Flow-mediated dilation and heart failure: a review with implications to physical rehabilitation

Dietary strategies and nutritional supplements in the management of heart failure: a systematic review

Background and objective

Heart failure (HF) is a syndrome of increased intracardiac pressure or decreased cardiac output. There is a lack of conclusive evidence to recommend the regular use of any dietary supplement in patients with HF. However, certain studies have shown nutritional interventions to be beneficial for patients with HF. Therefore, the purpose of this systematic review was to understand and map the updates of dietary interventions and nutritional supplementation measures related to patients with HF over the past 5 years.

Study design

A systematic review.

Methods

The PubMed, Web of Science, Scopus, and Cochrane Library databases were searched for randomized clinical trials on the association between dietary interventions and nutritional supplements and HF published between 2018 and 2023. A total of 1755 documents were retrieved, of which 19 were finalized for inclusion.

Results

The findings suggest that individualized nutritional support reduces mortality and risk of major cardiovascular events in chronic heart failure inpatients at high nutritional risk. The Mediterranean diet improves functionality, quality of life, and cardiac function. Additionally, supplementation with thiamine, ubiquinol, D-ribose, and L-arginine enhances left ventricular ejection fraction. Probiotic yogurt may effectively improve the inflammatory and antioxidative status of chronic heart failure. Whey protein and melatonin have a positive effect on improving endothelial function in HF patients.

Conclusion

Certain dietary interventions and nutritional supplements may provide some benefit to patients with HF. However, there is no relevant definitive evidence on the impact of nutritional interventions on the prognosis of HF, and more high-quality clinical trials are needed for further in-depth studies.

Systematic review registration

Identifier, CRD42024510847.

High-intensity interval training in patients with glaucoma (HIT-GLAUCOMA): protocol for a multicenter randomized controlled exercise trial

Background

Glaucoma stands as a prominent global cause of irreversible blindness and the primary treatment approach involves reducing intraocular pressure (IOP). However, around one-third of patients exhibit disease progression despite effective IOP reduction. Microvascular endothelial function, chronic inflammation, and oxidative stress are known to affect retinal neuronal networks and have been associated with disease severity and progression. Exercise training has the potential to counteract these mechanisms as add-on treatment to usual care.

Aims

The HIT-GLAUCOMA study will investigate the effects of a 6-month high-intensity interval training (HIIT) on intermediate endpoints such as local retinal microvascular and systemic large artery function, inflammation, and oxidative stress as well as clinical endpoints such as visual field indices, optic nerve rim assessment, retinal nerve fiber layer thickness, IOP, number of eye drops, vision-related quality of life and ocular surface disease symptomatology.

Methods

The study is a multi-center randomized controlled clinical trial in patients with both normal tension and high-tension primary open angle glaucoma. Across two study centers, 128 patients will be enrolled and randomized on a 1:1 basis into an exercise intervention group and a usual care control group. The primary microvascular endpoints are retinal arteriolar and venular flicker light-induced dilation at 6 months. The primary endpoint in the systemic circulation is brachial artery flow-mediated dilation at 6 months.

Anticipated results

We hypothesize that exercise therapy will improve retinal microvascular function and thus ocular blood flow in patients with glaucoma. As clinical outcomes, we will investigate the effect of exercise on visual field indices, optic nerve rim assessment, retinal nerve fiber layer thickness, IOP, number of eye drops, vision-related quality of life and ocular surface disease symptomatology.

Discussion

HIT-GLAUCOMA is a blueprint trial design to study the effect of exercise training on neurodegenerative and cardiovascular diseases. Importantly, patients are also expected to benefit from improvements in general health and cardiovascular co-morbidities. If proven effective, exercise may offer a new add-on treatment strategy to slow glaucoma progression.

Clinical Trial Registration Number

The trial is registered at Clinicaltrials.gov under the identifier NCT06058598 and is currently in the recruitment stage.

Endothelial Dysfunction and Heart Failure with Preserved Ejection Fraction-An Updated Review of the Literature

Heart failure (HF) is a clinical syndrome consisting of typical symptoms and signs due to structural and/or functional abnormalities of the heart, resulting in elevated intracardiac pressures and/or inadequate cardiac output. The vascular system plays a crucial role in the development and progression of HF regardless of ejection fraction, with endothelial dysfunction (ED) as one of the principal features of HF. The main ED manifestations (i.e., impaired endothelium-dependent vasodilation, increased oxidative stress, chronic inflammation, leukocyte adhesion, and endothelial cell senescence) affect the systemic and pulmonary haemodynamic and the renal and coronary circulation. The present review is aimed to discuss the contribution of ED to HF pathophysiology-in particular, HF with preserved ejection fraction-ED role in HF patients, and the possible effects of pharmacological and non-pharmacological approaches. For this purpose, relevant data from a literature search (PubMed, Scopus, EMBASE, and Medline) were reviewed. As a result, ED, assessed via venous occlusion plethysmography or flow-mediated dilation, was shown to be independently associated with poor outcomes in HF patients (e.g., mortality, cardiovascular events, and hospitalization due to worsening HF). In addition, SGLT2 inhibitors, endothelin antagonists, endothelial nitric oxide synthase cofactors, antioxidants, and exercise training were shown to positively modulate ED in HF. Despite the need for future research to better clarify the role of the vascular endothelium in HF, ED represents an interesting and promising potential therapeutic target.

Effects of photobiomodulation therapy (PBMT) over endothelial function in healthy individuals: a preliminary crossover clinical trial

Photobiomodulation therapy (PBMT) causes stimulatory effects that raise cell metabolism. The study aimed to evaluate the effects of PBMT on the endothelial function of healthy individuals. It was a controlled, randomized, crossover, triple-blind trial with 22 healthy volunteers (female: 77.3%), aged 25.45 years which were randomly divided into three groups. PBMT with gallium-aluminum-arsenide (GaAlAs) diode laser (810 nm, continuous-wave mode, 1000 mW, 0.28 cm²) was applied over the radial and ulnar artery regions in two parallel spots: group 1-30 J (n = 22, 107 J/cm²) per spot; group 2-60 J (n = 22, 214 J/cm²) per spot; and group 3-placebo (n = 22, sham). The endothelial function was measured before and immediately after PBMT by the flow-mediated dilation technique (%FMD) with high-resolution ultrasound. Statistical analysis was made with ANOVA for repeated measures, the effect size was measured by Cohen's d, and results are presented as mean and standard error (or 95% confidence intervals). A p-value < 0.05 was considered statistically significant. The %FMD increases 10.4% with 60 J (mean difference = 0.496 mm, 95% CI = 0.42 to 0.57, p < 0.001), 7.3% with 30 J (mean difference = 0.518 mm, 95% CI = 0.44 to 0.59, p < 0.001), and 4.7% with placebo (mean difference = 0.560 mm, 95% CI = 0.48 to 0.63, p < 0.001). We found a small effect size (p = 0.702; d de Cohen = 0.24) without statistical difference between interventions. PBMT with the energy density of 60 J and 30 J did not improve endothelial function.Trial registration number: NCT03252184 (01/09/2017).

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Vascular Function Recovery Following Saturation Diving

Background and Objectives: Saturation diving is a technique used in commercial diving. Decompression sickness (DCS) was the main concern of saturation safety, but procedures have evolved over the last 50 years and DCS has become a rare event. New needs have evolved to evaluate the diving and decompression stress to improve the flexibility of the operations (minimum interval between dives, optimal oxygen levels, etc.). We monitored this stress in saturation divers during actual operations. Materials and Methods: The monitoring included the detection of vascular gas emboli (VGE) and the changes in the vascular function measured by flow mediated dilatation (FMD) after final decompression to surface. Monitoring was performed onboard a diving support vessel operating in the North Sea at typical storage depths of 120 and 136 msw. A total of 49 divers signed an informed consent form and participated to the study. Data were collected on divers at surface, before the saturation and during the 9 h following the end of the final decompression. Results: VGE were detected in three divers at very low levels (insignificant), confirming the improvements achieved on saturation decompression procedures. As expected, the FMD showed an impairment of vascular function immediately at the end of the saturation in all divers but the divers fully recovered from these vascular changes in the next 9 following hours, regardless of the initial decompression starting depth. Conclusion: These changes suggest an oxidative/inflammatory dimension to the diving/decompression stress during saturation that will require further monitoring investigations even if the vascular impairement is found to recover fast.

Mini Trampoline, a New and Promising Way of SCUBA Diving Preconditioning to Reduce Vascular Gas Emboli?

Background: Despite evolution in decompression algorithms, decompression illness is still an issue nowadays. Reducing vascular gas emboli (VGE) production or preserving endothelial function by other means such as diving preconditioning is of great interest. Several methods have been tried, either mechanical, cardiovascular, desaturation aimed or biochemical, with encouraging results. In this study, we tested mini trampoline (MT) as a preconditioning strategy. Methods: In total, eight (five females, three males; mean age 36 ± 16 years; body mass index 27.5 ± 7.1 kg/m2) healthy, non-smoking, divers participated. Each diver performed two standardized air dives 1 week apart with and without preconditioning, which consisted of ±2 min of MT jumping. All dives were carried out in a pool (NEMO 33, Brussels, Belgium) at a depth of 25 m for 25 min. VGE counting 30 and 60 min post-dive was recorded by echocardiography together with an assessment of endothelial function by flow-mediated dilation (FMD). Results: VGE were significantly reduced after MT (control: 3.1 ± 4.9 VGE per heartbeat vs. MT: 0.6 ± 1.1 VGE per heartbeat, p = 0.031). Post-dive FMD exhibited a significant decrease in the absence of preconditioning (92.9% ± 7.4 of pre-dive values, p = 0.03), as already described. MT preconditioning prevented this FMD decrease (103.3% ± 7.1 of pre-dive values, p = 0.30). FMD difference is significant (p = 0.03). Conclusions: In our experience, MT seems to be a very good preconditioning method to reduce VGE and endothelial changes. It may become the easiest, cheapest and more efficient preconditioning for SCUBA diving.

Effects of Acute Hypobaric Hypoxia Exposure on Cardiovascular Function in Unacclimatized Healthy Subjects: A "Rapid Ascent" Hypobaric Chamber Study

Background: This study aimed to observe the effects of a fast acute ascent to simulated high altitudes on cardiovascular function both in the main arteries and in peripheral circulation. Methods: We examined 17 healthy volunteers, between 18 and 50 years old, at sea level, at 3842 m of hypobaric hypoxia and after return to sea level. Cardiac output (CO) was measured with Doppler transthoracic echocardiography. Oxygen delivery was estimated as the product of CO and peripheral oxygen saturation (SpO2). The brachial artery’s flow-mediated dilation (FMD) was measured with the ultrasound method. Post-occlusion reactive hyperemia (PORH) was assessed by digital plethysmography. Results: During altitude stay, peripheral oxygen saturation decreased (84.9 ± 4.2% of pre-ascent values; p < 0.001). None of the volunteers presented any hypoxia-related symptoms. Nevertheless, an increase in cardiac output (143.2 ± 36.2% of pre-ascent values, p < 0.001) and oxygen delivery index (120.6 ± 28.4% of pre-ascent values; p > 0.05) was observed. FMD decreased (97.3 ± 4.5% of pre-ascent values; p < 0.05) and PORH did not change throughout the whole experiment. Τhe observed changes disappeared after return to sea level, and normoxia re-ensued. Conclusions: Acute exposure to hypobaric hypoxia resulted in decreased oxygen saturation and increased compensatory heart rate, cardiac output and oxygen delivery. Pre-occlusion vascular diameters increase probably due to the reduction in systemic vascular resistance preventing flow-mediated dilation from increasing. Mean Arterial Pressure possibly decrease for the same reason without altering post-occlusive reactive hyperemia throughout the whole experiment, which shows that compensation mechanisms that increase oxygen delivery are effective.

A Prediction Equation to Estimate Vascular Endothelial Function in Different Body Mass Index Populations

Objective

Vascular endothelial dysfunction is considered an early predictor of endothelial injury and the initiating factor of atherosclerosis (AS). Brachial artery flow-mediated dilation (FMD) can detect endothelial injury early and provide important prognostic information beyond traditional cardiovascular (CV) risk factors. This study aimed to find the influencing factors of FMD and develop a simple prediction model in populations with different body mass indices (BMIs).

Methods

In total, 420 volunteers with different BMIs were recruited in our study. Subjects were randomly assigned to the derivation and validation cohorts (the ratio of the two was 1:2) with simple random sampling. The former was used for influencing factors searching and model construction of FMD and the latter was used for verification and performance evaluation.

Results

The population was divided into two groups, i.e., 140 people in the derivation group and 280 people in the verification group. Analyzing in the training data, we found that females had higher FMD than males (p < 0.05), and FMD decreased with age (p < 0.05). In people with diabetes, hypertension or obesity, FMD was lower than that in normal individuals (p < 0.05). Through correlation analysis and linear regression, we found the main influencing factors of FMD: BMI, age, waist-to-hip radio (WHR), aspartate aminotransferase (AST) and low-density lipoprotein (LDL). And we developed a simple FMD prediction model: FMD = −0.096BMI−0.069age−4.551WHR−0.015AST−0.242LDL+17.938, where R² = 0.599, and adjusted R² = 0.583. There was no statistically significant difference between the actual FMD and the predicted FMD in the verification group (p > 0.05). The intra-class correlation coefficient (ICC) was 0.77. In a Bland-Altman plot, the actual FMD and the predicted FMD also showed good agreement. This prediction model had good hints in CV risk stratification (area under curve [AUC]: 0.780, 95 % confidence intervals [95% CI]: 0.708–0.852, p < 0.001), with a sensitivity and specificity of 73.8 and 72.1%, respectively.

Conclusions

Males, older, obesity, hypertension, diabetes, smoking, etc. were risk factors for FMD, which was closely related to CV disease (CVD). We developed a simple equation to predict FMD, which showed good agreement between the training and validation groups. And it would greatly simplify clinical work and may help physicians follow up the condition and monitor therapeutic effect. But further validation and modification bears great significance.

Effect of SCUBA Diving on Ophthalmic Parameters

Background and Objective: Several cases of central serous chorioretinopathy (CSC) in divers have been reported in our medical retina center over the past few years. This study was designed to evaluate possible changes induced by SCUBA diving in ophthalmic parameters and especially subfoveal choroidal thickness (SFCT), since the choroid seems to play a crucial role in physiopathology of CSC. Materials and Methods: Intraocular pressure (IOP), SFCT, pachymetry, flow-mediated dilation (FMD), blood pressure, and heart rate were measured in 15 healthy volunteer divers before diving, 30 and 60 min after a standard deep dive of 25 m depth for 25 min in a dedicated diving pool (NEMO 33). Results: SFCT reduces significantly to 96.63 ± 13.89% of pre-dive values (p = 0.016) 30 min after diving. It recovers after 60 min reaching control values. IOP decreases to 88.05 ± 10.04% of pre-dive value at 30 min, then increases to 91.42 ± 10.35% of its pre-dive value (both p < 0.0001). Pachymetry shows a slight variation, but is significantly increased to 101.63 ± 1.01% (p = 0.0159) of the pre-dive value, and returns to control level after 60 min. FMD pre-dive was 107 ± 6.7% (p < 0.0001), but post-dive showed a diminished increase to 103 ± 6.5% (p = 0.0132). The pre-post difference was significant (p = 0.03). Conclusion: Endothelial dysfunction leading to arterial stiffness after diving may explain the reduced SFCT observed, but SCUBA diving seems to have miscellaneous consequences on eye parameters. Despite this clear influence on SFCT, no clear relationship between CSC and SCUBA diving can be drawn.

Full-Face Mask Use during SCUBA Diving Counters Related Oxidative Stress and Endothelial Dysfunction

Impaired flow mediated dilation (FMD), an index of vascular stress, is known after SCUBA diving. This is related to a dysfunction of nitric oxide (NO) availability and a disturbance of the redox status, possibly induced by hyperoxic/hyperbaric gas breathing. SCUBA diving is usually performed with a mask only covering “half face” (HF) and therefore forcing oral breathing. Nasal NO production is involved in vascular homeostasis and, as consequence, can significantly reduce NO possibly promoting vascular dysfunction. More recently, the utilization of “full-face” (FF) mask, allowing nasal breathing, became more frequent, but no reports are available describing their effects on vascular functions in comparison with HF masks. In this study we assessed and compared the effects of a standard shallow dive (20 min at 10 m) wearing either FF or a HF mask on different markers of vascular function (FMD), oxidative stress (ROS, 8-iso-PGF2α) and NO availability and metabolism (NO₂, NOx and 3-NT and iNOS expression). Data from a dive breathing a hypoxic (16% O₂ at depth) gas mixture with HF mask are shown allowing hyperoxic/hypoxic exposure. Our data suggest that nasal breathing might significantly reduce the occurrence of vascular dysfunction possibly due to better maintenance of NO production and bioavailability, resulting in a better ability to counter reactive oxygen and nitrogen species. Besides the obvious outcomes in terms of SCUBA diving safety, our data permit a better understanding of the effects of oxygen concentrations, either in normal conditions or as a strategy to induce selected responses in health and disease.

Impact of Physical Activity and Natural Bioactive Compounds on Endothelial Dysfunction in Chronic Kidney Disease

Chronic kidney disease (CKD) represents a world-wide public health problem. Inflammation, endothelial dysfunction (ED) and vascular calcifications are clinical features of CKD patients that increase cardiovascular (CV) mortality. CKD-related CV disease pathogenic mechanisms are not only associated with traditional factors such as arterial hypertension and dyslipidemia, but also with ED, oxidative stress and low-grade inflammation. The typical comorbidities of CKD contribute to reduce the performance and the levels of the physical activity in nephropathic patients compared to healthy subjects. Currently, the effective role of physical activity on ED is still debated, but the available few literature data suggest its positive contribution. Another possible adjuvant treatment of ED in CKD patients is represented by natural bioactive compounds (NBCs). Among these, minor polar compounds of extra virgin olive oil (hydroxytyrosol, tyrosol and oleocanthal), polyphenols, and vitamin D seem to exert a beneficial role on ED in CKD patients. The objective of the review is to evaluate the effectiveness of physical exercise protocols and/or NBCs on ED in CKD patients.

Clinical assessment of endothelial function in heart failure with preserved ejection fraction: A meta-analysis with meta-regressions

BACKGROUND

Endothelial dysfunction is a key mechanism in the development of cardiac remodelling and diastolic dysfunction in heart failure with preserved ejection fraction (HFpEF). Flow-mediated (FMD) and nitrate-mediated dilation (NMD) are noninvasive methods to assess endothelial function. We performed a meta-analysis evaluating the impact of HFpEF on FMD and NMD.

METHODS

PubMed, Web of Science, Scopus and EMBASE databases were systematically searched according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Differences were expressed as mean difference (MD) with 95% confidence intervals (95%CI). The random effects method was used.

RESULTS

A total of seven studies were included in the final analysis, 7 with data on FMD (326 HFpEF patients and 417 controls) and 3 on NMD (185 HFpEF patients and 271 controls). Compared to controls, HFpEF patients showed significantly lower FMD (MD: -1.929; 95%CI: -2.770, -1.088; P < .0001) and NMD values (MD: -2.795; 95%CI: -3.876, -1.715; P < .0001). Sensitivity analyses substantially confirmed results. Meta-regression models showed that increasing differences in E/A ratio (Z-score: -2.002; P = .045), E/E' ratio (Z-score: -2.181; P = .029) and left atrial diameter (Z-score: -1.951; P = .050) were linked to higher differences in FMD values between cases and controls.

CONCLUSIONS

Impaired endothelial function can be documented in HFpEF, with the possibility of a direct association between the severity of diastolic and endothelial dysfunction. Targeting endothelial dysfunction through pharmacological and rehabilitation strategies may represent an attractive therapeutic option.

Effect of melatonin supplementation on endothelial function in heart failure with reduced ejection fraction: A randomized, double-blinded clinical trial

Background

This study aimed to investigate the effect of melatonin supplementation on endothelial function in patients with heart failure with reduced ejection fraction (HFrEF).

Methods

This is an analysis of the MeHR trial, a randomized double‐blinded placebo‐controlled clinical trial with two parallel arms of 1:1. Oral 10 mg melatonin tablets or placebo was administered for 24 weeks. Deference in the percentage of flow‐mediated dilatation (FMD) after the intervention was the primary outcome.

Results

Ninety‐two patients were included in the study (age: 62.7±10.3 years, 87.0% male, ejection fraction (EF): 28.6±8.1). After adjustment for baseline FMD and age, a statistically significant difference in post‐treatment FMD in favor of the melatonin group was seen (estimated marginal means [95%CI], melatonin: 7.84% [6.69–8.98], placebo: 5.98% [4.84–7.12], p = .027). There was no significant difference in the mean of post‐treatment systolic/diastolic blood pressure, serum total antioxidant capacity, and serum malondialdehyde (MDA) between groups. Subgroup analysis showed significant improvement in FMD and MDA in the melatonin group in nondiabetic patients, while no difference was seen between study groups in diabetic patients.

Conclusions

Melatonin supplementation in HFrEF might improve endothelial function; however, this beneficial effect might not be seen in diabetic patients.

Impedance plethysmography-based method in the assessment of subclinical atherosclerosis

BACKGROUND AND AIMS

The aim of this study was to examine an association of individual and combined pulse waveform parameters derived from bioimpedance measurements, that is pulse waves from a distal impedance plethysmographic (IPG), a whole-body impedance cardiographic (ICG) and transformed distal impedance plethysmographic (tIPG) signals, with markers of subclinical atherosclerosis, i.e. carotid intima-media thickness (cIMT), brachial artery flow-mediated dilation (FMD) and carotid artery distensibility (Cdist). The level of the association was also compared for arterial pulse wave velocity (PWV) and cIMT, FMD, and Cdist.

METHODS

IPG, ICG, tIPG signals were measured from 1741 Finnish adults aged 30-45 years. The association between pulse wave parameters and cIMT, FMD and Cdist was studied using bootstrapped stepwise Akaike's Information Criterion method resulting in selection of parameters other than PWV, i.e. parameters having stronger association with cIMT, FMD and Cdist than PWV, in the model. Then risk scores were calculated from the selected pulse wave parameters and their association between cIMT, FMD and Cdist was studied with multivariable linear regression analysis.

RESULTS

The risk score was found to be the third strongest predictor of subclinical atherosclerosis as indicated by cIMT measurement, the second strongest predictor of FMD and the strongest predictor of Cdist. These findings show that several individual pulse wave parameters were associated more strongly with cIMT, FMD, and Cdist than PWV when adjusted with clinical risk factors.

CONCLUSIONS

Impedance based pulse waveform analysis provides a useful tool for assessing cardiovascular risk and estimating presence of structural changes in the vasculature.

Greater α1-adrenergic-mediated vasoconstriction in contracting skeletal muscle of patients with type 2 diabetes

Findings presented in this article are the first to show patients with type 2 diabetes mellitus have blunted hyperemic and vasodilatory responses to dynamic handgrip exercise. Moreover, we illustrate greater α1-adrenergic-mediated vasoconstriction may contribute to our initial observations. Collectively, these data suggest patients with type 2 diabetes may have impaired functional sympatholysis, which can contribute to their reduced exercise capacity.

Non-invasive ventilation improves exercise tolerance and peripheral vascular function after high-intensity exercise in COPD-HF patients

AIM

Evaluate the acute effects of non-invasive positive pressure ventilation (NiPPV) during high-intensity exercise on endothelial function in patients with coexisting chronic obstructive pulmonary disease (COPD) and heart failure (HF).

METHODS

This is a randomized, double blinded, sham-controlled study involving 14 COPD-HF patients, who underwent a lung function test and Doppler echocardiography. On two different days, patients performed incremental cardiopulmonary exercise testing (CPET) and two constant-work rate tests (80% of CPET peak) receiving Sham or NiPPV (bilevel mode - Astral 150) in a random order until the limit of tolerance (Tlim). Endothelial function was evaluated by flow mediated vasodilation (FMD) at three time points: 1) Baseline; 2) immediately post-exercise with NiPPV; and 3) immediately post-exercise with Sham.

RESULTS

Our patients had a mean age of 70 ± 7 years, FEV₁ 1.9 ± 0.7 L and LVEF 41 ± 9%. NIPPV resulted in an increased Tlim (NiPPV: 130 ± 29s vs Sham: 98 ± 29s p = 0.015) and SpO₂ (NiPPV: 94.7 ± 3.5% vs Sham: 92.7 ± 5.2% p = 0.03). Also, NiPPV was able to produce a significant increase in FMD (%) (NiPPV: 9.2 ± 3.1 vs Sham: 3.6 ± 0.7, p < 0.05), FMD (mm) (NiPPV: 0.41 ± 0.18 vs Sham: 0.20 ± 0.11, p < 0.05), Blood flow velocity (NiPPV: 33 ± 18 vs Baseline: 20 ± 14, p < 0.05) and Shear Stress (SS) (NiPPV: 72 ± 38 vs Baseline: 43 ± 25, p < 0.05). We found correlation between Tlim vs. ΔSS (p = 0.03; r = 0.57). Univariate-regression analysis revealed that increased SS influenced 32% of Tlim during exercise with NiPPV.

CONCLUSION

NiPPV applied during high-intensity exercise can acutely modulate endothelial function and improve exercise tolerance in COPD-HF patients. In addition, the increase of SS positively influences exercise tolerance.

Switch to direct anticoagulants and improved endothelial function in patients with chronic heart failure and atrial fibrillation

BACKGROUND

Chronic heart failure (CHF) is characterized by higher rates of atrial fibrillation (AF) and endothelial dysfunction (ED). First line anticoagulant therapy in AF is represented by direct oral anticoagulants (DOACs); several patients, however, are still treated with vitamin-K inhibitors. The use of DOACs is associated in previous studies with an improved vascular function. We therefore sought to evaluate possible changes in endothelial function assessed by flow-mediated dilation (FMD) in patients with CHF and AF shifting from warfarin to DOACs.

METHODS

Forty-three consecutive outpatients were enrolled in the study. FMD was assessed at baseline and after 4 months. Patients were compared according to AC therapy.

RESULTS

After the first measurement of FMD, 18 patients "switched" to DOACs because of poor compliance to warfarin therapy or time in therapeutic range, 19 patients continued to use DOACs, 6 warfarin. "Switched" patients to DOACs therapy showed an improved FMD (19.0 ± 6.6% vs 3.8 ± 1.3%, p < 0.0001); C-reactive protein (CRP) levels decreased in "switched" patients from 1.4 ± 0.5 to 1.0 ± 0.7 mg/dl (p < 0.05). FMD and CRP changes were not significant in patients who did not changed anticoagulant therapy. In switched patients, changes in CRP levels were proportional to FMD changes (r = -0.50, p < 0.05). Shifting from warfarin to DOACs was significantly correlated to improved FMD levels even at multivariable analysis (p < 0.05).

CONCLUSIONS

Switch from warfarin to DOACs in patents with CHF and AF was associated in an observational non randomized study with an improved endothelial function. Changes in FMD values were related to changes in CRP levels.

Effects of a High Fat Meal Associated with Water, Juice, or Champagne Consumption on Endothelial Function and Markers of Oxidative Stress and Inflammation in Young, Healthy Subjects

Endothelial dysfunction (ED), often linked to hypertriglyceridemia, is an early step of atherosclerosis. We investigated, in a randomized cross-over study, whether high-fat meal (HFM)-induced ED might be reduced by fruit juice or champagne containing polyphenols. Flow-mediated dilatation (FMD) and biological parameters (lipid profile, glycemia, inflammation, and oxidative stress markers) were determined before and two and three hours after the HFM in 17 healthy young subjects (24.6 ± 0.9 years) drinking water, juice, or champagne. Considering the entire group, despite significant hypertriglyceridemia (from 0.77 ± 0.07 to 1.41 ± 0.18 mmol/L, p < 0.001) and a decrease in Low Density Lipoprotein (LDL), the FMD was not impaired. However, the FMD decreased in 10 subjects (from 10.73 ± 0.95 to 8.13 ± 0.86 and 8.07 ± 1.16%; p < 0.05 and p < 0.01; 2 and 3 h, respectively, after the HFM), without concomitant change in concentration reactive protein or reactive oxygen species, but with an increase in glycemia. In the same subjects, the FMD did not decrease when drinking juice or champagne. In conclusion, HFM can impair the endothelial function in healthy young subjects. Fruit juice, rich in anthocyanins and procyanidins, or champagne, rich in simple phenolic acids, might reduce such alterations, but further studies are needed to determine the underlying mechanisms, likely involving polyphenols.