Combination of Flow-Mediated Vasodilation and Nitroglycerine-Induced Vasodilation Is More Effective for Prediction of Cardiovascular Events

Coronary and Systemic Vasodilator Responsiveness of Patients Receiving Conventional Intermittent or Nocturnal Hemodialysis

BACKGROUND

Nocturnal hemodialysis (nHD) restores the attenuated brachial artery vasodilator responsiveness of patients receiving conventional intermittent hemodialysis (iHD). Its impact on coronary vasodilatation is unknown.

METHODS

We evaluated 25 patients on hemodialysis who fulfilled transplant criteria: 15 on iHD (4-hour sessions, 3 d/wk) and 10 on nHD (≈40 h/wk over 8-10-hour sessions) plus 6 control participants. Following diagnostic angiography, left anterior descending (LAD) coronary flow reserve and mean luminal diameter were quantified at baseline and during sequential intracoronary administration of adenosine (infusion and bolus), nitroglycerin (bolus), acetylcholine (infusion), acetylcholine coinfused with vitamin C, and, finally, sublingual nitroglycerin.

RESULTS

Coronary flow reserve in those receiving nHD was augmented relative to iHD (3.28±0.26 versus 2.17±0.12 [mean±SEM]; P<0.03) but attenuated, relative to controls (4.80±0.63; P=0.011). Luminal dilatations induced by intracoronary adenosine and nitroglycerin were similar in nHD and controls but blunted in the iHD cohort (P<0.05 versus both). ACh elicited vasodilatation in controls but constriction in both dialysis groups (both P<0.05, versus control); vitamin C coinfusion had no effect. Sublingual nitroglycerin increased mid-left anterior descending diameter and reduced mean arterial pressure in controls (+15.2±2.68%; -16.00±1.60%) and in nHD recipients (+14.78±5.46%; -15.82±1.32%); iHD responses were markedly attenuated (+1.9±0.86%; -5.89±1.41%; P<0.05, all comparisons).

CONCLUSIONS

Coronary and systemic vasodilator responsiveness to both adenosine and nitroglycerin is augmented in patients receiving nHD relative to those receiving iHD, whereas vasoconstrictor responsiveness to acetylcholine does not differ. By improving coronary conduit and microvascular function, nHD may reduce the cardiovascular risk of patients on dialysis.

Seasonal variations in endothelium-dependent flow-mediated vasodilation and endothelium-independent nitroglycerine-induced vasodilation

Cardiovascular mortality has been shown to vary seasonally. However, it has not been determined whether vascular function is affected by the season. The purpose of this study was to investigate the associations of vascular function with season and outdoor temperature. Between April 2007 and March 2022, measurements of flow-mediated vasodilation (FMD) of the brachial artery as an index of endothelial function and nitroglycerine-induced vasodilation (NID) as an index of endothelium-independent vasodilation were performed in 2190 subjects. There was no significant seasonal difference in FMD (spring, 3.9 ± 3.1%; summer, 3.5 ± 3.0%; fall, 3.7 ± 3.0%; winter, 3.6 ± 3.2%; P = 0.14). There was no significant correlation between FMD and daily mean outdoor temperature (r = -0.02, P = 0.25). Multivariate analyses revealed that neither season (β = -0.020, P = 0.31) nor outdoor temperature (β = 0.005, P = 0.81) was significantly associated with FMD after adjustment for other confounding factors. There were significant seasonal differences in NID (spring, 12.8 ± 6.3%; summer, 12.0 ± 6.1%; fall, 11.7 ± 6.1%; winter, 12.3 ± 5.9%; P = 0.02). However, multivariate analysis revealed that there was no significant association between season and NID after adjustment for other confounding factors (β = -0.012, P = 0.56). There was no significant correlation between NID and daily outdoor mean temperature (r = -0.03, P = 0.17). Multivariate analysis revealed that outdoor temperature was not significantly associated with NID (β = -0.006, P = 0.78). There was no significant association of FMD or NID with season or outdoor temperature, suggesting that it is not necessary to take into account the effects of season and outdoor temperature on vascular function when interpreting the results of FMD and NID measurements. Public trials registry number: UMIN000039512.

Association of cumulative low-density lipoprotein cholesterol exposure with vascular function

BACKGROUND

The relationship between cumulative low-density lipoprotein cholesterol (LDL-C) exposure and progression of atherosclerosis remains uncertain.

OBJECTIVE

The aim of this study was to determine the relationship between cumulative LDL-C level and flow-mediated vasodilation (FMD), nitroglycerine-induced vasodilation (NID) and the presence of plaque in the common carotid artery (CCA).

METHODS

This was a cross-sectional study. We measured FMD in 8208 subjects, NID in 1822 subjects, and CCA plaque in 591 subjects who were not taking lipid-lowering drugs. The subjects were divided into four groups based on cumulative LDL-C exposure: <4000 mg·year/dL, 4000-4999 mg·year/dL, 5000-5999 mg·year/dL, and ≥6000 mg·year/dL.

RESULTS

The odds ratio of the lower quartile of FMD in the cholesterol-year-score <4000 mg·year/dL group was significantly higher than the odds ratios in the other groups. The odds ratio of the lower quartile of NID in the <4000 mg·year/dL group was significantly higher than the odds ratios in the 5000-5999 mg·year/dL and ≥6000 mg·year/dL groups. The odds ratio of the prevalence of CCA plaque in the <4000 mg·year/dL group was significantly higher than that in the ≥6000 mg·year/dL group.

CONCLUSIONS

Endothelial dysfunction occurred from cumulative LDL-C exposure of 4000 mg·year/dL, vascular smooth muscle dysfunction occurred from cumulative LDL-C exposure of 5000 mg·year/dL, and prevalence of CCA plaque occurred from cumulative LDL-C exposure of 6000 mg·year/dL. CLINICAL TRIAL REGISTRY INFORMATION: http://www.umin.ac.jp (UMIN000012950, UMIN000012951, and UMIN000012952, UMIN000003409).

Functional training improves peak oxygen consumption and quality of life of individuals with heart failure: a randomized clinical trial

BACKGROUND

Functional training may be an effective non-pharmacological therapy for heart failure (HF). This study aimed to compare the effects of functional training with strength training on peak VO₂ and quality of life in individuals with HF.

METHODS

A randomized, parallel-design and examiner-blinded controlled clinical trial with concealed allocation, intention-to-treat and per-protocol analyses. Twenty-seven participants with chronic HF were randomly allocated to functional or strength training group, to perform a 12-week physical training, three times per week, totalizing 36 sessions. Primary outcomes were the difference on peak VO₂ and quality of life assessed by cardiopulmonary exercise testing and Minnesota Living with Heart Failure Questionnaire, respectively. Secondary outcomes included functionality assessed by the Duke Activity Status Index and gait speed test, peripheral and inspiratory muscular strength, assessed by hand grip and manovacuometry testing, respectively, endothelial function by brachial artery flow-mediated dilation, and lean body mass by arm muscle circumference.

RESULTS

Participants were aged 60 ± 7 years, with left ventricular ejection fraction 29 ± 8.5%. The functional and strength training groups showed the following results, respectively: peak VO₂ increased by 1.4 ± 3.2 (16.9 ± 2.9 to 18.6 ± 4.8 mL.kg^-1.min^-1; p time = 0.011) and 1.5 ± 2.5 mL.kg^-1.min^-1 (16.8 ± 4.0 to 18.6 ± 5.5 mL.kg^-1.min^-1; p time = 0.011), and quality of life score decreased by 14 ± 15 (25.8 ± 14.8 to 10.3 ± 7.8 points; p time = 0.001) and 12 ± 28 points (33.8 ± 23.8 to 19.0 ± 15.1 points; p time = 0.001), but no difference was observed between groups (peak VO₂: p interaction = 0.921 and quality of life: p interaction = 0.921). The functional and strength training increased the activity status index by 6.5 ± 12 and 5.2 ± 13 points (p time = 0.001), respectively, and gait speed by 0.2 ± 0.3 m/s (p  time = 0.002) in both groups.

CONCLUSIONS

Functional and strength training are equally effective in improving peak VO₂, quality of life, and functionality in individuals with HF. These findings suggest that functional training may be a promising and innovative exercise-based strategy to treat HF.

TRIAL REGISTRATION

NCT03321682. Registered date: 26/10/2017.

A nomogram based on endothelial function and conventional risk factors predicts coronary artery disease in hypertensives

BACKGROUND

There is currently a lack of a precise, concise, and practical clinical prediction model for predicting coronary artery disease (CAD) in patients with essential hypertension (EH). This study aimed to construct a nomogram to predict CAD in patients with EH based on flow-mediated dilation (FMD) of brachial artery and traditional risk factors.

METHODS

Clinical data of 1752 patients with EH were retrospectively collected. High-resolution vascular ultrasound was used to detect FMD in all patients at the Fujian Hypertension Research Institute, China. Patients were divided into two groups, i.e. training group (n = 1204, from August 2000 to December 2013) and validation group (n = 548, from January 2014 to May 2016) according to the time of enrollment. Independent predictors of CAD were analyzed by multivariable logistic regression in the training group, and a nomogram was constructed accordingly. Finally, we evaluated the discrimination, calibration, and clinical applicability of the model using the area under curve (AUC) of receiver operating characteristic analysis, calibration curve combined with Hosmer-Lemeshow test, and decision curve, respectively.

RESULTS

There were 263 (21.8%) cases of EH combined with CAD in the training group. Multivariate logistic regression showed that FMD, age, duration of EH, waist circumference, and diabetes mellitus were independent influencing factors for CAD in EH patients. Smoking which was close to statistical significance (P = 0.062) was also included in the regression model to increase the accuracy. Ultimately, the nomogram for predicting CAD in EH patients was constructed according to above predictors after proper transformation. The AUC values of the training group and the validation group were 0.799 (95%CI 0.770-0.829) and 0.836 (95%CI 0.787-0.886), respectively. Calibration curve and Hosmer-Lemeshow test showed that the model had good calibration (training group: χ² = 0.55, P = 0.759; validation group: χ² = 1.62, P = 0.446). The decision curve also verified the clinical applicability of the nomogram.

CONCLUSION

The nomogram based on FMD and traditional risk factors (age, duration of EH disease, smoking, waist circumference and diabetes mellitus) can predict CAD high-risk group among patients with EH.

Obesity and Endothelial Function

Obesity is a major public health problem and is related to increasing rates of cardiovascular morbidity and mortality. Over 1.9 billion adults are overweight or obese worldwide and the prevalence of obesity is increasing. Obesity influences endothelial function through obesity-related complications such as hypertension, dyslipidemia, diabetes, metabolic syndrome, and obstructive sleep apnea syndrome. The excess fat accumulation in obesity causes adipocyte dysfunction and induces oxidative stress, insulin resistance, and inflammation leading to endothelial dysfunction. Several anthropometric indices and imaging modalities that are used to evaluate obesity have demonstrated an association between obesity and endothelial function. In the past few decades, there has been great focus on the mechanisms underlying endothelial dysfunction caused by obesity for the prevention and treatment of cardiovascular events. This review focuses on pathophysiological mechanisms of obesity-induced endothelial dysfunction and therapeutic targets of obesity.

Association between High Pericoronary Adipose Tissue Computed Tomography Attenuation and Impaired Flow-Mediated Dilation of the Brachial Artery

AIMS

Pericoronary adipose tissue (PCAT) attenuation on coronary computed tomography angiography (CTA) is a noninvasive biomarker for pericoronary inflammation and is associated with cardiac mortality. We aimed to investigate the association between PCAT attenuation and endothelial dysfunction assessed using flow-mediated dilation (FMD).

METHODS

A total of 119 outpatients who underwent both coronary CTA and FMD measurements were examined. PCAT attenuation values were assessed at the proximal 40-mm segments of all three major coronary arteries on coronary CTA. Endothelial function was assessed using FMD. Patients were then classified into two groups: those with endothelial dysfunction (FMD ＜4%, n=44) and those without endothelial dysfunction (FMD ≥ 4%, n=75).

RESULTS

In all three coronary arteries, PCAT attenuation was significantly higher in patients with endothelial dysfunction than in those without endothelial dysfunction. Multivariate logistic regression analysis revealed that PCAT attenuation in the right coronary artery (odds ratio [OR]=1.543; 95% confidence interval [CI]=1.004-2.369,p=0.048) and left anterior descending artery (OR=1.525, 95% CI=1.004-2.369, p=0.049) was an independent predictor of endothelial dysfunction. Subgroup analysis of patients with adverse CTA findings (significant stenosis and/or high-risk plaque) and those with coronary artery calcium score ＞100 showed that high PCAT attenuation in all three coronary arteries was a significant predictor of endothelial dysfunction.

CONCLUSION

High PCAT attenuation was significantly associated with FMD-assessed endothelial dysfunction in patients with suspected coronary artery disease. Our results suggest that endothelial dysfunction is one of the pathophysiological mechanisms linking pericoronary inflammation to cardiac mortality.

White blood cell count is not associated with flow-mediated vasodilation or nitroglycerine-induced vasodilation

It is well known that white blood cell (WBC) count is an independent predictor of cardiovascular events. However, associations of WBC count and WBC subtypes with endothelial function assessed by flow-mediated vasodilation (FMD) and vascular smooth muscle function assessed by nitroglycerine-induced vasodilation (NID) are unclear. The aim of this study was to determine the relationships of WBC count and WBC subtypes with vascular function assessed by FMD and NID. A total of 1351 subjects in whom FMD and NID had been measured were recruited from Hiroshima University Vascular Registry. Mean values were 3.7 ± 2.8% for FMD and 11.8 ± 5.9% for NID. WBC was not correlated with FMD or NID. NID was significantly correlated with lymphocytes in univariate analysis but not with other hematologic parameters. In multiple linear regression analyses, NID was not correlated with lymphocytes. In all subgroups including subgroups of age, gender, body mass index, hypertension, dyslipidemia, diabetes mellitus, smoking and tertile of WBC count, WBC count was not correlated with FMD or NID. WBC count and WBC subtypes were not associated with endothelial function assessed by FMD or vascular smooth muscle function assessed by NID. WBC count and vascular function assessed by FMD and NID may reflect different aspects of atherosclerosis.

Clinical Trial Registration Information: URL for Clinical Trial: http://www.umin.ac.jp Registration Number for Clinical Trial: UMIN000039512.

Serum Potassium Levels of 4.5 to Less Than 5.0 mmol/L Are Associated with Better Vascular Function

Aim: An experimental study showed that potassium inhibits the formation of reactive oxygen species by vascular cells. The purpose of this study was to investigate the association between serum potassium levels and vascular function.

Methods: We measured flow-mediated vasodilation (FMD) as an index of endothelial function in 3045 subjects (1964 men; mean age, 62.3±13.8 years) and nitroglycerine-induced vasodilation (NID) as an index of vascular smooth muscle function in 1578 subjects (1001 men; mean age, 61.8±16.3 years).

Results: In the 3045 subjects, there was a significant positive correlation between FMD and serum potassium levels (r=0.09,P＜0.001). Multivariate analysis revealed that serum potassium levels were significantly associated with FMD (β=0.109,P＜0.001). When subjects were divided into two groups based on treatment with drugs that could alter serum potassium levels, the association between serum potassium levels and FMD was significant both in subjects with (β=0.096,P＜0.001) and subjects without (β=0.123,P＜0.001) treatment with drugs that could alter serum potassium levels. In the 1578 subjects, there was a significant positive correlation between NID and serum potassium levels (r=0.11,P＜0.001). Multivariate analysis revealed that serum potassium levels were significantly associated with NID (β=0.098,P＜0.001). The association between serum potassium levels and NID was significant both in subjects with (β=0.121,P=0.001) and subjects without (β=0.083,P=0.03) treatment with drugs that could alter serum potassium levels.

Conclusions: Serum potassium levels of 4.5-＜5.0 mmol/L are associated with better vascular function regardless of the presence or absence of treatment with drugs that could alter serum potassium levels.

Vascular Dysfunction Predicts Future Deterioration of Left Ventricular Ejection Fraction in Patients with Heart Failure with Mildly Reduced Ejection Fraction

The purpose of this study was to evaluate whether heart failure with mildly reduced ejection fraction (HFmrEF) is associated with vascular dysfunction and whether vascular function predicts future deterioration of LVEF in patients with HFmrEF. We evaluated endothelial function assessed by flow-mediated vasodilation (FMD) and vascular smooth muscle function assessed by nitroglycerine-induced vasodilation (NID) in 69 patients with HFmrEF and 426 patients without HF and evaluated the future deterioration of LVEF, defined as a decrease in LVEF to <40%, in 39 patients with HFmrEF for up to 3 years. Both FMD and NID were significantly lower in patients with HFmrEF than in patients without HF. We categorized patients into two groups based on low tertiles of NID: a low group (NID of <7.0%) and an intermediate and high group (NID of ≥7.0%). There were significant differences between the Kaplan–Meier curves for the deterioration of LVEF in the two groups (p < 0.01). Multivariate Cox proportional hazard analysis revealed that NID of <7.0% was an independent predictor of future deterioration of LVEF in patients with HFmrEF. Both endothelial function and vascular smooth muscle function are impaired in patients with HFmrEF compared with those in patients without HF. In addition, low NID of <7.0% predicts future deterioration of LVEF.

Diagnostic and prognostic role of nitroglycerin-induced dilation in patients with suspected vasospastic angina, combined with ergonovine provocation test

The diagnostic and prognostic role of nitroglycerin-induced dilation (NID) combined with ergonovine provocation test in patients with suspected VSA patients is not clear. A total of 438 consecutive patients who underwent the ergonovine provocation test for the diagnosis of vasospastic angina (VSA) were enrolled. Patients with VSA (n = 52) had a significantly greater coronary response to ergonovine (− 84.3 ± 10.5% vs. − 38.4 ± 17.9%, p < 0.001) and NID (26.3 ± 31.0% vs. 12.5 ± 19.0%, p < 0.001) than non-VSA patients. However, positive NID (more than 13.8% dilation, n = 170) showed a poor accuracy (AUC 0.64 [95% CI: 0.56–0.73], p = 0.001, sensitivity 60.4%, specificity 61.3%) for the diagnosis of VSA by ergonovine provocation test. Major adverse cardiovascular events (MACE) occurred more frequently in the VSA group than in the non-VSA group (9.6% vs. 2.2%, p = 0.006). In addition, the positive NID group showed a lower rate of MACE than the negative NID group (1.2% vs. 4.3%, p = 0.021). Interestingly, the group of VSA with negative NID had poor prognosis than any other combinations (Log-rank, p < 0.0001). Although NID had a limited role in the detection of VSA defined by ergonovine provocation test, NID combined with the ergonovine provocation test has an additive prognostic role in the clinical outcomes in patients with suspected VSA.

High degree of prostate related LUTS in a prospective cross-sectional community study in Ghana (Mamprobi)

Background

Changing voiding patterns, volume and frequency, may sometimes be mistaken for anxiety, stress or increase in fluid consumption. In the aging male population, the commencement of lower urinary tract symptoms (LUTS) may be silent and perceived as “normal” and unrelated to Benign prostatic enlargement (BPE). The purpose of the study was to determine the prevalence of apparently “silent LUTS” (perceived asymptomatic LUTS) in men in a Ghanaian Community as well as its underlying risk factors.

Methods

One hundred and eleven (111) men (40–70 years) were recruited from a community in Ghana. The International Prostate Symptoms Score (IPSS) questionnaire (administered in the local language and English) and ultrasonographic imaging of the prostate volume (PV) were utlized to collect data. IPSS score >7 plus PV > 30 cm³ was definitive of lower urinary tract symptoms. Eighty-one (81) participants were classified “LUTS Negative” (LN) and 30, “LUTS Positive” (LP). Risk factors i.e., cholesterol (CHOL), triglyceride (TG), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), very low-density lipoprotein (VLDL), coronary risk (CR), BMI and Blood Pressure were also determined.

Results

The prevalence of LUTS using only IPSS definition alone was 42.3%. However, IPSS in combination with Prostate Volume gave a prevalence of 27.0%. LN subjects had enlarged prostate (41.98%) and LP, 100%. Quality of life (QoL) was better in the LUTS Negative than LUTS Positive group (p < 0.001). In the univariant analysis coronary risk, triglyceride and VLDL contributed to LUTS (p = 0.023, 0.22, 0.22, respectively). In a multivariant analysis HDL-C (p = 0.027), BMI (p = 0.047) and triglyceride (p = 0.019) significantly contributed to LUTS.

Conclusions

The prevalence of LUTS (42.3%) is high. Components of Metabolic Syndrome- HDL-C, BMI, and coronary risk were associated with LUTS. This emphasizes the need for community education.

Oral L-Arginine (5 g/day) for 14 Days Improves Microcirculatory Function in Healthy Young Women and Healthy and Type 2 Diabetes Mellitus Elderly Women

OBJECTIVE

The aim of this study was to investigate the effect of oral supplementation with L-arginine on serum biochemical profile, blood pressure, microcirculation, and vasoreactivity/endothelial function in young controls, and elderly women with and without type 2 diabetes mellitus (T2DM).

METHODS

Healthy young (n = 25), healthy elderly (n = 25), and elderly women with type 2 diabetes mellitus (T2DME, n = 23, glycated Hb ≥6.4% and mean of 7.7 years for duration of the disease), aged 18-30 and older than 65 years, respectively, were included in the study. All patients underwent biochemical analysis (fasting glycemia and lipidogram), arterial blood pressure, nailfold videocapillaroscopy (capillary diameters, functional capillary density [FCD], peak red blood cell velocity [RBCVmax] after 1 min ischemia, time to reach peak RBCV [TRBCVmax]), and venous occlusion plethysmography (vasoreactivity), before and after 14 days of oral supplementation with L-arginine (5 g/day).

RESULTS

L-Arginine did not change fasting glycemia and lipidogram, but it decreased systolic, diastolic, and mean arterial pressure in elderly women, increased RBCVmax in all groups, and did not decrease TRBCVmax in T2DME. Capillary diameters and FCD remained unchanged in all groups. L-Arginine improved vasoreactivity during reactive hyperemia and after sublingual nitroglycerin (0.4 mg) in all groups.

CONCLUSION

L-Arginine supplementation (5g/day during 14 days) was able to improve vascular/microvascular health in the elderly women with or without T2DM.

A body shape index is associated with endothelial dysfunction in both men and women

A body shape index (ABSI) was proposed for estimation of abdominal adiposity. ABSI has been reported to have associations with cardiovascular risk factors and cardiovascular events. However, there is no information on the association between ABSI and endothelial function. We examined cross-sectional associations of ABSI with endothelial function in 8823 subjects (6773 men and 2050 women). Subjects with a lower quartile of flow-mediated vasodilation (FMD) were defined as subjects having endothelial dysfunction. Pearson’s correlation coefficient analysis revealed that ABSI was negatively correlated with FMD (men, r = − 0.23, P = 0.003; women, r = − 0.32, P < 0.001). The areas under the curves of ABSI and body mass index to predict endothelial dysfunction were 0.64 (95% confidence interval [CI] 0.62–0.65) and 0.58 (95% CI 0.57–0.60) in men, and 0.68 (95% CI 0.66–0.71) and 0.59 (95% CI 0.56–0.61) in women, respectively. The cutoff values of ABSI for predicting subjects with endothelial dysfunction were 0.0796 (sensitivity, 55.2%; specificity, 65.5%) in men and 0.0823 (sensitivity, 56.2%; specificity, 73.4%) in women. Multivariate analysis revealed that an ABSI value higher than the cutoff value remained an independent predictor of endothelial dysfunction in both sexes. The results of our study suggest that ABSI calculation should be performed for evaluation of risk of cardiovascular events in both men and women.

Clinical trial registration information URL for Clinical Trial: https://www.umin.ac.jp/ctr/index.htm; Registration Number for Clinical Trial: UMIN000012952 (01/05/2010).

Volume Elastic Modulus, Vascular Function, and Vascular Structure in Patients with Cardiovascular Risk Factors

Aims: Volume elastic modulus (V _E ), an index of arterial elasticity, and arterial diameter of the brachial artery can be automatically measured by a newly developed oscillometric device. We investigated the associations of V _E with flow-mediated vasodilation (FMD), an index of endothelium-dependent vasodilation, nitroglycerine-induced vasodilation (NID), an index of endothelium-independent vasodilation, and intima-media thickness (IMT) of the brachial artery and association of oscillometrically measured brachial artery diameter with ultrasonographically measured brachial artery diameter in patients with cardiovascular risk factors.

Methods: Oscillometric measurements of V _E and brachial artery diameter and ultrasound measurements of brachial artery diameter, FMD, NID, and IMT of the brachial artery were performed in 50 patients with cardiovascular risk factors.

Results: The mean values were 2.1±0.4 mmHg/% for V _E , 0.31±0.05 mm for brachial IMT, 4.48±0.70 mm for oscillometric brachial artery diameter, and 4.30±0.55 mm for ultrasound brachial artery diameter. V _E significantly correlated with brachial IMT (r=0.51, P ＜0.001), whereas there was no significant correlation of V _E with FMD (r=-0.08, P =0.58) or NID (r=0.07, P =0.61). Multivariate analysis revealed that V _E was significantly associated with brachial IMT (β=0.33, P =0.04). Oscillometric brachial artery diameter significantly correlated with ultrasound brachial artery diameter (r=0.79, P ＜0.001). The Bland-Altman plot showed good agreement between oscillometric brachial artery diameter and ultrasound brachial artery diameter (mean difference, -0.17 mm; limits of agreement, -1.03 mm to 0.69 mm).

Conclusions: In patients with cardiovascular risk factors, V _E may represent atherosclerotic structural alterations of the vascular wall but not vascular function. The accuracy of oscillometric measurement of brachial artery diameter is acceptable.

The Effects of Ischemic Preconditioning Supplementation on Endothelial Function: A Systematic Review and Meta-Analysis

Objective

Ischemic preconditioning (IPC) has gradually been promoted in clinical practice to lower the risk of cardiovascular surgery and postoperative complications. We investigated the role of IPC on vascular endothelial function and the relationship between IPC, flow-mediated dilation (FMD), and brachial artery diameter (BAD).

Methods

Systematic searches were conducted in PubMed, Medline, Cochrane Library, Embase, and Scopus databases from their inception to March 20, 2020. This research included randomized controlled trials (RCTs) with adults, and the values of FMD and BAD were considered as the primary outcomes. Ten studies comprising 292 participants were included in the meta-analysis.

Results

Regarding FMD, we observed beneficial effects of IPC on endothelial function (standardized mean difference (SMD): 1.82; 95% confidence interval (CI): 0.64, 3.01; p < 0.001; I ² = 89.9%). However, the available evidence did not indicate that IPC affected BAD (SMD: 0.08; 95% CI: -0.03, 0.18; p > 0.05; I ² = 76.5%).

Conclusions

Our meta-analysis indicated a significant effect of IPC on the endothelial function of the blood vessels, affecting FMD but not BAD.

Lower triglyceride levels are associated with better endothelial function

BACKGROUND

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.

OBJECTIVE

The purpose of this study was to determine the relationship between triglycerides, especially low levels of triglycerides, and vascular function.

METHODS

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.

RESULTS

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.

CONCLUSIONS

FMD values were highest in subjects with extremely low levels of triglycerides (<50 mg/dL). Lower triglyceride levels were associated with better endothelial function.

CLINICAL TRIAL REGISTRATION INFORMATION

http://www.umin.ac.jp (University Hospital Medical Information Network Clinical Trials Registry) (UMIN000012950).

Noninvasive peripheral vascular function, incident cardiovascular disease, and mortality in the general population

Aims 

Evidence suggests that peripheral vascular function is related to cardiovascular disease (CVD) and mortality. We evaluated the associations of non-invasive measures of flow-mediated dilatation and peripheral arterial tonometry with incident CVD and mortality.

Methods and results 

In a post-hoc analysis of the community-based Gutenberg Health Study, median age 55 years (25th/75th percentile 46/65) and 49.5% women, we measured brachial artery flow-mediated dilatation (N=12 599) and fingertip peripheral arterial tonometry (N=11 125). After a follow-up of up to 11.7 years, we observed 595 incident CVD events, 106 cardiac deaths, and 860 deaths in total. Survival curves showed decreased event-free survival with higher mean brachial artery diameter and baseline pulse amplitude and better survival with higher mean flow-mediated dilatation and peripheral arterial tonometry ratio (all P_{log rank} <0.05). In multivariable-adjusted Cox regression analyses only baseline pulse amplitude was inversely related to mortality [hazard ratio (HR) per standard deviation increase, 0.86, 95% confidence interval (95% CI), 0.79–0.94; P=0.0009]. After exclusion of individuals with prevalent CVD the association was no longer statistically significant in multivariable-adjusted models (HR 0.91, 95% CI 0.81–1.02; P=0.11). None of the vascular variables substantially increased the C-index of a model comprising clinical risk factors.

Conclusions 

In our cohort, non-invasive measures of peripheral vascular structure and function did not reveal clinically relevant associations with incident CVD or mortality. Whether determination of pulse amplitude by peripheral arterial tonometry improves clinical decision-making in primary prevention needs to be demonstrated.

[EVALUATING THE RELATIONSHIP BETWEEN LOWER URINARY TRACT SYMPTOMS AND ENDOTHELIAL FUNCTION USING FLOW-MEDIATED DILATION, AND THE EFFECTS OF TADALAFIL]

(Objective) Recently, lower urinary tract symptoms (LUTS) were reported to be associated with endothelial dysfunction. Endothelial function is non-invasively measured by flow-mediated dilation (FMD). As tadalafil has the potential to improve atherosclerosis, we evaluated the relationship between LUTS and endothelial function using FMD, and the effects of tadalafil. (Patients and methods) We conducted FMD examinations for a total of 122 males, and analyzed its association with IPSS, OABSS, and cardiovascular risks. Furthermore, 21 BPH patients received 5 mg of tadalafil per day for one year. We defined the Low FMD group as FMD < 3.9% and the Control group as other values, and compared the effects of tadalafil between groups. (Results) In the 122 male patients, FMD was negatively correlated with nocturia and OABSS. Patients with hypertension or coronary artery disease had a lower FMD than those without.In the tadalafil administration study, the Low FMD group achieved greater improvement of IPSS, OABSS and FMD than the Control group. (Conclusion) FMD examination revealed that endothelial dysfunction is closely associated with LUTS in males, and that tadalafil is effective for patients with endothelial dysfunction.

A Randomized, Controlled Trial of the Effect of Allopurinol on Left Ventricular Mass Index in Hemodialysis Patients

Introduction

Increased left ventricular mass index (LVMI) is associated with mortality in end-stage renal disease. LVMI regression may improve outcomes. Allopurinol has reduced LVMI in randomized controlled trials in chronic kidney disease, diabetes, and ischemic heart disease. This study investigated whether allopurinol would regress LVMI in hemodialysis patients.

Methods

This was a randomized placebo-controlled double-blind multicenter trial funded by the British Heart Foundation (PG/12/72/29743). A total of 80 patients undergoing regular maintenance hemodialysis were recruited from NHS Tayside, NHS Greater Glasgow and Clyde and NHS Ayrshire and Arran in Scotland, UK. Participants were randomly assigned on a 1:1 ratio to 12 months of therapy with allopurinol 300 mg or placebo after each dialysis session. The primary outcome was change in LVMI, as assessed by cardiac magnetic resonance imaging (CMRI) at baseline and 12 months. Secondary outcomes were change in BP, flow-mediated dilation (FMD), augmentation indices (AIx), and pulse wave velocity (PWV).

Results

A total of 53 patients, with a mean age of 58 years, completed the study and had CMRI follow-up data for analysis. Allopurinol did not regress LVMI (change in LVMI: placebo +3.6 ± 10.4 g/m²; allopurinol: +1.6 ± 11 g/m²; P = 0.49). Allopurinol had no demonstrable effect on BP, FMD, AIx, or PWV.

Conclusion

Compared with placebo, treatment with allopurinol did not regress LVMI in this trial.

Endothelial function is preserved in light to moderate alcohol drinkers but is impaired in heavy drinkers in women: Flow-mediated Dilation Japan (FMD-J) study

Light to moderate alcohol consumption has protective effects on all-cause death and coronary artery disease in women. It is thought that light to moderate alcohol consumption has a beneficial effect on vascular function in women. We measured flow-mediated vasodilation (FMD) in 702 women aged 17-86 years who provided information on alcohol consumption. We divided the subjects into four groups: non-drinkers (0 g/week), light drinkers (>0 to 140 g/week), moderate drinkers (>140 to 280 g/week) and heavy drinkers (>280 g/week). There was no significant difference in FMD among the four groups. Multivariate regression analysis revealed that alcohol consumption in non-drinkers and light drinkers was not an independent predictor of FMD (β = -0.001, P = 0.98). We compared 50 moderate drinkers and 50 non-drinkers matched for age and medical histories and 22 heavy drinkers and 22 non-drinkers in matched pair analysis. There was no significant difference in FMD between moderate drinkers and non-drinkers (8.2±4.3% vs. 8.1±3.5, P = 0.91), while FMD in heavy drinkers was significantly lower than that in non-drinkers (5.9±2.5% vs. 8.9±3.5%, P = 0.002). These findings suggest that heavy alcohol consumption is associated with endothelial dysfunction but that light to moderate alcohol consumption is not associated with endothelial dysfunction in women. Clinical trial registration information This study was approved by principal authorities and ethical issues in Japan (University Hospital Medical Information Network UMIN000012952, 01/12/2009). www.umin.ac.jp/.

Albuminuria rather than glomerular filtration rate is associated with vascular endothelial function in patients with type 2 diabetes

AIMS

Albuminuria and reduced glomerular filtration rate (GFR) are manifestations of diabetic kidney disease and are both shown to be associated with cardiovascular outcomes. However, the differential association of albuminuria and reduced GFR with endothelial dysfunction, an early feature of atherosclerotic vascular damage, remains unclear. In this study, we investigated the association between albuminuria or estimated GFR (eGFR) and flow-mediated dilatation (FMD), a marker of endothelial function, in patients with type 2 diabetes.

METHODS

This study included 633 patients with type 2 diabetes. The FMD of the brachial artery was measured by ultrasonography. Albuminuria was evaluated by urinary albumin-to-creatinine ratio (ACR).

RESULTS

The mean FMD and eGFR, and the median value of ACR were 6.7%, 66.5 mL/min/1.73m² and 12.5 mg/g creatinine, respectively. Impaired FMD was found in patients with advanced stages of chronic kidney disease based on both GFR and albuminuria categories. Multivariate analysis after adjusting for potential confounders revealed that ACR, but not eGFR, was significantly and inversely associated with FMD.

CONCLUSIONS

Albuminuria is associated with FMD, independently of traditional cardiovascular risk factors in patients with type 2 diabetes. This study suggests a close relationship between albuminuria, rather than reduced GFR, and endothelial dysfunction in type 2 diabetes.

Association of Body Mass Index with Endothelial Function in Asian Men

BACKGROUND

The association of body weight with cardiovascular events is still controversial. We evaluated the relationship between body mass index (BMI) and endothelial function.

METHODS

We measured flow-mediated vasodilation (FMD) and BMI in 7682 men. All participants were divided into four groups by BMI: underweight (<18.5 kg/m²), normal weight (18.5 to 24.9 kg/m²), overweight (25.0 to 29.9 kg/m²), and obesity (≥30.0 kg/m²).

RESULTS

Multiple logistic regression analysis revealed that overweight (OR: 1.30, 95% CI: 1.14-1.47; P < 0.001) and obesity (OR: 1.40, 95% CI: 1.09-1.80; P = 0.009) were associated with an increased risk of a low quartile of FMD. In 5571 younger adults (<60 years), overweight (OR: 1.34, 95% CI: 1.16-1.55; P < 0.001) and obesity (OR: 1.37, 95% CI: 1.04-1.81; P = 0.03) were associated with an increased risk of a low quartile of FMD, and underweight (OR: 0.56, 95% CI: 0.35-0.89; P = 0.01) was associated with a reduced risk of a low quartile of FMD. In 2111 older adults (≥60 years), underweight (OR: 2.16, 95% CI: 1.22-3.80; P = 0.008) was associated with an increased risk of a low quartile of FMD, and overweight and obesity were not associated with a risk of a low quartile of FMD.

CONCLUSIONS

In Asian men, endothelial function was impaired in the overweight and obesity groups compared with that in the normal weight group. The risk for endothelial dysfunction was higher in obese younger adults than in obese older adults. The association of BMI with endothelial function may be different in young and elderly men.

CLINICAL TRIAL REGISTRATION INFORMATION

http://www.umin.ac.jp (University Hospital Medical Information Network Clinical Trials Registry) (UMIN000012952).

The fruit of Acanthopanax senticosus Harms improves arterial stiffness and blood pressure: a randomized, placebo-controlled trial

BACKGROUND/OBJECTIVES

Arterial stiffness and endothelial dysfunction are 2 of the independent predictors for cardiovascular disease, while Acanthopanax senticosus Harms (ASH) is a traditional medicinal plant that can improve cardiovascular health. This study aimed to investigate the efficacy of the fruit of ASH on vascular function in apparently healthy subjects.

SUBJECTS/METHODS

A 12-week, randomized, double-blind, placebo-controlled design, consisting of healthy adults with at least 2 of the following 3 conditions: borderline high blood pressure (BP; 120 mmHg ≤ systolic BP ≤ 160 mmHg or 80 mmHg ≤ diastolic BP ≤ 100 mmHg), smoking (≥10 cigarettes/day), and borderline blood lipid levels (220 ≤ total cholesterol ≤ 240, 130 ≤ low density lipoprotein cholesterol ≤ 165, or 150 ≤ triglyceride ≤ 220 mg/dL). Randomly assigned 76 subjects who received a placebo or 2 doses of ASH fruit (low, 500 mg/day; high, 1,000 mg/day) completed the intervention. Brachial-ankle pulse wave velocity (baPWV), flow-mediated dilation, carotid intima-media thickness, and BP were measured both at baseline and following the 12-week intervention. Endothelial nitric oxide synthase (eNOS) phosphorylation was assessed by western blotting.

RESULTS

Compared with the placebo group, the low-dose group showed more significant changes after the 12-week intervention period in terms of systolic BP (0.1 vs. −7.7 mmHg; P = 0.044), baPWV (31.3 vs. −98.7 cm/s; P = 0.007), and the ratio of phospho-eNOS/eNOS (0.8 vs. 1.22; P = 0.037).

CONCLUSIONS

These results suggest that ASH fruit extract at 500 mg/day has the potential to improve BP and arterial stiffness via endothelial eNOS activation in healthy adults with smoking and the tendency of having elevated BP or blood lipid parameters.

Trial Registration

Clinical Research Information Service Identifier: KCT0001072

Hematocrit, hemoglobin and red blood cells are associated with vascular function and vascular structure in men

High and low hematocrit (Hct) and hemoglobin (Hb) levels are associated with the risk of cardiovascular disease. The purpose of this study was to determine the relationships of Hct, Hb and red blood cells (RBCs) with vascular function and structure. We measured flow-mediated vasodilation (FMD), nitroglycerin-induced vasodilation (NID), brachial intima media thickness (IMT), and brachial-ankle pulse wave velocity (baPWV) in 807 men. The subjects were divided into six groups according to the levels of Hct, Hb and RBCs. NID was highest in the 46.0–48.9% Hct group among the six groups according to Hct levels. Brachial IMT was lowest in the 46.0–48.9% Hct group among the six groups. There were no significant differences in FMD and baPWV among the six groups. We used 46.0–48.9% Hct as a reference to define the lower tertile. The adjusted odds ratio of being in the low tertile of NID was significantly higher in the < 42.9% and ≥ 49.0% Hct groups. Adjusted odds ratio of being in the low tertile of brachial IMT was significantly lower in the < 39.9% Hct groups. Similar results were obtained for Hb and RBCs. Low and high levels of Hct, Hb and RBCs were associated with vascular smooth muscle dysfunction, and low Hct levels were associated with abnormal vascular structure. Increases in the levels of Hct, Hb and RBCs within normal ranges may have beneficial effects on the vasculature.

Effects of Unilateral Arm Warming or Cooling on the Modulation of Brachial Artery Shear Stress and Endothelial Function during Leg Exercise in Humans

Aim: We examined the effect of modulating the shear stress (SS) profile using forearm warming and cooling on subsequent endothelial function in the brachial artery (BA) during exercise.

Methods: Twelve healthy young subjects immersed their right forearm in water (15°C or 42°C) during a leg cycling exercise at 120–130 bpm for 60 min. The same exercise without water immersion served as a control. The BA diameter and blood velocity were simultaneously recorded using Doppler ultrasonography to evaluate the antegrade, retrograde, and mean shear rates (SRs, an estimate of SS) before, during, and after exercise. The endothelial function in the right BA was evaluated using flow-mediated dilation (FMD) (%) using two-dimensional high-resolution ultrasonography before (baseline) and 15 and 60 min after exercise.

Results: During exercise, compared with the control trial, higher antegrade and mean SRs and lower retrograde SRs were observed in the warm trial; conversely, lower antegrade and mean SRs and higher retrograde SRs were observed in the cool trial. At 15 min postexercise, no significant change was observed in the FMD from baseline in the warm (Δ%FMD: +1.6%, tendency to increase; p = 0.08) and control trials (Δ %FMD: +1.1%). However, in the cool trial, the postexercise FMD at 60 min decreased from baseline (Δ%FMD: −2.7%) and was lower than that of the warm (Δ%FMD: +1.5%) and control (Δ%FMD: +1.2%) trials. Accumulated changes in each SR during and after exercise were significantly correlated with postexercise FMD changes.

Conclusion: Modulation of shear profiles in the BA during exercise appears to be associated with subsequent endothelial function.

Noninvasive vascular function tests for the future prediction of primary cardiovascular diseases

OBJECTIVES

Cardiovascular diseases (CVDs) still remain the main causes of death and disability in the US and worldwide, and the prediction for their future incidence is not well established. The utilization of the new cardiovascular risk score (CVRS) developed by the new ACC/AHA blood pressure treatment guidelines has improved the 10-year prediction of CVDs. However, its predictive value could be further increased with the addition of other risk factors identified with the use of several noninvasive vascular tests. These tests include, the older tests such as flow-mediated dilation (FMD), pulse wave velocity (PWV), pulse pressure (PP), and the newly developed noninvasive vascular tests of, reactive hyperemia-peripheral arterial tonometry (RH-PAT), cardio-ankle vascular index (CAVI), and the inter-arm/inter-leg pressure difference (IAPD/ILPD).

METHODS

In order to get a current perspective regarding the usefulness of these new noninvasive vascular tests for the future prediction of CVDs, a Medline search of the English language literature was conducted between 2014 and 2019 using the terms cardiovascular disease, coronary heart disease, noninvasive vascular tests, risk factors, and 26 pertinent papers were retrieved.

RESULTS

The analysis of results from these papers showed that these noninvasive vascular tests have an independent predictive value for the future incidence of CVDs and hypertension. However, their long-term predictive value is not well established, since there are no currently, available data from long-term clinical outcome studies.

CONCLUSION

The analysis of data from the retrieved papers demonstrated that the new noninvasive vascular tests have an independent predictive value for the future incidence of CVDs and hypertension. However, their long-term predictive value is not established as yet for the lack of long-term outcome studies. When the currently ongoing long-term trials are completed, it is quite possible that the data from these tests added to CVRS could enhance its predictive value.

Metabolic and Cardiovascular Effects of Switching Thiazides to Amlodipine in Hypertensive Patients With and Without Type 2 Diabetes (the Diuretics and Diabetes Control Study)

Background: Different studies have indicated that thiazide diuretics can increase the risk of developing type 2 diabetes (T2D). Therefore, in this study, we investigated whether switching from hydrochlorothiazide (HCTZ) to amlodipine resulted in ameliorating different cardiovascular and metabolic measures in hypertensive patients with or without T2D. Methods: This study [Diuretics and Diabetes Control (DiaDiC)] was a 6-week, single-blind, single-center randomized controlled trial. The first 20 normal glucose-tolerant, 20 prediabetic, and 20 T2D consecutive patients were randomized to continue the previous antihypertensive treatment with HCTZ (12.5-25 mg/day) or to switch from HCTZ to amlodipine (2.5-10 mg/day). The primary endpoints were the absolute change in 7-day continuous subcutaneous glucose monitoring (CSGM) glycemia, serum uric acid concentrations, and endothelial function [measured as flow-mediated dilation (FMD)]. Other secondary endpoints were investigated, including changes in glycated hemoglobin (HbA₁c), glycemic variability from 7-day CSGM, and the estimated glomerular filtration rate (eGFR). Results: Amlodipine treatment was associated with a significant reduction in HbA₁c (P = 0.03) for both 7-day CSGM glycemia (P = 0.01) and glycemic variability (coefficient of variability %: HCTZ +3%, amlodipine -2.8%), and a reduction in uric acid concentrations (P < 0.001), especially in participants with T2D or prediabetes. Following amlodipine treatment, a significant increase in both eGFR (P = 0.01) and FMD (P = 0.02) was also observed. Conclusions: This study demonstrates that the replacement of HCTZ with amlodipine has several metabolic and cardiovascular beneficial effects. However, further intervention studies are necessary to confirm the clinical effects of thiazides, especially in diabetic people and in those at risk of diabetes.

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

Background

Diagnostic 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 Results

We 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%.

Conclusions

We 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

Triglycerides and endothelial function: molecular biology to clinical perspective

PURPOSE OF REVIEW

Recently, a high level of triglycerides has attracted much attention as an important residual risk factor of cardiovascular events. We will review and show the mechanisms underlying the association of endothelial dysfunction with hypertriglyceridemia and present clinical evidence for a relationship between endothelial function and triglycerides.

RECENT FINDINGS

Clinical studies have shown that hypertriglyceridemia is associated with endothelial dysfunction. It is likely that hypertriglyceridemia impairs endothelial function through direct and indirect mechanisms. Therefore, hypertriglyceridemia is recognized as a therapeutic target in the treatment of endothelial dysfunction. Although experimental and clinical studies have shown that fibrates and omega-3 fatty acids not only decrease triglycerides but also improve endothelial function, the effects of these therapies on cardiovascular events are controversial.

SUMMARY

Accumulating evidence suggests that hypertriglyceridemia is an independent risk factor for endothelial dysfunction. Triglycerides should be considered more seriously as a future target to reduce cardiovascular events. Results of ongoing studies may show the benefit of lowering triglycerides and provide new standards of care for patients with hypertriglyceridemia possibly through improvement in endothelial function.

Coffee and Endothelial Function: A Coffee Paradox?

Coffee is a popular beverage throughout the world. Coffee contains various chemical compounds (e.g., caffeine, chlorogenic acids, hydroxyhydroquinone, kahweol, cafestol, and complex chemical mixtures). Caffeine is also the most widely consumed pharmacological substance in the world and is included in various beverages (e.g., coffee, tea, soft drinks, and energy drinks), products containing chocolate, and drugs. The effects of coffee and caffeine on cardiovascular diseases remain controversial. It is well known that there are J-curve-type or U-curve-type associations of coffee consumption with cardiovascular events including myocardial infarction and stroke. However, there is little information on the direct and indirect effects of coffee consumption on endothelial function in humans. It is likely that the coffee paradox or caffeine paradox exists the association of coffee intake with cardiovascular diseases, cardiovascular outcomes, and endothelial function. This review focusses on the effects of coffee and caffeine on endothelial function from molecular mechanisms to clinical perspectives.

Hemodynamic and autonomic effects of low-dose glyceryl trinitrate used to test endothelium-independent vasodilation of the brachial artery

Smooth muscle function is explored by sublingual glyceryl trinitrate (GTN) administration to compare with endothelium-dependent vasodilation of the brachial artery by flow-mediated-dilation (FMD). This study compared the hemodynamic and autonomic effects of the two most often used GTN dosages. In 80 essential hypertensive patients (HT) and 60 normotensive subjects (NT), FMD of the brachial artery and endothelium-independent response to sublingual GTN (25 μg and 400 μg) were evaluated by high-resolution ultrasound and automated image analysis. In 10 HT, muscle sympathetic nerve activity (MSNA) was also assessed by microneurography. HT showed significantly (p < .01) lower FMD (5.5 ± 3.3%) compared to NT (6.9 ± 2.2%). The response to GTN 25 μg tended to be lower (HT:7.2 ± 3.3%; NT:7.9 ± 2.9%; p = .06), whereas response to GTN 400 μg was similar (HT:14.3 ± 4.8%, NT:14.5 ± 4.7%, p = ns). Blood pressure (BP) reduction induced by GTN 400 μg (systolic-BP:-3.2 ± 7.7 mm Hg, diastolic-BP:-4.7 ± 5.0 mm Hg) was greater (p < .001) compared to GTN 25 μg (systolic-BP:-0.7 ± 5.8 mm Hg, diastolic-BP:-0.7 ± 4.4 mm Hg). Changes in heart rate were also greater (+5.6 ± 6.4 bpm versus -0.2 ± 5.4 bpm, p < .001). This behaviour was similar in either NT or HT. MSNA was significantly increased by GTN 400 μg (31 ± 7bursts/min to 41 ± 6bursts/min, p < .001) but not by 25 μg (33 ± 9bursts/min to 37 ± 11bursts/min, p = .19). In conclusion, the administration of low-dose GTN allows exploring endothelium-independent vasodilation in FMD protocols, inducing only modest hemodynamic and sympathetic responses.

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

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

Relationships Between Calcium Channel Blockers and Vascular Function Tests

BACKGROUND

Differences between the effects of calcium channel blockers (CCBs) and other antihypertensive drugs on vascular function have not been fully investigated. The purpose of this study was to determine the confounding effect of CCBs on vascular function tests.

METHODS

We measured flow-mediated vasodilation (FMD), nitroglycerine-induced vasodilation (NID), and brachial-ankle pulse wave velocity (baPWV) in 1,134 subjects who underwent health-screening examinations or who visited the outpatient clinic at Hiroshima University Hospital.

RESULTS

FMD and NID were significantly lower (4.3 ± 3.2% vs. 2.3 ± 2.4% and 14.1 ± 5.8% vs. 10.6 ± 5.3%, P < 0.001, respectively) and baPWV was significantly higher (1,604 ± 412 cm/s vs. 1,715 ± 343 cm/s, P < 0.001) in subjects receiving CCB treatment than in subjects without CCB treatment. Multivariate analyses revealed that CCB treatment was significantly associated with lower FMD (β = -0.151, P < 0.001) and lower NID (β = -0.120, P < 0.001) but not with baPWV (β = 0.017, P = 0.42). Propensity score matching analyses revealed that FMD and NID were significantly lower and baseline brachial artery diameter was significantly larger in subjects receiving CCB monotherapy than in subjects without antihypertensive medication or subjects receiving non-CCB antihypertensive monotherapy.

CONCLUSIONS

CCB treatment was significantly associated with lower FMD and lower NID, which might be, at least in part, due to larger baseline brachia artery diameter, whereas there was no significant association between CCB treatment and baPWV. FMD and NID may be of no use as prognostic markers of cardiovascular events in individuals who have been receiving CCB treatment.

PUBLIC TRIALS REGISTRY NUMBER

Trial Number UMIN000003409.

Target of Triglycerides as Residual Risk for Cardiovascular Events in Patients With Coronary Artery Disease - Post Hoc Analysis of the FMD-J Study A

BACKGROUND

Circulating triglyceride (TG) levels are a current focus as a residual risk for cardiovascular (CV) events. We evaluated the relationship between circulating TG levels and future CV events in patients with coronary artery disease (CAD) who were treated with conventional therapy. Methods and Results: We analyzed data for 652 patients who were enrolled in the FMD-J Study A. We investigated the associations between serum TG levels and first major CV events (death from CV cause, nonfatal acute coronary syndrome (ACS), nonfatal stroke, and CAD) for a 3-year follow-up period. Patients were divided into 4 groups based on serum TG level: low-normal (<100 mg/dL), high-normal (100-149 mg/dL), borderline hypertriglyceridemia (150-199 mg/dL), and moderate hypertriglyceridemia (≥200 mg/dL). During a median follow-up period of 46.6 months, 14 patients died (9 from CV causes), 16 had nonfatal ACS, 6 had nonfatal stroke, and 54 had CAD. The Kaplan-Meier curves for first major CV event among the 4 groups were significantly different (P=0.04). After adjustment for various confounders, serum TG level ≥100 mg/dL were significantly associated with an increased risk of first major CV events compared with serum TG level <100 mg/dL.

CONCLUSIONS

Serum TG level may be a surrogate marker for predicting CV events in patients with CAD.

Unacylated Ghrelin Improves Vascular Dysfunction and Attenuates Atherosclerosis during High-Fat Diet Consumption in Rodents

Unacylated ghrelin (UnGhr) exerts several beneficial actions on vascular function. The aim of this study was to assess the effects of UnGhr on high-fat induced endothelial dysfunction and its underlying mechanisms. Thoracic aortas from transgenic mice, which were overexpressing UnGhr and being control fed either a standard control diet (CD) or a high-fat diet (HFD) for 16 weeks, were harvested and used for the assessment of vascular reactivity, endothelial nitric oxide synthase (eNOS) expression and activity, thiobarbituric acid reactive substances (TBARS) and glutathione levels, and aortic lipid accumulation by Oil Red O staining. Relaxations due to acetylcholine and to DEA-NONOate were reduced (p < 0.05) in the HFD control aortas compared to vessels from the CD animals. Overexpression of UnGhr prevented HFD-induced vascular dysfunction, while eNOS expression and activity were similar in all vessels. HFD-induced vascular oxidative stress was demonstrated by increased (p < 0.05) aortic TBARS and glutathione in wild type (Wt) mice; however, this was not seen in UnGhr mice. Moreover, increased (p < 0.05) HFD-induced lipid accumulation in vessels from Wt mice was prevented by UnGhr overexpression. In conclusion, chronic UnGhr overexpression results in improved vascular function and reduced plaque formation through decreased vascular oxidative stress, without affecting the eNOS pathway. This research may provide new insight into the mechanisms underlying the beneficial effects of UnGhr on the vascular dysfunction associated with obesity and the metabolic syndrome.

Endothelial dysfunction, abnormal vascular structure and lower urinary tract symptoms in men and women

BACKGROUND

Lower urinary tract symptoms (LUTS) is not only common symptoms in elderly men and women but also risk of future cardiovascular events. The purpose of this study was to evaluate the relationships of vascular function and structure with LUTS in men and women.

METHODS

We investigated flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation (NID) as vascular function, brachial-ankle pulse wave velocity (baPWV) as vascular structure, and LUTS assessed by International Prostate Symptom Score (IPSS) in 287 men and 147 women.

RESULTS

IPSS was significantly correlated with traditional cardiovascular risk factors, Framingham risk score, FMD, NID and baPWV. Moderate to severe LUTS was associated with the prevalence of coronary heart disease in men but not in women. In men, FMD and NID were significantly lower in the moderate to severe LUTS group than in the none to mild LUTS group (2.1 ± 2.0% vs. 4.0 ± 3.0% and 9.3 ± 6.1% vs. 12.8 ± 6.6%, P < 0.001, respectively). baPWV was significantly higher in the moderate to severe LUTS group than in the none to mild LUTS group (1722 ± 386 cm/s vs. 1509 ± 309 cm/s, P < 0.001). In multivariate analysis, FMD was independently associated with a decrease in the odds ratio of moderate to severe LUTS in men (OR: 0.83, 95% CI, 0.72-0.95; P = 0.008) but not in women. NID and baPWV were not independently associated with moderate to severe LUTS either in men or women.

CONCLUSIONS

These findings suggest that endothelial dysfunction is associated with LUTS in men. LUTS in men may be useful for a predictor of cardiovascular events.

CLINICAL TRIAL REGISTRATION INFORMATION

URL for Clinical Trial: http://UMIN; Registration Number for Clinical Trial: UMIN000003409.

Endothelial Dysfunction, Increased Arterial Stiffness, and Cardiovascular Risk Prediction in Patients With Coronary Artery Disease: FMD-J (Flow-Mediated Dilation Japan) Study A

Background

The usefulness of vascular function tests for management of patients with a history of coronary artery disease is not fully known.

Methods and Results

We measured flow‐mediated vasodilation (FMD) and brachial–ankle pulse wave velocity (baPWV) in 462 patients with coronary artery disease for assessment of the predictive value of FMD and baPWV for future cardiovascular events in a prospective multicenter observational study. The first primary outcome was coronary events, and the second primary outcome was a composite of coronary events, stroke, heart failure, and sudden death. During a median follow‐up period of 49.2 months, the first primary outcome occurred in 56 patients and the second primary outcome occurred in 66 patients. FMD above the cutoff value of 7.1%, derived from receiver‐operator curve analyses for the first and second primary outcomes, was significantly associated with lower risk of the first (hazard ratio, 0.27; 95% confidence interval, 0.06–0.74; P=0.008) and second (hazard ratio, 0.32; 95% confidence interval, 0.09–0.79; P=0.01) primary outcomes. baPWV above the cutoff value of 1731 cm/s was significantly associated with higher risk of the first (hazard ratio, 1.86; 95% confidence interval, 1.01–3.44; P=0.04) and second (hazard ratio, 2.19; 95% confidence interval, 1.23–3.90; P=0.008) primary outcomes. Among 4 groups stratified according to the combination of cutoff values of FMD and baPWV, stepwise increases in the calculated risk ratio for the first and second primary outcomes were observed.

Conclusions

In patients with coronary artery disease, both FMD and baPWV were significant predictors of cardiovascular events. The combination of FMD and baPWV provided further cardiovascular risk stratification.

Clinical Trial Registration

URL: http://www.umin.ac.jp. Unique identifier: UMIN000012950.

Chronic kidney disease is associated with vascular smooth muscle dysfunction but not with endothelial dysfunction

BACKGROUNDS

Nitroglycerine-induced vasodilation (NID) is usually assessed as a control test for flow-mediated vasodilation (FMD). However, NID per se is impaired in patients with high cardiovascular risk. The purpose of this study was to investigate the associations of chronic kidney disease (CKD) with NID and FMD.

METHODS

We measured NID and FMD in a total of 1567 adult subjects without end-stage renal disease (ESRD), 28% of whom had CKD as judged by measurements of estimated glomerular filtration rate (995 men and 572 women; mean age, 59.0±16.9years; age range, 18 to 92years).

RESULTS

NID was significantly smaller in patients with CKD than in those without CKD (10.8±6.0% vs. 12.7±5.7%, P<0.001). The prevalence of vascular smooth muscle dysfunction, defined as NID of less than the division point for the lowest quartile, was significantly higher in patients with CKD than in those without CKD (37.5% vs. 21.5%, P<0.001). Multivariate analysis revealed that CKD was independently associated with vascular smooth muscle dysfunction (OR: 1.36, 95% CI: 1.02 to 1.81, P=0.04). FMD was significantly smaller in patients with CKD than in those without CKD (3.1±2.8% vs. 4.0±3.0%, P<0.001). The prevalence of endothelial dysfunction, defined as FMD of less than the division point for the lowest quartile, was significantly higher in patients with CKD than in those without CKD (31.7% vs. 23.1%, P=0.002). However, CKD was not independently associated with endothelial dysfunction in an age- and sex-adjusted model (OR: 0.95, 95% CI: 0.71 to 1.26, P=0.72).

CONCLUSIONS

Non-ESRD CKD is independently associated with vascular smooth muscle dysfunction but not with endothelial dysfunction.

Optimal Target Level of Low-density Lipoprotein Cholesterol for Vascular Function in Statin Naïve Individuals

We investigated (1) the relationship between low-density lipoprotein cholesterol (LDL-C) and vascular function in patients receiving and those not receiving statin therapy and (2) optimal level of LDL-C for maintenance of vascular function. Flow-mediated vasodilation (FMD) and nitroglycerine-induced vasodilation (NID) were inversely correlated with LDL-C in the 957 statin naïve subjects but not in the 392 subjects receiving statin therapy. In statin naïve subjects, non-high LDL-C (≤100 mg/dL) was independently associated with a decrease in adjusted odds ratio of the low tertile of FMD (OR: 0.62, 95% CI: 0.45–0.85; P = 0.003) and NID (OR: 0.69, 95% CI: 0.50–0.96; P = 0.03). Adjusted odds ratio of the low tertile of FMD was significantly lower in the low LDL-C group (≤70 mg/dL) (OR: 0.47, 95% CI, 0.27–0.81; P = 0.006) and in the moderate LDL-C group (70.1–100 mg/dL) (OR: 0.66, 95% CI, 0.48–0.94; P = 0.02) than in the high LDL-C group (>100 mg/dL). There was no significant difference in FMD between the low LDL-C group and moderate LDL-C group. There were significant relationships of FMD and NID with LDL-C levels in statin naïve subjects. In a general population, LDL-C of ≤100 mg/dL may be the optimal target level for maintenance of endothelial function.