The effect of antihypertensive drugs on endothelial function as assessed by flow-mediated vasodilation in hypertensive patients

Risk factors of non-arteritic anterior ischaemic optic neuropathy and central retinal artery occlusion

AIM

To investigate the difference in risk factors between non-arteritic anterior ischaemic optic neuropathy (NAION) and central retinal artery occlusion (CRAO) and develop a predictive diagnostic nomogram.

METHODS

The study included 37 patients with monocular NAION, 20 with monocular CRAO, and 24 with hypertension. Gender, age, and systemic diseases were recorded. Blood routine, lipids, hemorheology, carotid and brachial artery doppler ultrasound, and echocardiography were collected. The optic disc area, cup area, and cup-to-disc ratio (C/D) of the unaffected eye in the NAION and CRAO group and the right eye in the hypertension group were measured.

RESULTS

The carotid artery intimal medial thickness (C-IMT) of the affected side of the CRAO group was thicker (P=0.039) and its flow-mediated dilation (FMD) was lower (P=0.049) than the NAION group. Compared with hypertension patients, NAION patients had higher whole blood reduced viscosity low-shear (WBRV-L) and erythrocyte aggregation index (EAI; P=0.045, 0.037), and CRAO patients had higher index of rigidity of erythrocyte (IR) and erythrocyte deformation index (EDI; P=0.004, 0.001). The optic cup and the C/D of the NAION group were smaller than the other two groups (P<0.0001). The diagnostic prediction model showed high diagnostic specificity (83.7%) and sensitivity (85.6%), which was highly related to hypertension, the C-IMT of the affected side, FMD, platelet (PLT), EAI, and C/D.

CONCLUSION

CRAO patients show thicker C-IMT and worse endothelial function than NAION. NAION and CRAO may be related to abnormal hemorheology. A small cup and small C/D may be involved in NAION. The diagnostic nomogram can be used to preliminarily identify NAION and CRAO.

Obesity does not alter vascular function and handgrip exercise hemodynamics in middle-aged patients with hypertension

Lifestyle modification including exercise training is often the first line of defense in the treatment of obesity and hypertension (HTN), however, little is known regarding how these potentially compounding disease states impact vasodilatory and hemodynamic responses at baseline and exercise. Therefore, this study sought to compare the impact of obesity on vascular function and hemodynamics at baseline and during handgrip (HG) exercise among individuals with HTN. Non-obese (13M/7F, 56 ± 16 yr, 25 ± 4 kg/m2) and obese (17M/4F, 50 ± 7 yr, 35 ± 4 kg/m2) middle-aged individuals with HTN forwent antihypertensive medication use for ≥2 wk before assessment of vascular function by brachial artery flow-mediated dilation (FMD) and exercise hemodynamics during progressive HG exercise at 15-30-45% maximal voluntary contraction (MVC). FMD was not different between Non-Obese (4.1 ± 1.7%) and Obese (5.2 ± 1.9%, P = 0.11). Systolic blood pressure (SBP) was elevated by ∼15% during the supine baseline and during HG exercise in the obese group. The blood flow response to HG exercise at 30% and 45% MVC was ∼20% greater (P < 0.05) in the obese group but not different after normalizing for the higher, albeit, nonsignificant differences in workloads (MVC: obese: 24 ± 5 kg, non-obese: 21 ± 5 kg, P = 0.11). Vascular conductance and the brachial artery shear-induced vasodilatory response during HG were not different between groups (P > 0.05). Taken together, despite elevated SBP during HG exercise, obesity does not lead to additional impairments in vascular function and peripheral exercising hemodynamics in patients with HTN. Obesity may not be a contraindication when prescribing exercise for the treatment of HTN among middle-aged adults, however, the elevated SBP should be appropriately monitored.NEW & NOTEWORTHY This study examined vascular function and handgrip exercise hemodynamics in obese and nonobese individuals with hypertension. Obesity, when combined with hypertension, was neither associated with additional vascular function impairments at baseline nor peripheral hemodynamics and vasodilation during exercise compared with nonobese hypertension. Interestingly, systolic blood pressure and pulse pressure were greater in the obese group during supine baseline and exercise. These findings should not be ignored and may be particularly important for rehabilitation strategies.

Relationship between Endothelial Dysfunction and Prevalence of Chronic Kidney Disease: The Circulatory Risk in Communities Study (CIRCS)

AIMS

Patients with chronic kidney disease (CKD) have a higher burden of cardiovascular morbidity and mortality than the general population. Endothelial dysfunction has been suggested to play a role in both glomerular filtration rate loss and cardiovascular damage. Thus, the present study aimed to evaluate the relationship between endothelial dysfunction and the prevalence of CKD in the general Japanese population.

METHODS

We conducted a cross-sectional study of 1042 men and women aged 30-81 years in two communities under the Circulatory Risk in Communities Study between 2013 and 2017. Endothelial function was evaluated by percent change of brachial artery flow-mediated dilation (%FMD) before and after the cuff inflation.

RESULTS

Among the total 1042 participants, there were 62 cases of CKD (~6%). The multivariable odds ratios (ORs) (95% confidence intervals [CIs]) of CKD according to quartiles of %FMD were 2.02 (0.68-5.99), 3.56 (1.27-9.94), and 3.14 (1.10-8.93) for the third to lowest quartile compared with the highest %FMD quartile; p for trend=0.02. The respective multivariable ORs (95% CIs) of CKD in subjects without antihypertensive medication use (39 cases among 886 subjects) were 1.83 (0.46-7.33), 3.41 (0.92-12.61), and 4.60 (1.22-17.31); p for trend=0.01, and that for one-point decrement in %FMD was 1.16 (1.00-1.35); p for interaction with the status of antihypertensive medication use was 0.12.

CONCLUSIONS

Our cross-sectional study suggested the relationship between endothelial dysfunction and the higher prevalence of CKD in the general Japanese population.

Thrombospondin-1 Serum Levels In Hypertensive Patients With Endothelial Dysfunction After One Year Of Treatment With Perindopril

Background

Thrombospondin-1 (TSP-1) is a matricellular functional protein of the extracellular matrix. As it is not constitutively present extracellularly, its secretion is enhanced in several situations, namely injury, chronic pathology, tissue remodeling, angiogenesis, and aging. Over the last decade, TSP-1 has been reported to be involved in complex and opposing biological effects on vasculature in the context of NO signaling. Several studies have reported high patient TSP-1 plasma levels, indicating that the protein can potentially serve as a prognostic marker for pulmonary arterial hypertension.

Materials and methods

Here, we aimed to quantify TSP-1 serum levels in hypertensive patients with endothelial dysfunction before and after one year of treatment with Perindopril (an antihypertensive drug with vasoprotective properties).

Results

After one year of treatment, TSP-1 levels increased in hypertensive patients compared to baseline (T0: 8061.9 ± 3684.80 vs T1: 15380±5887 ng/mL, p<0.001) and compared to non-hypertensive controls (9221.03 ± 6510.21 ng/mL). In contrast, pentraxin-3 plasma levels were decreased after one year of Perindopril treatment in both hypertensive (T0: 0.91 ± 0.51 vs T1: 0.50 ± 0.24 ng/mL, p<0.001) and control group (1.36 ±1.5 ng/mL) patients, although flow-mediated vasodilation and intima-media thickness assessment parameters were not significantly changed. Systolic and diastolic blood pressure values as well as levels of fibrinogen, high-sensitivity C-reactive protein, triglycerides, and alanine aminotransferase were found to be significantly lower after one year of treatment with Perindopril. High levels of TSP-1 strongly correlated with platelet count (positive), lymphocytes (positive), red cell distribution width-CV (positive), systolic blood pressure (negative), and mean corpuscular hemoglobin (negative) after one year of treatment. Blood urea nitrogen was found to be a protective factor for TSP-1, while glucose and heart rate were found to be risk factors prior to and after treatment.

Characterizing the relationship between flow-mediated vasodilation and radial artery tonometry in peripheral artery disease

BACKGROUND

Arterial stiffness, measured by the augmentation index (AIX) from radial artery tonometry, and endothelial dysfunction, measured by brachial-artery flow-mediated vasodilation (FMD), have each been associated with increased risk of cardiovascular events. However, their interrelationship in peripheral artery disease (PAD) patients is poorly understood.

MATERIALS AND METHODS

In a cross-sectional analysis of 123 vascular surgery outpatients, the association between FMD and AIX was examined in controls with atherosclerotic risk factors (n = 32) and patients with PAD (n = 91). PAD was defined as claudication symptoms with an ankle-brachial index of <0.9 or a history of revascularization for symptomatic PAD. Controls had an ankle-brachial index ≥0.9 and no history of atherosclerotic vascular disease.

RESULTS

Compared to controls, patients with PAD had lower FMD (6.3 ± 3.8 versus 8.4 ± 3.7, P = 0.008), while central AIX normalized to 75 beats per minute (25.5 ± 9.0 versus 19.3 ± 8.6, P = 0.001) and peripheral AIX (91.3 ± 14.5 versus 81.3 ± 11.4, P = 0.001) were higher. FMD was not significantly correlated with either central or peripheral AIX (central AIX: P = 0.58; peripheral AIX: P = 0.89) across the entire cohort, or in either the patients with PAD (central AIX: P = 0.48; peripheral AIX: P = 0.23) or controls (central AIX: P = 0.43; peripheral AIX: P = 0.92). In a multivariate model including FMD, higher AIX remained independently associated with PAD.

CONCLUSIONS

In an analysis of vascular surgery outpatients, no correlation between FMD and AIX was detected. Larger prospective studies are needed to determine whether the inclusion of both parameters improves predictive models for the early identification and potential risk stratification of PAD patients.

Detection of vasodilator drugs through microwave spectroscopy of Au NP colorimetric probes using a microwave metallic photonic crystal-inspired resonant probe

A low-cost, time-effective and easy-to-use novel analytical technique incorporating microwave spectroscopy of unmodified gold nanoparticles for the detection of selected vasodilator drugs.

Asymmetric dimethylarginine (ADMA) elevation and arginase up-regulation contribute to endothelial dysfunction related to insulin resistance in rats and morbidly obese humans

KEY POINTS

The presence of insulin resistance (IR) is determinant for endothelial dysfunction associated with obesity. Although recent studies have implicated the involvement of mitochondrial superoxide and inflammation in the defective nitric oxide (NO)-mediated responses and subsequent endothelial dysfunction in IR, other mechanisms could compromise this pathway. In the present study, we assessed the role of asymmetric dimethylarginine (ADMA) and arginase with respect to IR-induced impairment of endothelium-dependent vasodilatation in human morbid obesity and in a non-obese rat model of IR. We show that both increased ADMA and up-regulated arginase are determinant factors in the alteration of the l-arginine/NO pathway associated with IR in both models and also that acute treatment of arteries with arginase inhibitor or with l-arginine significantly alleviate endothelial dysfunction. These results help to expand our knowledge regarding the mechanisms of endothelial dysfunction that are related to obesity and IR and establish potential therapeutic targets for intervention.

ABSTRACT

Insulin resistance (IR) is determinant for endothelial dysfunction in human obesity. Although we have previously reported the involvement of mitochondrial superoxide and inflammation, other mechanisms could compromise NO-mediated responses in IR. We evaluated the role of the endogenous NOS inhibitor asymmetric dimethylarginine (ADMA) and arginase with respect to IR-induced impairment of l-arginine/NO-mediated vasodilatation in human morbid obesity and in a non-obese rat model of IR. Bradykinin-induced vasodilatation was evaluated in microarteries derived from insulin-resistant morbidly obese (IR-MO) and non-insulin-resistant MO (NIR-MO) subjects. Defective endothelial vasodilatation in IR-MO was improved by l-arginine supplementation. Increased levels of ADMA were detected in serum and adipose tissue from IR-MO. Serum ADMA positively correlated with IR score and negatively with pD2 for bradykinin. Gene expression determination by RT-PCR revealed not only the decreased expression of ADMA degrading enzyme dimethylarginine dimethylaminohydrolase (DDAH)1/2 in IR-MO microarteries, but also increased expression of arginase-2. Arginase inhibition improved endothelial vasodilatation in IR-MO. Analysis of endothelial vasodilatation in a non-obese IR model (fructose-fed rat) confirmed an elevation of circulating and aortic ADMA concentrations, as well as reduced DDAH aortic content and increased aortic arginase activity in IR. Improvement of endothelial vasodilatation in IR rats by l-arginine supplementation and arginase inhibition provided functional corroboration. These results demonstrate that increased ADMA and up-regulated arginase contribute to endothelial dysfunction as determined by the presence of IR in human obesity, most probably by compromising arginine availability. The results provide novel insights regarding the mechanisms of endothelial dysfunction related to obesity and IR and establish potential therapeutic targets for intervention.

Arterial wall elasticity measured using the phased tracking method and atherosclerotic risk factors in patients with type 2 diabetes

AIM

The aim of this study was to investigate the relationship between atherosclerotic manifestations and brachial and radial arterial wall elasticity (AWE) measured using the phased tracking method in patients with type 2 diabetes mellitus (T2DM).

METHODS

This study included T2DM patients (n= 220, mean age 59 years) without a history of stroke or coronary artery disease. The brachial AWE, radial AWE, carotid mean intima-media thickness (IMT), max-IMT and flow-mediated vasodilation (FMD) were measured. The patients were classified according to the number of atherosclerotic risk factors, including obesity, dyslipidemia and hypertension. Group 1 included T2DM patients only, group 2 included patients with two risk factors, group 3 included patients with three risk factors and group 4 included patients with four risk factors. The patients were also divided into two groups according to microangiopathic complications, including retinopathy and nephropathy. The between-group differences were analyzed.

RESULTS

The brachial AWE (548, 697, 755 and 771 kPa for groups 1, 2, 3 and 4, respectively) and radial AWE (532, 637, 717 and 782 kPa for groups 1, 2, 3 and 4, respectively) significantly increased in association with an increasing number of risk factors. The brachial AWE and radial AWE were significantly higher in the patients with microangiopathic complications than in those without microangiopathic complications (brachial AWE 797 and 694 kPa and radial AWE 780 and 660 kPa, respectively). Receiver operating characteristic curve analyses revealed that, for brachial AWE and radial AWE, the area under the curve was equal to the max-IMT and higher than the mean-IMT and FMD.

CONCLUSIONS

Upper limb AWE measurement can reflect the degree of atherosclerosis risk overload and may be useful for evaluating vascular complications in T2DM patients.