Flow-mediated Vasodilation Values Research Articles

Vascular function assessed by flow-mediated vasodilation and nitroglycerine-induced vasodilation in subjects with first-degree atrioventricular block

First-degree atrioventricular block (AVB) is a common electrocardiogram finding in clinical practice. Vascular dysfunction is associated with cardiovascular disease and events. There is no information on the association of AVB with vascular function. The purpose of this study was to evaluate the associations of PR interval with vascular function assessed in well-characterized subjects. A total of 2220 subjects were enrolled in this study. We evaluated endothelium-dependent vasodilatation assessed by flow-mediated vasodilation (FMD) and endothelium-independent vasodilatation assessed by nitroglycerine-induced vasodilation (NID) in 106 subjects with first-degree AVB (70 men; mean age, 64.3 ± 12.9 years) and 1241 subjects with normal PR interval (531 men; mean age, 56.1 ± 13.9 years). Subjects with first-degree AVB had a lower FMD value than that in subjects with normal PR interval (3.5 ± 2.4% vs. 4.9 ± 3.3%, P < 0.001). FMD was significantly lower in subjects with first-degree AVB than in subjects with normal PR interval even after adjustment of confounding factors for assessment of endothelium-dependent vasodilatation (OR: 1.73, 95% CI: 1.11–2.70; P = 0.015). Although NID was significantly lower in subjects with first-degree AVB than in subjects with normal PR interval (11.1 ± 6.0% vs. 13.6 ± 6.1%, P < 0.001), there was no significant difference in NID between the two groups in multivariate analysis (OR: 1.48, 95% CI: 0.91–2.41; P = 0.117). Both endothelium-dependent and endothelium-independent vasodilation in the brachial artery are impaired in parallel with the prolongation of atrioventricular conduction. After adjustments of confounding factors for vascular function, first-degree AVB is associated with impaired endothelium-dependent vasodilatation but not with impaired endothelium-independent vasodilatation. From the aspect of vascular function, it is unlikely that first-degree AVB is an electrocardiography abnormality with a good prognosis.

Endothelium-mediated vasodilation: associations with cardiometabolic diseases and their risk factors in aging

Aim. To evaluate the association of flow-mediated vasodilation (FMD) with cardiometabolic diseases (CMDs) and their risk factors (RF) in old age.Material and methods. The study was conducted in the Russian population cohort of the HAPIEE project (Novosibirsk, 2015-2018). Endothelial function was assessed in a random subsample (788 men and women aged 55-84 years) using ultrasound measurements of the brachial artery FMD. Endothelial dysfunction (ED) was recorded with FMD &lt;10%. Cardiovascular diseases (CVD) and risk factors were assessed using standard epidemiological methods.Results. The incidence of hypertension (HTN) was 78,8% (the same in men and women), major CVDs — 21,7% and 17,1%, type 2 diabetes (T2D) — 18,7% and 19,1% in men and women, respectively. The mean FMD values were 2,7% (SD 7,32) and 3,2% (7,19), while the prevalence of ED was 88,2% and 85,8% in men and women, respectively, and did not differ significantly by sex. Men with ED had higher levels of blood triglycerides (125,1 (71,23) vs 102,7 (45,79) mg/dl; p=0,033), waist/hip circumference indices (0,94 (0,050) vs 0,92 (0,076); p=0,009) and body weight (27,7 (45,79) vs 26,5 (4,36) kg/m2; p=0,077). In women, a tendency towards an association of ED with smoking was revealed (p=0,067). There were no associations of ED with HTN, T2D and CVD in men and women.Conclusion. The PMD test demonstrated a high incidence of ED in a population sample of 55-84 years old. ED is associated with metabolic risk factors in men and smoking in women. No associations of PMD with CMDs were found, presumably due to the high incidence of ED and cumulative disease in the elderly. Modification of metabolic risk factors and smoking cessation are relevant at any age to prevent the progression of ED.

Endothelial Dysfunction in Type 2 Diabetes Patients and its Association with Microvascular Complications: A Cross-sectional Study

Introduction: The prevalence of Type 2 Diabetes Mellitus (T2DM) is increasing worldwide. Microangiopathic and macroangiopathic complications are the main causes of morbidity and mortality in diabetes. Endothelial dysfunction is important in the early pathophysiology of vascular complications. Screening is very important in order to prevent these complications. Aim: To investigate endothelial dysfunction, as measured by Flow Mediated Vasodilation (FMD) of the brachial artery, in diabetic individuals. It also aims to explore the correlation between FMD and Glycated Haemoglobin (HbA1c), as well as the association between FMD and microvascular complications such as diabetic neuropathy, diabetic retinopathy, and albuminuria. Materials and Methods: This cross-sectional study was conducted at Mahatma Gandhi Medical College and Research Institute, Puducherry, India, between 2020 and 2021 on 160 patients. All patients diagnosed with T2DM, attending the Outpatient Department (OPD) or admitted to the ward, were enrolled in the study using consecutive sampling. FMD was measured for each patient, and Urine Albumin Creatinine Ratio (UACR) was also assessed. Diabetic retinopathy was evaluated through fundus examination, and diabetic neuropathy was screened using the monofilament test. Statistical analysis was performed using Statistical Package for Social Sciences (SPSS) version 27.0 to determine the correlation between FMD and these variables. Results: A total of 160 patients were enrolled in this study, including 104 (65%) males and 56 (35%) females. The median age was 52 years, and the participants had a median Body Mass Index (BMI) of 29.5 kg/m2 . The median HbA1c was 8.7%. The median Fasting Blood Sugar (FBS) and Postprandial Blood Sugar (PPBS) levels were 145 mg/dL and 242 mg/dL, respectively. The median FMD among all patients was 5.6%, with an Interquartile Range (IQR) of 4.9% to 6.6%. There was an inverse correlation between HbA1C and FMD values, with a correlation coefficient of -0.718 (p-value &lt;0.01), indicating a strong and significant inverse correlation. Patients with significant macroalbuminuria had a lower median FMD compared to non albuminuric patients, and this difference was statistically significant. The median FMD was also lower in patients with diabetic neuropathy and retinopathy. Conclusion: The study findings suggest that endothelial dysfunction, as measured by FMD, is significantly impaired in patients with elevated HbA1c and microvascular complications of diabetes mellitus.

Lack of impact of ipragliflozin on endothelial function in patients with type 2 diabetes: sub-analysis of the PROTECT study

BackgroundWe assessed the impact of 24 months of treatment with ipragliflozin, a sodium-glucose cotransporter 2 (SGLT2) inhibitor, on endothelial function in patients with type 2 diabetes as a sub-analysis of the PROTECT study.MethodsIn the PROTECT study, patients were randomized to receive either standard antihyperglycemic treatment (control group, n = 241 ) or add-on ipragliflozin treatment (ipragliflozin group, n = 241) in a 1:1 ratio. Among the 482 patients in the PROTECT study, flow-mediated vasodilation (FMD) was assessed in 32 patients in the control group and 26 patients in the ipragliflozin group before and after 24 months of treatment.ResultsHbA1c levels significantly decreased after 24 months of treatment compared to the baseline value in the ipragliflozin group, but not in the control group. However, there was no significant difference between the changes in HbA1c levels in the two groups (7.4 ± 0.8% vs. 7.0 ± 0.9% in the ipragliflozin group and 7.4 ± 0.7% vs. 7.3 ± 0.7% in the control group; P = 0.08). There was no significant difference between FMD values at baseline and after 24 months in both groups (5.2 ± 2.6% vs. 5.2 ± 2.6%, P = 0.98 in the ipragliflozin group; 5.4 ± 2.9% vs. 5.0 ± 3.2%, P = 0.34 in the control group). There was no significant difference in the estimated percentage change in FMD between the two groups (P = 0.77).ConclusionsOver a 24-month period, the addition of ipragliflozin to standard therapy in patients with type 2 diabetes did not change endothelial function assessed by FMD in the brachial artery.Trial registrationRegistration Number for Clinical Trial: jRCT1071220089 (https://jrct.niph.go.jp/en-latest-detail/jRCT1071220089).

Regular Consumption of Cocoa and Red Berries as a Strategy to Improve Cardiovascular Biomarkers via Modulation of Microbiota Metabolism in Healthy Aging Adults.

The aim of the present study was to analyze the effects of cocoa flavanols and red berry anthocyanins on cardiovascular biomarkers, such as homocysteine, angiotensin-converting enzyme (ACE), nitric oxide (NO), flow-mediated vasodilation (FMD), blood pressure and lipid profile. Additionally, we aimed to ascertain their possible interactions with microbiota related metabolites, such as secondary bile acids (SBA), short-chain fatty acids (SCFA) and trimethylamine N-oxide (TMAO). A randomized, parallel-group study, single-blind for the research team, was performed on 60 healthy volunteers between the ages of 45 and 85, who consumed 2.5 g/day of cocoa powder (9.59 mg/day of total flavanols), 5 g/day of a red berry mixture (13.9 mg/day of total anthocyanins) or 7.5 g/day of a combination of both for 12 weeks. The group that had consumed cocoa showed a significant reduction in TMAO (p = 0.03) and uric acid (p = 0.01) levels in serum, accompanied by an increase in FMD values (p = 0.03) and total polyphenols. corrected by creatinine (p = 0.03) after the intervention. These latter values negatively correlated with the TMAO concentration (R = -0.57, p = 0.02). Additionally, we observed an increase in carbohydrate fermentation in the groups that had consumed cocoa (p = 0.04) and red berries (p = 0.04) between the beginning and the end of the intervention. This increase in carbohydrate fermentation was correlated with lower levels of TC/HDL ratio (p = 0.01), systolic (p = 0.01) and diastolic blood pressure (p = 0.01). In conclusion, our study showed a positive modulation of microbiota metabolism after a regular intake of cocoa flavanols and red berry anthocyanins that led to an improvement in cardiovascular function, especially in the group that consumed cocoa.

Effect of urolithin A on the improvement of vascular endothelial function depends on the gut microbiota.

Urolithin A (UA) is a metabolite produced by gut microbiota from ingested ellagic acid. Although the effect of ellagic acid intake on vascular endothelial function (VEF) improvement has been reported, the effect of UA intake on VEF improvement remains obscure. In addition, UA has been reported to improve the intestinal barrier function, and UA may have improved VEF by gut microbiome alteration. In this study, we conducted a clinical trial to explore and analyze the effects of UA intake on vascular endothelial function (VEF) and characteristics of the intestinal environment, such as gut microbiome profiling and organic acid composition. A placebo-controlled, randomized, double-blinded, parallel group trial was conducted on participants who could metabolize small amounts of UA from ellagic acid (non-UA producers) and had relatively poor VEF. VEF was assessed using the flow-mediated vasodilatation (FMD) score. Participants were administered placebo, UA 10 mg/day, or UA 50 mg/day for 12 weeks. FMD was measured and fecal samples were collected at 0, 4, 8, and 12 weeks of treatment. Gut microbiome analysis and organic acid level measurements were performed to evaluate the effects of UA intake on the intestinal environment. This clinical trial is publicly registered at the UMIN-CTR, trial number: UMIN000042014. The gut microbiota of the UA 50 mg/day group showed a significant increase in alpha diversity (Faith's phylogenetic diversity). Four and nine microbial genera were significantly altered in the UA 10 mg/day and UA 50 mg/day groups, respectively (p < 0.05, not corrected). Participants whose FMD scores improved with UA intake had poor baseline FMD values as well as a low Bacillota/Bacteroidota ratio. Urolithin A intake alters the gut microbiota and improves their alpha diversity. In addition, the effect of UA on VEF correlated with the individual gut microbiota. Our results have practical implications for a new approach to providing healthcare that focuses on intestinal environment-based diet therapy.

Theoretical and Experimental Study on Assessment of Flow-Mediated Dilatation Using the Cuff Method in Brachial Arteries

Endothelial dysfunction has been shown to be an important risk factor in the pathogenesis of atherosclerosis, hypertension, and heart failure. The flow-mediated vasodilation (FMD) of the peripheral arteries is an endothelium-dependent function, which is assessed by measuring the diameter change in the brachial artery before and after ischemic stress. Brachial-artery ultrasound scanning (BAUS) is the gold standard for assessing the FMD in clinical practice. However, ultrasonography requires an operator or physician with a professional training to perform accurate measurement of the diameter of the brachial artery. Thus, some studies have used the cuff method to measure the FMD in percentage, the value of which is significantly larger than that using BAUS. The goal of this study was to explore this phenomenon. We explain the interaction between the volume changes (oscillation magnitudes in volume due to cardiac pulsations) of the artery and cuff bladder under different transmural pressures when a sphygmomanometer is wrapped around an upper arm. The compliance of the cuff bladder would be of a fixed value when the cuff pressure is low. The cuff-volume change could be replaced with a cuff-pressure change (oscillation magnitude in cuff pressure due to cardiac pulsation). With the cuff method, the FMDc could be assessed with pressure changes. Then, an inequality formula regarding FMD values by both BAUS (FMDu) and the cuff method (FMDc) was derived; FMDc &gt; 2*FMDu + FMDu2. In order to experimentally verify this inequality formula, fifty-one subjects, including thirty-eight healthy adults and thirteen patients with hypertension, participated in this study. The systolic and diastolic diameters of their brachial arteries and cuff-pressure changes due to cardiac pulsations were separately measured by BAUS and a pressure sensor before and after an ischemic stress. The results showed that FMDu and FMDc were 8.1 ± 4.3% and 121.6 ± 48.6% in the healthy group and 4.5 ± 1.1% and 55.2 ± 22.8% in the patient group, respectively. Thus, the experimental findings comply with the theoretically derived inequality formula.

Relationship between hemoglobin A1c level and flow-mediated vasodilation in patients with type 2 diabetes mellitus receiving antidiabetic drugs.

ABSTRACTAims/IntroductionDiabetes mellitus is associated with endothelial dysfunction. However, it is still controversial as to whether antidiabetic drug treatment affects endothelial function. The purpose of this study was to evaluate the relationships of the hemoglobin A1c (HbA1c) level with flow‐mediated vasodilation (FMD) and nitroglycerine‐induced vasodilation (NID) in patients with type 2 diabetes mellitus who are receiving antidiabetic drugs.Materials and MethodsThe FMD was measured in 866 patients with type 2 diabetes mellitus who were receiving antidiabetic drugs (625 men and 241 women; mean age: 62 ± 10 years). The patients were divided into four groups according to HbA1c levels: <6.5, 6.5–6.9, 7.0–7.9, and ≥8.0%.ResultsThere was an inverted U‐shaped pattern of association of the HbA1c level with the FMD at an HbA1c level of about 7% of the peak of FMD in patients with type 2 diabetes mellitus who were receiving antidiabetic drugs. The FMD was significantly smaller in the HbA1c <6.5% group than in the HbA1c 6.5–6.9% group and the HbA1c 7.0–7.9% group (P < 0.001 and P < 0.001, respectively). The FMD values were similar in the HbA1c <6.5% group and HbA1c ≥8.0% group (P = 0.10). There were no significant differences in NID among the four groups (P = 0.98).ConclusionsThese findings suggest that a low HbA1c <6.5% as well as a high HbA1c ≥8.0% is associated with endothelial dysfunction in patients with type 2 diabetes mellitus who are receiving antidiabetic drugs and that vascular smooth muscle function is similar in such patients regardless of the HbA1c level.

Short stature is associated with low flow-mediated vasodilation in Japanese men.

An inverse association between height and the risk of cardiovascular disease has been reported. The objective of this study was to examine the association between height and endothelial function assessed by flow-mediated vasodilation (FMD). We evaluated cross-sectional associations of height with FMD in 7682 Japanese men. All participants were divided into four groups based on height: <155.0 cm, 155.0-164.9 cm, 165.0-174.9 cm, and ≥175.0 cm. Subjects in a lower quartile of FMD were defined as subjects having low FMD values. Univariate regression analysis revealed that height was significantly correlated with FMD (r = 0.14, p < 0.001). FMD values were 4.6 ± 3.1% in the <155.0 cm group, 5.2 ± 3.1% in the 155.0-164.9 cm group, 5.7 ± 3.1% in the 165.0-174.9 cm group and 6.1 ± 3.2% in the ≥175.0 cm group. FMD significantly increased in relation to an increase in height. Multiple logistic regression analysis revealed that higher height groups were significantly associated with a decreased risk of low FMD value compared with the <155.0 cm group after adjustments for age, presence of hypertension, dyslipidemia, diabetes, current smoking, and brachial artery diameter. FMD was low in subjects with a short stature compared with that in subjects with tall stature. Individuals with a short stature may require intensive interventions to reduce the risk of cardiovascular events.Clinical Trial Registration Information: URL for Clinical Trials: http://www.umin.ac.jp Registration Number for Clinical Trials: UMIN000012952.

Stair climbing activity and vascular function in patients with hypertension.

We evaluated the relationship between daily stair climbing activity and vascular function as assessed by flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation (NID). This study was a cross-sectional study. A total of 374 patients with hypertension were enrolled. The subjects were divided into three groups based on their daily stair climbing habit: no stairs group, climbing stairs to the 2nd-floor group, and climbing stairs to the ≥3rd-floor group. There was a significant difference in FMD between the ≥3rd-floor group and the other two groups (3.3 ± 2.5% vs. 2.3 ± 2.7% and 2.4 ± 2.7%, p = 0.02, respectively). FMD values were similar in the no stairs group and the 2nd-floor group (p = 0.96). There was a significant difference in NID between the no stairs group and the other two groups (7.4 ± 4.2% vs. 10.9 ± 5.3% and 11.3 ± 5.1%, p < 0.001, respectively). NID values were similar in the second-floor group and the ≥3rd-floor group (p = 0.86). These findings suggest that both endothelial function and vascular smooth muscle function are impaired in individuals who do not climb stairs and that endothelial function but not vascular smooth muscle function is impaired in individuals who climb stairs to the second floor compared with individuals who climb stairs to the ≥3rd floor. Stair climbing activity, a simple method for assessing daily physical activity, may reflect vascular function in patients with hypertension.

Inconvenient relationship of haemoglobin A1c level with endothelial function in type 2 diabetes in a cross-sectional study

ObjectiveThe aim of this study was to determine the relationship of haemoglobin A1c (HbA1c) level with flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation (NID) in patients with type 2 diabetes.DesignCross-sectional study.Setting22...

Lower triglyceride levels are associated with better endothelial function

Increased serum triglyceride levels are independently associated with endothelial dysfunction. However, there is little evidence to define normal levels of triglycerides and there is little information on endothelial function in subjects with extremely low levels of triglycerides. The purpose of this study was to determine the relationship between triglycerides, especially low levels of triglycerides, and vascular function. We measured flow-mediated vasodilation (FMD) in 7047 subjects and nitroglycerine-induced vasodilation (NID) in 1017 subjects. We divided the subjects into eight groups by triglyceride levels: <50 mg/dL, 50-69 mg/dL, 70-89 mg/dL, 90-109 mg/dL, 110-129 mg/dL, 130-149 mg/dL, 150-199 mg/dL, and ≥200 mg/dL. FMD was significantly higher in subjects with triglyceride levels of <50 mg/dL than in subjects with triglyceride levels of 50-69 mg/dL, 70-89 mg/dL, 90-109 mg/dL, 110-129 mg/dL, 130-149 mg/dL, 150-199 mg/dL, and ≥200 mg/dL (p=0.002, p<0.001, p<0.001, p<0.001, p<0.001, p<0.001, and p<0.001, respectively). Using triglyceride levels of >200 mg/dL as a reference, the odds ratios for a lower quartile of FMD were significantly lower in the <50 mg/dL group, 50-69 mg/dL group, 70-89 mg/dL group, and 90-109 mg/dL group after adjustment for age, gender and other cardiovascular risk factors. There was a slight negative correlation between NID and triglycerides (r=-0.074; p=0.019). However, there was no significant differences in NID among the eight groups. FMD values were highest in subjects with extremely low levels of triglycerides (<50 mg/dL). Lower triglyceride levels were associated with better endothelial function. http://www.umin.ac.jp (University Hospital Medical Information Network Clinical Trials Registry) (UMIN000012950).

Low Levels of Low-Density Lipoprotein Cholesterol and Endothelial Function in Subjects without Lipid-Lowering Therapy.

An elevation of serum low-density lipoprotein cholesterol (LDL-C) levels has been associated with endothelial dysfunction in statin naïve subjects. However, there is no information on endothelial function in subjects with extremely low levels of LDL-C. The purpose of the present study was to determine the relationship of LDL-C levels, especially low levels of LDL-C, with endothelial function. Endothelial function assessed by flow-mediated vasodilation (FMD) measurement and LDL-C levels were evaluated in 7120 subjects without lipid-lowering therapy. We divided the subjects into five groups by LDL-C levels: <70 mg/dL, 70–99 mg/dL, 100–119 md/dL, 120–139 mg/dL, and ≥140 mg/dL. FMD values were significantly smaller in subjects with LDL-C levels of ≥140 mg/dL than in those with LDL-C levels of 70–99 mg/dL and 100–119 mg/dL (p < 0.001 and p = 0.004, respectively). The FMD values in the LDL-C of <70 mg/dL group were not significantly different from those in the other groups. To evaluate the relationship of extremely low LDL-C levels with endothelial function, we divided the subjects with LDL-C of <70 mg/dL into those with LDL-C levels of <50 mg/dL and 50–69 mg/dL. FMD values were similar in the LDL-C <50 mg/dL group and ≥50 mg/dL group in the propensity score-matched population (p = 0.570). A significant benefit was not found in subjects with low LDL-C levels from the aspect of endothelial function.

The effect of PCOS status on atherosclerosis markers and cardiovascular disease risk factors in young women with vitamin D deficiency

Objective To investigate whether polycystic ovary syndrome (PCOS) had further deteriorating influence on endothelial function or cardiometabolic parameters in women with vitamin D deficiency during reproductive age. Study design The study group was composed of women with PCOS and vitamin D deficiency and insufficiency between the ages of 18 and 35 years. Age and body mass index (BMI)-matched women were chosen as controls. Serum 25(OH) Vit D levels below 20 ng/mL were considered as vitamin D deficiency. The cutoff level of vitamin D insufficiency was suggested at 30 ng/mL. Serum FSH, LH, estradiol, testosterone, DHEA-S, fasting glucose, total cholesterol, HDL, LDL, triglyceride levels were analyzed. Carotid artery intima-media thickness (CIMT) was measured, and the flow-mediated vasodilation (FMD) was calculated. Results CIMT and FMD values in both vitamin D deficiency and insufficiency subgroups showed no significant difference between PCOS and non-PCOS groups. There was a weak negative correlation between BMI, waist/hip ratio, CRP, and 25(OH) Vitamin D. Conclusion PCOS is a heterogeneous disease with different combinations of the diagnostic components. Vitamin D is an important variable for a healthy cardiovascular system. We did not find any difference in early atherosclerotic markers and cardiometabolic features between PCOS and non-PCOS group with Vitamin D deficiency.

Relationship between high-density lipoprotein cholesterol levels and endothelial function in women: a cross-sectional study

ObjectivesThe purpose of this study was to evaluate the relationship between high-density lipoprotein cholesterol (HDL-C) levels and endothelial function in women.DesignCross-sectional study.Setting22 university hospitals and affiliated clinics in Japan.Participants1719 Japanese...

Relationship between brachial flow-mediated dilation and carotid intima-media thickness in patients with coronary artery disease.

Although flow-mediated vasodilation (FMD) of brachial artery and carotid intima-media thickness (IMT) are important surrogate markers in the process of atherosclerosis, information about relationship between both markers is insufficient. In the present study, we assessed extensively the relationship in patients with coronary artery disease (CAD). The values of brachial FMD and carotid ultrasonography findings in 159 patients (67±8 years, 130 males) with angiographically verified CAD were retrospectively analyzed. In all patients, mean carotid IMT tended to be correlated with FMD, although the correlation was not statistically significant (R=-0.149, P=0.061). Maximum IMT was not correlated with the FMD (R=0.053, P=0.508). In addition, carotid artery diameter was significantly correlated with the FMD (R=0.290, P=0.0002). Prevalence of high IMT value (≥1.0 mm) was higher in the abnormal FMD group (4%>; N.=67), compared with the normal FMD group (≥7%; N.=24; P<0.05). Carotid artery diameter was larger in abnormal FMD group, compared with both groups of normal FMD (P<0.01) and borderline FMD (4-7%; N.=68) (P<0.01). In all patients, receiver operating characteristics analysis demonstrated that cut-off value of FMD to predict the prevalence of ischemic stroke was 3.7% (AUC=0.735, P<0.001). The cut-off value of maximum IMT was 1.9 mm, but was not significant (AUC=0.522, P=0.829). Brachial FMD and carotid IMT would be different in clinical significance as a surrogate marker for pathophysiology of atherosclerotic disease.

Diagnostic Criteria of Flow‐Mediated Vasodilation for Normal Endothelial Function and Nitroglycerin‐Induced Vasodilation for Normal Vascular Smooth Muscle Function of the Brachial Artery

BackgroundDiagnostic criteria of flow‐mediated vasodilation (FMD), an index of endothelial function, and nitroglycerin‐induced vasodilation (NID), an index of vascular smooth muscle function, of the brachial artery have not been established. The purpose of this study was to propose diagnostic criteria of FMD and NID for normal endothelial function and normal vascular smooth muscle function.Methods and ResultsWe investigated the cutoff values of FMD and NID in subjects with (risk group) and those without cardiovascular risk factors or cardiovascular diseases (no‐risk group) in 7277 Japanese subjects (mean age 51.4±10.8 years) from the Flow‐Mediated Dilation Japan study and the Flow‐Mediated Dilatation Japan Registry study for analysis of the cutoff value of FMD and in 1764 Japanese subjects (62.2±16.1 years) from the registry of Hiroshima University Hospital for analysis of the cutoff value of NID. Receiver‐operator characteristic curve analysis of FMD to discriminate subjects in the no‐risk group from patients in the risk group showed that the optimal cutoff value of FMD to diagnose subjects in the no‐risk group was 7.1%. Receiver‐operator characteristic curve analysis of NID to discriminate subjects in the no‐risk group from patients in the risk group showed that the optimal cutoff value of NID to diagnose subjects in the no‐risk group was 15.6%.ConclusionsWe propose that the cutoff value for normal endothelial function assessed by FMD of the brachial artery is 7.1% and that the cutoff value for normal vascular smooth muscle function assessed by NID of the brachial artery is 15.6% in Japanese subjects.Clinical Trial Registration http://www.umin.ac.jp Unique identifiers: UMIN000012950, UMIN000012951, UMIN000012952, and UMIN000003409

Flow-Mediated Vasodilatation which is diagnostic method of endothelial dysfunctions change in atrial septal defect patients before and after closure of the ASD

Aim: Atrial septal defect secondary pulmonary hypertension causes disruption of the endothelial structure, resulting in an increase in vasoconstrictor mediators and a decrease in vasodilator mediators. These changes on the endothelial system alter the flow in the pulmonary vein and the systemic vein bed. This also has an effect on flow mediated vasodilatation. Our purpose in this study is to evaluate the endothelial dysfunction after atrial septal defect closure via flow mediated vasodilatation. Material and Methods: Total 51 patients with pre and one mount after post treatment secundum-type atrial septal defect and 40 healthy volunteers were prospectively enrolled. Atrial septal defect was treated with transcathater closure procedure. Flow mediated vasodilatation was measured to evaluate endothelial function prior to and one month after the defect was closured.Results: Flow-mediated vasodilatation values were significantly higher in an atrial septal defect′s patient than in the healthy volunteer (11.2 ± 1.01 m/s vs. 12.7 ± 1.18 m/s, P 0.001). Flow-mediated vasodilatation values were significantly reduced at the follow-up one month after the procedure compared to baseline. Moreover, there was a significant negative correlation between pulmonary arterial pressure values and flow-mediated vasodilatation (r=-0.347; p=0.013) in the pretreatment group.Conclusion: Flow-mediated vasodilatation values were significantly lower in the right cardiac chambers, and the systolic pulmonary arterial pressure was improved. This result has shown us that atrial septal defect closure may benefit from endothelial dysfunction.

Flow-Mediated Vasodilation and Reactive Hyperemia Index in Heart Failure with Reduced or Preserved Ejection Fraction.

Vascular endothelial dysfunction is part of the underlying pathophysiology of heart failure. However, there are no reports in which vascular endothelial function of both conduit arteries and microvasculature was assessed in patients with heart failure. This study was aimed to assess vascular endothelial function separately in heart failure with reduced (HFrEF) and preserved ejection fraction (HFpEF). We performed simultaneous measurement of both flow-mediated vasodilation for endothelial function of conduit arteries and reactive hyperemia-peripheral arterial tonometry for that of microvasculature in 88 consecutive patients with chronic heart failure. In 55 patients with ischemic heart disease as an underlying cause of heart failure, flow-mediated vasodilation value was comparable between the two groups of HFrEF (left ventricular ejection fraction < 50%, n = 31) and HFpEF (left ventricular ejection fraction ≥ 50%, n = 24). Reactive hyperemia index measured by reactive hyperemia peripheral arterial tonometry, however, was lower in HFrEF patients compared to HFpEF patients (P = 0.014). In contrast, among 33 patients with non-ischemic heart disease, the degree of flow-mediated vasodilation was lower in HFpEF patients (n = 18) compared with HFrEF patients (n = 15) (P = 0.009), while reactive hyperemia index was comparable between the two groups. The clinical and pathophysiological significance of endothelial function in heart failure differs between conduit artery and microvasculature, and these differences may contribute to the underlying pathophysiology of HFpEF and HFrEF, as well as in ischemic heart disease and non-ischemic heart disease.

Correlations of carotid intima-media thickness with endothelial function and atherosclerosis degree in patients with type 2 diabetes mellitus.

To investigate the correlation of carotid intima-media thickness (IMT) with endothelial function and atherosclerosis degree in patients with type 2 diabetes mellitus. A total of 80 patients with type 2 diabetes mellitus admitted and treated in our hospital from January 2017 to January 2018 were selected and randomly divided into two groups (n = 40). Patients who were definitely diagnosed with type 2 diabetes mellitus were selected as observation group, and individuals who received health examination and were excluded from type 2 diabetes mellitus were enrolled as control group. The diagnosed proportions of carotid plaque, Crouse scores, endothelial-dependent flow-mediated vasodilation (FMD) function and nitroglycerin-mediated dilation (NMD) function of the brachial arteries in the two groups were compared. The indexes related to vascular endothelial functions [vascular endothelial growth factor (VEGF), endothelin-1 (ET-1) and nitric oxide (NO) levels] in the two groups were detected. The correlations of Crouse score with brachial arterial FMD value, VEGF level, ET-1 level and NO level in observation group were analyzed. The diagnosed proportion of carotid plaque in observation group was significantly higher than that in control group (P < 0.05), and the Crouse score in observation group was higher than that in control group (P < 0.05). The brachial arterial FMD value in observation group was remarkably lower than that in control group (P < 0.05). Compared with control group, VEGF and ET-1 levels were significantly reduced in observation group (P < 0.05), with the statistical increase of NO level (P < 0.05). In observation group, the Crouse score was negatively correlated with the brachial arterial FMD value, VEGF level and ET-1 level, whereas positively correlated with the NO level (P < 0.05). Our data show that the carotid IMT is increased significantly among patients with type 2 diabetes mellitus, and the vascular endothelial function is impaired. Moreover, after the occurrence of atherosclerosis, we found the carotid IMT is negatively correlated with endothelial-dependent FMD, as well as levels of VEGF and ET-1, whereas shows positive correlation with the vasodilative factor NO.