recently, it was demonstrated that spermidine-induced autophagy reduces the risk of cardiovascular disease in mice. Intestinal bacteria are a major source of polyamines, including spermidine. We previously reported that the intake of both Bifidobacterium animalis subsp. lactis (Bifal) and arginine (Arg) increases the production of putrescine, a spermidine precursor, in the gut. Here, we investigated the effects of Bifal and Arg consumption on endothelial function in healthy subjects. Healthy individuals with body mass index (BMI) near the maximum value in the “healthy” range (BMI: 25) (n = 44) were provided normal yogurt containing Bifal and Arg (Bifal + Arg YG) or placebo (normal yogurt) for 12 weeks in this randomized, double-blinded, placebo-controlled, parallel-group comparative study. The reactive hyperemia index (RHI), the primary outcome, was measured using endo-peripheral arterial tone (EndoPAT). The change in RHI from week 0 to 12 in the Bifal + Arg YG group was significantly higher than that in the placebo group, indicating that Bifal + Arg YG intake improved endothelial function. At week 12, the concentrations of fecal putrescine and serum putrescine and spermidine in the Bifal + Arg YG group were significantly higher than those in the placebo group. This study suggests that consuming Bifal + Arg YG prevents or reduces the risk of atherosclerosis.

Blue light exposure decreases systolic blood pressure, arterial stiffness, and improves endothelial function in humans.

Previous studies have shown that ultraviolet light can lead to the release of nitric oxide from the skin and decrease blood pressure. In contrast to visible light the local application of ultraviolet light bears a cancerogenic risk. Here, we investigated whether whole body exposure to visible blue light can also decrease blood pressure and increase endothelial function in healthy subjects. In a randomised crossover study, 14 healthy male subjects were exposed on 2 days to monochromatic blue light or blue light with a filter foil (control light) over 30 minutes. We measured blood pressure (primary endpoint), heart rate, forearm vascular resistance, forearm blood flow, endothelial function (flow-mediated dilation), pulse wave velocity and plasma nitric oxide species, nitrite and nitroso compounds (secondary endpoints) during and up to 2 hours after exposure. Blue light exposure significantly decreased systolic blood pressure and increased heart rate as compared to control. In parallel, blue light significantly increased forearm blood flow, flow-mediated dilation, circulating nitric oxide species and nitroso compounds while it decreased forearm vascular resistance and pulse wave velocity. Whole body irradiation with visible blue light at real world doses improves blood pressure, endothelial function and arterial stiffness by nitric oxide released from photolabile intracutanous nitric oxide metabolites into circulating blood.

Comparison of the effects of 1 MHz and 3 MHz therapeutic ultrasound on endothelium-dependent vasodilation of humans: a randomised clinical trial

ObjectiveTo compare the effects of different waveforms of 1MHz and 3MHz therapeutic ultrasound on endothelial function in healthy subjects. DesignRandomised placebo-controlled, crossover study with concealed allocation and assessor blinding. SettingImaging Centre of the University Hospital. ParticipantsThirty volunteers aged between 18 and 35 years were divided into two homogeneous groups (1MHz and 3MHz). InterventionsContinuous (CUT; 0.4W/cm2SATA), pulsed (PUT; 20% duty cycle, 0.08W/cm2SATA) and placebo waveforms (equipment off) of ultrasound (1MHz and 3MHz) were randomized and applied over the brachial artery for 5minutes. Main outcome measuresEndothelial function was evaluated using the flow-mediated dilation (FMD) technique. ResultsBoth 1MHz [CUT: mean difference 4%, 95% confidence interval (CI) 2 to 6%, P<0.001; PUT: mean difference 4%, 95% CI 2 to 6%, P<0.001] and 3MHz (CUT: mean difference 4%, 95% CI 2 to 6%, P<0.001; PUT: mean difference 4%, 95% CI 2 to 6%, P<0.001) of therapeutic ultrasound increased %FMD by approximately 4% compared with the placebo waveforms. The endothelium-dependent vasodilator responses were the same for both types of waves and frequencies. No differences in baseline diameter, hyperaemic flow, and nitroglycerin-mediated diameter and vasodilation were observed between groups. ConclusionBoth CUT and PUT ultrasound waveforms improved endothelial function. The 1MHz and 3MHz frequencies of therapeutic ultrasound led to similar improvement in endothelial function in healthy volunteers.Clinical trial registration number RBR-4z5z3t.

The acute effect of black tea consumption on resistance artery endothelial function in healthy subjects. A randomized controlled trial

Black tea is a main source of flavonoids in the Western diet and has been associated with reduced risk for cardiovascular disease, possibly through lowering blood pressure. These effects may be mediated through improving endothelial function of resistance arteries. The aim of this study was therefore to examine the acute impact of black tea on forearm resistance artery endothelial function in healthy, normotensive middle-aged subjects. Twenty middle-aged men and women (age-range 45-75 years) were recruited into a double-blind, randomized, placebo-controlled crossover intervention study. Forearm resistance artery blood flow (FBF, measured using venous occlusion plethysmography) in response to incremental doses of acetylcholine, sodium nitroprusside and L-NG-monomethyl arginine were determined 2h after consumption of either black tea containing ∼400mg flavonoids (equivalent to 2-3 cups of tea) or a taste- and color-matched placebo. The mean FBF-response to acetylcholine after tea consumption was 23% higher compared to the response after placebo (95% CI:-20%,+88%), but this difference did not reach statistical significance (P=0.32). No significant differences in the FBF-responses to sodium nitroprusside and L-NG-monomethyl arginine were found between the tea and placebo interventions (P=0.96 and 0.74, respectively). Correcting FBF for changes in blood pressure did not alter the outcomes. We found no evidence that acute intake of black tea significantly altered endothelium-dependent vasodilation of forearm resistance arteries in healthy middle-aged subjects. Interventions with a longer duration of tea ingestion are required to further explore the (long-term) impact of tea flavonoids on blood pressure regulatory mechanisms. This trial was registered at clinicaltrials.gov as NCT02328339.

Iberian Cured-Ham Consumption Improves Endothelial Function in Healthy Subjects.

Previous studies have shown that dietary components such as oleic acid or polyphenols exert beneficial effects on endothelium. We aimed to assess the impact of regular consumption of Iberian cured-ham (ICH) on endothelial function. An open-label, randomized controlled parallel study. Volunteers recruited through advertisements at a hospital in Madrid, Spain. 102 Caucasian adults (76.8% females) aged 25-55 years, and free from cardiometabolic disease. Participants were randomized to an ICH-enriched ad libitum diet or an ad libitum diet without ICH for 6 weeks. Subjects in ICH group were randomly provided with either acorn- or mixed-fed ICH, and followed up for an additional 6-week period under their usual diet. Clinical parameters, biomarkers of endothelial function and oxidative stress, microvascular vasodilatory response to hyperemia and arterial stiffness were measured before and after the intervention. After 6 weeks, a larger decrease in PAI-1 was observed in subjects consuming ICH compared to the Control group (-6.2±17.7 vs. 0.3±1.4 ng/ml; p=0.020). Similarly, microvascular vasodilatory response to hyperemia showed a significant increase (112.4±391.7 vs. -56.0±327.9%; p=0.007). However, neither oxidative stress, hemodynamic nor clinical parameters differed significantly over the study. Additionally, after stopping ICH consumption, improvements in PAI-1 remained for 6 additional weeks with respect to baseline (p=0.006). The present study demonstrates, for the first time, that regular consumption of ICH improves endothelial function in healthy adults. Strategies aimed to preserve or improve the endothelial function may have implications in vascular aging beyond the prevention of the atherothrombotic disease.

Vascular reactivity and biomarkers of endothelial function in healthy subjects exposed to acute hypobaric hypoxia

AimsThe aim of this study was to evaluate the effects of acute hypobaric hypoxia (HH) on vascular reactivity and biochemical markers associated with endothelial function (EF). Main methodsTen healthy subjects were exposed to a simulated altitude of 4,000meters above sea level for 4hours in a hypobaric chamber. Vascular reactivity was measured by the flow-mediated vasodilatation (FMVD) test. Endothelin-1, high sensitive-C reactive protein (hsCRP), vascular cell adhesion molecule 1, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), paraoxonase and adiponectin levels, and FMVD were evaluated before and after the exposure. Key findingsSubjects were young (age: 32±6years), lean [body mass index: 23.9±2.0kg/m2, waist circumference: 77(IQR: 72–80) cm], and presented normal clinical and biochemical parameters. No significant changes were evidenced in FMVD in response to HH (pre: 0.45 (0.20–0.70) vs. during: 0.50 (0.20–1.22) mm; p=0.594). On the other hand, endothelin-1 (+54%, p<0.05), hsCRP (+37%, p<0.001), IL-6 (+75%, p<0.05), TNF-α (+75%, p<0.05), and adiponectin (−39%, p<0.01) levels were significantly altered post-HH. FMVD was increased in 7 subjects, and it was decreased in 3 individuals during HH exposure. Interestingly, when EF biomarkers were compared between these two subgroups of subjects, only post exposure-adiponectin levels were significantly different (49±5 vs. 38±6μg/ml, respectively, p<0.05). SignificanceHH exposure had an effect on endothelin-1, adiponectin, hsCRP, IL-6, and TNF-α concentration. However, adiponectin was the only biomarker associated with an altered vascular reactivity.

Abstract 377: Retrograde Shear Stress does not Alter Endothelial Function in Healthy Subjects

Introduction: Endothelial dysfunction is a precursor and plays a significant role in development of atherosclerosis. Retrograde flow and resulting retrograde shear stress has been shown to adversely affect the endothelial function but the results may be flawed due to experimental conditions. Change in the limb position might result in increase in retrograde flow and adversely affect endothelial function. We hypothesized that elevation of arm above the level of the heart will result in increased retrograde flow and reduced endothelial function as measured by flow mediated dilation (FMD). Methods: We enrolled 27 healthy subjects after obtaining informed consent. Endothelial function was measured by FMD in brachial artery before and after arm elevation with elbow support for 30 minutes in fasting state. Flow velocities were recorded and analyzed at baseline, 10 and 20 minutes after arm elevation and at the end of 30 minutes. Results: The mean retrograde flow velocity was 9.9 ± 7.75 cm/sec at baseline, which increased to 15.8 ± 6.56 cm/sec (p=0.0019) after arm elevation. Out of the 27 subjects 21 (78%) subjects had increase in retrograde flow (20% or more). The difference in FMD change between the groups with increased or no change in retrograde flow was statistically non-significant (p=0.4). Conclusion: In conclusion arm elevation for 30 minutes was associated with statistically significant increase in retrograde flow without significant change in endothelial function in normal healthy subjects. The change in endothelial function between subjects who had augmented retrograde shear and those who did not was statistically not significant.

Effects Of Acute Sleep Deprivation On The Vascular Endothelial Function In Healthy Subjects

Sleep deprivation (SD) is associated with an increased risk of cardiovascular diseases. However, less is known about the early effects of acute sleep deprivation on the vascular endothelial function. PURPOSE: The aim of this study was to investigate the effects of sleep deprivation on the vascular endothelial function determined by flow-mediated vasodilation (FMD) and the profile of mood states in healthy subjects. METHODS: Seven healthy recreationally active adult males were studied under two experimental trials on at six separate days. The brachial systolic and diastolic blood pressure (SBP, DBP) were measured using a volume-plethysmographic apparatus in the supine position. In order to measure FMD, the forearm cuff inflation to 50 mmHg over their SBP for five minutes and subsequent deflation were performed. The measurements of the right brachial artery diameter were taken using a high-resolution ultrasound device. The FMD was then estimated as the percent change in the arterial diameter over the baseline value at maximal dilation during reactive hyperemia. The Profile of Mood States (POMS) test was also applied for the subjects. All measurements were obtained after a night with regular sleep (RS) and after a night with SD. RESULTS: Both of the SBP and DBP after SD were significantly higher compared with those after RS (117.0±15.8 vs. 108.8±9.9 mmHg, 64.4±12.5 vs. 58.7±5.5 mmHg, p<0.05). The FMD was significantly lower after SD compared with RS (5.17±1.25 vs. 7.01±2.25 %, p<0.05). The tension-anxiety(4.9±3.2 vs. 2.0±2.8), depression (3.4±3.1 vs. 0.7±1.1), anger-hostility (2.4±2.3 vs. 0.1±0.3), fatigue (11.9±4.2 vs. 2.9±3.6), and confusion (6.1±4.5 vs. 2.0±2.0) scores were significantly higher after SD compared with RD (p<0.05). CONCLUSIONS: Even one night of sleep deprivation appears to elevate negative mood states and to cause vascular endothelial dysfunction. These findings support the idea that optimal sleep may be an important factors for reducing the risk of cardiovascular disease.

The MRI evaluation of nitric-oxide mediated systemic endothelial function and coronary endothelial function in healthy subjects and patients with coronary artery disease

Background Endothelial cell release of nitric oxide (NO) is one indicator of vascular health. Coronary arteries develop atherosclerotic disease, while left internal mammary arteries (IMA), which are frequently used as bypass conduits in patients with disease, do not. Endothelial cell function of vessels can be assessed by the response to isometric handgrip exercise (IHE); normal function is evidenced by an increase in cross sectional area(CSA), flow velocity(FV) and blood flow(BF), and an abnormal response by no increase in these variables. Recently, the combination of coronary MRI and isometric handgrip exercise (IHE) was shown to noninvasively quantify coronary endothelial function (CEF). We tested the hypotheses that: 1) IMA vasoreactivity to IHE is measurable using coronary 3T MRI 2) endothelial function of IMA differs from that of coronary arteries in patients with coronary atherosclerotic disease (CAD) whereas in healthy subjects endothelial function of the two vascular beds is similar and 3) the IMA response to IHE is primarily mediated by NO, thus reflecting endothelial function.

Elevation in blood flow and shear rate prevents hyperglycemia-induced endothelial dysfunction in healthy subjects and those with type 2 diabetes

Hyperglycemia, commonly present after a meal, causes transient impairment in endothelial function. We examined whether increases in blood flow (BF) protect against the hyperglycemia-mediated decrease in endothelial function in healthy subjects and patients with type 2 diabetes mellitus (T2DM). Ten healthy subjects and 10 age- and sex-matched patients with T2DM underwent simultaneous bilateral assessment of brachial artery endothelial function by means of flow-mediated dilation (FMD) using high-resolution echo-Doppler. FMD was examined before and 60, 120, and 150 min after a 75-g oral glucose challenge. We unilaterally manipulated BF by heating one arm between minute 30 and minute 60. Oral glucose administration caused a statistically significant, transient increase in blood glucose in both groups (P < 0.001). Forearm skin temperature, brachial artery BF, and shear rate significantly increased in the heated arm (P < 0.001), and to a greater extent compared with the nonheated arm in both groups (interaction effect P < 0.001). The glucose load caused a transient decrease in FMD% (P < 0.05), whereas heating significantly prevented the decline (interaction effect P < 0.01). Also, when correcting for changes in diameter and shear rate, we found that the hyperglycemia-induced decrease in FMD can be prevented by local heating (P < 0.05). These effects on FMD were observed in both groups. Our data indicate that nonmetabolically driven elevation in BF and shear rate can similarly prevent the hyperglycemia-induced decline in conduit artery endothelial function in healthy volunteers and in patients with type 2 diabetes. Additional research is warranted to confirm that other interventions that increase BF and shear rate equally protect the endothelium when challenged by hyperglycemia.

Excessive dietary phosphorus intake impairs endothelial function in young healthy men: a time- and dose-dependent study.

Excessive dietary phosphorus (P) has been speculated to be a risk factor for cardiovascular disease (CVD). Here, we performed a double-blinded crossover study to investigate the time- and dose-dependent effects of dietary P intake on endothelial function in healthy subjects. Sixteen healthy male volunteers were given meals containing 400, 800, and 1,200 mg P (P400, P800, and P1200 meals, respectively) with at least 7 days between doses. There were no differences in nutritional composition among the experimental diets except for P content. Blood biochemistry data and flow-mediated dilation (%FMD) of the brachial artery were measured while fasted, at 0 h, 1 h, 2 h, and 4 h after meal ingestion, and the next morning while fasted. The P800 and P1200 meals significantly increased serum P levels at 1-4 h after ingestion. A significant decrease in %FMD was observed between 1-4 h,while the P400 meal did not affect %FMD. We observed no differences among meals in serum P levels or %FMD the next morning. A significant negative correlation was observed between %FMD and serum P. These results indicate that excessive dietary P intake can acutely impair endothelial function in healthy people.

Interactions between cocoa flavanols and inorganic nitrate: Additive effects on endothelial function at achievable dietary amounts

Dietary intervention studies have shown that flavanols and inorganic nitrate can improve vascular function, suggesting that these two bioactives may be responsible for beneficial health effects of diets rich in fruits and vegetables. We aimed to study interactions between cocoa flavanols (CF) and nitrate, focusing on absorption, bioavailability, excretion, and efficacy to increase endothelial function. In a double-blind randomized, dose–response crossover study, flow-mediated dilation (FMD) was measured in 15 healthy subjects before and at 1, 2, 3, and 4h after consumption of CF (1.4–10.9mg/kg bw) or nitrate (0.1–10mg/kg bw). To study flavanol–nitrate interactions, an additional intervention trial was performed with nitrate and CF taken in sequence at low and high amounts. FMD was measured before (0h) and at 1h after ingestion of nitrate (3 or 8.5mg/kg bw) or water. Then subjects received a CF drink (2.7 or 10.9mg/kg bw) or a micro- and macronutrient-matched CF-free drink. FMD was measured at 1, 2, and 4h thereafter. Blood and urine samples were collected and assessed for CF and nitric oxide (NO) metabolites with HPLC and gas-phase reductive chemiluminescence. Finally, intragastric formation of NO after CF and nitrate consumption was investigated. Both CF and nitrate induced similar intake-dependent increases in FMD. Maximal values were achieved at 1h postingestion and gradually decreased to reach baseline values at 4h. These effects were additive at low intake levels, whereas CF did not further increase FMD after high nitrate intake. Nitrate did not affect flavanol absorption, bioavailability, or excretion, but CF enhanced nitrate-related gastric NO formation and attenuated the increase in plasma nitrite after nitrate intake. Both flavanols and inorganic nitrate can improve endothelial function in healthy subjects at intake amounts that are achievable with a normal diet. Even low dietary intake of these bioactives may exert relevant effects on endothelial function when ingested together.

Lowering of oxidative stress improves endothelial function in healthy subjects with habitually low intake of fruit and vegetables: A randomized controlled trial of antioxidant- and polyphenol-rich blackcurrant juice

Inadequate intake of the recommended five-a-day fruit and vegetable portions might contribute to increased cardiovascular disease risk. We assessed the effects of dietary intake of a blackcurrant juice drink, rich in vitamin C and polyphenols, on oxidative stress and vascular function. This was a double-blind, placebo-controlled, parallel group study of 66 healthy adults who habitually consume <2 portions of fruit and vegetables per day. Participants were randomly allocated to consume 250ml of placebo (flavored water) or low or high blackcurrant juice drink four times a day for 6 weeks. Flow-mediated dilation (FMD) and plasma concentrations of F2-isoprostanes and vitamin C were measured. In the high blackcurrant juice drink group FMD increased significantly (5.8±3.1 to 6.9±3.1%, P=0.022) compared with the placebo group (6.0±2.2 to 5.1±2.4%). Plasma vitamin C concentration increased significantly in the low (38.6±17.6 to 49.4±21.0µmol/L, P<0.001) and high (34.6±20.4 to 73.8±23.3µmol/L, P<0.001) blackcurrant juice drink groups compared with the placebo group (38.1±21.0 to 29.0±17.6µmol/L). F2-isoprostane concentrations were significantly lower in the high blackcurrant juice drink group (225±64pg/ml) compared with the low blackcurrant juice drink (257±69pg/ml, P=0.002) and placebo group (254±59pg/ml, P=0.003). At follow-up, changes in plasma vitamin C correlated significantly with changes in FMD (r=0.308, P=0.044). Consumption of blackcurrant juice drink high in vitamin C and polyphenols can decrease oxidative stress and improve vascular health in individuals with habitually low dietary fruit and vegetable intake.

Effects of a typical acute oral calcium load on arterial properties and endothelial function in healthy subjects.

Often recommended, calcium supplements have been incriminated as increasing the risk of cardiovascular events, whereas dietary calcium has generally been exonerated. As a first step to address the vascular safety of such dietary measures at the clinical nutritionist toolbox, we sought to determine and compare the acute effects of a typical oral calcium load, provided either as a supplement or as food, on vascular parameters assessed noninvasively in healthy subjects. In this acute, cross-over, random-order intervention, 11 young and healthy vitamin D-sufficient volunteers (8 women/3 men, 33±6.1 years, body mass index 22.6±2.3 kg/m(2)), ingested 600 mg of calcium twice, once as calcium citrate and the other time from dairy products. Biochemical, vascular and hemodynamic parameters, before and 2 h after each challenge, were compared. Arterial stiffness was studied by measuring pulse wave velocity, augmentation index and large (C1) and small (C2) arterial compliance. Endothelial function was assessed by flow-mediated dilation (FMD). Despite effective calcium loading accompanied by a significant 60% parathyroid hormone level reduction on both occasions, there were no clinically significant changes in the vascular parameters neither in comparison with baseline, nor between the studies. A decrease in heart rate with no change in cardiac output was noticed after the supplement. An effective calcium load has no clinically significant untoward effect on the vascular properties of young healthy subjects, regardless of its source. Additional studies should determine whether this holds true for chronic calcium supplementation, particularly in subjects with a priori vascular impairment.

Usefulness of Brachial Artery Flow-Mediated Dilation to Predict Long-Term Cardiovascular Events in Subjects Without Heart Disease

Endothelial dysfunction is considered an important prognostic factor in atherosclerosis. To determine the long-term association of brachial artery flow-mediated dilation (FMD) and adverse cardiovascular (CV) events in healthy subjects, we prospectively assessed brachial FMD in 618 consecutive healthy subjects with no apparent heart disease, 387 men (63%), and mean age 54 ± 11 years. After overnight fasting and discontinuation of all medications for ≥12 hours, FMD was assessed using high-resolution linear array ultrasound. Subjects were divided into 2 groups: FMD ≤11.3% (n = 309) and >11.3% (n = 309), where 11.3% is the median FMD, and were comparable regarding CV risk factors, lipoproteins, fasting glucose, C-reactive protein, concomitant medications, and Framingham 10-year risk score. In a mean clinical follow-up of 4.6 ± 1.8 years, the composite CV events (all-cause mortality, nonfatal myocardial infarction, hospitalization for heart failure or angina pectoris, stroke, coronary artery bypass grafting, and percutaneous coronary interventions) were significantly more common in subjects with FMD ≤11.3% rather than >11.3% (15.2% vs 1.2%, p = 0.0001, respectively). Univariate analysis demonstrated that the median FMD significantly predicted CV events (odds ratio 2.78, 95% CI 1.35 to 5.71, p <0.001). Multivariate analysis, controlling for traditional CV risk factors, demonstrated that median FMD was the best independent predictor of long-term CV adverse events (odds ratio 2.93, 95% CI 1.28 to 6.68, p <0.001). In conclusion, brachial artery median FMD independently predicts long-term adverse CV events in healthy subjects with no apparent heart disease in addition to those derived from traditional risk factor assessment.

Acute and chronic effects of exercise on circulating endothelial progenitor cells in healthy and diseased patients

Exercise is known to improve endothelial function in healthy subjects as well as patients with cardiovascular disease and this might be partially related to a regeneration of diseased endothelium by circulating progenitor cells (EPCs). EPCs are a subgroup of peripheral blood monocytes that contribute to re-endothelialization of injured endothelium as well as neovascularization of ischemic lesions. Cross-sectional studies have indicated that chronic, regular physical activity has a positive effect on the levels of circulating EPCs. This is associated with an improvement of endothelial dysfunction that is induced by apoptosis due to the underlying aging process or accelerated by cardiovascular risk factors. Furthermore, it is well established that chronic exercise training has the potency to mobilize EPCs from the bone marrow. For patients with cardiac disease this is of clinical importance since EPCs have been implicated in vascular repair and revascularization. Studies are needed to refine the best mode of exercise training that will upregulate circulating EPCs as well as to clarify the kinetics of EPCs after the termination of different exercise sessions in different diseases and medication. Whether there is a direct link between enhanced mobilization of EPCs via exercise and improvement of disease and prognosis remains a hypothesis which needs to be further evaluated.

(-)-Epicatechin-induced calcium independent eNOS activation: roles of HSP90 and AKT

Cardiovascular disease (CVD) is a leading determinant of mortality and morbidity in the world. Epidemiologic studies suggest that flavonoid intake plays a role in the prevention of CVD. Consumption of cocoa products rich in flavonoids lowers blood pressure and improves endothelial function in healthy subjects as well as in subjects with vascular dysfunction such as smokers and diabetics. The vascular actions of cocoa follow the stimulation of nitric oxide (NO). These actions can be reproduced by the administration of the cocoa flavanol (-)-epicatechin (EPI). Previously, using human endothelial cells cultured in calcium-free media, we documented EPI effects on eNOS independently of its translocation from the plasmalemma. To further define the mechanisms behind EPI-eNOS activation in Ca(2+) -deprived endothelial cells, we evaluated the effects of EPI on the eNOS/AKT/HSP90 signaling pathway. Results document an EPI-induced phosphorylation/activation of eNOS, AKT, and HSP90. We also demonstrate that EPI induces a partial AKT/HSP90 migration from the cytoplasm to the caveolar membrane fraction. Immunoprecipitation assays of caveolar fractions demonstrate a physical association between HSP90, AKT, and eNOS. Thus, under Ca(2+)-free conditions, EPI stimulates NO synthesis via the formation of an active complex between eNOS, AKT, and HSP90.